From e0c6872cf40896c7be36b11dcc744620f10adf1d Mon Sep 17 00:00:00 2001
From: Norbert Preining <norbert@preining.info>
Date: Mon, 2 Sep 2019 13:46:59 +0900
Subject: Initial commit

---
 macros/latex/contrib/listings/listings.dtx | 16933 +++++++++++++++++++++++++++
 1 file changed, 16933 insertions(+)
 create mode 100644 macros/latex/contrib/listings/listings.dtx

(limited to 'macros/latex/contrib/listings/listings.dtx')

diff --git a/macros/latex/contrib/listings/listings.dtx b/macros/latex/contrib/listings/listings.dtx
new file mode 100644
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--- /dev/null
+++ b/macros/latex/contrib/listings/listings.dtx
@@ -0,0 +1,16933 @@
+% \iffalse
+%
+% Trademarks appear throughout this documentation without any trademark
+% symbol, so you can't assume that a name is free. There is no intention
+% of infringement; the usage is to the benefit of the trademark owner.
+%
+%
+%  S O F T W A R E   L I C E N S E
+% =================================
+%
+% The files  listings.dtx  and  listings.ins  and all files generated
+% from only these two files are referred to as `the listings package'
+% or simply `the package'. lstdrvrs.dtx  and the files generated from
+% that file are `drivers'.
+%
+% The listings package is copyright 1996--2004 Carsten Heinz, and
+% continued maintenance on the package is copyright 2006--2007 Brooks
+% Moses. From 2013 on copyright is Jobst Hoffmann, who is the maintainer
+% since july 2013. The drivers are copyright 1997/1998/1999/2000/2001/
+% 2002/2003/2004/2006/2007/2013 any individual author listed in the
+% driver files.
+%
+% The listings package and its drivers may be distributed and/or modified
+% under the conditions of the LaTeX Project Public License, either version
+% 1.3 of this license or (at your option) any later version.
+% The latest version of this license is in
+%   http://www.latex-project.org/lppl.txt
+% and version 1.3c or later is part of all distributions of LaTeX
+% version 2003/12/01 or later.
+%
+% The package has the LPPL maintenance status "maintained".
+%
+% The Current Maintainer is Jobst Hoffmann <j.hoffmann(at)fh-aachen.de>.
+%
+% end of software license
+%
+%
+%<*driver>
+\documentclass[a4paper]{ltxdoc}
+\DisableCrossrefs
+\OnlyDescription
+
+\usepackage{lstdoc,textcomp}
+\usepackage{mdframed}           % frames for external files
+\usepackage{moreverb}           % writing external files
+\usepackage{xcolor}             % because of colouring the background
+
+\makeindex
+
+\begin{document}
+    \DocInput{listings.dtx}
+\end{document}
+%</driver>
+% \fi
+%
+%^^A
+%^^A  Command/key to aspect relation
+%^^A ================================
+%^^A
+%\lstisaspect[strings]{string,morestring,deletestring,stringstyle,showstringspaces}
+%\lstisaspect[comments]{comment,morecomment,deletecomment,commentstyle}
+%\lstisaspect[comment styles]{b,d,l,n,s,ib,id,il,in,is}
+%\lstisaspect[pod]{printpod,podcomment}
+%\lstisaspect[escape]{texcl,escapebegin,escapeend,escapechar,escapeinside,mathescape}
+%\lstisaspect[keywords]{sensitive,classoffset,keywords,morekeywords,^^A
+%   deletekeywords,keywordstyle,ndkeywords,morendkeywords,deletendkeywords,^^A
+%   ndkeywordstyle,keywordsprefix,otherkeywords}
+%\lstisaspect[emph]{emph,moreemph,deleteemph,emphstyle}
+%\lstisaspect[tex]{texcs,moretexcs,deletetexcs,texcsstyle}
+%\lstisaspect[directives]{directives,moredirectives,deletedirectives,directivestyle}
+%\lstisaspect[html]{tag,usekeywordsintag,tagstyle,markfirstintag}
+%\lstisaspect[keywordcomments]{keywordcomment,morekeywordcomment,^^A
+%   deletekeywordcomment,keywordcommentsemicolon}
+%\lstisaspect[index]{index,moreindex,deleteindex,indexstyle,\string\lstindexmacro}
+%\lstisaspect[procnames]{procnamestyle,indexprocnames,procnamekeys,^^A
+%   moreprocnamekeys,deleteprocnamekeys}
+%\lstisaspect[style]{style,\string\lstdefinestyle,\string\lst@definestyle,^^A
+%   \string\lststylefiles}
+%\lstisaspect[language]{language,alsolanguage,defaultdialect,^^A
+%   \string\lstalias,\string\lstdefinelanguage,\string\lst@definelanguage,^^A
+%   \string\lstloadlanguages,\string\lstlanguagefiles}
+%\lstisaspect[formats]{format,fmtindent,\string\lstdefineformat,^^A
+%   \string\lst@defineformat,\string\lstformatfiles}
+%\lstisaspect[labels]{numbers,numberstyle,numbersep,stepnumber,^^A
+%   numberblanklines,firstnumber,\string\thelstnumber,numberfirstline}
+%\lstisaspect[lineshape]{xleftmargin,xrightmargin,resetmargins,linewidth,^^A
+%   lineskip,breaklines,breakindent,breakautoindent,prebreak,postbreak,^^A
+%   breakatwhitespace}
+%\lstisaspect[frames]{framexleftmargin,framexrightmargin,framextopmargin,^^A
+%   framexbottommargin,backgroundcolor,fillcolor,rulecolor,rulesepcolor,^^A
+%   rulesep,framerule,framesep,frameshape,frameround,frame}
+%\lstisaspect[make]{makemacrouse}
+%\lstisaspect[fancyvrb]{fancyvrb,fvcmdparams,morefvcmdparams}
+%\lstisaspect[lgrind]{lgrindef,\string\lstlgrindeffile}
+%\lstisaspect[hyper]{hyperref,morehyperref,deletehyperref,hyperanchor,hyperlink}
+%\lstisaspect[kernel]{basewidth,fontadjust,columns,flexiblecolumns,identifierstyle,^^A
+%   tabsize,showtabs,tab,showspaces,keepspaces,formfeed,SelectCharTable,^^A
+%   MoreSelectCharTable,extendedchars,alsoletter,alsodigit,alsoother,excludedelims,^^A
+%   literate,basicstyle,print,firstline,lastline,linerange,nolol,captionpos,abovecaptionskip,^^A
+%   belowcaptionskip,label,title,caption,\string\lstlistingname,boxpos,float,^^A
+%   floatplacement,aboveskip,belowskip,everydisplay,showlines,emptylines,gobble,name,^^A
+%   \string\lstname,\string\lstlistlistingname,\string\lstlistoflistings,^^A
+%   \string\lstnewenvironment,\string\lstinline,\string\lstinputlisting,lstlisting,^^A
+%   \string\lstloadaspects,\string\lstset,\string\thelstlisting,\string\lstaspectfiles,^^A
+%   inputencoding,delim,moredelim,deletedelim,upquote,numberbychapter,^^A
+%   \string\lstMakeShortInline,\string\lstDeleteShortInline}
+%\lstisaspect[doc]{lstsample,lstxsample}^^A environment
+%\lstisaspect[experimental]{includerangemarker,rangebeginprefix,rangebeginsuffix,^^A
+%   rangeendprefix,rangeendsuffix,rangeprefix,rangesuffix}
+%
+%^^A
+%^^A  The long awaited beginning of documentation
+%^^A =============================================
+%^^A
+%\newbox\abstractbox
+%\setbox\abstractbox=\vbox{
+%	\begin{abstract}
+%	The \packagename{listings} package is a source code printer for \LaTeX.
+%	You can typeset stand alone files as well as listings with an environment
+%   similar to \texttt{verbatim} as well as you can print code snippets using
+%   a command similar to |\verb|.
+%	Many parameters control the output and if your preferred programming
+%   language isn't already supported, you can make your own definition.
+%	\end{abstract}}
+%
+% \title{\vspace*{-2\baselineskip}The \textsf{Listings} Package}
+% \author{Copyright 1996--2004, Carsten Heinz%
+%    \\ Copyright 2006--2007, Brooks Moses
+%    \\ Copyright 2013--, Jobst Hoffmann
+%    \\ Maintainer: Jobst Hoffmann\thanks{Jobst %
+%       Hoffmann became the maintainer of the \packagename{listings}
+%       package in 2013; see the Preface for details.}~ %
+%    \textless\lstemail\textgreater}
+% \date{2019/02/27\enspace\enspace Version 1.8b\ \box\abstractbox}
+% \def\lstemail{\href{mailto:j.hoffmann@fh-aachen.de}{\texttt{j.hoffmann(at)fh-aachen.de}}}
+% \ifhyper
+%    \hypersetup{pdfsubject=Package guide,pdfauthor=Jobst Hoffmann <j.hoffmann(at)fh-aachen.de>}
+% \fi
+%
+% \csname @twocolumntrue\endcsname
+% \maketitle
+%^^A \enlargethispage{2\baselineskip}
+% \csname @starttoc\endcsname{toc}
+% \onecolumn
+%
+%
+% \section*{Preface}
+%
+% \paragraph{Transition of package maintenance}
+% The \TeX\ world lost contact with Carsten Heinz in late 2004, shortly after
+% he released version 1.3b of the \packagename{listings} package.  After many
+% attempts to reach him had failed, Hendri Adriaens took over maintenance of
+% the package in accordance with the LPPL's procedure for abandoned packages.
+% He then passed the maintainership of the package to Brooks Moses, who had
+% volunteered for the position while this procedure was going through. The
+% result is known as listings version 1.4.
+%
+% This release, version 1.5, is a minor maintenance release since
+% I accepted maintainership of the package.  I would like to thank Stephan
+% Hennig who supported the Lua language definitions. He is the one who
+% asked for the integration of a new language and gave the impetus to me to
+% become the maintainer of this package.
+%
+%
+% \paragraph{News and changes}
+% Version 1.5 is the fifth bugfix release.  There are no changes
+% in this version, but two extensions: support of modern Fortran (2003,
+% 2008) and Lua.
+%
+%
+% \vfill
+% \paragraph{Thanks}
+% There are many people I have to thank for fruitful communication, posting
+% their ideas, giving error reports, adding programming languages to
+% \texttt{lstdrvrs.dtx}, and so on. Their names are listed in section
+% \ref{uClosingAndCredits}.
+%
+% \paragraph{Trademarks}
+% Trademarks appear throughout this documentation without any trademark
+% symbol; they are the property of their respective trademark owner.
+% There is no intention of infringement; the usage is to the benefit of the
+% trademark owner.
+%
+%
+% \clearpage
+%
+%
+% \part{User's guide}
+%
+%
+% \section{Getting started}\label{uGettingStarted}
+%
+%
+% \subsection{A minimal file}\label{uAMinimalFile}
+%
+% Before using the \packagename{listings} package, you should be familiar with
+% the \LaTeX\ typesetting system. You need not to be an expert.
+% Here is a minimal file for \packagename{listings}.
+% \begin{verbatim}
+%    \documentclass{article}
+%    \usepackage{listings}
+%
+%    \begin{document}
+%    \lstset{language=Pascal}
+%
+%      % Insert Pascal examples here.
+%
+%    \end{document}\end{verbatim}
+% Now type in this first example and run it through \LaTeX.
+% \begin{advise}
+% \item Must I do that really?
+%       \advisespace
+%       Yes and no. Some books about programming say this is good.
+%       What a mistake! Typing takes time---which is wasted if the code is clear to
+%       you. And if you need that time to understand what is going on, the
+%       author of the book should reconsider the concept of presenting the
+%       crucial things---you might want to say that about this guide even---or
+%       you're simply inexperienced with programming. If only the latter case
+%       applies, you should spend more time on reading (good) books about
+%       programming, (good) documentations, and (good) source code from other
+%       people. Of course you should also make your own experiments.
+%       You will learn a lot. However, running the example through \LaTeX\
+%       shows whether the \packagename{listings} package is installed correctly.
+% \item The example doesn't work.
+%       \advisespace
+%       Are the two packages \packagename{listings} and \packagename{keyval}
+%       installed on your system? Consult the administration tool of your
+%       \TeX\ distribution, your system administrator, the local \TeX\ and
+%       \LaTeX\ guides, a \TeX\ FAQ, and section \ref{rInstallation}---in
+%       that order. If you've checked \emph{all} these sources and are
+%       still helpless, you might want to write a post to a \TeX\ newsgroup
+%       like \texttt{comp.text.tex}.
+% \item Should I read the software license before using the package?
+%       \advisespace
+%       Yes, but read this \emph{Getting started} section first to decide
+%       whether you are willing to use the package.^^A ;-)
+% \end{advise}
+%
+%
+% \subsection{Typesetting listings}
+%
+% Three types of source codes are supported: code snippets, code segments, and
+% listings of stand alone files.  Snippets are placed inside paragraphs and the
+% others as separate paragraphs---the difference is the same as between text
+% style and display style formulas.
+% \begin{advise}
+% \item No matter what kind of source you have, if a listing contains national
+%       characters like \'e, \L, \"a, or whatever, you must tell the
+%       package about it! Section \lstref{uSpecialCharacters} discusses this issue.
+% \end{advise}
+%
+% \paragraph{Code snippets}
+% The well-known \LaTeX\ command |\verb| typesets code snippets verbatim.
+% The new command |\lstinline| pretty-prints the code, for example
+%`\lstinline!var i:integer;!' is typeset by
+%`{\rstyle|\lstinline|}|!var i:integer;!|'. The exclamation marks delimit
+% the code and can be replaced by any character not in the code;
+% |\lstinline$var i:integer;$| gives the same result.
+%
+% \paragraph{Displayed code}
+% The \texttt{lstlisting} environment typesets the enclosed source code. Like
+% most examples, the following one shows verbatim \LaTeX\ code on the right
+% and the result on the left. You might take the right-hand side, put it into
+% the minimal file, and run it through \LaTeX.
+% \begin{lstsample}[lstlisting]{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% It can't be easier.
+% \begin{advise}
+% \item That's not true. The name `\texttt{listing}' is shorter.
+%       \advisespace
+%       Indeed. But other packages already define environments with that name.
+%       To be compatible with such packages, all commands and environments of
+%       the \packagename{listings} package use the prefix `\texttt{lst}'.
+% \end{advise}
+% The environment provides an optional argument. It tells the package to
+% perform special tasks, for example, to print only the lines 2--5:
+% \begin{lstsample}{\lstset{frame=trbl,framesep=0pt}\label{gFirstKey=ValueList}}{}
+%    \begin{lstlisting}[firstline=2,
+%                       lastline=5]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item Hold on! Where comes the frame from and what is it good for?
+%       \advisespace
+%       You can put frames around all listings except code snippets.
+%       You will learn how later. The frame shows that empty lines at the end
+%       of listings aren't printed. This is line 5 in the example.
+% \item Hey, you can't drop my empty lines!
+%       \advisespace
+%       You can tell the package not to drop them:
+%       The key `\ikeyname{showlines}' controls these empty lines and is
+%       described in section \ref{rTypesettingListings}. Warning: First
+%       read ahead on how to use keys in general.
+% \item I get obscure error messages when using `\ikeyname{firstline}'.
+%       \advisespace
+%       That shouldn't happen. Make a bug report as described in section
+%       \lstref{uTroubleshooting}.
+% \end{advise}
+%
+% \paragraph{Stand alone files}
+% Finally we come to |\lstinputlisting|, the command used to pretty-print
+% stand alone files. It has one optional and one file name argument.
+% Note that you possibly need to specify the relative path to the file.
+% Here now the result is printed below the verbatim code since both together
+% don't fit the text width.
+% \begin{lstsample}{\lstset{comment=[l]\%,columns=fullflexible}}^^A
+%       {\lstset{alsoletter=\\,emph=\\lstinputlisting,emphstyle=\rstyle}^^A
+%       \lstaspectindex{\lstinputlisting}{}}
+%    \lstinputlisting[lastline=4]{listings.sty}
+% \end{lstsample}
+% \begin{advise}
+% \item The spacing is different in this example.
+%       \advisespace
+%       Yes. The two previous examples have aligned columns, i.e.~columns with
+%       identical numbers have the same horizontal position---this package
+%       makes small adjustments only. The columns in the example here are not
+%       aligned. This is explained in section \ref{uFixedAndFlexibleColumns}
+%       (keyword: full flexible column format).
+% \end{advise}
+%
+% Now you know all pretty-printing commands and environments. It remains
+% to learn the parameters which control the work of the \packagename{listings}
+% package. This is, however, the main task. Here are some of them.
+%
+%
+% \subsection{Figure out the appearance}\label{gFigureOutTheAppearance}
+%
+% Keywords are typeset bold, comments in italic shape, and spaces in strings
+% appear as \textvisiblespace. You don't like these settings? Look at this:
+%\ifcolor
+% \begin{lstxsample}[basicstyle,keywordstyle,identifierstyle,commentstyle,^^A
+%       stringstyle,showstringspaces]
+%    \lstset{% general command to set parameter(s)
+%        basicstyle=\small,          % print whole listing small
+%        keywordstyle=\color{black}\bfseries\underbar,
+%                                    % underlined bold black keywords
+%        identifierstyle=,           % nothing happens
+%        commentstyle=\color{white}, % white comments
+%        stringstyle=\ttfamily,      % typewriter type for strings
+%        showstringspaces=false}     % no special string spaces
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}[basicstyle,keywordstyle,identifierstyle,commentstyle,^^A
+%       stringstyle,showstringspaces]
+%    \lstset{% general command to set parameter(s)
+%        basicstyle=\small,          % print whole listing small
+%        keywordstyle=\bfseries\underbar,
+%                                    % underlined bold keywords
+%        identifierstyle=,           % nothing happens
+%        commentstyle=\itshape,      % default
+%        stringstyle=\ttfamily,      % typewriter type for strings
+%        showstringspaces=false}     % no special string spaces
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+%\ifcolor
+% \begin{advise}
+% \item You've requested white coloured comments, but I can see the comment
+%       on the left side.
+%       \advisespace
+%       There are a couple of possible reasons:
+%       (1) You've printed the documentation on nonwhite paper.
+%       (2) If you are viewing this documentation as a \texttt{.dvi}-file, your
+%           viewer seems to have problems with colour specials. Try to print
+%           the page on white paper.
+%       (3) If a printout on white paper shows the comment, the colour
+%           specials aren't suitable for your printer or printer driver.
+%           Recreate the documentation and try it again---and ensure that
+%           the \packagename{color} package is well-configured.
+% \end{advise}
+%\fi
+% The styles use two different kinds of commands. |\ttfamily| and |\bfseries|
+% both take no arguments but |\underbar| does; it underlines the following
+% argument. In general, the \emph{very last} command may read exactly one
+% argument, namely some material the package typesets. There's one exception.
+% The last command of \ikeyname{basicstyle} \emph{must not} read any
+% tokens---or you will get deep in trouble.
+% \begin{advise}
+% \item `|basicstyle=\small|' looks fine, but comments look really bad with
+%       `|commentstyle=\tiny|' and empty basic style, say.
+%       \advisespace
+%       Don't use different font sizes in a single listing.
+% \item But I really want it!
+%       \advisespace
+%       No, you don't.
+%^^A       The package adjusts internal data after selecting the basic style at
+%^^A       the beginning of each listing. This is a problem if you change the
+%^^A       font size for comments or strings, for example.
+%^^A       Section \ref{rColumnAlignment} shows how to overcome this.
+%^^A       But once again: Don't use different font sizes in a single listing
+%^^A       unless you really know what you are doing.
+% \end{advise}
+%
+% \paragraph{Warning}\label{wStrikingStyles}
+% You should be very careful with striking styles; the recent example is rather
+% moderate---it can get horrible. \emph{Always use decent highlighting.}
+% Unfortunately it is difficult to give more recommendations since they depend
+% on the type of document you're creating. Slides or other presentations often
+% require more striking styles than books, for example.
+% In the end, it's \emph{you} who have to find the golden mean!
+%
+%
+% \subsection{Seduce to use}\label{gSeduceToUse}
+%
+% You know all pretty-printing commands and some main parameters. Here now
+% comes a small and incomplete overview of other features. The table of
+% contents and the index also provide information.
+%
+% \paragraph{Line numbers}
+% are available for all displayed listings, e.g.~tiny numbers on the left, each
+% second line, with 5pt distance to the listing:
+% \begin{lstxsample}[numbers,numberstyle,stepnumber,numbersep]
+%    \lstset{numbers=left, numberstyle=\tiny, stepnumber=2, numbersep=5pt}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item I can't get rid of line numbers in subsequent listings.
+%       \advisespace
+%       `|numbers=none|' turns them off.
+% \item Can I use these keys in the optional arguments?
+%       \advisespace
+%       Of course. Note that optional arguments modify values for one
+%       particular listing only: you change the appearance, step or distance
+%       of line numbers for a single listing. The previous values are
+%       restored afterwards.
+% \end{advise}
+% The environment allows you to interrupt your listings: you can end a listing
+% and continue it later with the correct line number even if there are other
+% listings in between. Read section \ref{uLineNumbers} for a thorough
+% discussion.
+%
+% \paragraph{Floating listings}
+% Displayed listings may float:
+% \begin{lstsample}{\lstset{frame=tb}}{}
+%    \begin{lstlisting}[float,caption=A floating example]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% Don't care about the parameter \ikeyname{caption} now. And if you put the
+% example into the minimal file and run it through \LaTeX, please don't wonder:
+% you'll miss the horizontal rules since they are described elsewhere.
+% \begin{advise}
+% \item \LaTeX's float mechanism allows one to determine the placement of floats.
+%       How can I do that with these?
+%       \advisespace
+%       You can write `|float=tp|', for example.
+% \end{advise}
+%
+% \paragraph{Other features}
+% There are still features not mentioned so far: automatic breaking of long
+% lines, the possibility to use \LaTeX\ code in listings, automated indexing,
+% or personal language definitions.
+% One more little teaser? Here you are. But note that the result is not
+% produced by the \LaTeX\ code on the right alone. The main parameter is
+% hidden.
+% \begin{lstsample}{^^A
+%   \lstset{literate={:=}{{$\gets$}}1 {<=}{{$\leq$}}1 {>=}{{$\geq$}}1 ^^A
+%     {<>}{{$\neq$}}1}}{}
+%    \begin{lstlisting}
+%    if (i<=0) then i := 1;
+%    if (i>=0) then i := 0;
+%    if (i<>0) then i := 0;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% You're not sure whether you should use \packagename{listings}?
+% Read the next section!
+%
+%
+% \subsection{Alternatives}
+%
+% \begin{advise}
+% \item Why do you list alternatives?
+%       \advisespace
+%       Well, it's always good to know the competitors.^^A :-)
+% \item I've read the descriptions below and the \packagename{listings} package
+%       seems to incorporate all the features. Why should I use one of the
+%       other programs?
+%       \advisespace
+%       Firstly, the descriptions give a taste and not a complete overview,
+%       secondly, \packagename{listings} lacks some properties, and, ultimately,
+%       you should use the program matching your needs most precisely.
+% \end{advise}
+% This package is certainly not the final utility for typesetting source code.
+% Other programs do their job very well, if you are not satisfied with
+% \packagename{listings}. Some are independent of \LaTeX, others come as
+% separate program plus \LaTeX\ package, and others are packages which
+% don't pretty-print the source code. The second type includes converters,
+% cross compilers, and preprocessors. Such programs create \LaTeX\ files
+% you can use in your document or stand alone ready-to-run \LaTeX\ files.
+%
+% Note that I'm not dealing with any literate programming tools here, which
+% could also be alternatives. However, you should have heard of the
+% \texttt{WEB} system, the tool Prof.~Donald E.~Knuth developed and made use
+% of to document and implement \TeX.
+%
+% \paragraph{\href{http://www.infres.enst.fr/~demaille/a2ps}{\packagename{a2ps}}}
+% started as `ASCII to PostScript' converter, but today you can invoke the
+% program with \texttt{--pretty-print=}\meta{language} option. If your
+% favourite programming language is not already supported, you can write your
+% own so-called style sheet. You can request line numbers, borders, headers,
+% multiple pages per sheet, and many more. You can even print symbols like
+% $\forall$ or $\alpha$ instead of their verbose forms. If you just want
+% program listings and not a document with some listings, this is the best
+% choice.
+%
+% \paragraph{\href{http://mirror.ctan.org/support/lgrind}{\packagename{LGrind}}}
+% is a cross compiler and comes with many predefined programming languages.
+% For example, you can put the code on the right in your document, invoke
+% \packagename{LGrind} with \texttt{-e} option (and file names), and run the
+% created file through \LaTeX. You should get a result similar to the
+% left-hand side:
+% \begin{center}
+% \begin{minipage}{0.45\linewidth}
+%\iflgrind
+%    \LGindent=0pt
+%    \LGinlinefalse\LGbegin\lgrinde
+%    \L{\LB{\K{for}_\V{i}:=\V{maxint}_\K{to}_\N{0}_\K{do}}}
+%    \L{\LB{\K{begin}}}
+%    \L{\LB{____\C{}\{_do_nothing_\}\CE{}}}
+%    \L{\LB{\K{end};}}
+%    \L{\LB{}}
+%    \L{\LB{\V{Write}(\S{}{'}Case_insensitive_{'}\SE{});}}
+%    \L{\LB{\V{WritE}(\S{}{'}Pascal_keywords.{'}\SE{});}}
+%    \endlgrinde\LGend
+%\else
+%    \packagename{LGrind} not installed.
+%\fi
+% \end{minipage}
+% \begin{minipage}{0.45\linewidth}
+% \begin{verbatim}
+% %[
+% for i:=maxint to 0 do
+% begin
+%     { do nothing }
+% end;
+%
+% Write('Case insensitive ');
+% WritE('Pascal keywords.');
+% %]\end{verbatim}
+% \end{minipage}
+% \end{center}
+% If you use |%(| and |%)| instead of |%[| and |%]|, you get a code snippet
+% instead of a displayed listing. Moreover you can get line numbers to the
+% left or right, use arbitrary \LaTeX\ code in the source code, print symbols
+% instead of verbose names, make font setup, and more. You will (have to)
+% like it (if you don't like \packagename{listings}).
+%
+% Note that \packagename{LGrind} contains code with a no-sell license and is
+% thus nonfree software.
+%
+% \paragraph{\href{ftp://axp3.sv.fh-mannheim.de/cvt2latex}{\packagename{cvt2ltx}}}
+% is a family of `source code to \LaTeX' converters for C, Objective C, \Cpp,
+% IDL and Perl. Different styles, line numbers and other qualifiers can be
+% chosen by command-line option. Unfortunately it isn't documented how other
+% programming languages can be added.
+%
+% \paragraph{\href{http://mirror.ctan.org/support/C++2LaTeX-1_1pl1}{\packagename{\Cpp2\LaTeX}}}
+% is a C/\Cpp\ to \LaTeX\ converter. You can specify the fonts for comments,
+% directives, keywords, and strings, or the size of a tabulator. But as far as
+% I know you can't number lines.
+%
+% \paragraph{\href{http://mirror.ctan.org/support/slatex}{\packagename{S\LaTeX}}}
+% is a pretty-printing Scheme program (which invokes \LaTeX\ automatically)
+% especially designed for Scheme and other Lisp dialects. It supports stand
+% alone files, text and display listings, and you can even nest the
+% commands/environments if you use \LaTeX\ code in comments, for example.
+% Keywords, constants, variables, and symbols are definable and use of
+% different styles is possible. No line numbers.
+%
+% \paragraph{\href{http://mirror.ctan.org/support/tiny_c2l}^^A
+%   {\packagename{tiny\textunderscore c2ltx}}}
+% is a C/\Cpp/Java to \LaTeX\ converter based on \packagename{cvt2ltx} (or the
+% other way round?). It supports line numbers, block comments, \LaTeX\ code
+% in/as comments, and smart line breaking. Font selection and tabulators are
+% hard-coded, i.e.~you have to rebuild the program if you want to change the
+% appearance.
+%
+% \paragraph{\href{http://mirror.ctan.org/macros/latex/contrib/misc}{\packagename{listing}}}
+% ---note the missing \packagename{s}---is not a pretty-printer and the
+% aphorism about documentation at the end of \texttt{listing.sty} is not
+% true.\space ^^A :-)
+% It defines |\listoflistings| and a nonfloating environment for listings.
+% All font selection and indention must be done by hand. However, it's
+% useful if you have another tool doing that work, e.g.~\packagename{LGrind}.
+%
+% \paragraph{\href{http://mirror.ctan.org/macros/latex/contrib/alg}{\packagename{alg}}}
+% provides essentially the same functionality as \packagename{algorithms}.
+% So read the next paragraph and note that the syntax will be different.
+%
+% \paragraph{\href{http://mirror.ctan.org/macros/latex/contrib/algorithms}^^A
+%   {\packagename{algorithms}}}
+% goes a quite different way. You describe an algorithm and the package
+% formats it, for example
+% \begin{center}
+% \begin{minipage}{0.45\linewidth}
+%\ifalgorithmicpkg
+%    \begin{algorithmic}
+%    \IF {$i\leq0$}
+%    \STATE $i\gets1$
+%    \ELSE\IF {$i\geq0$}
+%    \STATE $i\gets0$
+%    \ENDIF\ENDIF
+%    \end{algorithmic}
+%\else
+%    \packagename{algorithms} not installed.
+%\fi
+% \end{minipage}
+% \begin{minipage}{0.45\linewidth}
+% \begin{verbatim}
+%\begin{algorithmic}
+%\IF{$i\leq0$}
+%\STATE $i\gets1$
+%\ELSE\IF{$i\geq0$}
+%\STATE $i\gets0$
+%\ENDIF\ENDIF
+%\end{algorithmic}\end{verbatim}
+% \end{minipage}
+% \end{center}
+% As this example shows, you get a good looking algorithm even from a bad
+% looking input. The package provides a lot more constructs like |for|-loops,
+% |while|-loops, or comments. You can request line numbers, `ruled', `boxed'
+% and floating algorithms, a list of algorithms, and you can customize the
+% terms \textbf{if}, \textbf{then}, and so on.
+%
+% \paragraph{\href{http://www.mimuw.edu.pl/~wolinski/pretprin.html}^^A
+%   {\packagename{pretprin}}}
+% is a package for pretty-printing texts in formal languages---as the title
+% in TUGboat, Volume 19 (1998), No.~3 states. It provides environments which
+% pretty-print \emph{and} format the source code. Analyzers for Pascal and
+% Prolog are defined; adding other languages is easy---if you are or get a bit
+% familiar with automatons and formal languages.
+%
+% \paragraph{\packagename{alltt}}
+% defines an environment similar to \texttt{verbatim} except that |\|, |{| and
+% |}| have their usual meanings. This means that you can use commands in the
+% verbatims, e.g.~select different fonts or enter math mode.
+%
+% \paragraph{\href{http://mirror.ctan.org/macros/latex/contrib/moreverb}^^A
+%   {\packagename{moreverb}}}
+% requires \packagename{verbatim} and provides verbatim output to a file,
+% `boxed' verbatims and line numbers.
+%
+% \paragraph{\packagename{verbatim}}
+% defines an improved version of the standard \texttt{verbatim} environment and
+% a command to input files verbatim.
+%
+% \paragraph{\href{http://mirror.ctan.org/macros/latex/contrib/fancyvrb}^^A
+%   {\packagename{fancyvrb}}}
+% is, roughly speaking, a superset of \packagename{alltt},
+% \packagename{moreverb}, and \packagename{verbatim}, but many more parameters
+% control the output. The package provides frames, line numbers on the left or
+% on the right, automatic line breaking (difficult), and more. For example, an
+% interface to \packagename{listings} exists, i.e.~you can pretty-print source
+% code automatically.
+% The package \packagename{fvrb-ex} builds on \packagename{fancyvrb} and
+% defines environments to present examples similar to the ones in this guide.
+%
+%
+% \section{The next steps}\label{uTheNextSteps}
+%
+% Now, before actually using the \packagename{listings} package, you should
+% \emph{really} read the software license. It does not cost much time and
+% provides information you probably need to know.
+%
+%
+% \subsection{Software license}\label{uSoftwareLicense}
+%
+% The files \texttt{listings.dtx} and \texttt{listings.ins} and all
+% files generated from only these two files are referred to as `the
+% \packagename{listings} package' or simply `the package'.
+% \texttt{lstdrvrs.dtx} and the files generated from that file are
+% `drivers'.
+%
+% \paragraph{Copyright}
+%   The \packagename{listings} package is copyright 1996--2004 Carsten Heinz,
+%   and copyright 2006 Brooks Moses.  The drivers are copyright any individual
+%   author listed in the driver files.
+%
+% \paragraph{Distribution and modification}
+%   The \packagename{listings} package and its drivers may be distributed
+%   and/or modified under the conditions of the LaTeX Project Public License,
+%   either version 1.3 of this license or (at your option) any later version.
+%   The latest version of this license is in
+%      \href{http://www.latex-project.org/lppl.txt}{http://www.latex-project.org/lppl.txt}
+%   and version 1.3c or later is part of all distributions of LaTeX version
+%  2003/12/01 or later.
+%
+% \paragraph{Contacts}
+%   Read section \lstref{uTroubleshooting} on how to submit a bug report.
+%   Send all other comments, ideas, and additional programming languages to
+%   \lstemail\ using \texttt{listings} as part of the subject.
+%
+%
+% \subsection{Package loading}\label{uPackageLoading}
+%
+% As usual in \LaTeX, the package is loaded by
+%    |\usepackage[|\meta{options}|]{listings}|,
+% where |[|\meta{options}|]| is optional and gives a comma separated list of
+% options. Each either loads an additional \packagename{listings} aspect, or
+% changes default properties. Usually you don't have to take care of such
+% options. But in some cases it could be necessary: if you want to compile
+% documents created with an earlier version of this package or if you use
+% special features. Here's an incomplete list of possible options.
+% \begin{advise}
+% \item Where is a list of all of the options?
+%       \advisespace
+%       In the developer's guide since they were introduced to debug the
+%       package more easily. Read section \ref{uHowTos} on how to get that
+%       guide.
+% \end{advise}
+% \begin{description}
+% \item[\normalfont\texttt{0.21}]\leavevmode
+%
+%       invokes a compatibility mode for compiling documents written for
+%       \packagename{listings} version 0.21.
+%
+% \item[\normalfont\texttt{draft}]\leavevmode
+%
+%       The package prints no stand alone files, but shows the captions and
+%       defines the corresponding labels.
+%       Note that a global |\documentclass|-option \texttt{draft} is
+%       recognized, so you don't need to repeat it as a package option.
+%
+% \item[\normalfont\texttt{final}]\leavevmode\label{uoption:final}
+%
+%       Overwrites a global \texttt{draft} option.
+%
+% \item[\normalfont\texttt{savemem}]\leavevmode
+%
+%       tries to save some of \TeX's memory. If you switch between languages
+%       often, it could also reduce compile time. But all this depends on the
+%       particular document and its listings.
+% \end{description}
+% Note that various experimental features also need explicit loading via
+% options. Read the respective lines in section \ref{rExperimentalFeatures}.
+%
+% \medbreak
+% After package loading it is recommend to load all used dialects of programming
+% languages with the following command. It is faster to load several languages
+% with one command than loading each language on demand.
+% \begin{syntax}
+% \item {\rstyle\icmdname\lstloadlanguages}\marg{comma separated list of languages}
+%
+%       Each language is of the form \oarg{dialect}\meta{language}. Without
+%       the optional \oarg{dialect} the package loads a default dialect. So
+%       write `|[Visual]C++|' if you want Visual \Cpp\ and `|[ISO]C++|' for
+%       ISO \Cpp. Both together can be loaded by the command
+%       |\lstloadlanguages{[Visual]C++,[ISO]C++}|.
+%
+%       Table \ref{uPredefinedLanguages} on page \pageref{uPredefinedLanguages}
+%       shows all defined languages and their dialects.
+% \end{syntax}
+%^^A After or even before language loading, you might want to define default
+%^^A dialects---just to be independent of configuration files.
+%
+%
+% \subsection{The key=value interface}\label{uTheKey=ValueInterface}
+%
+% This package uses the \packagename{keyval} package from the
+% \packagename{graphics} bundle by David Carlisle. Each parameter is
+% controlled by an associated key and a user supplied value. For example,
+% \ikeyname{firstline} is a key and |2| a valid value for this key.
+%
+% The command {\rstyle\icmdname\lstset} gets a comma separated list of
+% ``key|=|value'' pairs. The first list with more than a single entry is on
+% page \pageref{gFirstKey=ValueList}: |firstline=2,lastline=5|.
+% \begin{advise}
+% \item So I can write `|\lstset{firstline=2,lastline=5}|' once for all?
+%       \advisespace
+%       No. `\ikeyname{firstline}' and `\ikeyname{lastline}' belong to a small
+%       set of
+%       keys which are only used on individual listings. However, your command is
+%       not illegal---it has no effect. You have to use these keys inside the
+%       optional argument of the environment or input command.
+% \item What's about a better example of a key|=|value list?
+%       \advisespace
+%       There is one in section \ref{gFigureOutTheAppearance}.
+% \item `|language=[77]Fortran|' does not work inside an optional argument.
+%       \advisespace
+%       You must put braces around the value if a value with optional argument
+%       is used inside an optional argument. In the case here write
+%       `|language={[77]Fortran}|' to select Fortran 77.
+% \item If I use the `\ikeyname{language}' key inside an optional argument, the
+%       language isn't active when I typeset the next listing.
+%       \advisespace
+%       All parameters set via `|\lstset|' keep their values up to the end of
+%       the current environment or group. Afterwards the previous values are
+%       restored. The optional parameters of the two pretty-printing commands
+%       and the `\texttt{lstlisting}' environment take effect on the particular
+%       listing only, i.e.~values are restored immediately. For example, you
+%       can select a main language and change it for special listings.
+% \item \icmdname\lstinline\ has an optional argument?
+%       \advisespace
+%       Yes. And from this fact comes a limitation: you can't use the left
+%       bracket `|[|' as delimiter unless you specify at least an empty
+%       optional argument as in `|\lstinline[][var i:integer;[|'.
+%       If you forget this, you will either get a ``runaway argument'' error
+%       from \TeX, or an error message from the \packagename{keyval} package.
+% \end{advise}
+%
+%
+% \subsection{Programming languages}\label{uProgrammingLanguages}
+%
+% You already know how to activate programming languages---at least Pascal.
+% An optional parameter selects particular dialects of a language. For example,
+% |language=[77]Fortran| selects Fortran 77 and |language=[XSC]Pascal| does the
+% same for Pascal XSC. The general form is
+%    {\rstyle\ikeyname{language}}|=|\oarg{dialect}\meta{language}.
+% If you want to get rid of keyword, comment, and string detection, use
+% |language={}| as an argument to |\lstset| or as optional argument.
+%
+% Table \ref{uPredefinedLanguages} shows all predefined languages and dialects.
+% Use the listed names as \meta{language} and \meta{dialect}, respectively. If
+% no dialect or `empty' is given in the table, just don't specify a dialect.
+% Each underlined dialect is default; it is selected if you leave out
+% the optional argument. The predefined defaults are the newest language
+% versions or standard dialects.
+%^^A
+%^^A  Make table of predefined languages.
+%^^A
+%\let\lstlanguages\empty
+%\makeatletter
+%\@for\lst@temp:={lstlang1.sty,lstlang2.sty,lstlang3.sty}\do
+%    {\IfFileExists\lst@temp{}{\let\lstlanguages\relax}}
+%\makeatother
+%\ifx\lstlanguages\relax
+%    \PackageWarningNoLine{Listings}
+%        {Standard drivers not available.\MessageBreak
+%         Please check your installation.\MessageBreak
+%         Compilation aborted}
+%    \csname @@end\expandafter\endcsname
+%\fi
+%\lstscanlanguages\lstlanguages{lstlang1.sty,lstlang2.sty,lstlang3.sty}{}^^A
+%\def\topfigrule{\hrule\kern-0.4pt\relax}^^A
+%\let\botfigrule\topfigrule
+%\belowcaptionskip=\smallskipamount
+% \begin{table}[tbhp]
+% \small
+% \caption{Predefined languages.
+%          Note that some definitions are preliminary, for example HTML and XML.
+%          Each underlined dialect is the default dialect.}^^A
+%          \label{uPredefinedLanguages}^^A
+% \makeatletter
+% \setbox\@tempboxa\hbox{^^A
+%    \InputIfFileExists{listings.cfg}{\lst@InputCatcodes}{}}^^A
+% \lstprintlanguages\lstlanguages
+% \end{table}
+%^^A
+%^^A end of table
+%^^A
+%\lstset{defaultdialect=[doc]Pascal}^^A restore
+% \begin{advise}
+% \item How can I define default dialects?
+%       \advisespace
+%       Check section \ref{rLanguagesAndStyles} for `\keyname{defaultdialect}'.
+% \item I have C code mixed with assembler lines. Can \packagename{listings}
+%       pretty-print such source code, i.e.~highlight keywords and comments of
+%       both languages?
+%       \advisespace
+%       `\ikeyname{alsolanguage}|=|\oarg{dialect}\meta{language}' selects a
+%       language additionally to the active one. So you only have to write a
+%       language definition for your assembler dialect, which doesn't interfere
+%       with the definition of C, say. Moreover you might want to use the key
+%       `\keyname{classoffset}' described in section \ref{rLanguagesAndStyles}.
+% \item How can I define my own language?
+%       \advisespace
+%       This is discussed in section \ref{rLanguageDefinitions}. And if you
+%       think that other people could benefit by your definition, you might
+%       want to send it to the address in section \ref{uSoftwareLicense}.
+%       Then it will be published under the \LaTeX\ Project Public License.
+% \end{advise}
+% Note that the arguments \meta{language} and \meta{dialect} are case
+% insensitive and that spaces have no effect.
+%
+% There is at least one language (VDM, Vienna Development Language,
+% \url{http://www.vdmportal.org}) which is not directly supported by the
+% \packagename{listings} package. It needs a package for its own:
+% \packagename{vdmlisting}. On the other hand \packagename{vdmlisting} uses
+% the \packagename{listings} package and so it should be mentioned in this
+% context.
+%
+%
+% \subsubsection{Preferences}\label{uPreferences}
+%
+% Sometimes authors of language support provide their own configuration
+% preferences. These may come either from their personal experience or
+% from the settings in an IDE and can be defined as a \packagename{listings}
+% style. From version 1.5b of the \packagename{listings} package on these
+% styles are provided as files with the name
+% |listings-|\meta{language}|.prf|, \meta{language} is the name of the
+% supported programming language in lowercase letters.
+%
+% So if an user of the \packagename{listings} package wants to use these
+% preferences, she/he can say for example when using Python
+% \begin{quote}
+%     |\input{listings-python.prf}|
+% \end{quote}
+% at the end of her/his |listings.cfg| configuration file as long as the
+% file |listings-python.prf| resides in the \TeX{} search path. Of course
+% that file can be changed according to the user's preferences.
+%
+% At the moment there are five such preferences files:
+% \begin{enumerate}
+%   \item |listings-acm.prf|
+%   \item |listings-bash.prf|
+%   \item |listings-fortran.prf|
+%   \item |listings-lua.prf|
+%   \item |listings-python.prf|
+% \end{enumerate}
+% All contributors are invited to supply more personal preferences.
+%
+%
+% \subsection{Special characters}\label{uSpecialCharacters}
+%
+%
+% \paragraph{Tabulators}
+% You might get unexpected output if your sources contain tabulators.
+% The package assumes tabulator stops at columns 9, 17, 25, 33, and so on.
+% This is predefined via |tabsize=8|. If you change the eight to the number
+% $n$, you will get tabulator stops at columns $n+1,2n+1,3n+1,$ and so on.
+% \begin{lstsample}[tabsize]{}{}
+%    \lstset{tabsize=2}
+%    \begin{lstlisting}
+%    123456789
+%    	{ one tabulator }
+%    		{ two tabs }
+%    123		{ 123 + two tabs }
+%    \end{lstlisting}
+% \end{lstsample}
+% For better illustration, the left-hand side uses |tabsize=2| but the verbatim
+% code |tabsize=4|. Note that |\lstset| modifies the values for all following
+% listings in the same environment or group. This is no problem here since the
+% examples are typeset inside minipages. If you want to change settings for a
+% single listing, use the optional argument.
+%
+%
+% \paragraph{Visible tabulators and spaces}
+% One can make spaces and tabulators visible:
+% \begin{lstsample}[showspaces,showtabs,tab]{}{}
+%    \lstset{showspaces=true,
+%            showtabs=true,
+%            tab=\rightarrowfill}
+%    \begin{lstlisting}
+%        for i:=maxint to 0 do
+%        begin
+%    	{ do nothing }
+%        end;
+%    \end{lstlisting}
+% \end{lstsample}
+% If you request \ikeyname{showspaces} but no \ikeyname{showtabs},
+% tabulators are converted to visible spaces.
+% The default definition of \ikeyname{tab} produces a `wide visible space'
+% \lstinline[showtabs]!	!. So you might want to use |$\to$|, |$\dashv$|
+% or something else instead.
+% \begin{advise}
+% \item Some sort of advice: (1) You should really indent lines of source code
+%       to make listings more readable. (2) Don't indent some lines with
+%       spaces and others via tabulators. Changing the tabulator size (of your
+%       editor or pretty-printing tool) completely disturbs the columns.
+%       (3) As a consequence, never share your files with differently tab sized
+%       people!^^A true only if you use tabulators, just :-)
+% \item To make the \LaTeX\ code more readable, I indent the environments'
+%       program listings. How can I remove that indention in the output?
+%       \advisespace
+%       Read `How to gobble characters' in section \ref{uHowTos}.
+% \end{advise}
+%
+%
+% \paragraph{Form feeds}
+% Another special character is a form feed causing an empty line by default.
+% {\rstyle\ikeyname{formfeed}}|=\newpage| would result in a new page every
+% form feed. Please note that such definitions (even the default) might get
+% in conflict with frames.
+%
+%
+% \paragraph{National characters}
+% If you type in such characters directly as characters of codes 128--255 and
+% use them also in listings, let the package know it---or you'll get really
+% funny results. {\rstyle\ikeyname{extendedchars}}|=true| allows and
+% |extendedchars=false| prohibits \packagename{listings} from handling
+% extended characters in listings. If you use them, you should load
+% \packagename{fontenc}, \packagename{inputenc} and/or
+% any other package which defines the characters.
+% \begin{advise}
+% \item I have problems using \packagename{inputenc} together with
+%       \packagename{listings}.
+%       \advisespace
+%       This could be a compatibility problem. Make a bug report as described
+%       in section \lstref{uTroubleshooting}.
+% \end{advise}
+% The extended characters don't cover Arabic, Chinese, Hebrew, Japanese, and so
+% on---specifically, any encoding which uses multiple bytes per character.
+%
+% Thus, if you use the a package that supports multibyte characters, such as
+% the \packagename{CJK} or \packagename {ucs} packages for Chinese and
+% UTF-8 characters, you must avoid letting \packagename{listings}
+% process the extended characters.  It is generally best to also specify
+% |extendedchars=false| to avoid having \packagename{listings} get entangled
+% in the other package's extended-character treatment.
+%
+% If you do have a listing contained within a CJK environment, and want to have
+% CJK characters inside the listing, you can place them within a comment that
+% escapes to \LaTeX -- see section \ref{rEscapingToLaTeX} for how to do that.
+% (If the listing is not inside a CJK environment, you can simply put a small
+% CJK environment within the escaped-to-\LaTeX portion of the comment.)
+%
+% Similarly, if you are using UTF-8 extended characters in a listing, they must
+% be placed within an escape to \LaTeX.
+%
+% Also, section \ref{uNationalCharacters} has a few details on how to work with
+% extended characters in the context of $\Lambda$.
+%
+%
+% \subsection{Line numbers}\label{uLineNumbers}
+%
+% You already know the keys \ikeyname{numbers}, \ikeyname{numberstyle},
+% \ikeyname{stepnumber}, and \ikeyname{numbersep} from section
+% \ref{gSeduceToUse}. Here now we deal with continued listings.
+% You have two options to get consistent line numbering across listings.
+%
+% \begin{lstsample}[firstnumber]{\lstset{numbers=left,numberstyle=\tiny,^^A
+%       stepnumber=2,numbersep=5pt}}{}
+%    \begin{lstlisting}[firstnumber=100]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    \end{lstlisting}
+%    And we continue the listing:
+%    \begin{lstlisting}[firstnumber=last]
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% In the example, \ikeyname{firstnumber} is initially set to 100; some lines
+% later the value is \texttt{last}, which continues the numbering of the last
+% listing. Note that the empty line at the end of the first part is not printed
+% here, but it counts for line numbering. You should also notice that you can
+% write |\lstset{firstnumber=last}| once and get consecutively numbered code
+% lines---except you specify something different for a particular listing.
+%
+% On the other hand you can use |firstnumber=auto| and name your listings.
+% Listings with identical names (case sensitive!) share a line counter.
+% \begin{lstsample}[name]{\lstset{numbers=left,numberstyle=\tiny,stepnumber=2,numbersep=5pt}}{}
+%    \begin{lstlisting}[name=Test]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%
+%    \end{lstlisting}
+%    And we continue the listing:
+%    \begin{lstlisting}[name=Test]
+%    Write('Case insensitive ');
+%    WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% The next |Test| listing goes on with line number {\makeatletter\lstno@Test},
+% no matter whether there are other listings in between.
+% \begin{advise}
+% \item Okay. And how can I get decreasing line numbers?
+%       \advisespace
+%       Sorry, what?
+%       \advisespace
+%       Decreasing line numbers as on page \pageref{rDecreasingLabels}.
+%       \advisespace
+%       May I suggest to demonstrate your individuality by other means?
+%       If you differ, you should try a negative `\ikeyname{stepnumber}'
+%       (together with `\ikeyname{firstnumber}').
+% \end{advise}
+%
+% Read section \ref{uHowTos} on how to reference line numbers.
+%
+%
+% \subsection{Layout elements}
+%
+% It's always a good idea to structure the layout by vertical space,
+% horizontal lines, or different type sizes and typefaces. The best to stress
+% whole listings are---not all at once---colours, frames, vertical space, and
+% captions. The latter are also good to refer to listings, of course.
+%
+% \paragraph{Vertical space}
+% The keys {\rstyle\ikeyname{aboveskip}} and {\rstyle\ikeyname{belowskip}}
+% control the vertical space above and below displayed listings. Both keys get
+% a dimension or skip as value and are initialized to |\medskipamount|.
+%
+% \paragraph{Frames}
+% The key \ikeyname{frame} takes the verbose values \keyvalue{none},
+% \keyvalue{leftline}, \keyvalue{topline}, \keyvalue{bottomline},
+% \keyvalue{lines} (top and bottom), \keyvalue{single} for single frames, or
+% \keyvalue{shadowbox}.
+% \begin{lstsample}[frame]{}{}
+%    \begin{lstlisting}[frame=single]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item The rules aren't aligned.
+%       \advisespace
+%       This could be a bug of this package or a problem with your
+%       \texttt{.dvi} driver. \emph{Before} sending a bug report to the package
+%       author, modify the parameters described in section \ref{rFrames}
+%       heavily. And do this step by step!
+%       For example, begin with `|framerule=10mm|'. If the rules are
+%       misaligned by the same (small) amount as before, the problem does not
+%       come from the rule width. So continue with the next parameter.  Also,
+%       Adobe Acrobat sometimes has single-pixel rounding errors which can
+%       cause small misalignments at the corners when PDF files are displayed
+%       on screen; these are unfortunately normal.
+% \end{advise}
+% Alternatively you can control the rules at the \texttt{t}op, \texttt{r}ight,
+% \texttt{b}ottom, and \texttt{l}eft directly by using the four initial letters
+% for single rules and their upper case versions for double rules.
+% \begin{lstsample}[frame]{}{}
+%    \begin{lstlisting}[frame=trBL]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% Note that a corner is drawn if and only if both adjacent rules are requested.
+% You might think that the lines should be drawn up to the edge, but what's
+% about round corners? The key \ikeyname{frameround} must get exactly four
+% characters as value. The first character is attached to the upper right
+% corner and it continues clockwise. `\texttt{t}' as character makes the
+% corresponding corner round.
+% \begin{lstsample}[frameround]{}{}
+%    \lstset{frameround=fttt}
+%    \begin{lstlisting}[frame=trBL]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% Note that \ikeyname{frameround} has been used together with |\lstset| and thus
+% the value affects all following listings in the same group or environment.
+% Since the listing is inside a \texttt{minipage} here, this is no problem.
+% \begin{advise}
+% \item Don't use frames all the time, and in particular not with short listings.
+%       This would emphasize nothing. Use frames for $10\%$ or even less of
+%       your listings, for your most important ones.
+% \item If you use frames on floating listings, do you really want frames?
+%       \advisespace
+%       No, I want to separate floats from text.
+%       \advisespace
+%       Then it is better to redefine \LaTeX's `|\topfigrule|' and
+%       `|\botfigrule|'. For example, you could write
+%       `|\renewcommand*\topfigrule{\hrule\kern-0.4pt\relax}|' and make the
+%       same definition for |\botfigrule|.
+% \end{advise}
+%
+% \paragraph{Captions}
+% Now we come to \ikeyname{caption} and \ikeyname{label}. You might guess
+% (correctly) that they can be used in the same manner as \LaTeX's |\caption|
+% and |\label| commands, although here it is also possible to have a caption
+% regardless of whether or not the listing is in a float:
+% \begin{lstsample}[caption,label]{\lstset{xleftmargin=.05\linewidth}}{}
+%    \begin{lstlisting}[caption={Useless code},label=useless]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% Afterwards you could refer to the listing via |\ref{useless}|. By default
+% such a listing gets an entry in the list of listings, which can be printed
+% with the command {\rstyle\icmdname\lstlistoflistings}. The key
+% {\rstyle\ikeyname{nolol}} suppresses an entry for both the environment or
+% the input command. Moreover, you can specify a short caption for the list
+% of listings:
+%    \keyname{caption}|={|\oarg{short}\meta{long}|}|.
+% Note that the whole value is enclosed in braces since an optional value is
+% used in an optional argument.
+%
+% If you don't want the label \texttt{\lstlistingname} plus number, you should
+% use \ikeyname{title}:
+% \begin{lstsample}[title]{\lstset{xleftmargin=.05\linewidth}}{}
+%    \begin{lstlisting}[title={`Caption' without label}]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item Something goes wrong with `\keyname{title}' in my document: in front of
+%       the title is a delimiter.
+%       \advisespace
+%       The result depends on the document class; some are not compatible.
+%       Contact the package author for a work-around.
+% \end{advise}
+%
+% \paragraph{Colours}
+% One more element. You need the \packagename{color} package and can then
+% request coloured background via
+% \ikeyname{backgroundcolor}|=|\meta{color command}.
+% \begin{advise}
+% \item Great! I love colours.
+%       \advisespace
+%       Fine, yes, really. And I like to remind you of the warning about
+%       striking styles on page \pageref{wStrikingStyles}.
+% \end{advise}
+%\ifcolor
+% \begin{lstxsample}[backgroundcolor]
+%    \lstset{backgroundcolor=\color{yellow}}
+% \end{lstxsample}
+%\else
+% \begin{verbatim}
+%    color package not installed\end{verbatim}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}[frame=single,
+%                       framerule=0pt]
+%    for i:=maxint to 0 do
+%    begin
+%        j:=square(root(i));
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% The example also shows how to get coloured space around the whole listing:
+% use a frame whose rules have no width.
+%
+%
+% \subsection{Emphasize identifiers}\label{uEmphasizeIdentifiers}
+%
+% Recall the pretty-printing commands and environment. |\lstinline| prints
+% code snippets, |\lstinputlisting| whole files, and \texttt{lstlisting}
+% pieces of code which reside in the \LaTeX\ file. And what are these
+% different `types' of source code good for? Well, it just happens that a
+% sentence contains a code fragment. Whole files are typically included in or
+% as an appendix. Nevertheless some books about programming also include such
+% listings in normal text sections---to increase the number of pages.
+% Nowadays source code should be shipped on disk or CD-ROM and only the main
+% header or interface files should be typeset for reference. So, please, don't
+% misuse the \packagename{listings} package. But let's get back to the topic.
+%
+% Obviously `\texttt{lstlisting} source code' isn't used to make an executable
+% program from. Such source code has some kind of educational purpose or even
+% didactic.
+% \begin{advise}
+% \item What's the difference between educational and didactic?
+%       \advisespace
+%       Something educational can be good or bad, true or false.
+%       Didactic is true by definition.^^A :-)
+% \end{advise}
+% Usually \emph{keywords} are highlighted when the package typesets a piece of
+% source code. This isn't necessary for readers who know the programming
+% language well. The main matter is the presentation of interface, library or
+% other functions or variables. If this is your concern, here come the right
+% keys. Let's say, you want to emphasize the functions |square| and |root|,
+% for example, by underlining them. Then you could do it like this:
+% \begin{lstxsample}[emph,emphstyle]
+%    \lstset{emph={square,root},emphstyle=\underbar}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        j:=square(root(i));
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item Note that the list of identifiers |{square,root}| is enclosed in
+%       braces. Otherwise the \packagename{keyval} package would complain
+%       about an undefined key \keyname{root} since the comma finishes the
+%       key=value pair.
+%       Note also that you \emph{must} put braces around the value if you
+%       use an optional argument of a key inside an optional argument of a
+%       pretty-printing command. Though it is not necessary, the following
+%       example uses these braces. They are typically forgotten when they
+%       become necessary,
+% \end{advise}
+%
+% Both keys have an optional \meta{class number} argument for multiple
+% identifier lists:
+%\ifcolor
+% \begin{lstxsample}[emph,emphstyle]
+%    \lstset{emph={square},      emphstyle=\color{red},
+%            emph={[2]root,base},emphstyle={[2]\color{blue}}}
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}[emph,emphstyle]
+%    \lstset{emph={square},      emphstyle=\underbar,
+%            emph={[2]root,base},emphstyle={[2]\fbox}}
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        j:=square(root(i));
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item What is the maximal \meta{class number}?
+%       \advisespace
+%       $2^{31}-1=2\,147\,483\,647$. But \TeX's memory will exceed before you
+%       can define so many different classes.
+% \end{advise}
+%
+% One final hint: Keep the lists of identifiers disjoint. Never use a keyword
+% in an `emphasize' list or one name in two different lists. Even if your
+% source code is highlighted as expected, there is no guarantee that it is
+% still the case if you change the order of your listings or if you use the
+% next release of this package.
+%
+%
+%\iffalse
+% \subsection{*Listing alignment}\label{uListingAlignment}
+%
+% The examples are typeset with centered \texttt{minipage}s. That's the reason
+% why you can't see that line numbers are printed in the margin. Now we
+% separate the minipage margin and the minipage by a vertical rule:
+% \begin{lstsample}{\lstset{frame=l,framesep=0pt,numberstyle=\tiny,stepnumber=2,^^A
+%     numbersep=5pt}}{}
+%    Some text before
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% The listing is lined up with the normal text. The parameter \ikeyname{xleftmargin}
+% moves the listing to the right (or left if the dimension is negative).
+% \begin{lstsample}{\lstset{frame=l,framesep=0pt,numberstyle=\tiny,stepnumber=2,^^A
+%     numbersep=5pt}}{}
+%    Some text before
+%    \begin{lstlisting}[xleftmargin=15pt]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+%
+%    \begin{lstlisting}{ }
+%    Write('Insensitive');
+%    WritE('keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% Note again that optional arguments change settings for single listings.
+%
+% If you use environments like \texttt{itemize} or \texttt{enumerate}, there
+% is `natural' indention coming from these environments. By default the
+% \packagename{listings} package respects this. But you might use
+% |resetmargins=true| (or |false|) to make your own decision. You can use it
+% together with |xleftmargin|, of course.
+% \begin{advise}
+% \item I get heavy overfull |\hbox|es from some listings.
+%       \advisespace
+%       This comes from long lines in your listings. You have some options
+%       to get rid of the overful |\hbox|es. Firstly I recommend to typeset
+%       listings in smaller fonts than the surrounding text, for example
+%       `|basicstyle=\small|'. Secondly you might want to use the flexible
+%       column format. Thirdly you can increase the line width or set it
+%       explicitly, refer section \ref{rMarginsAndLineShape}.
+%       If all this doesn't help, you might want to change
+%       `\ikeyname{basewidth}', but be careful! The two unknown items are
+%       explained in the next section.
+% \end{advise}
+%
+% You might need to control the vertical position of listings with the
+% \ikeyname{boxpos} key, for example, if you use them in \texttt{minipage} or
+% \texttt{tabular} environments. Here `listings' means \texttt{lstlisting} or
+% |\lstinputlisting|. As the following example shows, you can even place such
+% listings inside paragraphs, but you must force the package to do this by
+% enclosing the listing in |\hbox{| and |}|.
+% \begin{advise}
+% \item Is it good form to use the \TeX-primitive `|\hbox|' in a \LaTeX\
+%       document?
+%       \advisespace
+%       No, it's not. But \LaTeX's `|\mbox|' does not work in this example:
+% \end{advise}
+% \begin{lstsample}{}{}
+%    Here are some multi-line listings inside a paragraph.
+%    The `boxpos' key controls their vertical alignment:
+%    \hbox{\begin{lstlisting}[boxpos=c]
+%    center
+%    center
+%    \end{lstlisting}}
+%    \hbox{\begin{lstlisting}[boxpos=b]
+%    bottom baseline
+%    bottom baseline
+%    \end{lstlisting}}
+%    \hbox{\begin{lstlisting}[boxpos=t]
+%    top baseline
+%    top baseline
+%    \end{lstlisting}}
+% \end{lstsample}
+%\fi
+%
+%
+% \subsection{Indexing}\label{uIndexing}
+%
+% Indexing is just like emphasizing identifiers---I mean the usage:
+% \begin{lstxsample}[index]
+%    \lstset{index={square},index={[2]root}}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        j:=square(root(i));
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% Of course, you can't see anything here. You will have to look at the index.
+% \begin{advise}
+% \item Why is the `\ikeyname{index}' key able to work with multiple identifier
+%       lists?
+%       \advisespace
+%       This question is strongly related to the `{\rstyle\ikeyname{indexstyle}}'
+%       key. Someone might want to create multiple indexes or want to insert
+%       prefixes like `|constants|', `|functions|', `|keywords|', and so on.
+%       The `\ikeyname{indexstyle}' key works like the other style keys except
+%       that the last token \emph{must} take an argument, namely the
+%       (printable form of the) current identifier.
+%
+%       You can define `|\newcommand\indexkeywords[1]{\index{keywords, #1}}|'
+%       and make similar definitions for constant or function names. Then
+%       `|indexstyle=[1]\indexkeywords|' might meet your purpose. This becomes
+%       easier if you want to create multiple indexes with the
+%       \href{http://mirror.ctan.org/macros/latex/contrib/camel}
+%       {\packagename{index}} package.
+%       If you have defined appropriate new indexes, it is possible to write
+%       `|indexstyle=\index[keywords]|', for example.
+%
+% \item Let's say, I want to index all keywords. It would be annoying to
+%       type in all the keywords again, specifically if the used programming
+%       language changes frequently.
+%       \advisespace
+%       Just read ahead.
+% \end{advise}
+% The \ikeyname{index} key has in fact two optional arguments. The first is the
+% well-known \meta{class number}, the second is a comma separated list of other
+% keyword classes whose identifiers are indexed. The indexed identifiers then
+% change automatically with the defined keywords---not automagically, it's not
+% an illusion.^^A :-)
+%
+% Eventually you need to know the names of the keyword classes. It's usually
+% the key name followed by a class number, for example, |emph2|, |emph3|,
+% \ldots, |keywords2| or |index5|. But there is no number for the first order
+% classes |keywords|, |emph|, |directives|, and so on.
+% \begin{advise}
+% \item `|index=[keywords]|' does not work.
+%       \advisespace
+%       The package can't guess which optional argument you mean. Hence you
+%       must specify both if you want to use the second one. You should try
+%       `|index=[1][keywords]|'.
+% \end{advise}
+%
+%
+% \subsection{Fixed and flexible columns}\label{uFixedAndFlexibleColumns}
+%
+% The first thing a reader notices---except different styles for keywords,
+% etc.---is the column alignment. Arne John Glenstrup invented the flexible
+% column format in 1997. Since then some efforts were made to develop this
+% branch farther. Currently four column formats are provided: fixed, flexible,
+% space-flexible, and full flexible. Take a close look at the following
+% examples.
+% \begin{center}
+% \lstset{style={},language={}}
+% \def\sample{\begin{lstlisting}^^J WOMEN\ \ are^^A
+%                               ^^J \ \ \ \ \ \ \ MEN^^A
+%                               ^^J WOMEN are^^A
+%                               ^^J better MEN^^J \end{lstlisting}}
+% \begin{tabular}{@{}c@{\qquad\quad}c@{\qquad\quad}c@{\qquad\quad}c@{}}
+% {\rstyle\ikeyname{columns}}|=| & \texttt{fixed} & \texttt{flexible} & \texttt{fullflexible}\\
+%          & (at {\makeatletter\lst@widthfixed})
+%          & (at {\makeatletter\lst@widthflexible})
+%          & (at {\makeatletter\lst@widthflexible})\\
+% \noalign{\medskip}
+%   \lstset{basicstyle=\ttfamily,basewidth=0.51em}\sample
+% & \lstset{columns=fixed}\sample
+% & \lstset{columns=flexible}\sample
+% & \lstset{columns=fullflexible}\sample
+% \end{tabular}
+% \end{center}
+% \begin{advise}
+% \item Why are women better men?
+%       \advisespace
+%       Do you want to philosophize? Well, have I ever said that the
+%       statement ``women are better men'' is true? I can't even remember this
+%       about ``women are men'' \ldots . ^^A ;-)
+% \end{advise}
+% In the abstract one can say: The fixed column format ruins the spacing
+% intended by the font designer, while the flexible formats ruin the column
+% alignment (possibly) intended by the programmer. Common to all is that the
+% input characters are translated into a sequence of basic output units like
+% \begingroup \lstset{gobble=6,xleftmargin=\leftmargini}
+% \makeatletter
+%^^A  Make \fbox around each output unit.
+% \fboxsep=0pt
+% \def\lst@alloverstyle#1{\fbox{\kern-\fboxrule\strut#1}\kern-\fboxrule}
+% \begin{lstlisting}[basewidth=1em]
+%     if x=y then write('align')
+%            else print('align');
+% \end{lstlisting}
+% Now, the fixed format puts $n$ characters into a box of width $n\times{}
+% $`base width', where the base width is {\makeatletter\lst@widthfixed} in the
+% example. The format shrinks and stretches the space between the characters
+% to make them fit the box. As shown in the example, some character strings look
+%    \hbox to 2em{b\hss a\hss d}
+% or
+%    \hbox to 2em{w\hss o\hss r\hss s\hss e},
+% but the output is vertically aligned.
+% \endgroup
+%
+% If you don't need or like this, you should use a flexible format. All
+% characters are typeset at their natural width. In particular, they never
+% overlap. If a word requires more space than reserved, the rest of the line
+% simply moves to the right. The difference between the three formats is that
+% the full flexible format cares about nothing else, while the normal flexible
+% and space-flexible formats try to fix the column alignment if a character
+% string needs less space than `reserved'.  The normal flexible format will
+% insert make-up space to fix the alignment at spaces, before and after
+% identifiers, and before and after sequences of other characters; the
+% space-flexible format will only insert make-up space by stretching
+% existing spaces.  In the flexible example above, the two MENs are vertically
+% aligned since some space has been inserted in the fourth line to fix the
+% alignment. In the full flexible format, the two MENs are not aligned.
+%
+% Note that both flexible modes printed the two blanks in the first line as a
+% single blank, but for different reasons: the normal flexible format fixes
+% the column alignment (as would the space-flexible format), and the full
+% flexible format doesn't care about the second space.
+%
+%
+% \section{Advanced techniques}\label{uAdvancedTechniques}
+%
+%
+% \subsection{Style definitions}
+%
+% It is obvious that a pretty-printing tool like this requires some kind of
+% language selection and definition. The first has already been described and
+% the latter is convered by the next section. However, it is very convenient
+% to have the same for printing styles: at a central place of your document
+% they can be modified easily and the changes take effect on all listings.
+%
+% Similar to languages,
+%    {\rstyle\ikeyname{style}}|=|\meta{style name}
+% activates a previously defined style. A definition is as easy:
+%    {\rstyle|\lstdefinestyle|}\marg{style name}\marg{key=value list}.
+% Keys not used in such a definition are untouched by the corresponding style
+% selection, of course. For example, you could write
+% \begin{verbatim}
+%   \lstdefinestyle{numbers}
+%       {numbers=left, stepnumber=1, numberstyle=\tiny, numbersep=10pt}
+%   \lstdefinestyle{nonumbers}
+%       {numbers=none}\end{verbatim}
+% and switch from listings with line numbers to listings without ones and vice
+% versa simply by |style=nonumbers| and |style=numbers|, respectively.
+% \begin{advise}
+% \item You could even write
+%           `|\lstdefinestyle{C++}{language=C++,style=numbers}|'.
+%       Style and language names are independent of each other and so might
+%       coincide. Moreover it is possible to activate other styles.
+%
+% \item It's easy to crash the package using styles. Write
+%       '|\lstdefinestyle{crash}{style=crash}|' and '|\lstset{style=crash}|'.
+%       \TeX's capacity will exceed, sorry [parameter stack size]. Only bad
+%       boys use such recursive calls, but only good girls use this package.
+%       Thus the problem is of minor interest.^^A :-)
+% \end{advise}
+%
+%
+% \subsection{Language definitions}\label{uLanguageDefinitions}
+%
+% These are like style definitions except for an optional dialect name and an
+% optional base language---and, of course, a different command name and
+% specialized keys. In the simple case it's
+%    {\rstyle|\lstdefinelanguage|}\marg{language name}\marg{key=value list}.
+% For many programming languages it is sufficient to specify keywords and
+% standard function names, comments, and strings. Let's look at an example.
+% \begin{lstxsample}[morekeywords,sensitive,morecomment,morestring]
+%    \lstdefinelanguage{rock}
+%      {morekeywords={one,two,three,four,five,six,seven,eight,
+%          nine,ten,eleven,twelve,o,clock,rock,around,the,tonight},
+%       sensitive=false,
+%       morecomment=[l]{//},
+%       morecomment=[s]{/*}{*/},
+%       morestring=[b]",
+%      }
+% \end{lstxsample}
+% \begingroup \csname lst@EndWriteFile\endcsname
+% \bigbreak
+%
+% \noindent
+% There isn't much to say about keywords. They are defined like identifiers
+% you want to emphasize. Additionally you need to specify whether they are
+% case sensitive or not. And yes: you could insert |[2]| in front of the
+% keyword \texttt{one} to define the keywords as `second order' and print them
+% in |keywordstyle={[2]...}|.
+% \begin{advise}
+% \item I get a `\texttt{Missing = inserted for }|\ifnum|' error when I select
+%       my language.
+%       \advisespace
+%       Did you forget the comma after `|keywords={...}|'? And if you encounter
+%       unexpected characters after selecting a language (or style), you have
+%       probably forgotten a different comma or you have given to many
+%       arguments to a key, for example, |morecomment=[l]{--}{!}|.
+% \end{advise}
+%
+% So let's turn to comments and strings. Each value starts with a
+% \emph{mandatory} \oarg{type} argument followed by a changing number of
+% opening and closing delimiters. Note that each delimiter (pair) requires a
+% key=value on its own, even if types are equal. Hence, you'll need to insert
+% \texttt{morestring=[b]'} if single quotes open and close string or character
+% literals in the same way as double quotes do in the example.
+%
+% Eventually you need to know the types and their numbers of delimiters. The
+% reference guide contains full lists, here we discuss only the most common.
+% For strings these are {\rstyle\texttt{b}} and {\rstyle\texttt{d}} with one
+% delimiter each. This delimiter opens and closes the string and inside a
+% string it is either escaped by a \texttt backslash or it is \texttt doubled.
+% The comment type {\rstyle\texttt{l}} requires exactly one delimiter, which
+% starts a comment on any column. This comment goes up to the end of line.
+% The other two most common comment types are {\rstyle\texttt{s}} and
+% {\rstyle\texttt{n}} with two delimiters each. The first delimiter opens a
+% comment which is terminated by the second delimiter. In contrast to the
+% \texttt s-type, \texttt n-type comments can be nested.
+% \begin{lstxsample}[b,d,l,s,n]
+%    \lstset{morecomment=[l]{//},
+%            morecomment=[s]{/*}{*/},
+%            morecomment=[n]{(*}{*)},
+%            morestring=[b]",
+%            morestring=[d]'}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    "str\"ing "    not a string
+%    'str''ing '    not a string
+%    // comment line
+%    /* comment/**/ not a comment
+%    (* nested (**) still comment
+%       comment  *) not a comment
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{advise}
+% \item Is it \emph{that} easy?
+%       \advisespace
+%       Almost. There are some troubles you can run into. For example, if
+%       `\texttt{-*}' starts a comment line and `\texttt{-*-}' a string
+%       (unlikely but possible), then you must define the shorter delimiter
+%       first.
+%       Another problem: by default some characters are not allowed inside
+%       keywords, for example `\texttt{-}', `\texttt{:}', `\texttt{.}', and
+%       so on. The reference guide covers this problem by introducing some
+%       more keys, which let you adjust the standard character table
+%       appropriately. But note that white space characters are prohibited
+%       inside keywords.
+% \end{advise}
+% Finally remember that this section is only an introduction to language
+% definitions. There are more keys and possibilities.
+%
+%
+% \subsection{Delimiters}\label{uDelimiters}
+%
+% You already know two special delimiter classes: comments and strings.
+% However, their full syntax hasn't been described so far. For example,
+% \ikeyname{commentstyle} applies to all comments---unless you specify
+% something different. The \emph{optional} \oarg{style} argument follows the
+% \emph{mandatory} \oarg{type} argument.
+%\ifcolor
+% \begin{lstxsample}
+%    \lstset{morecomment=[l][keywordstyle]{//},
+%            morecomment=[s][\color{white}]{/*}{*/}}
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}
+%    \lstset{morecomment=[l][keywordstyle]{//},
+%            morecomment=[s][\underbar]{/*}{*/}}
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    // bold comment line
+%    a single /* comment */
+%    \end{lstlisting}
+% \end{lstsample}
+% As you can see, you have the choice between specifying the style explicitly
+% by \LaTeX\ commands or implicitly by other style keys. But, you're right,
+% some implicitly defined styles have no seperate keys, for example the second
+% order keyword style. Here---and never with the number 1---you just append
+% the order to the base key: \texttt{keywordstyle2}.
+%
+% You ask for an application? Here you are: one can define different printing
+% styles for `subtypes' of a comment, for example
+%\ifcolor
+% \begin{lstxsample}
+%    \lstset{morecomment=[s][\color{blue}]{/*+}{*/},
+%            morecomment=[s][\color{red}]{/*-}{*/}}
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}
+%    \lstset{morecomment=[s][\upshape]{/*+}{*/},
+%            morecomment=[s][\bfseries]{/*-}{*/}}
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{\lstset{morecomment=[s]{/*}{*/}}}{}
+%    \begin{lstlisting}
+%    /*  normal comment */
+%    /*+    keep cool   */
+%    /*-     danger!    */
+%    \end{lstlisting}
+% \end{lstsample}
+% Here, the comment style is not applied to the second and third line.
+% \begin{advise}
+% \item Please remember that both `extra' comments must be defined \emph{after}
+%       the normal comment, since the delimiter `\texttt{/*}' is a substring of
+%       `\texttt{/*+}' and `\texttt{/*-}'.
+%
+% \item I have another question. Is `\texttt{language=}\meta{different
+%       language}' the only way to remove such additional delimiters?
+%       \advisespace
+%       Call {\rstyle\ikeyname{deletecomment}} and/or
+%       {\rstyle\ikeyname{deletestring}} with the same arguments to remove
+%       the delimiters (but you don't need to provide the optional style
+%       argument).
+% \end{advise}
+% Eventually, you might want to use the prefix \texttt{i} on any comment type.
+% Then the comment is not only invisible, it is completely discarded from the
+% output!
+% \begin{lstxsample}[is]
+%    \lstset{morecomment=[is]{/*}{*/}}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    begin /* comment */ end
+%    begin/* comment */end
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% Okay, and now for the real challenges. More general delimiters can be defined
+% by the key {\rstyle\ikeyname{moredelim}}. Legal types are {\rstyle\texttt{l}}
+% and {\rstyle\texttt{s}}. These types can be preceded by an \texttt{i}, but
+% this time \emph{only the delimiters} are discarded from the output. This way
+% you can select styles by markers.
+% \begin{lstxsample}
+%    \lstset{moredelim=[is][\ttfamily]{|}{|}}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    roman |typewriter|
+%    \end{lstlisting}
+% \end{lstsample}
+% You can even let the package detect keywords, comments, strings, and other
+% delimiters inside the contents.
+% \begin{lstxsample}
+%    \lstset{moredelim=*[s][\itshape]{/*}{*/}}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    /* begin
+%      (* comment *)
+%       ' string ' */
+%    \end{lstlisting}
+% \end{lstsample}
+% Moreover, you can force the styles to be applied cumulatively.
+% \begin{lstxsample}
+%    \lstset{moredelim=**[is][\ttfamily]{|}{|}, % cumulative
+%            moredelim=*[s][\itshape]{/*}{*/}}  % not so
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    /* begin
+%       ' string '
+%       |typewriter| */
+%
+%    | begin
+%     ' string '
+%     /*typewriter*/ |
+%    \end{lstlisting}
+% \end{lstsample}
+% Look carefully at the output and note the differences. The second
+% \texttt{begin} is not printed in bold typewriter type since standard
+% \LaTeX\ has no such font.
+%
+% This suffices for an introduction. Now go and find some more applications.
+%
+%
+% \subsection{Closing and credits}\label{uClosingAndCredits}
+%
+% You've seen a lot of keys but you are far away from knowing all of them.
+% The next step is the real use of the \packagename{listings} package.
+% Please take the following advice. Firstly, look up the known commands and
+% keys in the reference guide to get a notion of the notation there. Secondly,
+% poke around with these keys to learn some other parameters. Then, hopefully,
+% you'll be prepared if you encounter any problems or need some special things.
+%
+% \begin{advise}
+% \item
+% There is one question `you' haven't asked all the last pages: who is to
+% blame. Carsten Heinz wrote the guides, coded the \packagename{listings}
+% package and wrote some language drivers. Brooks Moses currently maintains
+% the package.  Other people defined more languages
+% or contributed their ideas; many others made bug reports, but only the first
+% bug finder is listed.
+%^^A
+%^^A Thanks for error reports (first bug finder only), new programming
+%^^A languages, etc.
+%^^A Special thanks for communication which lead to kernel extensions, and to
+%^^A Hendri Adriaens for reviving maintenance on the package.
+%^^A
+% Special thanks go to (alphabetical order)
+% \begin{quote}
+% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth
+%   \lstthanks{Hendri~Adriaens}{-},
+%   \lstthanks{Andreas~Bartelt}{Andreas.Bartelt@Informatik.Uni-Oldenburg.DE},
+%   \lstthanks{Jan~Braun}{Jan.Braun@tu-bs.de},
+%   \lstthanks{Denis~Girou}{Denis.Girou@idris.fr},
+%   \lstthanks{Arne~John~Glenstrup}{panic@diku.dk},
+%   \lstthanks{Frank~Mittelbach}{frank.mittelbach@latex-project.org},
+%   \lstthanks{Rolf~Niepraschk}{niepraschk@PTB.DE},
+%   \lstthanks{Rui~Oliveira}{rco@di.uminho.pt},
+%   \lstthanks{Jens~Schwarzer}{schwarzer@schwarzer.dk}, and
+%   \lstthanks{Boris~Veytsman}{boris@plmsc.psu.edu}.
+% \end{quote}
+% Moreover we wish to thank
+% \begin{quote}
+% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth
+%   \lstthanks{Bj{\o}rn~{\AA}dlandsvik}{bjorn@imr.no},
+%   \lstthanks{Omair-Inam~Abdul-Matin}{-},
+%   \lstthanks{Gaurav~Aggarwal}{gaurav@ics.uci.edu},
+%   \lstthanks{Jason~Alexander}{jalex@ea.oac.uci.edu},
+%   \lstthanks{Andrei~Alexandrescu}{-},
+%   \lstthanks{Holger~Arndt}{-},
+%   \lstthanks{Donald~Arseneau}{ASND@erich.triumf.ca},
+%   \lstthanks{David~Aspinall}{David.Aspinall@ed.ac.uk},
+%   \lstthanks{Frank~Atanassow}{-},
+%   \lstthanks{Claus~Atzenbeck}{Claus.Atzenbeck@stud.uni-regensburg.de},
+%   \lstthanks{Michael~Bachmann}{-},
+%   \lstthanks{Luca~Balzerani}{-},
+%   \lstthanks{Peter~Bartke}{bartke@inf.fu-berlin.de} (big thankyou), ^^A beta tester
+%   \lstthanks{Heiko~Bauke}{-},
+%   \lstthanks{Oliver~Baum}{oli.baum@web.de},
+%   \lstthanks{Ralph~Becket}{rbeck@microsoft.com},
+%   \lstthanks{Andres~Becerra~Sandoval}{abecerra@univalle.edu.co},
+%   \lstthanks{Kai~Below}{below@tu-harburg.de},
+%   \lstthanks{Matthias~Bethke}{-},
+%   \lstthanks{Javier~Bezos}{javier.bezos@bancoval.es},
+%   \lstthanks{Olaf~Trygve~Berglihn}{olafb@pvv.org},
+%      ^^A {1999/11/29}{3-char comment delimiter don't work (Python)}
+%   \lstthanks{Geraint~Paul~Bevan}{geraint@users.sf.net},
+%   \lstthanks{Peter~Biechele}{peter.biechele@physik.uni-freiburg.de},
+%   \lstthanks{Beat~Birkhofer}{beat@birkhofer.ch},
+%   \lstthanks{Fr\'ed\'eric~Boulanger}{Frederic.Boulanger@supelec.fr},
+%   \lstthanks{Byron~K.~Boulton}{bkboulton@berriehill.com},
+%   \lstthanks{Joachim~Breitner}{-},
+%   \lstthanks{Martin~Brodbeck}{Martin.Brodbeck@gmx.de},
+%   \lstthanks{Walter~E.~Brown}{WB@fnal.gov},
+%   \lstthanks{Achim~D.~Brucker}{brucker@informatik.uni-freiburg.de},
+%   \lstthanks{J\'an Bu\v{s}a}{-},
+%   \lstthanks{Thomas~ten~Cate}{-},
+%   \lstthanks{David~Carlisle}{davidc@nag.co.uk},
+%   \lstthanks{Bradford~Chamberlain}{brad@cs.washington.edu},
+%   \lstthanks{Brian~Christensen}{-},
+%   \lstthanks{Neil~Conway}{-},
+%   \lstthanks{Patrick~Cousot}{Patrick.Cousot@wanadoo.fr},
+%   \lstthanks{Xavier~Cr\'egut}{cregut@enseeiht.fr},
+%   \lstthanks{Christopher~Creutzig}{-},
+%   \lstthanks{Holger~Danielsson}{dani@fbg.schwerte.de},
+%   \lstthanks{Andreas~Deininger}{deininger@uni-kassel.de},
+%   \lstthanks{Robert~Denham}{Robert.Denham@dnr.qld.gov.au},
+%   \lstthanks{Detlev~Dr\"oge}{droege@informatik.uni-koblenz.de},
+%   \lstthanks{Anders~Edenbrandt}{Anders.Edenbrandt@dna.lth.se},
+%   \lstthanks{Mark~van~Eijk}{mark@luon.net},
+%   \lstthanks{Norbert~Eisinger}{Norbert.Eisinger@informatik.uni-muenchen.de},
+%   \lstthanks{Brian~Elmegaard}{-},
+%   \lstthanks{Jon~Ericson}{Jon.Ericson@jpl.nasa.gov},
+%   \lstthanks{Thomas~Esser}{te@dbs.uni-hannover.de},
+%   \lstthanks{Chris~Edwards}{edwch00p@infoscience.otago.ac.nz},
+%   \lstthanks{David~John~Evans}{Matrix.Software@dial.pipex.com},
+%   \lstthanks{Tanguy~Fautr\'e}{tfautre@pandora.be},
+%   \lstthanks{Ulrike~Fischer}{-},
+%   \lstthanks{Robert~Frank}{rf7@ukc.ac.uk},
+%   \lstthanks{Michael~Franke}{-},
+%   \lstthanks{Ignacio~Fern\'andez~Galv\'an}{-},
+%   \lstthanks{Martine~Gautier}{-}
+%   \lstthanks{Daniel~Gazard}{gazard_d@epita.fr},
+%   \lstthanks{Daniel~Gerigk}{Daniel.Gerigk@ePost.de},
+%   \lstthanks{Dr.~Christoph~Giess}{-},
+%   \lstthanks{KP~Gores}{kp.gores@web.de},
+%   \lstthanks{Adam~Grabowski}{adam@mizar.org},
+%   \lstthanks{Jean-Philippe~Grivet}{grivet@cnrs-orleans.fr},
+%   \lstthanks{Christian~Gudrian}{Christian.Gudrian@kawo1.rwth-aachen.de},
+%   \lstthanks{Jonathan~de~Halleux}{dehalleux@auto.ucl.ac.be},
+%   \lstthanks{Carsten~Hamm}{carsten.hamm@siemens.com},
+%   \lstthanks{Martina~Hansel}{Martina.Hansel@fhtw-berlin.de},
+%   \lstthanks{Harald~Harders}{h.harders@tu-bs.de},
+%   \lstthanks{Christian~Haul}{haul@dvs1.informatik.tu-darmstadt.de},
+%   \lstthanks{Aidan~Philip~Heerdegen}{Aidan.Heerdegen@anu.edu.au},
+%   \lstthanks{Jim~Hefferon}{Hefferon9@aol.com},
+%   \lstthanks{Heiko~Heil}{info@heiko-heil.de},
+%   \lstthanks{J\"urgen~Heim}{heim@astro.uni-tuebingen.de},
+%   \lstthanks{Martin~Heller}{-},
+%   \lstthanks{Stephan~Hennig}{-},
+%   \lstthanks{Alvaro~Herrera}{alvherre@dcc.uchile.cl},
+%   \lstthanks{Richard~Hoefter}{hoefter@gmx.de},
+%   \lstthanks{Dr.~Jobst~Hoffmann}{HOFFMANN@rz.rwth-aachen.de},
+%   \lstthanks{Torben~Hoffmann}{toho@it.dtu.dk},
+%   \lstthanks{Morten~H\o gholm}{-},
+%   \lstthanks{Berthold~H\"ollmann}{bhoel@starship.python.net},
+%   \lstthanks{G\'erard~Huet}{-},
+%   \lstthanks{Hermann~H\"uttler}{hermann.huettler@gmx.net},
+%   \lstthanks{Ralf~Imh\"auser}{snoopy@tribal.line.org},
+%   \lstthanks{R.~Isernhagen}{R.Isernhagen@FH-Wolfenbuettel.DE},
+%   \lstthanks{Oldrich~Jedlicka}{ojedlick@students.zcu.cz},
+%   \lstthanks{Dirk~Jesko}{jesko@iti.cs.uni-magdeburg.de},
+%   \lstthanks{Lo\"\i c~Joly}{-},
+%   \lstthanks{Christian~Kaiser}{chk@combit.net},
+%   \lstthanks{Bekir~Karaoglu}{karabekirus@yahoo.com},
+%   \lstthanks{Marcin~Kasperski}{Marcin.Kasperski@softax.com.pl},
+%   \lstthanks{Christian~Kindinger}{chkind@uni-wuppertal.de},
+%   \lstthanks{Steffen~Klupsch}{steffen@vlsi.informatik.tu-darmstadt.de},
+%   \lstthanks{Markus~Kohm}{-},
+%   \lstthanks{Peter~K\"oller}{pkoeller@metaprojekt.de} (big thankyou), ^^A beta tester
+%   \lstthanks{Reinhard~Kotucha}{Reinhard.Kotucha@web.de},
+%   \lstthanks{Stefan~Lagotzki}{info@lagotzki.de},
+%   \lstthanks{Tino~Langer}{langer@tournex.de},
+%   \lstthanks{Rene~H.~Larsen}{rhl@traceroute.dk},
+%   \lstthanks{Olivier~Lecarme}{ol@i3s.unice.fr},
+%   \lstthanks{Thomas~Leduc}{Thomas.Leduc@lsv.ens-cachan.fr},
+%   \lstthanks{Dr.~Peter~Leibner}{Peter.Leibner@sta.siemens.de},
+%   \lstthanks{Thomas~Leonhardt}{leonhardt@informatik.tu-darmstadt.de}
+%      (big thankyou), ^^A beta tester
+%   \lstthanks{Magnus~Lewis-Smith}{Magnus.Lewis-Smith@pace.co.uk},
+%   \lstthanks{Knut~Lickert}{knut.lickert@gmx.de},
+%   \lstthanks{Benjamin~Lings}{-},
+%   \lstthanks{Dan~Luecking}{luecking@uark.edu},
+%   \lstthanks{Peter~L\"offler}{-},
+%   \lstthanks{Markus~Luisser}{-},
+%   \lstthanks{Kris~Luyten}{no email available},
+%   \lstthanks{Jos\'e~Romildo~Malaquias}{romildo@urano.iceb.ufop.br},
+%   \lstthanks{Andreas~Matthias}{amat@kabsi.at},
+%   \lstthanks{Patrick~TJ~McPhee}{ptjm@interlog.com},
+%   ^^A \lstthanks{Brooks~Moses}{-},
+%   \lstthanks{Riccardo~Murri}{riccardo.murri@gmx.it},
+%   \lstthanks{Knut~M\"uller}{knut@physik3.gwdg.de},
+%   \lstthanks{Svend~Tollak~Munkejord}{svendm@efisms.energy.sintef.no},
+%   \lstthanks{Gerd~Neugebauer}{gerd.neugebauer@gmx.de},
+%   \lstthanks{Torsten~Neuer}{tneuer@inwise.de},
+%   \lstthanks{Enzo~Nicosia}{-},
+%   \lstthanks{Michael~Niedermair}{m.g.n@gmx.de},
+%   \lstthanks{Xavier~Noria}{fxn@hashref.com},
+%   \lstthanks{Heiko~Oberdiek}{oberdiek@ruf.uni-freiburg.de},
+%   \lstthanks{Xavier~Olive}{-},
+%   \lstthanks{Alessio~Pace}{-},
+%   \lstthanks{Markus~Pahlow}{pahlowm@mar.dfo-mpo.gc.ca},
+%   \lstthanks{Morten~H.~Pedersen}{mhp@dadlnet.dk},
+%   \lstthanks{Xiaobo~Peng}{-},
+%   \lstthanks{Zvezdan~V.~Petkovic}{zpetkovic@acm.org},
+%   \lstthanks{Michael~Piefel}{piefel@informatik.hu-berlin.de},
+%   \lstthanks{Michael~Piotrowski}{mxp@linguistik.uni-erlangen.de},
+%   \lstthanks{Manfred~Piringer}{sz0490@rrze.uni-erlangen.de},
+%   \lstthanks{Vincent~Poirriez}{Vincent.Poirriez@univ-valenciennes.fr},
+%   \lstthanks{Adam~Prugel-Bennett}{apb@ecs.soton.ac.uk},
+%   \lstthanks{Ralf~Quast}{rquast@hs.uni-hamburg.de},
+%   \lstthanks{Aslak~Raanes}{araanes@ifi.ntnu.no},
+%   \lstthanks{Venkatesh~Prasad~Ranganath}{vranganath@cox.net},
+%   \lstthanks{Tobias~Rapp}{-},
+%   \lstthanks{Jeffrey~Ratcliffe}{-},
+%   \lstthanks{Georg~Rehm}{Georg.Rehm@germanistik.uni-giessen.de},
+%   \lstthanks{Fermin~Reig}{reig@ics.uci.edu},
+%   \lstthanks{Detlef~Reimers}{dreimers@aol.com},
+%   \lstthanks{Stephen~Reindl}{stephen.reindl@vodafone.com},
+%   \lstthanks{Franz~Rinnerthaler}{-},
+%   \lstthanks{Peter~Ruckdeschel}{Peter.Ruckdeschel@uni-bayreuth.de},
+%   \lstthanks{Magne~Rudshaug}{magne@ife.no},
+%   \lstthanks{Jonathan~Sauer}{jonathan.sauer@gmx.de},
+%   \lstthanks{Vespe~Savikko}{vespe@cs.tut.fi},
+%   \lstthanks{Mark~Schade}{-},
+%   \lstthanks{Gunther~Schmidl}{gschmidl@gmx.at},
+%   \lstthanks{Andreas~Schmidt}{-},
+%   \lstthanks{Walter~Schmidt}{wschmi@arcor.de},
+%   \lstthanks{Christian~Schneider}{-},
+%   \lstthanks{Jochen~Schneider}{jschneider@ds3.etech.haw-hamburg.de},
+%   \lstthanks{Benjamin~Schubert}{benjamin.schubert@berlin.de},
+%   \lstthanks{Sebastian~Schubert}{-},
+%   \lstthanks{Uwe~Siart}{uwe.siart@ei.tum.de},
+%   \lstthanks{Axel~Sommerfeldt}{axel@sommerfeldt.net},
+%   \lstthanks{Richard~Stallman}{-},
+%   \lstthanks{Nigel~Stanger}{nstanger@infoscience.otago.ac.nz},
+%   \lstthanks{Martin~Steffen}{ms@informatik.uni-kiel.de},
+%   \lstthanks{Andreas~Stephan}{Andreas.Stephan@victoria.de},
+%   \lstthanks{Stefan~Stoll}{stoll@phys.chem.ethz.ch},
+%   \lstthanks{Enrico~Straube}{no email available},
+%   \lstthanks{Werner~Struckmann}{struck@ips.cs.tu-bs.de},
+%   \lstthanks{Martin~S\"u\ss kraut}{Edon.Myder@web.de},
+%   \lstthanks{Gabriel~Tauro}{gabriel@informatik.uni-jena.de},
+%   \lstthanks{Winfried~Theis}{theis@statistik.uni-dortmund.de},
+%   \lstthanks{Jens~T.~Berger~Thielemann}{jensthi@ifi.uio.no},
+%   \lstthanks{William~Thimbleby}{-},
+%   \lstthanks{Arnaud~Tisserand}{arnaud.tisserand@ens-lyon.fr},
+%   \lstthanks{Jens~Troeger}{-},
+%   \lstthanks{Kalle~Tuulos}{kalle.tuulos@nic.fi},
+%   \lstthanks{Gregory~Van~Vooren}{Gregory.VanVooren@rug.ac.be},
+%   \lstthanks{Timothy~Van~Zandt}{tvz@econ.insead.edu},
+%   \lstthanks{J\"org~Viermann}{-},
+%   \lstthanks{Thorsten~Vitt}{vitt@informatik.hu-berlin.de},
+%   \lstthanks{Herbert~Voss}{voss@perce.de} (big thankyou), ^^A beta tester
+%   \lstthanks{Edsko~de~Vries}{devriese@tcd.ie},
+%   \lstthanks{Herfried~Karl~Wagner}{hirf@gmx.at},
+%   \lstthanks{Dominique~de~Waleffe}{ddw@miscrit.be},
+%   \lstthanks{Bernhard~Walle}{-},
+%   \lstthanks{Jared~Warren}{warren@cs.queensu.ca},
+%   \lstthanks{Michael~Weber}{mweber@informatik.hu-berlin.de},
+%   \lstthanks{Sonja~Weidmann}{Sonja.Weidmann@gmx.de},
+%   \lstthanks{Andreas~Weidner}{-},
+%   \lstthanks{Herbert~Weinhandl}{weinhand@grz08u.unileoben.ac.at},
+%   \lstthanks{Robert~Wenner}{robert.wenner@gmx.de},
+%   \lstthanks{Michael~Wiese}{wiese@itwm.uni-kl.de},
+%   \lstthanks{James~Willans}{-},
+%   \lstthanks{J\"orn~Wilms}{wilms@rocinante.colorado.edu},
+%   \lstthanks{Kai~Wollenweber}{kai@ece.WPI.EDU},
+%   \lstthanks{Ulrich~G.~Wortmann}{uliw@erdw.ethz.ch},
+%   \lstthanks{Cameron~H.G.~Wright}{-},
+%   \lstthanks{Joseph~Wright}{joseph.wright@morningstar2.co.uk},
+%   \lstthanks{Andrew~Zabolotny}{-}, and
+%   \lstthanks{Florian~Z\"ahringer}{-}.
+% \end{quote}
+% There are probably other people who contributed to this package.
+% If I've missed your name, send an email.
+% \end{advise}
+%
+%
+% \part{Reference guide}
+%
+%
+% \section{Main reference}\label{rMainReference}
+%
+% Your first training is completed. Now that you've left the User's guide, the
+% friend telling you what to do has gone. Get more practice and become a
+% journeyman!^^A :-)
+% \begin{advise}
+% \item Actually, the friend hasn't gone. There are still some advices, but
+%       only from time to time.
+% \end{advise}
+%
+%
+% \subsection{How to read the reference}
+%
+% Commands, keys and environments are presented as follows.
+% \begin{syntax}
+% \item[1.0,default,hints] \texttt{command}, \texttt{environment} or
+%       \keyname{key} with \meta{parameters}
+%
+%       This field contains the explanation; here we describe the other fields.
+%
+%       If present, the label in the left margin provides extra information:
+%       `\textit{addon}' indicates additionally introduced functionality,
+%       `\textit{changed}' a modified key, `\textit{data}' a command just
+%       containing data (which is therefore adjustable via |\renewcommand|),
+%       and so on. Some keys and functionality are `\emph{bug}'-marked or
+%       with a \dag-sign. These features might change in future or could be
+%       removed, so use them with care.
+%
+%       If there is verbatim text touching the right margin, it is the
+%       predefined value. Note that some keys default to this value every
+%       listing, namely the keys which can be used on individual listings only.
+% \end{syntax}
+% Regarding the parameters, please keep in mind the following:
+% \begin{enumerate}
+% \item A list always means a comma separated list. You must put braces around
+%       such a list. Otherwise you'll get in trouble with the
+%       \packagename{keyval} package; it complains about an undefined key.
+% \item You must put parameter braces around the whole value of a key if you
+%       use an \oarg{optional argument} of a key inside an optional
+%       \oarg{key=value list}:
+%       |\begin{lstlisting}[caption=|{\rstyle|{|}|[one]two|{\rstyle|}|}|]|.
+% \item Brackets `|[ ]|' usually enclose optional arguments and must be typed
+%       in verbatim. Normal brackets `[ ]' always indicate an optional argument
+%       and must not be typed in. Thus |[*]| must be typed in exactly as is,
+%       but [|*|] just gets |*| if you use this argument.
+% \item A vertical rule indicates an alternative, e.g.~^^A
+%       \meta{\alternative{true,false}} allows either \texttt{true} or
+%       \texttt{false} as arguments.
+% \item If you want to enter one of the special characters |{}#%\|, this
+%       character must be escaped with a backslash. This means that you must
+%       write |\}| for the single character `right brace'---but of course not
+%       for the closing paramater character.
+% \end{enumerate}
+%
+%
+% \subsection{Typesetting listings}\label{rTypesettingListings}
+%
+% \begin{syntax}
+%   \item[0.19] \rcmdname\lstset\marg{key=value list}
+%
+%     sets the values of the specified keys, see also section
+%     \ref{uTheKey=ValueInterface}.  The parameters keep their values up to
+%     the end of the current group.  In contrast, all optional
+%     \meta{key=value list}s below modify the parameters for single
+%     listings only.
+%
+%   \item[0.18]
+%     \rcmdname\lstinline\oarg{key=value list}\meta{character}^^A
+%     \meta{source code}\meta{same character}
+%
+%     works like |\verb| but respects the active language and style.
+%     These listings use flexible columns unless requested differently
+%     in the optional argument, and do not support frames or background
+%     colors.  You can write `|\lstinline!var i:integer;!|' and get
+%     `\lstinline!var i:integer;!'.
+%
+%     Since the command first looks ahead for an optional argument, you
+%     must provide at least an empty one if you want to use |[| as
+%     \meta{character}.
+%
+%     \dag\ An experimental implementation has been done to support the
+%     syntax |\lstinline|\oarg{key=value list}\marg{source code}. Try it
+%     if you want and report success and failure. A known limitation is
+%     that inside another argument the last source code token must not
+%     be an explicit space token---and, of course, using a listing inside
+%     another argument is itself experimental, see section
+%     \ref{rListingsInsideArguments}.
+%
+%     Another limitation is that this feature can't be used in cells of a
+%     |tabular|-environment. See section \ref{uListingsArguments} for a
+%     workaround.
+%
+%     See also section \ref{rShortInline} for commands to create short
+%     analogs for the |\lstinline| command.
+%
+%   \item[0.15] |\begin{|\texttt{\rstyle lstlisting}|}|\oarg{key=value
+%           list}
+%
+%       \leavevmode\hspace*{-\leftmargini}|\end{|\texttt{\rstyle
+%       lstlisting}|}|
+%
+%       typesets the code in between as a displayed listing.
+%
+%       In contrast to the environment of the \packagename{verbatim}
+%       package, \LaTeX\ code on the same line and after the end of
+%       environment is typeset respectively executed.
+%
+%     \item[0.1] \rcmdname\lstinputlisting\oarg{key=value list}\marg{file
+%       name}
+%
+%       typesets the stand alone source code file as a displayed listing.
+%   \end{syntax}
+%
+%
+%   \subsection{Options}
+%
+% The following sections describe all the keys that can be used to
+% influence the appearance of the listing.
+%
+%
+% \subsubsection{Searching for files}
+%
+% \begin{syntax}
+%   \item[1.8, {}] \rkeyname{inputpath}|=|\meta{path}
+%
+%     defines the path, where the file given by \meta{file name} resides.
+%
+%     \rkeyname{inputpath} overrules the |TEXINPUTS| environment variable,
+%     which means that a file residing on one of the paths given by
+%     |TEXINPUTS| isn't found anymore, if \meta{path} isn't part of
+%     |TEXINPUTS|.
+%
+%     \rkeyname{inputpath} set as option of \rcmdname\lstinputlisting{}
+%     overrules the value set by \rcmdname\lstset.
+% \end{syntax}
+%
+%
+% \subsubsection{Space and placement}
+%
+% \begin{syntax}
+%   \item[0.20,floatplacement] \rkeyname{float}|=|[|*|]\meta{subset of
+%     \textup{\texttt{tbph}}}\syntaxor\rkeyname{float}
+%
+%     makes sense on individual displayed listings only and lets them
+%     float.  The argument controls where \LaTeX\ is \emph{allowed} to put
+%     the float: at the top or bottom of the current/next page, on a
+%     separate page, or here where the listing is.
+%
+%     The optional star can be used to get a double-column float in a
+%     two-column document.
+%
+%   \item[0.21,tbp] \rkeyname{floatplacement}|=|\meta{place specifiers}
+%
+%     is used as place specifier if \keyname{float} is used without value.
+%
+%   \item[0.21,\medskipamount] \rkeyname{aboveskip}|=|\meta{dimension}
+%   \item[0.21,\medskipamount] \rkeyname{belowskip}|=|\meta{dimension}
+%
+%     define the space above and below displayed listings.
+%
+%   \item[0.17,0pt,\dag] \rkeyname{lineskip}|=|\meta{dimension}
+%
+%     specifies additional space between lines in listings.
+%
+%   \item[0.18,c,\dag] \rkeyname{boxpos}|=|\meta{\alternative{b,c,t}}
+%
+%     Sometimes the \packagename{listings} package puts a |\hbox| around a
+%     listing---or it couldn't be printed or even processed correctly.  The
+%     key determines the vertical alignment to the surrounding material:
+%     bottom baseline, centered or top baseline.
+% \end{syntax}
+%
+%
+% \subsubsection{The printed range}
+%
+% \begin{syntax}
+%   \item[0.12,true]
+%     \rkeyname{print}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{print}
+%
+%     controls whether an individual displayed listing is typeset. Even if
+%     set false, the respective caption is printed and the label is
+%     defined.
+%
+%     Note: If the package is loaded without the \texttt{draft} option, you
+%     can use this key together with |\lstset|. In the other case the key
+%     can be used to typeset particular listings despite using the
+%     \texttt{draft} option.
+%
+%   \item[0.1,1] \rkeyname{firstline}|=|\meta{number}
+%   \item[0.1,9999999] \rkeyname{lastline}|=|\meta{number}
+%
+%     can be used on individual listings only. They determine the physical
+%     input lines used to print displayed listings.
+%
+%   \item[1.2]
+%     \rkeyname{linerange}|={|\meta{first1}\texttt-\meta{last1}\texttt,^^A
+%     \meta{first2}\texttt-\meta{last2}\texttt, and so
+%     on|}|\label{uoption:linerange}
+%
+%     can be used on individual listings only. The given line ranges of the
+%     listing are displayed. The intervals must be sorted and must not
+%     intersect.
+%
+%   \item[0.20,false]
+%     \rkeyname{showlines}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{showlines}
+%
+%     If true, the package prints empty lines at the end of listings.
+%     Otherwise these lines are dropped (but they count for line
+%     numbering).
+%
+%   \item[1.0] \rkeyname{emptylines}|=|[|*|]\meta{number}
+%
+%     sets the maximum of empty lines allowed. If there is a block of more
+%     than \meta{number} empty lines, only \meta{number} ones are printed.
+%     Without the optional star, line numbers can be disturbed when blank
+%     lines are omitted; with the star, the lines keep their original
+%     numbers.
+%
+%   \item[0.19,0] \rkeyname{gobble}|=|\meta{number}
+%
+%     gobbles \meta{number} characters at the beginning of each
+%     \emph{environment} code line. This key has no effect on
+%     \cs{lstinline} or \cs{lstinputlisting}.
+%
+%     Tabulators expand to \ikeyname{tabsize} spaces before they are
+%     gobbled.  Code lines with fewer than \ikeyname{gobble} characters are
+%     considered empty.  Never indent the end of environment by more
+%     characters.
+% \end{syntax}
+%
+%
+% \subsubsection{Languages and styles}\label{rLanguagesAndStyles}
+%
+% Please note that the arguments \meta{language}, \meta{dialect}, and
+% \meta{style name} are case insensitive and that spaces have no effect.
+% \begin{syntax}
+% \item[0.18,{{}}] \rkeyname{style}|=|\meta{style name}
+%
+%       activates the key=value list stored with |\lstdefinestyle|.
+%
+% \item[0.19] \rcmdname\lstdefinestyle\marg{style name}\marg{key=value list}
+%
+%       stores the key=value list.
+%
+% \item[0.17,{{}}] \rkeyname{language}|=|\oarg{dialect}\meta{language}
+%
+%       activates a (dialect of a) programming language. The `empty' default
+%       language detects no keywords, no comments, no strings, and so on; it
+%       may be useful for typesetting plain text.
+%       If \meta{dialect} is not specified, the package chooses the default
+%       dialect, or the empty dialect if there is no default dialect.
+%
+%       Table \ref{uPredefinedLanguages} on page \pageref{uPredefinedLanguages}
+%       lists all languages and dialects provided by \texttt{lstdrvrs.dtx}.
+%       The predefined default dialects are underlined.
+%
+% \item[0.21] \rkeyname{alsolanguage}|=|\oarg{dialect}\meta{language}
+%
+%       activates a (dialect of a) programming language in addition to the
+%       current active one. Note that some language definitions interfere with
+%       each other and are plainly incompatible; for instance, if one is case
+%       sensitive and the other is not.
+%
+%       Take a look at the \ikeyname{classoffset} key in section
+%       \ref{rFigureOutTheAppearance} if you want to highlight the keywords
+%       of the languages differently.
+%
+% \item[0.19] \rkeyname{defaultdialect}|=|\oarg{dialect}\meta{language}
+%
+%       defines \meta{dialect} as default dialect for \meta{language}.
+%       If you have defined a default dialect other than empty, for example
+%       |defaultdialect=[iama]fool|, you can't select the empty dialect, even
+%       not with |language=[]fool|.
+% \end{syntax}
+%
+% Finally, here's a small list of language-specific keys.
+% \begin{syntax}
+%   \item[0.19,false,optional]
+%     \rkeyname{printpod}|=|\meta{\alternative{true,false}}
+%
+%     prints or drops PODs in Perl.
+%
+%   \item[0.20,true,{renamed,optional}]
+%     \rkeyname{usekeywordsintag}|=|\meta{\alternative{true,false}}^^A
+%     \label{uoption:usekeywordsintag}
+%
+%     The package either use the first order keywords in tags or prints all
+%     identifiers inside |<>| in keyword style.
+%
+%   \item[1.1,{{}},optional]
+%     \rkeyname{tagstyle}|=|\meta{style}\label{uoption:tagstyle}
+%
+%     determines the style in which tags and their content is printed.
+%
+%   \item[1.1,false,optional]
+%     \rkeyname{markfirstintag}|=|\meta{style}\label{uoption:markfirstintag}
+%
+%     prints the first name in tags with keyword style.
+%
+%   \item[0.20,true,optional]
+%     \rkeyname{makemacrouse}|=|\meta{\alternative{true,false}}
+%
+%     Make specific: Macro use of identifiers, which are defined as first
+%     order keywords, also prints the surrounding
+%     |$(| and |)| in keyword style. e.g.~you could get
+%     \textbf{\textdollar(}\textbf{strip} \textdollar(BIBS)\textbf{)}.  If
+%     deactivated you get \textdollar(\textbf{strip} \textdollar(BIBS)).
+% \end{syntax}
+%
+%
+% \subsubsection{Figure out the appearance}\label{rFigureOutTheAppearance}
+%
+% \begin{syntax}
+%   \item[0.18,{{}}] \rkeyname{basicstyle}|=|\meta{basic style}
+%
+%     is selected at the beginning of each listing. You could use
+%     |\footnotesize|, |\small|, |\itshape|, |\ttfamily|, or something like
+%     that. The last token of \meta{basic style} must not read any
+%     following characters.
+%
+%   \item[0.18,{{}}] \rkeyname{identifierstyle}|=|\meta{style}
+%   \item[0.11,\itshape] \rkeyname{commentstyle}|=|\meta{style}
+%   \item[0.12,{{}}] \rkeyname{stringstyle}|=|\meta{style}
+%
+%     determines the style for non-keywords, comments, and strings. The
+%     \emph{last} token can be an one-parameter command like |\textbf| or
+%     |\underbar|.
+%
+%   \item[0.11,\bfseries,addon]
+%     \rkeyname{keywordstyle}|=|\oarg{number}[\textasteriskcentered]^^A
+%     \meta{style}\label{roption:keywordstyle}
+%
+%     is used to print keywords.  The optional \meta{number} argument is
+%     the class number to which the style should be applied.
+%
+%     Add-on: If you use the optional star after the (optional) class
+%     number, the keywords are printed uppercase\,---\,even if a language
+%     is case sensitive and defines lowercase keywords only. Maybe there
+%     should also be an option for lowercase keywords \ldots
+%
+%   \item[0.19,keywordstyle,deprecated]
+%     \rkeyname{ndkeywordstyle}|=|\meta{style}
+%
+%     is equivalent to |keywordstyle=2|\meta{style}.
+%
+%   \item[1.0,0] \rkeyname{classoffset}|=|\meta{number}
+%
+%     is added to all class numbers before the styles, keywords,
+%     identifiers, etc.~are assigned. The example below defines the
+%     keywords directly; you could do it indirectly by selecting two
+%     different languages.
+% \end{syntax}
+%\ifcolor
+% \begin{lstxsample}
+%    \lstset{classoffset=0,
+%            morekeywords={one,three,five},keywordstyle=\color{red},
+%            classoffset=1,
+%            morekeywords={two,four,six},keywordstyle=\color{blue},
+%            classoffset=0}% restore default
+% \end{lstxsample}
+%\else
+% \begin{lstxsample}
+%    \lstset{classoffset=0,
+%            morekeywords={one,three,five},keywordstyle=\itshape,
+%            classoffset=1,
+%            morekeywords={two,four,six},keywordstyle=\bfseries},
+%            classoffset=0}% restore default
+% \end{lstxsample}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}
+%    one two three
+%    four five six
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{syntax}
+%   \item[0.20,keywordstyle,{addon,bug,optional}]
+%     \rkeyname{texcsstyle}|=|[|*|]\oarg{class
+%     number}\meta{style}\label{roption:texcsstyle}
+%   \item[0.20,keywordstyle,optional]
+%     \rkeyname{directivestyle}|=|\meta{style}
+%
+%     determine the style of \TeX\ control sequences and directives.  Note
+%     that these keys are present only if you've chosen an appropriate
+%     language.
+%
+%     The optional star of |texcsstyle| also highlights the backslash in
+%     front of the control sequence name. Note that this option is set for
+%     all |texcs| lists.
+%
+%     Bug: \texttt{texcs\ldots} interferes with other keyword lists. If,
+%     for example, \texttt{emph} contains the word \texttt{foo}, then the
+%     control sequence |\foo| will show up in \texttt{emphstyle}.
+%
+%   \item[0.21] \rkeyname{emph}|=|\oarg{number}\marg{identifier list}
+%   \item[0.21] \rkeyname{moreemph}|=|\oarg{number}\marg{identifier list}
+%   \item[0.21] \rkeyname{deleteemph}|=|\oarg{number}\marg{identifier list}
+%   \item[0.21] \rkeyname{emphstyle}|=|\oarg{number}\marg{style}
+%
+%     respectively define, add or remove the \meta{identifier list} from
+%     `emphasize class \meta{number}', or define the style for that class.
+%     If you don't give an optional argument, the package assumes
+%     \meta{number}$\,=1$.
+%
+%     These keys are described more detailed in section
+%     \ref{uEmphasizeIdentifiers}.
+%
+%   \item[1.0]
+%     \rkeyname{delim}|=|[\texttt*[\texttt*]]\texttt[\meta{type}\texttt]^^A
+%     [\texttt[\meta{style}\texttt]]\meta{delimiter\textup(s\textup)}
+%   \item[1.0]
+%     \rkeyname{moredelim}|=|[\texttt*[\texttt*]]\texttt[\meta{type}\texttt]^^A
+%     [\texttt[\meta{style}\texttt]]\meta{delimiter\textup(s\textup)}
+%   \item[1.0]
+%     \rkeyname{deletedelim}|=|[\texttt*[\texttt*]]\texttt[\meta{type}\texttt]^^A
+%     \meta{delimiter\textup(s\textup)}
+%
+%     define, add, or remove user supplied delimiters.  (Note that this
+%     does not affect strings or comments.)
+%
+%     In the first two cases \meta{style} is used to print the delimited
+%     code (and the delimiters). Here, \meta{style} could be something like
+%     |\bfseries| or |\itshape|, or it could refer to other styles via
+%     \texttt{keywordstyle}, \texttt{keywordstyle2}, \texttt{emphstyle},
+%     etc.
+%
+%     Supported types are \texttt{l} and \texttt{s}, see the comment keys
+%     in section \ref{uLanguageDefinitions} for an explanation. If you use
+%     the prefix \texttt i, i.e.~\texttt{il} or \texttt{is}, the delimiters
+%     are not printed, which is some kind of invisibility.
+%
+%     If you use one optional star, the package will detect keywords,
+%     comments, and strings inside the delimited code. With both optional
+%     stars, aditionally the style is applied cumulatively; see section
+%     \ref{uDelimiters}.
+% \end{syntax}
+%
+%
+% \subsubsection{Getting all characters right}
+%
+% \begin{syntax}
+%   \item[0.18,true]
+%     \rkeyname{extendedchars}|=|\meta{\alternative{true,false}}^^A
+%     \syntaxor\rkeyname{extendedchars}
+%
+%     allows or prohibits extended characters in listings, that means
+%     (national) characters of codes 128--255. If you use extended
+%     characters, you should load \packagename{fontenc} and/or
+%     \packagename{inputenc}, for example.
+%
+%   \item[1.0,{{}}] \rkeyname{inputencoding}|=|\meta{encoding}
+%
+%     determines the input encoding. The usage of this key requires the
+%     \packagename{inputenc} package; nothing happens if it's not loaded.
+%
+%   \item[1.1,false]
+%     \rkeyname{upquote}|=|\meta{\alternative{true,false}}\label{uoption:upquote}
+%
+%     determines whether the left and right quote are printed |`'| or
+%     \texttt{\textasciigrave\textquotesingle}.  This key requires the
+%     \packagename{textcomp} package if true.
+%
+%   \item[0.12,8] \rkeyname{tabsize}|=|\meta{number}
+%
+%     sets tabulator stops at columns
+%     $\meta{number}+1$, $2\cdot\meta{number}+1$,
+%     $3\cdot\meta{number}+1$, and so on.  Each tabulator in a listing
+%     moves the current column to the next tabulator stop.
+%
+%   \item[0.20,false] \rkeyname{showtabs}|=|\meta{\alternative{true,false}}
+%
+%     make tabulators visible or invisible. A visible tabulator looks like
+%     \lstinline[showtabs]!	!, but that can be changed. If you choose
+%     invisible tabulators but visible spaces, tabulators are converted to
+%     an appropriate number of spaces.
+%
+%   \item[0.20] \rkeyname{tab}|=|\meta{tokens}
+%
+%     \meta{tokens} is used to print a visible tabulator. You might want to
+%     use |$\to$|, |$\mapsto$|,
+%     |$\dashv$| or something like that instead of the strange default
+%     definition.
+%
+%   \item[0.20,false]
+%     \rkeyname{showspaces}|=|\meta{\alternative{true,false}}
+%
+%     lets all blank spaces appear {\textvisiblespace} or as blank spaces.
+%
+%   \item[0.12,true]
+%     \rkeyname{showstringspaces}|=|\meta{\alternative{true,false}}
+%
+%     lets blank spaces in strings appear {\textvisiblespace} or as blank
+%     spaces.
+%
+%   \item[0.19,\bigbreak] \rkeyname{formfeed}|=|\meta{tokens}
+%
+%     Whenever a listing contains a form feed, \meta{tokens} is executed.
+% \end{syntax}
+%
+%
+% \subsubsection{Line numbers}\label{rLineNumbers}
+%
+% \begin{syntax}
+%   \item[1.0,none]
+%     \rkeyname{numbers}|=|\meta{\alternative{none,left,right}}
+%
+%     makes the package either print no line numbers, or put them on the
+%     left or the right side of a listing.
+%
+%   \item[0.16,1] \rkeyname{stepnumber}|=|\meta{number}
+%
+%     All lines with ``line number $\equiv
+%     0$ modulo \meta{number}'' get a line number.  If you turn line
+%     numbers on and off with \keyname{numbers}, the parameter
+%     \keyname{stepnumber} will keep its value. Alternatively you can turn
+%     them off via |stepnumber=0| and on with a nonzero number, and keep
+%     the value of \keyname{numbers}.
+%
+%   \item[1.1,false]
+%     \rkeyname{numberfirstline}|=|\meta{\alternative{true,false}}^^A
+%     \label{uoption:numberfirstline}
+%
+%     The first line of each listing gets numbered (if numbers are on at
+%     all) even if the line number is not divisible by
+%     \keyname{stepnumber}.
+%
+%   \item[0.16,{{}}] \rkeyname{numberstyle}|=|\meta{style}
+%
+%     determines the font and size of the numbers.
+%
+%   \item[0.19,10pt] \rkeyname{numbersep}|=|\meta{dimension}
+%
+%     is the distance between number and listing.
+%
+%   \item[1.0,true]
+%     \rkeyname{numberblanklines}|=|\meta{\alternative{true,false}}
+%
+%     If this is set to false, blank lines get no printed line number.
+%
+%   \item[0.20,auto]
+%     \rkeyname{firstnumber}|=|\meta{\alternative{auto,last,\normalfont\meta{number}}}
+%
+%     \texttt{auto} lets the package choose the first number: a new listing
+%     starts with number one, a named listing continues the most recent
+%     same-named listing (see below), and a stand alone file begins with
+%     the number corresponding to the first input line.
+%
+%     \texttt{last} continues the numbering of the most recent listing and
+%     \meta{number} sets it to the number.
+%
+%   \item[1.0] \rkeyname{name}|=|\meta{name}
+%
+%     names a listing. Displayed environment-listings with the same name
+%     share a line counter if |firstnumber=auto| is in effect.
+%
+%   \item[0.20,\arabic{lstnumber},data] \rcmdname\thelstnumber
+%
+%     prints the lines' numbers.
+% \end{syntax}
+% We show an example on how to redefine |\thelstnumber|. But if you test it,
+% you won't get the result shown on the left.
+% \begin{lstxsample}
+%    \renewcommand*\thelstnumber{\oldstylenums{\the\value{lstnumber}}}
+% \end{lstxsample}
+% \begin{lstsample}{\lstset{stepnumber=-1}\label{rDecreasingLabels}}{}
+%    \begin{lstlisting}[numbers=left,
+%                       firstnumber=753]
+%    begin { empty lines }
+%
+%
+%
+%
+%
+%
+%    end; { empty lines }
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{advise}
+%   \item The example shows a sequence
+%     $n,n+1,\ldots,n+7$ of 8 three-digit figures such that the sequence
+%     contains each digit
+%     $0,1,\ldots,9$.  But 8 is not minimal with that property.  Find the
+%     minimal number and prove that it is minimal.  How many minimal
+%     sequences do exist?
+%
+%     Now look at the generalized problem: Let
+%     $k\in\{1,\ldots,10\}$ be given.  Find the minimal number
+%     $m\in\{1,\ldots,10\}$ such that there is a sequence
+%     $n,{n+1},\ldots,\allowbreak{n+m-1}$ of $m$
+%     $k$-digit figures which contains each digit
+%     $\{0,\ldots,9\}$.  Prove that the number is minimal.  How many
+%     minimal sequences do exist?
+%
+%     If you solve this problem with a computer, write a \TeX\ program!
+% \end{advise}
+%
+%
+% \subsubsection{Captions}
+%
+% In despite of \LaTeX\ standard behaviour, captions and floats are independent
+% from each other here; you can use captions with non-floating listings.
+% \begin{syntax}
+% \item[0.21] \rkeyname{title}|=|\meta{title text}
+%
+%       is used for a title without any numbering or label.
+%
+% \item[0.20] \rkeyname{caption}|={|\oarg{short}\meta{caption text}|}|
+%
+%       The caption is made of \cs{lstlistingname} followed by a running
+%       number, a seperator, and \meta{caption text}. Either the caption text
+%       or, if present, \meta{short} will be used for the list of listings.
+%
+% \item[0.21] \rkeyname{label}|=|\meta{name}
+%
+%       makes a listing referable via |\ref|\marg{name}.
+%
+% \item[0.16] \rcmdname\lstlistoflistings
+%
+%       prints a list of listings. Each entry is with descending priority
+%       either the short caption, the caption, the file name or the name of the
+%       listing, see also the key \keyname{name} in section \ref{rLineNumbers}.
+%
+% \item[1.0] \rkeyname{nolol}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{nolol}
+%
+%       If true, the listing does not make it into the list of listings.
+%
+% \item[0.16,Listings,data] \rcmdname\lstlistlistingname
+%
+%       The header name for the list of listings.
+%
+% \item[0.20,Listing,data] \rcmdname\lstlistingname
+%
+%       The caption label for listings.
+%
+% \item[0.20,\arabic{lstlisting},data] \rcmdname\thelstlisting
+%
+%       prints the running number of the caption.
+%
+% \item[1.4,true] \rkeyname{numberbychapter}|=|\meta{\alternative{true,false}}
+%
+%       If true, and |\thechapter| exists, listings are numbered by chapter.
+%       Otherwise, they are numbered sequentially from the beginning of the
+%       document.  This key can only be used before |\begin{document}|.
+%
+% \item[0.19] \rcmdname\lstname
+%
+%       prints the name of the current listing which is either the file name or
+%       the name defined by the \keyname{name} key. This command can be used to
+%       define a caption or title template, for example by
+%       |\lstset{caption=\lstname}|.
+%
+% \item[0.20,t] \rkeyname{captionpos}|=|\meta{subset of \textup{\texttt{tb}}}
+%
+%       specifies the positions of the caption: top and/or bottom of the
+%       listing.
+%
+% \item[0.20,\smallskipamount] \rkeyname{abovecaptionskip}|=|\meta{dimension}
+% \item[0.20,\smallskipamount] \rkeyname{belowcaptionskip}|=|\meta{dimension}
+%
+%       is the vertical space respectively above or below each caption.
+% \end{syntax}
+%
+%
+% \subsubsection{Margins and line shape}\label{rMarginsAndLineShape}
+%
+% \begin{syntax}
+%   \item[0.21,\linewidth] \rkeyname{linewidth}|=|\meta{dimension}
+%
+%     defines the base line width for listings. The following three keys
+%     are taken into account additionally.
+%
+%   \item[0.19,0pt] \rkeyname{xleftmargin}|=|\meta{dimension}
+%   \item[1.0,0pt] \rkeyname{xrightmargin}|=|\meta{dimension}
+%
+%     The dimensions are used as extra margins on the left and right. Line
+%     numbers and frames are both moved accordingly.
+%
+%   \item[0.19,false]
+%     \rkeyname{resetmargins}|=|\meta{\alternative{true,false}}
+%
+%     If true, indention from list environments like \texttt{enumerate} or
+%     \texttt{itemize} is reset, i.e.~not used.
+%
+%   \item[0.20,false]
+%     \rkeyname{breaklines}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{breaklines}
+%
+%     activates or deactivates automatic line breaking of long lines.
+%
+%   \item[1.2,false]
+%     \rkeyname{breakatwhitespace}|=|\meta{\alternative{true,false}}^^A
+%     \syntaxor\rkeyname{breakatwhitespace}\label{uoption:breakatwhitespace}
+%
+%     If true, it allows line breaks only at white space.
+%
+%   \item[0.20,{{}}] \rkeyname{prebreak}|=|\meta{tokens}
+%   \item[0.20,{{}}] \rkeyname{postbreak}|=|\meta{tokens}
+%
+%     \meta{tokens} appear at the end of the current line respectively at
+%     the beginning of the next (broken part of the) line.
+%
+%     You must not use dynamic space (in particular spaces) since
+%     internally we use |\discretionary|.  However |\space| is redefined to
+%     be used inside \meta{tokens}.
+%
+%   \item[0.20,20pt] \rkeyname{breakindent}|=|\meta{dimension}
+%
+%     is the indention of the second, third, \ldots\ line of broken lines.
+%
+%   \item[0.20,true]
+%     \rkeyname{breakautoindent}|=|\meta{\alternative{true,false}}^^A
+%     \syntaxor\rkeyname{breakautoindent}
+%
+%     activates or deactivates automatic indention of broken lines. This
+%     indention is used additionally to \ikeyname{breakindent}, see the
+%     example below.  Visible spaces or visible tabulators might set this
+%     auto indention to zero.
+% \end{syntax}
+% In the following example we use tabulators to create long lines, but the
+% verbatim part uses |tabsize=1|.
+% \begin{lstxsample}
+%    \lstset{postbreak=\space, breakindent=5pt, breaklines}
+% \end{lstxsample}
+% \begin{lstsample}{\lstset{string=[d]",tabsize=6}}{\lstset{tabsize=1}\hfuzz=1in}
+%    \begin{lstlisting}
+%    		"A long string is broken!"
+%    			"Another long line."
+%    \end{lstlisting}
+%
+%    \begin{lstlisting}[breakautoindent
+%                                 =false]
+%    		{ Now auto indention is off. }
+%    \end{lstlisting}
+% \end{lstsample}
+%
+%
+% \subsubsection{Frames}\label{rFrames}
+%
+% \begin{syntax}
+%   \item[1.0,none]
+%     \rkeyname{frame}|=|\meta{\alternative{none,leftline,topline,bottomline,^^A
+%       lines,single,shadowbox}}
+%
+%     draws either no frame, a single line on the left, at the top, at the
+%     bottom, at the top and bottom, a whole single frame, or a shadowbox.
+%
+%     Note that \packagename{fancyvrb} supports the same frame types except
+%     \texttt{shadowbox}. The shadow color is \keyname{rulesepcolor}, see
+%     below.
+%
+%   \item[0.19,{{}}] \rkeyname{frame}|=|\meta{subset of
+%     \textup{\texttt{trblTRBL}}}
+%
+%     The characters \texttt{trblTRBL} designate lines at the top and
+%     bottom of a listing and to lines on the right and left. Upper case
+%     characters are used to draw double rules. So |frame=tlrb| draws a
+%     single frame and |frame=TL| double lines at the top and on the left.
+%
+%     Note that frames usually reside outside the listing's space.
+%
+%   \item[0.20,ffff]
+%     \rkeyname{frameround}|=|\meta{\alternative{t,f}}\meta{\alternative{t,f}}^^A
+%     \meta{\alternative{t,f}}\meta{\alternative{t,f}}
+%
+%     The four letters designate the top right, bottom right, bottom left
+%     and top left corner. In this order. \texttt{t} makes the according
+%     corner round. If you use round corners, the rule width is controlled
+%     via |\thinlines| and |\thicklines|.
+%
+%     Note: The size of the quarter circles depends on \keyname{framesep}
+%     and is independent of the extra margins of a frame. The size is
+%     possibly adjusted to fit \LaTeX's circle sizes.
+%
+%   \item[0.19,3pt] \rkeyname{framesep}|=|\meta{dimension}
+%   \item[0.19,2pt] \rkeyname{rulesep}|=|\meta{dimension}
+%
+%     control the space between frame and listing and between double rules.
+%
+%   \item[0.19,0.4pt] \rkeyname{framerule}|=|\meta{dimension}
+%
+%     controls the width of the rules.
+%
+%   \item[1.0,0pt] \rkeyname{framexleftmargin}|=|\meta{dimension}
+%   \item[1.0,0pt] \rkeyname{framexrightmargin}|=|\meta{dimension}
+%   \item[1.0,0pt] \rkeyname{framextopmargin}|=|\meta{dimension}
+%   \item[1.0,0pt] \rkeyname{framexbottommargin}|=|\meta{dimension}
+%
+%     are the dimensions which are used additionally to \keyname{framesep}
+%     to make up the margin of a frame.
+%
+%   \item[0.21] \rkeyname{backgroundcolor}|=|\meta{color command}
+%   \item[0.21] \rkeyname{rulecolor}|=|\meta{color command}
+%   \item[1.0] \rkeyname{fillcolor}|=|\meta{color command}
+%   \item[1.0] \rkeyname{rulesepcolor}|=|\meta{color command}
+%
+%     specify the colour of the background, the rules, the space between
+%     `text box' and first rule, and of the space between two rules,
+%     respectively.  Note that the value requires a |\color| command, for
+%     example \keyname{rulecolor}|=\color{blue}|.
+% \end{syntax}
+% \ikeyname{frame} does not work with |fancyvrb=true| or when the package
+% internally makes a |\hbox| around the listing! And there are certainly more
+% problems with other commands; please take the time to make a (bug) report.
+%\ifcolor
+% \begin{lstxsample}
+%    \lstset{framexleftmargin=5mm, frame=shadowbox, rulesepcolor=\color{blue}}
+% \end{lstxsample}
+%\else
+%    \lstset{framexleftmargin=5mm, frame=shadowbox}
+%\fi
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}[numbers=left]
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% Note here the use of |framexleftmargin| to include the line numbers inside
+% the frame.
+%
+% Do you want exotic frames? Try the following key if you want, for example,
+% \begin{lstsample}{\lstset{frameshape={RYRYNYYYY}{yny}{yny}{RYRYNYYYY}}}{}
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{syntax}
+%   \item[0.20,,\dag] \rkeyname{frameshape}|=|\marg{top shape}\marg{left
+%     shape}\marg{right shape}\marg{bottom shape}
+%
+%     gives you full control over the drawn frame parts.  The arguments are
+%     not case sensitive.
+%
+%     Both \meta{left shape} and \meta{right shape} are `left-to-right'
+%     \alternative{y,n} character sequences (or empty). Each |y| lets the
+%     package draw a rule, otherwise the rule is blank. These vertical
+%     rules are drawn `left-to-right' according to the specified shapes.
+%     The example above uses |yny|.
+%
+%     \meta{top shape} and \meta{bottom shape} are `left-rule-right'
+%     sequences (or empty). The first `left-rule-right' sequence is
+%     attached to the most inner rule, the second to the next, and so on.
+%     Each sequence has three characters: `rule' is either |y| or |n|;
+%     `left' and `right' are |y|, |n| or |r| (which makes a corner round).
+%     The example uses |RYRYNYYYY| for both shapes: |RYR| describes the
+%     most inner (top and bottom) frame shape, |YNY| the middle, and |YYY|
+%     the most outer.
+% \end{syntax}
+% To summarize, the example above used
+% \begin{verbatim}
+%    \lstset{frameshape={RYRYNYYYY}{yny}{yny}{RYRYNYYYY}}\end{verbatim}
+% Note that you are not resticted to two or three levels.
+% However you'll get in trouble if you use round corners when they are too big.
+%
+%
+% \subsubsection{Indexing}
+%
+% \begin{syntax}
+%   \item[0.19] \rkeyname{index}|=|\oarg{number}\oarg{keyword
+%     classes}\marg{identifiers}
+%   \item[0.21] \rkeyname{moreindex}|=|\oarg{number}\oarg{keyword
+%     classes}\marg{identifiers}
+%   \item[0.21] \rkeyname{deleteindex}|=|\oarg{number}\oarg{keyword
+%     classes}\marg{identifiers}
+%
+%     define, add and remove \meta{identifiers} and \meta{keyword classes}
+%     from the index class list \meta{number}. If you don't specify the
+%     optional number, the package assumes \meta{number} $=1$.
+%
+%     Each appearance of the explicitly given identifiers and each
+%     appearance of the identifiers of the specified \meta{keyword classes}
+%     is indexed.  For example, you could write |index=[1][keywords]| to
+%     index all keywords. Note that |[1]| is required here---otherwise we
+%     couldn't use the second optional argument.
+%
+%   \item[0.19,\lstindexmacro]
+%     \rkeyname{indexstyle}|=|\oarg{number}\meta{tokens
+%     \textup(one-parameter command\textup)}
+%
+%     \meta{tokens} actually indexes the identifiers for the list
+%     \meta{number}. In contrast to the style keys, \meta{tokens}
+%     \emph{must} read exactly one parameter, namely the identifier.
+%     Default definition is\icmdname{\lstindexmacro}\vspace*{-\itemsep}
+% \begin{verbatim}
+%    \newcommand\lstindexmacro[1]{\index{{\ttfamily#1}}}\end{verbatim}
+%       \vspace*{-\itemsep}which you shouldn't modify.
+%       Define your own indexing commands and use them as argument to this key.
+%   \end{syntax}
+% Section \ref{uIndexing} describes this feature in detail.
+%
+%
+% \subsubsection{Column alignment}\label{rColumnAlignment}
+%
+% \begin{syntax}
+%   \item[1.0,{[c]fixed}]
+%     \rkeyname{columns}|=|\oarg{\alternative{c,l,r}}\meta{alignment}
+%
+%     selects the column alignment.  The \meta{alignment} can be |fixed|,
+%     |flexible|, |spaceflexible|, or |fullflexible|; see section
+%     \ref{uFixedAndFlexibleColumns} for details.
+%
+%     The optional |c|, |l|, or |r| controls the horizontal orientation of
+%     smallest output units (keywords, identifiers, etc.). The arguments
+%     work as follows, where vertical bars visualize the effect:
+%     $\vert$\lstinline[columns={[c]fixed}]!listing!$\vert$,
+%     $\vert$\lstinline[columns={[l]fixed}]!listing!$\vert$, and
+%     $\vert$\lstinline[columns={[r]fixed}]!listing!$\vert$ in fixed column
+%     mode,
+%     $\vert$\lstinline[columns={[c]flexible}]!listing!$\vert$,
+%     $\vert$\lstinline[columns={[l]flexible}]!listing!$\vert$, and
+%     $\vert$\lstinline[columns={[r]flexible}]!listing!$\vert$ with
+%     flexible columns, and
+%     $\vert$\lstinline[columns={[c]fullflexible}]!listing!$\vert$,
+%     $\vert$\lstinline[columns={[l]fullflexible}]!listing!$\vert$, and
+%     $\vert$\lstinline[columns={[r]fullflexible}]!listing!$\vert$ with
+%     space-flexible or full flexible columns (which ignore the optional
+%     argument, since they do not add extra space around printable
+%     characters).
+%
+%   \item[0.18,false]
+%     \rkeyname{flexiblecolumns}|=|\meta{\alternative{true,false}}^^A
+%     \syntaxor\rkeyname{flexiblecolumns}
+%
+%     selects the most recently selected flexible or fixed column format,
+%     refer to section \ref{uFixedAndFlexibleColumns}.
+%
+%   \item[0.21,false,\dag]
+%     \rkeyname{keepspaces}|=|\meta{\alternative{true,false}}
+%
+%     |keepspaces=true| tells the package not to drop spaces to fix column
+%     alignment and always converts tabulators to spaces.
+%
+%   \item[0.16] \rkeyname{basewidth}|=|\meta{dimension}\syntaxor
+%   \item[0.18,{{0.6em,0.45em}}]
+%     \rkeyname{basewidth}|={|\meta{fixed}|,|\meta{flexible mode}|}|
+%
+%     sets the width of a single character box for fixed and flexible
+%     column mode (both to the same value or individually).
+%
+%   \item[0.20,false]
+%     \rkeyname{fontadjust}|=|\meta{\alternative{true,false}}^^A
+%     \syntaxor\rkeyname{fontadjust}
+%
+%     If true the package adjusts the base width every font selection.
+%     This makes sense only if \ikeyname{basewidth} is given in font
+%     specific units like `em' or `ex'---otherwise this boolean has no
+%     effect.
+%
+%     After loading the package, it doesn't adjust the width every font
+%     selection: it looks at \ikeyname{basewidth} each listing and uses the
+%     value for the whole listing. This is possibly inadequate if the style
+%     keys in section \ref{rFigureOutTheAppearance} make heavy font size
+%     changes, see the example below.
+%
+%     Note that this key might disturb the column alignment and might have
+%     an effect on the keywords' appearance!
+% \end{syntax}
+% \begin{lstsample}{\lstset{basicstyle=\normalsize}}{}
+%    \lstset{commentstyle=\scriptsize}
+%    \begin{lstlisting}
+%    { scriptsize font
+%      doesn't look good }
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+% \begin{lstsample}{\lstset{basicstyle=\normalsize,commentstyle=\scriptsize}}{}
+%    \begin{lstlisting}[fontadjust]
+%    { scriptsize font
+%      looks better now }
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+%
+% \subsubsection{Escaping to \LaTeX}\label{rEscapingToLaTeX}
+%
+% \textbf{Note:} {\itshape Any escape to \LaTeX\ may disturb the column
+% alignment since the package can't control the spacing there.}
+% \begin{syntax}
+% \item[0.18,false] \rkeyname{texcl}|=|\meta{\alternative{true,false}}\syntaxor\rkeyname{texcl}
+%
+%       activates or deactivates \LaTeX\ comment lines. If activated, comment
+%       line delimiters are printed as usual, but the comment line text (up to
+%       the end of line) is read as \LaTeX\ code and typeset in comment style.
+% \end{syntax}
+% The example uses \Cpp\ comment lines (but doesn't say how to define them).
+% Without |\upshape| we would get \textit{calculate} since the comment style
+% is |\itshape|.
+% \begin{lstsample}{\lstset{morecomment=[l]//}}{}
+%    \begin{lstlisting}[texcl]
+%    // \upshape calculate $a_{ij}$
+%      A[i][j] = A[j][j]/A[i][j];
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{syntax}
+%   \item[0.19,false]
+%     \rkeyname{mathescape}|=|\meta{\alternative{true,false}}
+%
+%     activates or deactivates special behaviour of the dollar sign.  If
+%     activated a dollar sign acts as \TeX's text math shift.
+%
+%     This key is useful if you want to typeset formulas in listings.
+%
+%   \item[0.19,{{}}]
+%     \rkeyname{escapechar}|=|\meta{character}\syntaxor\rkeyname{escapechar}|={}|
+%
+%     If not empty the given character escapes the user to \LaTeX: all code
+%     between two such characters is interpreted as \LaTeX\ code. Note that
+%     \TeX's special characters must be entered with a preceding backslash,
+%     e.g.~|escapechar=\%|.
+%
+%   \item[0.20,{{}}]
+%     \rkeyname{escapeinside}|=|\meta{character}\meta{character}^^A
+%     \syntaxor\rkeyname{escapeinside}|={}|
+%
+%     Is a generalization of \ikeyname{escapechar}. If the value is not
+%     empty, the package escapes to \LaTeX\ between the first and second
+%     character.
+%
+%   \item[0.20,{{}}] \rkeyname{escapebegin}|=|\meta{tokens}
+%   \item[0.20,{{}}] \rkeyname{escapeend}|=|\meta{tokens}
+%
+%     The tokens are executed at the beginning respectively at the end of
+%     each escape, in particular for \ikeyname{texcl}.  See section
+%     \ref{uNationalCharacters} for an application.
+% \end{syntax}
+%
+% \begin{lstsample}{\lstset{morecomment=[l]//}}{}
+%    \begin{lstlisting}[mathescape]
+%    // calculate $a_{ij}$
+%      $a_{ij} = a_{jj}/a_{ij}$;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{lstsample}{\lstset{morecomment=[l]//}}{}
+%    \begin{lstlisting}[escapechar=\%]
+%    // calc%ulate $a_{ij}$%
+%      %$a_{ij} = a_{jj}/a_{ij}$%;
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% \begin{lstsample}{\lstset{morecomment=[l]//}}{}
+%    \lstset{escapeinside=`'}
+%    \begin{lstlisting}
+%    // calc`ulate $a_{ij}$'
+%      `$a_{ij} = a_{jj}/a_{ij}$';
+%    \end{lstlisting}
+% \end{lstsample}
+% In the first example the comment line up to $a_{ij}$ has been typeset by the
+% \packagename{listings} package in comment style. The $a_{ij}$ itself is
+% typeset in `\TeX\ math mode' without comment style. About half of the
+% comment line of the second example has been typeset by this package, and
+% the rest is in `\LaTeX\ mode'.
+%
+% To avoid problems with the current and future version of this package:
+% \begin{enumerate}
+% \item Don't use any commands of the \packagename{listings} package when you
+%       have escaped to \LaTeX.
+% \item Any environment must start and end inside the same escape.
+% \item You might use |\def|, |\edef|, etc., but do not assume that the
+%       definitions are present later, unless they are |\global|.
+% \item |\if \else \fi|, groups, math shifts |$| and |$$|, \ldots\ must be
+%       balanced within each escape.
+% \item \ldots
+% \end{enumerate}
+% Expand that list yourself and mail me about new items.
+%
+%
+% \subsection{Interface to \textsf{fancyvrb}}
+%
+% The \packagename{fancyvrb} package---fancy verbatims---from Timothy van Zandt
+% provides macros for reading, writing and typesetting verbatim code. It has
+% some remarkable features the \packagename{listings} package doesn't have.
+% (Some are possible, but you must find somebody who will implement them |;-)|.
+% \begin{syntax}
+%   \item[0.19] \rkeyname{fancyvrb}|=|\meta{\alternative{true,false}}
+%
+%     activates or deactivates the interface. If active, verbatim code is
+%     read by \packagename{fancyvrb} but typeset by \packagename{listings},
+%     i.e.~with emphasized keywords, strings, comments, and so on.
+%     Internally we use a very special definition of
+%     |\FancyVerbFormatLine|.
+%
+%     This interface works with |Verbatim|, |BVerbatim| and |LVerbatim|.
+%     But you shouldn't use \packagename{fancyvrb}'s
+%     \keyname{defineactive}.  (As far as I can see it doesn't matter since
+%     it does nothing at all, but for safety \ldots .)  If
+%     \packagename{fancyvrb} and \packagename{listings} provide similar
+%     functionality, you should use \packagename{fancyvrb}'s.
+%
+%   \item[1.1,{\overlay 1}]
+%     \rkeyname{fvcmdparams}|=|\meta{command$_1$}\meta{number$_1$}^^A
+%     \ldots\label{uoption:fvcmdparams}
+%   \item[1.1]
+%     \rkeyname{morefvcmdparams}|=|\meta{command$_1$}\meta{number$_1$}^^A
+%     \ldots\label{uoption:morefvcmdparams}
+%
+%     If you use \packagename{fancyvrb}'s \keyname{commandchars}, you must
+%     tell the \packagename{listings} package how many arguments each
+%     command takes. If a command takes no arguments, there is nothing to
+%     do.
+%
+%     The first (third, fifth, \ldots) parameter to the keys is the command
+%     and the second (fourth, sixth, \ldots) is the number of arguments
+%     that command takes. So, if you want to use |\textcolor{red}{keyword}|
+%     with the \packagename{fancyvrb}-\packagename{listings} interface, you
+%     should write |\lstset{morefvcmdparams=\textcolor 2}|.
+% \end{syntax}
+%
+% \iffancyvrb
+% \begin{lstsample}{}{}
+%    \lstset{morecomment=[l]\ }% :-)
+%    \fvset{commandchars=\\\{\}}
+%
+%    \begin{BVerbatim}
+%    First verbatim line.
+%    \fbox{Second} verbatim line.
+%    \end{BVerbatim}
+%
+%    \par\vspace{72.27pt}
+%
+%    \lstset{fancyvrb}
+%    \begin{BVerbatim}
+%    First verbatim line.
+%    \fbox{Second} verbatim line.
+%    \end{BVerbatim}
+%    \lstset{fancyvrb=false}
+% \end{lstsample}
+% The lines typeset by the \packagename{listings} package are wider since the
+% default \ikeyname{basewidth} doesn't equal the width of a single typewriter type
+% character. Moreover, note that the first space begins a comment as defined at
+% the beginning of the example.
+% \else
+% \begin{center}
+%    \packagename{fancyvrb} seems to be unavailable on your platform, thus the
+%    example couldn't be printed here.
+% \end{center}
+% \fi
+%
+%
+% \subsection{Environments}\label{rEnvironments}
+%
+% If you want to define your own pretty-printing environments, try the
+% following command. The syntax comes from \LaTeX's |\newenvironment|.
+% \begin{syntax}
+% \item[0.19] \rcmdname\lstnewenvironment\\
+%       \marg{name}\oarg{number}\oarg{opt.~default~arg.}\\
+%       |{|\meta{starting code}|}|\\
+%       |{|\meta{ending code}|}|
+% \end{syntax}
+% As a simple example we could just select a particular language.
+% \begin{lstxsample}
+%    \lstnewenvironment{pascal}
+%        {\lstset{language=pascal}}
+%        {}
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{pascal}
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    \end{pascal}
+% \end{lstsample}
+% Doing other things is as easy, for example, using more keys and adding an
+% optional argument to adjust settings each listing:
+% \begin{verbatim}
+%\lstnewenvironment{pascalx}[1][]
+%    {\lstset{language=pascal,numbers=left,numberstyle=\tiny,float,#1}}
+%    {}\end{verbatim}
+%
+%
+% \subsection{Short Inline Listing Commands}\label{rShortInline}
+%
+% Short equivalents of |\lstinline| can also be defined, in a manner similar
+% to the short verbatim macros provided by \packagename{shortvrb}.
+%
+% \begin{syntax}
+% \item[1.4] \rcmdname\lstMakeShortInline[\oarg{options}]\meta{character}
+%
+%       defines \meta{character} to be an equivalent of
+%       |\lstinline|[\oarg{options}]\meta{character},
+%       allowing for a convenient syntax when using lots of inline listings.
+%
+% \item[1.4] \rcmdname\lstDeleteShortInline\meta{character}
+%
+%       removes a definition of \meta{character} created by |\lstMakeShortInline|,
+%       and returns \meta{character} to its previous meaning.
+% \end{syntax}
+%
+%
+% \subsection{Language definitions}\label{rLanguageDefinitions}
+%
+% You should first read section \ref{uLanguageDefinitions} for an introduction
+% to language definitions. Otherwise you're probably unprepared for the full
+% syntax of |\lstdefinelanguage|.
+% \begin{syntax}
+%   \item[0.19] \rcmdname\lstdefinelanguage\syntaxnewline[\oarg{dialect}]^^A
+%     \marg{language}\syntaxnewline[\oarg{base dialect}^^A
+%     \marg{and base language}]\syntaxnewline\marg{key=value list}^^A
+%     \syntaxnewline[\oarg{list of required aspects ^^A
+%     \textup(keywordcomments,texcs,etc.\textup)}]
+%
+%		defines the (given dialect of the) programming language \meta{language}.
+%       If the language definition is based on another definition, you must
+%       specify the whole \oarg{base dialect}\marg{and base language}. Note
+%       that an empty \meta{base dialect} uses the default dialect!
+%
+%       The last optional argument should specify all required aspects. This is
+%       a delicate point since the aspects are described in the developer's
+%       guide. You might use existing languages as templates. For example,
+%       ANSI C uses \aspectname{keywords}, \aspectname{comments},
+%       \aspectname{strings} and \aspectname{directives}.
+%
+%       \icmdname{\lst@definelanguage} has the same syntax and is used to
+%       define languages in the driver files.
+%
+% \begin{advise}
+% \item Where should I put my language definition?
+%       \advisespace
+%       If you need the language for one particular document, put it into
+%       the preamble of that document. Otherwise create the local file
+%       `\texttt{lstlang0.sty}' or add the definition to that file, but use
+%       `|\lst@definelanguage|' instead of `|\lstdefinelanguage|'.
+%       However, you might want to send the definition to the address in
+%       section \ref{uSoftwareLicense}. Then it will be included with the
+%       rest of the languages distributed with the package, and published under
+%       the \LaTeX\ Project Public License.
+% \end{advise}
+%
+% \item[0.18] \rcmdname\lstalias\marg{alias}\marg{language}
+%
+%       defines an alias for a programming language. Each \meta{alias} is
+%       redirected to the same dialect of \meta{language}.
+%       It's also possible to define an alias for one particular dialect only:
+%
+% \item[0.18] \rcmdname\lstalias\oarg{alias dialect}\marg{alias}\oarg{dialect}\marg{language}
+%
+%       Here all four parameters are \emph{nonoptional} and an alias with empty
+%       \meta{dialect} will select the default dialect. Note that aliases
+%       cannot be chained: The two aliases `|\lstalias{foo1}{foo2}|' and
+%       `|\lstalias{foo2}{foo3}|' will \emph{not} redirect |foo1| to |foo3|.
+% \end{syntax}
+% All remaining keys in this section are intended for building language
+% definitions. \emph{No other key should be used in such a definition!}
+%
+%
+% \paragraph{Keywords}
+% We begin with keyword building keys. Note: {\itshape If you want to enter
+% {\upshape|\|, |{|, |}|, |%|, |#|} or {\upshape|&|} as (part of) an argument
+% to the keywords below, you must do it with a preceding backslash!}
+% \begin{syntax}
+%   \item[1.0,,{\dag bug}] \rkeyname{keywordsprefix}|=|\meta{prefix}
+%
+%     All identifiers starting with \meta{prefix} will be printed as first
+%     order keywords.
+%
+%     Bugs: Currently there are several limitations.  (1) The prefix is
+%     always case sensitive.  (2) Only one prefix can be defined at a time.
+%     (3) If used `standalone' outside a language definition, the key might
+%     work only after selecting a nonempty language (and switching back to
+%     the empty language if necessary).  (4) The key does not respect the
+%     value of \keyname{classoffset} and has no optional class
+%     \meta{number} argument.
+%
+%   \item[0.11] \rkeyname{keywords}|=|\oarg{number}\marg{list of keywords}
+%   \item[0.11] \rkeyname{morekeywords}|=|\oarg{number}\marg{list of
+%     keywords}
+%   \item[0.18] \rkeyname{deletekeywords}|=|\oarg{number}\marg{list of
+%     keywords}
+%
+%     define, add to or remove the keywords from keyword list
+%     \meta{number}.  The use of \keyname{keywords} is discouraged since it
+%     deletes all previously defined keywords in the list and is thus
+%     incompatible with the \keyname{alsolanguage} key.
+%
+%     Please note the keys \ikeyname{alsoletter} and \ikeyname{alsodigit}
+%     below if you use unusual charaters in keywords.
+%
+%   \item[0.19,,deprecated] \rkeyname{ndkeywords}|=|\marg{list of keywords}
+%   \item[0.19,,deprecated] \rkeyname{morendkeywords}|=|\marg{list of
+%     keywords}
+%   \item[0.19,,deprecated] \rkeyname{deletendkeywords}|=|\marg{list of
+%     keywords}
+%
+%     define, add to or remove the keywords from keyword list 2; note that
+%     this is equivalent to |keywords=[2]|\ldots etc.  The use of
+%     \keyname{ndkeywords} is strongly discouraged.
+%
+%   \item[0.19,,{addon,optional}] \rkeyname{texcs}|=|\oarg{class
+%     number}\marg{list of control sequences \textup(without
+%     backslashes\textup)}
+%   \item[0.20,,{addon,optional}] \rkeyname{moretexcs}|=|\oarg{class
+%     number}\marg{list of control sequences \textup(without
+%     backslashes\textup)}
+%   \item[0.21,,{addon,optional}] \rkeyname{deletetexcs}|=|\oarg{class
+%     number}\marg{list of control sequences \textup(without
+%     backslashes\textup)}
+%
+%     Ditto for control sequences in \TeX\ and \LaTeX.
+%
+%   \item[0.18,,optional] \rkeyname{directives}|=|\marg{list of compiler
+%     directives}
+%   \item[0.21,,optional] \rkeyname{moredirectives}|=|\marg{list of
+%     compiler directives}
+%   \item[0.21,,optional] \rkeyname{deletedirectives}|=|\marg{list of
+%     compiler directives}
+%
+%     defines compiler directives in C, \Cpp, Objective-C, and POV.
+%
+%   \item[0.14] \rkeyname{sensitive}|=|\meta{\alternative{true,false}}
+%
+%     makes the keywords, control sequences, and directives case sensitive
+%     and insensitive, respectively. This key affects the keywords, control
+%     sequences, and directives only when a listing is processed. In all
+%     other situations they are case sensitive, for example,
+%     |deletekeywords={save,Test}| removes `save' and `Test', but neither
+%     `SavE' nor `test'.
+%
+%   \item[0.19] \rkeyname{alsoletter}|=|\marg{character sequence}
+%   \item[0.19] \rkeyname{alsodigit}|=|\marg{character sequence}
+%   \item[0.19] \rkeyname{alsoother}|=|\marg{character sequence}
+%
+%     All identifiers (keywords, directives, and such) consist of a letter
+%     followed by alpha-numeric characters (letters and digits).  For
+%     example, if you write |keywords={one-two,\#include}|, the minus sign
+%     must become a digit and the sharp a letter since the keywords can't
+%     be detected otherwise.
+%
+%     Table \ref{rStdCharTable} show the standard configuration of the
+%     \packagename{listings} package. The three keys overwrite the default
+%     behaviour. Each character of the sequence becomes a letter, digit and
+%     other, respectively.
+%
+%   \item[0.20] \rkeyname{otherkeywords}|=|\marg{keywords}
+%
+%     Defines keywords that contain other characters, or start with digits.
+%     Each given `keyword' is printed in keyword style, but without
+%     changing the `letter', `digit' and `other' status of the
+%     characters. This key is designed to define keywords like |=>|, |->|,
+%     |-->|, |--|, |::|, and so on. If one keyword is a subsequence of
+%     another (like |--| and |-->|), you must specify the shorter first.
+%
+%   \item[0.20,,{renamed,optional}]
+%     \rkeyname{tag}|=|\meta{character}\meta{character}^^A
+%     \syntaxor\rkeyname{tag}|={}|\label{uoption:tag}
+%
+%     The first order keywords are active only between the first and second
+%     character. This key is used for HTML.
+% \end{syntax}
+%
+% \begin{table}[tb]
+% \caption{Standard character table}\label{rStdCharTable}
+% \begin{tabular}{ll}
+% class & characters\\
+% \noalign{\smallskip}
+% letter & \texttt{A B C D E F G H I J K L M N O P Q R S T U V W X Y Z}\\
+%        & \texttt{a b c d e f g h i j k l m n o p q r s t u v w x y z}\\
+%        & \texttt{@ \textdollar\ } |_|\\
+% digit  & \texttt{0 1 2 3 4 5 6 7 8 9}\\
+% other  & \texttt{!\ " \#\ \%\ \&\ ' ( ) * + , - .\ / :\ ; < = > ?}\\
+%        & {\catcode`\|=12\texttt{[ \char92\ ] \textasciicircum\ \char123\
+%            | \char125\ \textasciitilde}}\\
+% space  & chr(32)\\
+% tabulator & chr(9)\\
+% form feed & chr(12)\\
+% \noalign{\smallskip}
+% \end{tabular}
+% \par\noindent
+% Note: Extended characters of codes 128--255 (if defined) are \emph{currently}
+% letters.
+% \end{table}
+%
+%
+% \paragraph{Strings}
+% \begin{syntax}
+%   \item[0.12]
+%     \rkeyname{string}|=|\oarg{\alternative{b,d,m,bd,s}}\marg{delimiter
+%     \textup(character\textup)}
+%   \item[0.21]
+%     \rkeyname{morestring}|=|\oarg{\alternative{b,d,m,bd,s}}\marg{delimiter}
+%   \item[0.21]
+%     \rkeyname{deletestring}|=|\oarg{\alternative{b,d,m,bd,s}}\marg{delimiter}
+%
+%     define, add to or delete the delimiter from the list of string
+%     delimiters. Starting and ending delimiters are the same, i.e.~in the
+%     source code the delimiters must match each other.
+%
+%     The optional argument is the type and controls the how the delimiter
+%     itself is represented in a string or character literal: it is escaped
+%     by a |b|ackslash, |d|oubled (or both is allowed via |bd|).
+%     Alternately, the type can refer to an unusual form of delimiter:
+%     |s|tring delimiters (akin to the |s| comment type) or |m|atlab-style
+%     delimiters.  The latter is a special type for Ada and Matlab and
+%     possibly other languages where the string delimiters are also used
+%     for other purposes.  It is equivalent to |d|, except that a string
+%     does not start after a letter, a right parenthesis, a right bracket,
+%     or some other characters.
+% \end{syntax}
+%
+%
+% \paragraph{Comments}
+% \begin{syntax}
+%   \item[0.13]
+%     \rkeyname{comment}|=|\oarg{type}\meta{delimiter\textup(s\textup)}
+%   \item[0.21]
+%     \rkeyname{morecomment}|=|\oarg{type}\meta{delimiter\textup(s\textup)}
+%   \item[0.21]
+%     \rkeyname{deletecomment}|=|\oarg{type}\meta{delimiter\textup(s\textup)}
+%
+%     Ditto for comments, but some types require more than a single
+%     delimiter. The following overview uses \keyname{morecomment} as the
+%     example, but the examples apply to \keyname{comment} and
+%     \keyname{deletecomment} as well.
+%
+%   \item[0.13] \keyname{morecomment}|=[l]|\meta{delimiter}
+%
+%     The delimiter starts a comment line, which in general starts with the
+%     delimiter and ends at end of line. If the character sequence |//|
+%     should start a comment line (like in \Cpp, Comal 80 or Java),
+%     |morecomment=[l]//| is the correct declaration. For Matlab it would
+%     be |morecomment=[l]\%|---note the preceding backslash.
+%
+%   \item[0.13] \keyname{morecomment}|=[s]|\marg{delimiter}\marg{delimiter}
+%
+%     Here we have two delimiters. The second ends a comment starting with
+%     the first delimiter. If you require two such comments you can use
+%     this type twice. C, Java, PL/I, Prolog and SQL all define single
+%     comments via |morecomment=[s]{/*}{*/}|, and Algol does it with
+%     |morecomment=[s]{\#}{\#}|, which means that the sharp delimits both
+%     beginning and end of a single comment.
+%
+%   \item[0.13] \keyname{morecomment}|=[n]|\marg{delimiter}\marg{delimiter}
+%
+%     is similar to type |s|, but comments can be nested. Identical
+%     arguments are not allowed---think a while about it!  Modula-2 and
+%     Oberon-2 use |morecomment=[n]{(*}{*)}|.
+%
+%   \item[0.18] \keyname{morecomment}|=[f]|\meta{delimiter}
+%   \item[0.18] \keyname{morecomment}|=[f][commentstyle]|\oarg{n=preceding
+%     columns}\meta{delimiter}
+%
+%     The delimiter starts a comment line if and only if it appears on a
+%     fixed column-number, namely if it is in column $n$ (zero based).
+%
+%   \item[0.17,,optional] \rkeyname{keywordcomment}|=|\marg{keywords}
+%   \item[0.21,,optional] \rkeyname{morekeywordcomment}|=|\marg{keywords}
+%   \item[0.21,,optional] \rkeyname{deletekeywordcomment}|=|\marg{keywords}
+%
+%     A keyword comment begins with a keyword and ends with the same
+%     keyword.  Consider |keywordcomment={comment,co}|. Then
+%     `\textbf{comment}\allowbreak\ldots\textbf{comment}' and
+%     `\textbf{co}\ldots\textbf{co}' are comments.
+%
+%   \item[0.17,,optional]
+%     \rkeyname{keywordcommentsemicolon}|=|\marg{keywords}\marg{keywords}^^A
+%     \marg{keywords}
+%
+%     The definition of a `keyword comment semicolon' requires three
+%     keyword lists, e.g.~|{end}{else,end}{comment}|. A semicolon always
+%     ends such a comment. Any keyword of the first argument begins a
+%     comment and any keyword of the second argument ends it (and a
+%     semicolon also); a comment starting with any keyword of the third
+%     argument is terminated with the next semicolon only. In the example
+%     all possible comments are `\textbf{end}\ldots\textbf{else}',
+%     `\textbf{end}\ldots\textbf{end}' (does not start a comment again) and
+%     `\textbf{comment}\ldots;' and `\textbf{end}\ldots;'.  Maybe a curious
+%     definition, but Algol and Simula use such comments.
+%
+%     Note: The keywords here need not to be a subset of the defined
+%     keywords. They won't appear in keyword style if they aren't.
+%
+%   \item[0.17,,optional]
+%     \rkeyname{podcomment}|=|\meta{\alternative{true,false}}
+%
+%     activates or deactivates PODs---Perl specific.
+% \end{syntax}
+%
+%
+% \subsection{Installation}\label{rInstallation}
+%
+% \paragraph{Software installation}
+% \begin{enumerate}
+% \item Following the \TeX\ directory structure (TDS), you should put the files
+%       of the \packagename{listings} package into directories as follows:
+%       \begin{center}
+%       \begin{tabular}{lcl}
+%       \texttt{listings.pdf}&$\to$&\texttt{texmf/doc/latex/listings}\\
+%       \texttt{listings.dtx}, \texttt{listings.ins},\\
+%       \texttt{listings.ind}, \texttt{lstpatch.sty},\\
+%       \texttt{lstdrvrs.dtx}&$\to$&\texttt{texmf/source/latex/listings}
+%       \end{tabular}
+%       \end{center}
+%       Note that you may not have a patch file \texttt{lstpatch.sty}.
+%       If you don't use the TDS, simply adjust the directories below.
+% \item	Create the directory \texttt{texmf/tex/latex/listings} or, if it exists
+%       already, remove all
+%       files except \texttt{lst}\meta{whatever}\texttt{0.sty} and
+%       \texttt{lstlocal.cfg} from it.
+% \item	Change the working directory to \texttt{texmf/source/latex/listings}
+%       and run \texttt{listings.ins} through \TeX.
+% \item Move the generated files to \texttt{texmf/tex/latex/listings} if this
+%       is not already done.
+%       \begin{center}
+%       \begin{tabular}{lcl}
+%       \texttt{listings.sty}, \texttt{lstmisc.sty},
+%           &&\qquad(kernel and add-ons)\\
+%       \texttt{listings.cfg},
+%           &&\qquad(configuration file)\\
+%       \texttt{lstlang}\meta{number}\texttt{.sty},
+%           &&\qquad(language drivers)\\
+%       \texttt{lstpatch.sty}&$\to$&\texttt{texmf/tex/latex/listings}
+%       \end{tabular}
+%       \end{center}
+% \item If your \TeX\ implementation uses a file name database, update it.
+% \item If you receive a patch file later on, put it where
+%       \texttt{listings.sty} is (and update the file name database).
+% \end{enumerate}
+% Note that \packagename{listings} requires at least version 1.10 of the
+% \packagename{keyval} package included in the \packagename{graphics} bundle by
+% David Carlisle.
+%
+%
+% \paragraph{Software configuration}
+% Read this only if you encounter problems with the standard configuration or
+% if you want the package to suit foreign languages, for example.
+%
+% Never modify a file from the \packagename{listings} package, in particular
+% not the configuration file. Each new installation or new version overwrites
+% it. The software license allows modification, but I can't recommend it.
+% It's better to create one or more of the files
+% \begin{center}
+% \begin{tabular}{lcl}
+% \texttt{lstmisc0.sty} & for & local add-ons
+%                               (see the developer's guide),\\
+% \texttt{lstlang0.sty} & for & local language definitions
+%                               (see \ref{rLanguageDefinitions}), and\\
+% \texttt{lstlocal.cfg} & as  & local configuration file
+% \end{tabular}
+% \end{center}
+% and put them in the same directory as the other \packagename{listings} files.
+% These three files are not touched by a new installation unless you remove them.
+% If \texttt{lstlocal.cfg} exists, it is loaded after \texttt{listings.cfg}.
+% You might want to change one of the following parameters.
+% \begin{syntax}
+% \item[,,data] \rcmdname\lstaspectfiles\quad contains~\rlap{\texttt{\lstaspectfiles}}
+% \item[,,data] \rcmdname\lstlanguagefiles\quad contains~\rlap{\texttt{\lstlanguagefiles}}
+%
+%       The package uses the specified files to find add-ons and language
+%       definitions.
+% \end{syntax}
+% Moreover, you might want to adjust
+%   \icmdname\lstlistlistingname,
+%   \icmdname\lstlistingname,
+%   \ikeyname{defaultdialect},
+%   \icmdname\lstalias, or
+%   \icmdname\lstalias
+% \ as described in earlier sections.
+%
+%
+% \section{Experimental features}\label{rExperimentalFeatures}
+%
+% This section describes the more or less unestablished parts of this package.
+% It's unlikely that they will all be removed (unless stated explicitly), but
+% they are liable to (heavy) changes and improvements. Such features have been
+% \dag-marked in the last sections. So, if you find anything \dag-marked here,
+% you should be very, very careful.
+%
+%
+% \subsection{Listings inside arguments}\label{rListingsInsideArguments}
+%
+% There are some things to consider if you want to use |\lstinline| or the
+% listing environment inside arguments. Since \TeX\ reads the argument before
+% the `\lst-macro' is executed, this package can't do anything to preserve the
+% input: spaces shrink to one space, the tabulator and the end of line are
+% converted to spaces, \TeX's comment character is not printable, and so on.
+% Hence, \emph{you} must work a bit more. You have to put a backslash in front
+% of each of the following four characters: |\{}%|. Moreover you must protect
+% spaces in the same manner if: (i) there are two or more spaces following each
+% other or (ii) the space is the first character in the line.
+% That's not enough: Each line must be terminated with a `line feed' |^^J|.
+% And you can't escape to \LaTeX\ inside such listings!
+%
+% The easiest examples are with |\lstinline| since we need no line feed.
+% \begin{verbatim}
+%\footnote{\lstinline{var i:integer;} and
+%          \lstinline!protected\ \ spaces! and
+%          \fbox{\lstinline!\\\{\}\%!}}\end{verbatim}
+% yields\lstset{language=Pascal}\footnote{\lstinline{var i:integer;} and
+%          \lstinline!protected\ \ spaces! and
+%          \fbox{\lstinline!\\\{\}\%!}}
+% if the current language is Pascal. Note that this example shows another
+% experimental feature: use of argument braces as delimiters. This is
+% described in section \ref{rTypesettingListings}.
+%
+% And now an environment example:
+% \begin{lstsample}{\lstset{language={}}}{}
+%    \fbox{%
+%    \begin{lstlisting}^^J
+%    \ !"#$\%&'()*+,-./^^J
+%    0123456789:;<=>?^^J
+%    @ABCDEFGHIJKLMNO^^J
+%    PQRSTUVWXYZ[\\]^_^^J
+%    `abcdefghijklmno^^J
+%    pqrstuvwxyz\{|\}~^^J
+%    \end{lstlisting}}
+% \end{lstsample}
+% \begin{advise}
+% \item You might wonder that this feature is still experimental. The reason:
+%       You shouldn't use listings inside arguments; it's not always safe.
+% \end{advise}
+%
+%
+% \subsection{\dag\ Export of identifiers}\label{rExportOfIdentifiers}
+%
+% It would be nice to export function or procedure names. In general that's a
+% dream so far. The problem is that programming languages use various syntaxes
+% for function and procedure declaration or definition. A general interface is
+% completely out of the scope of this package---that's the work of a compiler
+% and not of a pretty-printing tool. However, it is possible for particular
+% languages: in Pascal, for instance, each function or procedure definition and
+% variable declaration is preceded by a particular keyword.
+% Note that you must request the following keys with the \texttt{procnames} option:
+% |\usepackage[procnames]{listings}|.
+% \begin{syntax}
+% \item[0.19,{{}},{\dag optional}] \rkeyname{procnamekeys}|=|\marg{keywords}
+% \item[0.21,,\dag optional] \rkeyname{moreprocnamekeys}|=|\marg{keywords}
+% \item[0.21,,\dag optional] \rkeyname{deleteprocnamekeys}|=|\marg{keywords}
+%
+%		each specified keyword indicates a function or procedure definition.
+%		Any identifier following such a keyword appears in `procname' style.
+%		For Pascal you might use\vspace{-.5\baselineskip}
+% \begin{verbatim}
+%    procnamekeys={program,procedure,function}\end{verbatim}
+%
+% \item[0.19,keywordstyle,\dag optional] \rkeyname{procnamestyle}|=|\meta{style}
+%
+%		defines the style in which procedure and function names appear.
+%
+% \item[0.19,false,\dag optional] \rkeyname{indexprocnames}|=|\meta{\alternative{true,false}}
+%
+%		If activated, procedure and function names are also indexed.
+% \end{syntax}
+% \begin{TODO}
+% The \aspectname{procnames} aspect is unsatisfactory (and has been unchanged
+% at least since 2000). It marks and indexes the function definitions so far, but
+% it would be possible to mark also the following function calls, for example.
+% A key could control whether function names are added to a special keyword
+% class, which then appears in `procname' style. But should these names be
+% added globally? There are good reasons for both. Of course, we would also
+% need a key to reset the name list.
+% \end{TODO}
+%
+%
+% \subsection{\dag\ Hyperlink references}\label{rHyperReferences}
+%
+% This very small aspect must be requested via the \texttt{hyper} option since it
+% is experimental. One possibility for the future is to combine this aspect
+% with \aspectname{procnames}. Then it should be possible to click on a
+% function name and jump to its definition, for example.
+% \begin{syntax}
+% \item[0.21,,{\dag optional}] \rkeyname{hyperref}|=|\marg{identifiers}
+% \item[0.21,,{\dag optional}] \rkeyname{morehyperref}|=|\marg{identifiers}
+% \item[0.21,,{\dag optional}] \rkeyname{deletehyperref}|=|\marg{identifiers}
+%
+%       hyperlink the specified identifiers (via \packagename{hyperref}
+%       package). A `click' on such an identifier jumps to the previous
+%       occurrence.
+%
+% \item[0.21,\hyper@@anchor,{\dag optional}] \rkeyname{hyperanchor}|=|\meta{two-parameter macro}
+% \item[0.21,\hyperlink,{\dag optional}] \rkeyname{hyperlink}|=|\meta{two-parameter macro}
+%
+%       set a hyperlink anchor and link, respectively.
+%       The defaults are suited for the \packagename{hyperref} package.
+% \end{syntax}
+%
+%
+% \subsection{Literate programming}
+%
+% We begin with an example and hide the crucial key=value list.
+% \begin{lstsample}{%
+%   \lstset{literate={:=}{{$\gets$}}1 {<=}{{$\leq$}}1 {>=}{{$\geq$}}1 ^^A
+%     {<>}{{$\neq$}}1}}{}
+%    \begin{lstlisting}
+%    var i:integer;
+%
+%    if (i<=0) i := 1;
+%    if (i>=0) i := 0;
+%    if (i<>0) i := 0;
+%    \end{lstlisting}
+% \end{lstsample}
+% Funny, isn't it? We could leave |i := 0| in our listings instead of
+% i| |$\gets$| |0, but that's not literate!  ^^A :-)
+% Now you might want to know how this has been done. Have a \emph{close}
+% look at the following key.
+% \begin{syntax}
+%   \item[0.20,,\dag] \rkeyname{literate}|=|[|*|]\meta{replacement
+%     item}\ldots\meta{replacement item}
+%
+%     First note that there are no commas between the items. Each item
+%     consists of three arguments: \marg{replace}\marg{replacement
+%     text}\marg{length}.  \meta{replace} is the original character
+%     sequence.  Instead of printing these characters, we use
+%     \meta{replacement text}, which takes the width of \meta{length}
+%     characters in the output.
+%
+%     Each `printing unit' in \meta{replacement text} \emph{must} be in
+%     braces unless it's a single character. For example, you must put
+%     braces around |$\leq$|.  If you want to replace |<-1->| by
+%     |$\leftarrow1\rightarrow$|, the replacement item would be
+%     |{<-1->}{{$\leftarrow$}1{$\rightarrow$}}3|.  Note the braces around
+%     the arrows.
+%
+%     If one \meta{replace} is a subsequence of another \meta{replace}, you
+%     must define the shorter sequence first. For example, |{-}| must be
+%     defined before |{--}| and this before |{-->}|.
+%
+%     The optional star indicates that literate replacements should not be
+%     made in strings, comments, and other delimited text.
+% \end{syntax}
+% In the example above, I've used
+% \begin{verbatim}
+%  literate={:=}{{$\gets$}}1 {<=}{{$\leq$}}1 {>=}{{$\geq$}}1 {<>}{{$\neq$}}1\end{verbatim}
+% \begin{TODO}
+% Of course, it's good to have keys for adding and removing single
+% \meta{replacement item}s. Maybe the key(s) should work in the same fashion
+% as the string and comment definitions, i.e.~one item per key=value.
+% This way it would be easier to provide better auto-detection in case of a
+% subsequence.
+% \end{TODO}
+%
+%
+% \subsection{\textsf{LGrind} definitions}\label{rLGrindDefinitions}
+%
+% Yes, it's a nasty idea to steal language definitions from other programs.
+% Nevertheless, it's possible for the \packagename{LGrind} definition
+% file---at least partially. Please note that this file must be found by
+% \TeX.
+% \begin{syntax}
+% \item[0.21,,{optional}] \rkeyname{lgrindef}|=|\meta{language}
+%
+%       scans the \texttt{lgrindef} language definition file for
+%       \meta{language} and activates it if present. Note that not all
+%       \packagename{LGrind} capabilities have a \packagename{listings}
+%       analogue.
+%
+%       Note that `Linda' language doesn't work properly since it defines
+%       compiler directives with preceding `|#|' as keywords.
+%
+% \item[0.21,lgrindef.,{data,optional}] \rcmdname\lstlgrindeffile
+%
+%       contains the (path and) name of the definition file.
+% \end{syntax}
+%
+%
+% \subsection{\dag\ Automatic formatting}
+%
+% \lstloadaspects{formats}^^A
+% The automatic source code formatting is far away from being good. First of
+% all, there are no general rules on how source code should be formatted. So
+% `format definitions' must be flexible. This flexibility requires a complex
+% interface, a powerful `format definition' parser, and lots of code lines
+% behind the scenes. Currently, format definitions aren't flexible enough
+% (possibly not the definitions but the results). A single `format item' has
+% the form
+% \begin{itemize}\item[]
+%     \meta{input chars}|=|\oarg{exceptional chars}\meta{pre}\oarg{^^A
+%       \texttt{\string\string}}\meta{post}
+% \end{itemize}
+% Whenever \meta{input chars} aren't followed by one of the \meta{exceptional
+% chars}, formatting is done according to the rest of the value. If |\string|
+% isn't specified, the input characters aren't printed (except it's an
+% identifier or keyword). Otherwise \meta{pre} is `executed' before printing
+% the original character string and \meta{post} afterwards. These two are
+% `subsets' of
+% \begin{itemize}
+% \item |\newline| ---ensuring a new line;
+% \item |\space| ---ensuring a whitespace;
+% \item |\indent| ---increasing indention;
+% \item |\noindent| ---descreasing indention.
+% \end{itemize}
+% Now we can give an example.\lstaspectindex{\lstdefineformat}{}\lstaspectindex{format}{}
+% \begin{lstxsample}
+%    \lstdefineformat{C}{%
+%        \{=\newline\string\newline\indent,%
+%        \}=\newline\noindent\string\newline,%
+%        ;=[\ ]\string\space}
+% \end{lstxsample}
+% \begin{lstsample}{\lstset{language={}}}{}
+%    \begin{lstlisting}[format=C]
+%    for (int i=0;i<10; i++){/* wait */};
+%    \end{lstlisting}
+% \end{lstsample}
+% Not good. But there is a (too?) simple work-around:
+% \begin{lstxsample}
+%    \lstdefineformat{C}{%
+%        \{=\newline\string\newline\indent,%
+%        \}=[;]\newline\noindent\string\newline,%
+%        \};=\newline\noindent\string\newline,%
+%        ;=[\ ]\string\space}
+% \end{lstxsample}
+% \begin{lstsample}{\lstset{language={}}}{}
+%    \begin{lstlisting}[format=C]
+%    for (int i=0;i<10; i++){/* wait */};
+%    \end{lstlisting}
+% \end{lstsample}
+% Sometimes the problem is just to find a suitable format definition.
+% Further formatting is complicated.
+% Here are only three examples with increasing level of difficulty.
+% \begin{enumerate}
+% \item Insert horizontal space to separate function/procedure name and
+%       following parenthesis or to separate arguments of a function,
+%       e.g.~add the space after a comma (if inside function call).
+% \item Smart breaking of long lines. Consider long `and/or' expressions.
+%       Formatting should follow the logical structure!
+% \item Context sensitive formatting rules. It can be annoying if empty
+%       or small blocks take three or more lines in the output---think of
+%       scrolling down all the time. So it would be nice if the block
+%       formatting was context sensitive.
+% \end{enumerate}
+% Note that this is a very first and clumsy attempt to provide automatic
+% formatting---clumsy since the problem isn't trivial. Any ideas are welcome.
+% Implementations also. Eventually you should know that you must request format
+% definitions at package loading, e.g.~via |\usepackage[formats]{listings}|.
+%
+% \subsection{Arbitrary linerange markers}\label{rArbitraryLinerangeMarkers}
+%
+% Instead of using \keyname{linerange} with line numbers, one can use text
+% markers. Each such marker consists of a \meta{prefix}, a \meta{text}, and a
+% \meta{suffix}. You once (or more) define prefixes and suffixes and then use
+% the marker text instead of the line numbers.
+% \begin{lstxsample}
+%    \lstset{rangeprefix=\{\ ,% curly left brace plus space
+%            rangesuffix=\ \}}% space plus curly right brace
+% \end{lstxsample}
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}%
+%          [linerange=loop\ 2-end]
+%    { loop 1 }
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    { end }
+%    { loop 2 }
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    { end }
+%    \end{lstlisting}
+% \end{lstsample}
+% Note that \TeX's special characters like the curly braces, the space, the
+% percent sign, and such must be escaped with a backslash.
+% \begin{syntax}
+% \item[1.2] \rkeyname{rangebeginprefix}|=|\meta{prefix}
+% \item[1.2] \rkeyname{rangebeginsuffix}|=|\meta{suffix}
+% \item[1.2] \rkeyname{rangeendprefix}|=|\meta{prefix}
+% \item[1.2] \rkeyname{rangeendsuffix}|=|\meta{suffix}
+%
+%       define individual prefixes and suffixes for the begin- and end-marker.
+%
+% \item[1.2] \rkeyname{rangeprefix}|=|\meta{prefix}
+% \item[1.2] \rkeyname{rangesuffix}|=|\meta{suffix}
+%
+%       define identical prefixes and suffixes for the begin- and end-marker.
+%
+% \item[1.2,true] \rkeyname{includerangemarker}|=|\meta{\alternative{true,false}}
+%
+%       shows or hides the markers in the output.
+% \end{syntax}
+% \begin{lstsample}{\lstset{rangeprefix=\{\ ,rangesuffix=\ \}}}{}
+%    \begin{lstlisting}%
+%          [linerange=loop\ 1-end,
+%           includerangemarker=false,
+%           frame=single]
+%    { loop 1 }
+%    for i:=maxint to 0 do
+%    begin
+%        { do nothing }
+%    end;
+%    { end }
+%    \end{lstlisting}
+% \end{lstsample}
+%
+%
+% \subsection{Multicolumn Listings}\label{rMulticolumnListings}
+%
+% When the \packagename{multicol} package is loaded, it can be used to typeset
+% multi-column listings.  These are specified with the |multicols| key.  For
+% example:
+% \begin{lstsample}{}{}
+%    \begin{lstlisting}[multicols=2]
+%    if (i < 0)
+%      i = 0
+%      j = 1
+%    end if
+%    if (j < 0)
+%      j = 0
+%    end if
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% The multicolumn option is known to fail with some keys.
+%
+% \begin{advise}
+% \item Which keys?
+%       \advisespace
+%       Unfortunately, I don't know.  Carsten left the code for this option
+%       in the version 1.3b patch file with only that cryptic note for
+%       documentation.  Bug reports would be welcome, though I don't promise
+%       that they're fixable.  ---Brooks
+% \end{advise}
+%
+%
+%\iffalse
+% \section{Forthcoming ?}
+%
+% This section is rather rudimentary. It just lists some things I don't want
+% to forget.
+%
+% First of all, I'd like to support even more languages, for example Maple,
+% PostScript, and so on. Fortunately my lifetime is limited, so other
+% people may do that work. Please (e-)mail me your language definitions.
+%
+% Then, there are several ideas for the future. Some have already been stated
+% as `to do's; some came from other people and are stated below; some more are
+% far from being implemented,
+%   e.g.~\keyname{linerange}|=|\oarg{inter}\marg{line range list}
+% which prints all lines in the range and executes \meta{inter} when omitting
+% some code lines. The main problem here are frames and background colours;
+% what should happen to them? In fact, the problem is how this can be coded.
+% Another idea is to change the background colour (or the basic style) for
+% particular code blocks. This, too, is not easy.
+%
+%^^A Auto-detect whether surplus space (from spaces and tabs) isn't needed to fix
+%^^A alignment of wide character combinations like |==| or |<>|.
+%^^A
+%^^A Make package compatible to calc package.
+%^^A
+%^^A Rewrite \lst@LAS, \lst@DefDriver, \lst@Require to distinguish loading
+%^^A of languages (which don't need base languages at once) and aspects
+%^^A (which need required aspects to be loaded).
+%
+% \lsthelper{Vincent~Poirriez}{1999/11/18}{code examples inside caml comments}:
+% Inside caml comments, |[| and |]| should print the code in
+% between in basicstyle (or another newly introduced style). Nesting of these
+% `code example delimiters' is allowed, e.g.~|(* [[x;y]] *)|.
+%
+% \lsthelper{Claus~Atzenbeck}{1999/12/03}{`extendedchars=false' doesn't issue
+% warning when extended characters are used}: issue warning in final mode if
+% \ikeyname{extendedchars}|=false| but extended chars are used.
+%
+% \lsthelper{Andreas~Matthias}{2000/01/04}{define header/footer to print
+% the listing name}: Make the header/footer print the listing name. Some
+% people asked for continued captions.
+%\fi
+%
+%
+% \part{Tips and tricks}
+%
+% Note: This part of the documentation is under construction.
+% Section \ref{uHowTos} must be sorted by topic and ordered in some way.
+% Moreover a new section `Examples' is planned, but not written.
+% Lack of time is the main problem \ldots
+%
+%
+% \section{Troubleshooting}\label{uTroubleshooting}
+%
+% If you're faced with a problem with the \packagename{listings} package, there are
+% some steps you should undergo before you make a bug report. First you should
+% consult the reference guide to see whether the problem is already known. If not,
+% create a \emph{minimal} file which reproduces the problem. Follow these
+% instructions:
+% \begin{enumerate}
+% \item Start from the minimal file in section \ref{uAMinimalFile}.
+% \item Add the \LaTeX\ code which causes the problem, but keep it short.
+%       In particular, keep the number of additional packages small.
+% \item Remove some code from the file (and the according packages) until the
+%       problem disappears. Then you've found a crucial piece.
+% \item Add this piece of code again and start over with step 3 until all code
+%       and all packages are substantial.
+% \item You now have a minimal file. Send a bug report to the address on the
+%       first page of this documentation and include the minimal file together
+%       with the created \texttt{.log}-file. If you use a very special package
+%       (i.e.~one not on CTAN), also include the package if its software license
+%       allows it.
+% \end{enumerate}
+%
+%
+% \section{Bugs and workarounds}\label{uBugsWorkarounds}
+%
+% \subsection{Listings inside arguments}\label{uListingsArguments}
+%
+% At the moment it isn't possible to use \verb-\lstinline{...}- in a cell
+% of a table\makeatletter\@ifundefined{r@uProcessingInline}{}{%
+% (see section \ref{uProcessingInline} on page \pageref{uProcessingInline}
+% for more information)},%
+% \makeatother%
+% but it is possible to define a wrapper macro
+% which can be used instead of \verb-\lstinline{...}-:
+% \begin{lstsample}[lstlisting]{}{}
+%    \newcommand\foo{\lstinline{t}}
+%    \newcommand\foobar[2][]{\lstinline[#1]{#2}}
+%
+%    \begin{tabular}{ll}
+%    \foo & a variable\\
+%    \foobar[language=java]{int u;} & a declaration
+%    \end{tabular}
+% \end{lstsample}
+%
+%
+% \subsection{Listings with a background colour and \LaTeX{} escaped
+% formulas}
+% \label{uListingsBackgroundColour}
+%
+% If there is any text escaped to \LaTeX{} with some coloured background
+% and surrounding frames, then there are gaps in the background as well as
+% in the lines making up the frame.
+% \begin{lstsample}[lstlisting]{}{}
+%    \begin{lstlisting}[language=C, mathescape,
+%      backgroundcolor=\color{yellow!10}, frame=tlb]
+%    /* the following code computes $\displaystyle\sum_{i=1}^{n}i$ */
+%    for (i = 1; i <= limit; i++) {
+%      sum += i;
+%    }
+%    \end{lstlisting}
+% \end{lstsample}
+%
+% At the moment there is only one workaround:
+% \begin{itemize}
+%   \item Write your code into an external file \meta{filename}.
+%   \item Input your code by |\lstinputlisting|\meta{filename} into your
+%     document and surround it with a frame generated by |\begin{mdframed}|
+%     \ldots{} |\end{mdframed}|.
+% \end{itemize}
+% \begin{lstsample}[lstlisting]{}{}
+%    \begin{verbatimwrite}{temp.c}
+%    /* the following code computes $\displaystyle\sum_{i=1}^{n}i$ */
+%    for (i = 1; i <= limit; i++) {
+%      sum += i;
+%    }
+%    \end{verbatimwrite}
+%    \begin{mdframed}[backgroundcolor=yellow!10, rightline=false]
+%      \lstinputlisting[language=C,mathescape,frame={}]{./temp.c}
+%    \end{mdframed}
+% \end{lstsample}
+% For more information about the |verbatimwrite| environment have a look at
+% \cite{Fairbairns:moreverb}, the |mdframed| environment is deeply discussed in
+% \cite{DanielSchubert:mdframed}.
+%
+%
+% \section{How tos}\label{uHowTos}
+%
+%
+% \subsubsection*{How to reference line numbers}
+% Perhaps you want to put |\label{|\meta{whatever}|}| into a \LaTeX\ escape which is
+% inside a comment whose delimiters aren't printed?  If you did that, the compiler
+% won't see the \LaTeX\ code since it would be inside a comment, and the
+% \packagename{listings} package wouldn't print anything since the delimiters would
+% be dropped and |\label| doesn't produce any printable output, but you could still
+% reference the line number. Well, your wish is granted.
+%
+% In Pascal, for example, you could make the package recognize the `special'
+% comment delimiters |(*@| and |@*)| as begin-escape and end-escape sequences.
+% Then you can use this special comment for |\label|s and other things.
+% \begin{lstsample}{\lstset{numberstyle=\tiny,stepnumber=2,numbersep=5pt}}{}
+%    \lstset{escapeinside={(*@}{@*)}}
+%
+%    \begin{lstlisting}
+%    for i:=maxint to 0 do
+%    begin
+%        { comment }(*@\label{comment}@*)
+%    end;
+%    \end{lstlisting}
+%    Line \ref{comment} shows a comment.
+% \end{lstsample}
+% \begin{advise}
+% \item Can I use `|(*@|' and `|*)|' instead?
+%       \advisespace
+%       Yes.
+% \item Can I use `|(*|' and `|*)|' instead?
+%       \advisespace
+%       Sure. If you want this.
+% \item Can I use `|{@|' and `|@}|' instead?
+%       \advisespace
+%       No, never! The second delimiter is not allowed. The character `|@|' is
+%       defined to check whether the escape is over. But reading the lonely
+%       `end-argument' brace, \TeX\ encounters the error `\texttt{Argument of @
+%       has an extra \char125}'. Sorry.
+% \item Can I use `|{|' and `|}|' instead?
+%       \advisespace
+%       No. Again the second delimiter is not allowed. Here now \TeX\ would
+%       give you a `\texttt{Runaway argument}' error. Since `|}|' is defined to
+%       check whether the escape is over, it won't work as `end-argument' brace.
+% \item And how can I use a comment line?
+%       \advisespace
+%       For example, write `|escapeinside={//*}{\^^M}|'. Here |\^^M| represents
+%       the end of line character.
+% \end{advise}
+%
+%
+% \subsubsection*{How to gobble characters}
+% To make your \LaTeX\ code more readable, you might want to indent your
+% \texttt{lstlisting} listings. This indention should not show up in the
+% pretty-printed listings, however, so it must be removed. If you indent each code
+% line by three characters, you can remove them via |gobble=3|:
+% \begin{lstsample}{}{\lstset{showspaces}}
+%    \begin{lstlisting}[gobble=3]
+%    1  for i:=maxint to 0 do
+%     2 begin
+%      3    { do nothing }
+%    123end;
+%
+%       Write('Case insensitive ');
+%       WritE('Pascal keywords.');
+%    \end{lstlisting}
+% \end{lstsample}
+% Note that empty lines and the beginning and the end of the environment
+% need not respect the indention. However, never indent the end by more than
+% `\ikeyname{gobble}' characters. Moreover note that tabulators expand to
+% |tabsize| spaces before we gobble.
+% \begin{advise}
+% \item Could I use `\ikeyname{gobble}' together with `|\lstinputlisting|'?
+%       \advisespace
+%       Yes, but it has no effect.
+%
+% \item Note that `\ikeyname{gobble}' can also be set via `|\lstset|'.
+% \end{advise}
+%
+%
+% \subsubsection*{How to include graphics}
+% \lsthelper{Herbert~Weinhandl}{1999/09/06}{listings + eps} found a very easy
+% way to include graphics in listings. Thanks for contributing this idea---an
+% idea I would never have had.
+%
+% Some programming languages allow the dollar sign to be part of an identifier.
+% But except for intermediate function names or library functions, this
+% character is most often unused. The \packagename{listings} package defines
+% the \ikeyname{mathescape} key, which lets `|$|' escape to \TeX's math mode.
+% This makes the dollar character an excellent candidate for our purpose here:
+% use a package which can include a graphic, set \ikeyname{mathescape} true,
+% and include the graphic between two dollar signs, which are inside a comment.
+%
+% The following example is originally from a header file I got from Herbert.
+% For the presentation here I use the \texttt{lstlisting} environment and an
+% excerpt from the header file. The |\includegraphics| command is from
+% David Carlisle's \packagename{graphics} bundle.
+% \begin{verbatim}
+%   \begin{lstlisting}[mathescape=true]
+%   /*
+%    $ \includegraphics[height=1cm]{defs-p1.eps} $
+%    */
+%   typedef struct {
+%     Atom_T          *V_ptr;   /* pointer to Vacancy in grid    */
+%     Atom_T          *x_ptr;   /* pointer to (A|B) Atom in grid */
+%   } ABV_Pair_T;
+%   \end{lstlisting}\end{verbatim}
+% The result looks pretty good. Unfortunately you can't see it, because the
+% graphic wasn't available when the manual was typeset.
+%
+%
+% \subsubsection*{How to get closed frames on each page}
+% The package supports closed frames only for listings which don't cross pages.
+% If a listing is split on two pages, there is neither a bottom rule at the
+% bottom of a page, nor a top rule on the following page. If you insist on
+% these rules, you might want to use \texttt{framed.sty} by Donald Arseneau.
+% Then you could write
+% \begin{verbatim}
+%    \begin{framed}
+%    \begin{lstlisting}
+%      or \lstinputlisting{...}
+%    \end{lstlisting}
+%    \end{framed}\end{verbatim}
+% The package also provides a \texttt{shaded} environment. If you use it, you
+% shouldn't forget to define \texttt{shadecolor} with the \packagename{color}
+% package.
+%
+%
+% \subsubsection*{How to print national characters with $\Lambda$ and
+%   \packagename{listings}}\label{uNationalCharacters}
+%
+% Apart from typing in national characters directly, you can use the `escape'
+% feature described in section \ref{rEscapingToLaTeX}.
+% The keys \ikeyname{escapechar}, \ikeyname{escapeinside}, and \ikeyname{texcl}
+% allow partial usage of \LaTeX\ code.
+%
+% Now, if you use $\Lambda$ (Lambda, the \LaTeX\ variant for Omega) and want,
+% for example, Arabic comment lines, you need not write |\begin{arab}|
+% \ldots\ |\end{arab}| each escaped comment line. This can be automated:
+% \begin{verbatim}
+%    \lstset{escapebegin=\begin{arab},escapeend=\end{arab}}
+%
+%    \begin{lstlisting}[texcl]
+%    // Replace text by Arabic comment.
+%    for (int i=0; i<1; i++) { };
+%    \end{lstlisting}\end{verbatim}
+% If your programming language doesn't have comment lines, you'll have to use
+% \ikeyname{escapechar} or \ikeyname{escapeinside}:
+% \begin{verbatim}
+%    \lstset{escapebegin=\begin{greek},escapeend=\end{greek}}
+%
+%    \begin{lstlisting}[escapeinside=`']
+%    /* `Replace text by Greek comment.' */
+%    for (int i=0; i<1; i++) { };
+%    \end{lstlisting}\end{verbatim}
+% Note that the delimiters |`| and |'| are essential here. The example doesn't
+% work without them. There is a more clever way if the comment delimiters of
+% the programming language are single characters, like the braces in Pascal:
+% \begin{verbatim}
+%    \lstset{escapebegin=\textbraceleft\begin{arab},
+%            escapeend=\end{arab}\textbraceright}
+%
+%    \begin{lstlisting}[escapeinside=\{\}]
+%    for i:=maxint to 0 do
+%    begin
+%        { Replace text by Arabic comment. }
+%    end;
+%    \end{lstlisting}\end{verbatim}
+% Please note that the `interface' to $\Lambda$ is completely untested.
+% Reports are welcome!
+%
+%
+% \subsubsection*{How to get bold typewriter type keywords}
+% Use the \href{http://mirror.ctan.org/fonts/luximono}{\packagename{LuxiMono}} package.
+%
+% \iffalse
+% Many people asked for bold typewriter fonts since they aren't included in
+% the \LaTeX\ standard distribution. Here now one answer on how to use them
+% in spite of that.
+% \begin{advise}
+% \item Please note that I personally don't regard the following as a good
+%       solution. Such a bold typewriter type is too heavy. It would be better
+%       to use a light version of \texttt{cmtt} as basic font and \texttt{cmtt}
+%       or a \emph{slightly} heavier type for keywords.
+%
+% \item Why don't you tell us how to use the better solution?
+%       \advisespace
+%       A light version of \texttt{cmtt} doesn't exist. If it's once available,
+%       you can do a similar job as described below.
+% \end{advise}
+% First of all, you'll need Metafont source files for bold typewriter, e.g.~
+% \texttt{cmbtt8.mf}, \texttt{cmbtt9.mf} and \texttt{cmbtt10.mf} from
+% \href{ftp://ftp.dante.de/tex-archive/fonts/cm/mf-extra/bold}
+%      {CTAN/fonts/cm/mf-extra/bold}.
+% Secondly you have to create \texttt{.tfm}-files, i.e.~run the Metafont
+% program on these sources. This is possibly done automatically when you use
+% the fonts in a document. Finally you must tell \LaTeX\ that you've installed
+% bold typewriter fonts. Just use
+% \begin{verbatim}
+%    \DeclareFontShape{OT1}{cmtt}{bx}{n}
+%         {<5><6><7><8>cmbtt8%
+%          <9>cmbtt9%
+%          <10><10.95>cmbtt10%
+%          <12><14.4><17.28><20.74><24.88>cmbtt10%
+%          }{}\end{verbatim}
+% in the preamble of your document. If you use these fonts often, you might
+% want to make a local copy of \texttt{ot1cmtt.fd} and replace the declaration
+% there. But note that you're not allowed to distributed the modified file
+% under its original name!
+% \fi
+%
+%
+% \subsubsection*{How to work with plain text}
+% If you want to use \packagename{listings} to set plain text (perhaps with
+% line numbers, or like |verbatim| but with line wrapping, or so forth, use
+% the empty language: |\lstset{language=}|.
+%
+%
+% \subsubsection*{How to get the developer's guide}
+% In the \emph{source directory} of the listings package, i.e.~where
+% the \texttt{.dtx} files are, create the file \texttt{ltxdoc.cfg} with the
+% following contents.
+% \begin{verbatim}
+%    \AtBeginDocument{\AlsoImplementation}\end{verbatim}
+% Then run \texttt{listings.dtx} through \LaTeX\ twice, run Makeindex (with
+% the |-s gind.ist| option), and then run \LaTeX\ one last time on
+% \texttt{listings.dtx}. This creates the whole documentation including User's
+% guide, Reference guide, Developer's guide, and Implementation.
+%
+% If you can run the (GNU) make program, executing the command
+% \begin{verbatim}
+%    make all\end{verbatim}
+% or
+% \begin{verbatim}
+%    make listings-devel.pdf\end{verbatim}
+% or
+% \begin{verbatim}
+%    make pdf-devel\end{verbatim}
+% gives the same result---it is called \texttt{listings-devel.pdf}.
+%
+% \makeatletter
+%^^A \def\index@prologue{\section*{Index}\markboth{Index}{Index}}
+% \def\index@prologue{\part{Index}\markboth{Index}{Index}}
+% \makeatother
+%^^A \StopEventually{\lstcheckreference\setcounter{IndexColumns}{2}\PrintIndex}
+% \StopEventually{%
+% \begin{thebibliography}{MDB01}
+%
+%     \bibitem[Fai11]{Fairbairns:moreverb}
+%       Robin Fairbairns.
+%       \newblock{The \textsf{moreverb} package}, 2011.
+%
+%     \bibitem[DS13]{DanielSchubert:mdframed}
+%       Marco Daniel and Elke Schubert.
+%       \newblock{The \textsf{mdframed} package}, 2013.
+% \end{thebibliography}
+% \setcounter{IndexColumns}{2}\PrintIndex}
+%
+%
+% \part{Developer's guide}
+%
+% First I must apologize for this developer's guide since some parts are not
+% explained as well as possible. But note that you are in a pretty good shape:
+% this developer's guide exists! ^^A :-)
+% You might want to peek into section \ref{dPackageExtensions} before reading
+% section \ref{dBasicConcepts}.
+%
+%
+% \section{Basic concepts}\label{dBasicConcepts}
+%
+% The functionality of the \packagename{listings} package appears to be
+% divided into two parts: on the one hand commands which actually typeset
+% listings and on the other via |\lstset| adjustable parameters. Both could
+% be implemented in terms of \lst-aspects, which are simply collections of
+% public keys and commands and internal hooks and definitions. The package
+% defines a couple of aspects, in particular the kernel, the main engine.
+% Other aspects drive this engine, and language and style definitions tell
+% the aspects how to drive. The relations between car, driver and assistant
+% driver are exactly reproduced---and I'll be your driving instructor.
+%
+%
+% \subsection{Package loading}\label{dPackageLoading}
+%
+% Each option in |\usepackage[|\meta{options}|]{listings}| loads an aspect or
+% \emph{prevents} the package from loading it if the aspect name is
+% \emph{preceded by an exclamation mark}. This mechanism was designed to clear
+% up the dependencies of different package parts and to debug the package. For
+% this reason there is another option:
+% \begin{syntax}
+% \item[0.21,,option] \texttt{noaspects}\leavevmode
+%
+%       deletes the list of aspects to load. Note that, for example, the
+%       option lists |0.21,!labels,noaspects| and |noaspects| are essentially
+%       the same: the kernel is loaded and no other aspect.
+% \end{syntax}
+% This is especially useful for aspect-testing since we can load exactly the
+% required parts. Note, however, that an aspect is loaded later if a predefined
+% programming language requests it. One can load aspects also by hand:
+% \begin{syntax}
+% \item[0.20] |\lstloadaspects|\marg{comma separated list of aspect names}
+%
+%       loads the specified aspects if they are not already loaded.
+% \end{syntax}
+% Here now is a list of all aspects and related keys and commands---in the hope
+% that this list is complete.
+% \begin{description}
+% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth\relax
+% \item[\aspectname{strings}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{strings}
+%
+% \item[\aspectname{comments}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{comments}
+%
+% \item[\aspectname{pod}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{pod}
+%
+% \item[\aspectname{escape}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{escape}
+%
+% \item[\aspectname{writefile}] requires 1 |\toks|, 1 |\write|
+%
+%       |\lst@BeginWriteFile|, |\lst@BeginAlsoWriteFile|, |\lst@EndWriteFile|
+%
+% \item[\aspectname{style}]\leavevmode
+%
+%       empty style, \lstprintaspectkeysandcmds{style}
+%
+% \item[\aspectname{language}]\leavevmode
+%
+%       empty language, \lstprintaspectkeysandcmds{language}
+%
+% \item[\aspectname{keywords}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{keywords}
+%
+% \item[\aspectname{emph}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{emph}
+%
+% \item[\aspectname{html}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{html}
+%
+% \item[\aspectname{tex}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{tex}
+%
+% \item[\aspectname{directives}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{directives}
+%
+% \item[\aspectname{index}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{index}
+%
+% \item[\aspectname{procnames}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{procnames}
+%
+% \item[\aspectname{keywordcomments}]
+%       requires \aspectname{keywords}, \aspectname{comments}
+%
+%       \lstprintaspectkeysandcmds{keywordcomments}
+%
+% \item[\aspectname{labels}] requires 2 |\count|
+%
+%       \lstprintaspectkeysandcmds{labels}
+%
+% \item[\aspectname{lineshape}] requires 2 |\dimen|
+%
+%       \lstprintaspectkeysandcmds{lineshape}
+%
+% \item[\aspectname{frames}] requires \aspectname{lineshape}
+%
+%       \lstprintaspectkeysandcmds{frames}
+%
+% \item[\aspectname{make}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{make}
+%
+% \item[\aspectname{doc}] requires \aspectname{writefile} and 1 |\box|
+%
+%       \lstprintaspectkeysandcmds{doc}
+%
+% \item[\aspectname{0.21}] defines old keys in terms of the new ones.
+% \item[\aspectname{fancyvrb}] requires 1 |\box|
+%
+%       \lstprintaspectkeysandcmds{fancyvrb}
+%
+% \item[\aspectname{lgrind}]\leavevmode
+%
+%       \lstprintaspectkeysandcmds{lgrind}
+%
+% \item[\aspectname{hyper}] requires \aspectname{keywords}
+%
+%       \lstprintaspectkeysandcmds{hyper}
+% \end{description}
+% The kernel allocates 6 |\count|, 4 |\dimen| and 1 |\toks|.
+% Moreover it defines the following keys, commands, and environments:
+% \begin{itemize}\item[]
+% \hyphenpenalty=10000\relax \rightskip=0pt plus \linewidth\relax
+%       \lstprintaspectkeysandcmds{kernel}, \keyname{fancyvrb}
+% \end{itemize}
+%
+%
+% \subsection{How to define \lst-aspects}\label{dHowToDefineLstAspects}
+%
+% There are at least three ways to add new functionality: (a) you write an
+% aspect of general interest, send it to me, and I'll just paste it into the
+% implementation; (b) you write a `local' aspect not of general interest; or
+% (c) you have an idea for an aspect and make me writing it. (a) and (b) are
+% good choices.^^A :-)
+%
+% An aspect definition starts with |\lst@BeginAspect| plus arguments and ends
+% with the next |\lst@EndAspect|. In particular, aspect definitions can't be
+% nested.
+% \begin{syntax}
+% \item[0.20] |\lst@BeginAspect|[\oarg{list of required aspects}]\marg{aspect name}
+% \item[0.20] |\lst@EndAspect|
+% \end{syntax}
+% The optional list is a comma separated list of required aspect names.
+% The complete aspect is not defined in each of the following cases:
+% \begin{enumerate}
+% \item \meta{aspect name} is empty.
+% \item The aspect is already defined.
+% \item A required aspect is neither defined nor loadable via
+%       |\lstloadaspects|.
+% \end{enumerate}
+% Consequently you can't define a part of an aspect and later on another part.
+% But it is possible to define aspect $A_1$ and later aspect $A_2$ which
+% requires $A_1$.
+% \begin{advise}
+% \item Put local add-ons into `\texttt{lstmisc0.sty}'---this file is searched
+%       first by default. If you want to make add-ons for one particular
+%       document just replace the surrounding `|\lst@BeginAspect|' and
+%       `|\lst@EndAspect|' by `|\makeatletter|' and `|\makeatother|' and use
+%       the definitions in the preamble of your document. However, you have to
+%       load required aspects on your own.
+% \end{advise}
+% You can put any \TeX\ material in between the two commands, but note that
+% definitions must be |\global| if you need them later---\LaTeX's |\newcommand|
+% makes local definitions and can't be preceded by |\global|. So use the
+% following commands, |\gdef|, and commands described in later sections.
+% \begin{syntax}
+% \item[0.20] |\lst@UserCommand|\meta{macro}\meta{parameter text}\marg{replacement text}
+%
+%       The macro is (mainly) equivalent to |\gdef|. The purpose is to
+%       distinguish user commands and internal global definitions.
+%
+% \item[0.19] |\lst@Key|\marg{key name}\marg{init value}[\oarg{default value}]\marg{definition}
+% \item[0.19] |\lst@Key|\marg{key name}|\relax|[\oarg{default value}]\marg{definition}
+%
+%       defines a key using the \packagename{keyval} package from David
+%       Carlisle. \meta{definition} is the replacement text of a macro with
+%       one parameter. The argument is either the value from `key=value' or
+%       \meta{default value} if no `=value' is given. The helper macros
+%       |\lstKV@...| below might simplify \meta{definition}.
+%
+%       The key is not initialized if the second argument is |\relax|.
+%       Otherwise \meta{init value} is the initial value given to the key.
+%       Note that we locally switch to |\globalsdefs=1| to ensure that
+%       initialization is not effected by grouping.
+%
+% \item[0.19] |\lst@AddToHook|\marg{name of hook}\marg{\TeX\ material}
+%
+%       adds \TeX\ material at predefined points. Section \ref{dHooks} lists
+%       all hooks and where they are defined respectively executed.
+%       |\lst@AddToHook{A}{\csa}| before |\lst@AddToHook{A}{\csb}|
+%       \emph{does not} guarantee that |\csa| is executed before |\csb|.
+%
+% \item[0.20] |\lst@AddToHookExe|\marg{name of hook}\marg{\TeX\ material}
+%
+%       also executes \meta{\TeX\ material} for initialization. You might use
+%       local variables---local in the sense of \TeX\ and/or usual programming
+%       languages---but when the code is executed for initialization all
+%       assignments are global: we set |\globaldefs| locally to one.
+%
+% \item[0.20] |\lst@UseHook|\marg{name of hook}
+%
+%       executes the hook.
+% \end{syntax}
+% \begin{advise}
+% \item Let's look at two examples. The first extends the package by adding
+%       some hook-material. If you want status messages, you might write
+% \begin{verbatim}
+%    \lst@AddToHook{Init}{\message{\MessageBreak Processing listing ...}}
+%    \lst@AddToHook{DeInit}{\message{complete.\MessageBreak}}\end{verbatim}
+%       The second example introduces two keys to let the user control the
+%       messages. The macro |\lst@AddTo| is described in section
+%       \ref{dGeneralPurposeMacros}.
+% \begin{verbatim}
+%   \lst@BeginAspect{message}
+%   \lst@Key{message}{Annoying message.}{\gdef\lst@message{#1}}
+%   \lst@Key{moremessage}\relax{\lst@AddTo\lst@message{\MessageBreak#1}}
+%   \lst@AddToHook{Init}{\typeout{\MessageBreak\lst@message}}
+%   \lst@EndAspect\end{verbatim}
+%       However, there are certainly aspects which are more useful.
+% \end{advise}
+% The following macros can be used in the \meta{definition} argument of the
+% |\lst@Key| command to evaluate the argument. The additional prefix |KV|
+% refers to the \packagename{keyval} package.
+% \begin{syntax}
+% \item[0.19] |\lstKV@SetIf|\marg{value}\meta{if macro}
+%
+%       \meta{if macro} becomes |\iftrue| if the first character of
+%       \meta{value} equals |t| or |T|. Otherwise it becomes |\iffalse|.
+%       Usually you will use |#1| as \meta{value}.
+%
+% \item[1.0] \cs{lstKV@SwitchCases}\marg{value}\\
+%   |{|\meta{string 1}|&|\meta{execute 1}|\\|\\
+%   | |\meta{string 2}|&|\meta{execute 2}|\\|\\
+%   \hbox to 3em{\hfill\vdots}\\
+%   | |\meta{string $n$}|&|\meta{execute $n$}|}|\marg{else}
+%
+%       Either execute \meta{else} or the \meta{value} matching part.
+%
+%       This implementation of C. Heinz has a problem\label{gAmpersand}, if
+%       the listing is part of a tabular environment as found out by
+%       \lsthelper{Nasser~M.~Abbasi}{2016/05/25}{possible bug in listings
+%       package}. \lsthelper{David~Carlisle}{2016/05/25}{%
+%       http://tex.stackexchange.com/questions/311383/^^A
+%         adding-frame-none-to-lstlisting-options-in-lstdefinestyle^^A
+%         -gives-error-with-tabu}
+%       gave a hint how to avoid this problem and so the separator |&| is
+%       replaced by |:|.
+%
+% \item[0.20] |\lstKV@TwoArg|\marg{value}\marg{subdefinition}
+% \item[0.20] |\lstKV@ThreeArg|\marg{value}\marg{subdefinition}
+% \item[0.20] |\lstKV@FourArg|\marg{value}\marg{subdefinition}
+%
+%       \meta{subdefinition} is the replacement text of a macro with two,
+%       three, and four parameters. We call this macro with the arguments given
+%       by \meta{value}. Empty arguments are added if necessary.
+%
+% \item[0.19] |\lstKV@OptArg|\oarg{default arg.}\marg{value}\marg{subdefinition}
+%
+%       |[|\meta{default arg.}|]| is \emph{not} optional. \meta{subdefinition}
+%       is the replacement text of a macro with parameter text |[##1]##2|.
+%       Note that the macro parameter character |#| is doubled since used
+%       within another macro. \meta{subdefinition} accesses these arguments
+%       via |##1| and |##2|.
+%
+%       \meta{value} is usually the argument |#1| passed by the
+%       \packagename{keyval} package. If \meta{value} has no optional argument,
+%       \meta{default arg.} is inserted to provide the arguments to
+%       \meta{subdefinition}.
+%
+% \item[0.21] |\lstKV@XOptArg|\oarg{default arg.}\marg{value}\meta{submacro}
+%
+%       Same as |\lstKV@OptArg| but the third argument \meta{submacro} is
+%       already a definition and not replacement text.
+%
+% \item[0.20] |\lstKV@CSTwoArg|\marg{value}\marg{subdefinition}
+%
+%       \meta{value} is a \texttt comma \texttt separated list of one or two
+%       arguments. These are given to the subdefinition which is the
+%       replacement text of a macro with two parameters. An empty second
+%       argument is added if necessary.
+% \end{syntax}
+% \begin{advise}
+% \item One more example. The key `\keyname{sensitive}' belongs to the aspect
+%       \aspectname{keywords}. Therefore it is defined in between
+%       `|\lst@BeginAspect{keywords}|' and `|\lst@EndAspect|', which is not shown
+%       here.
+% \begin{verbatim}
+%   \lst@Key{sensitive}\relax[t]{\lstKV@SetIf{#1}\lst@ifsensitive}
+%   \lst@AddToHookExe{SetLanguage}{\let\lst@ifsensitive\iftrue}\end{verbatim}
+%       The last line is equivalent to
+% \begin{verbatim}
+%   \lst@AddToHook{SetLanguage}{\let\lst@ifsensitive\iftrue}
+%   \global\let\lst@ifsensitive\iftrue\end{verbatim}
+%       We initialize the variable globally since the user might request an
+%       aspect in a group. Afterwards the variable is used locally---there is
+%       no |\global| in \meta{\TeX\ material}. Note that we could define and
+%       init the key as follows:
+% \begin{verbatim}
+%   \lst@Key{sensitive}t[t]{\lstKV@SetIf{#1}\lst@ifsensitive}
+%   \lst@AddToHook{SetLanguage}{\let\lst@ifsensitive\iftrue}\end{verbatim}
+%\end{advise}
+%
+%
+% \subsection{Internal modes}\label{dInternalModes}
+%
+% You probably know \TeX's conditional commands |\ifhmode|, |\ifvmode|,
+% |\ifmmode|, and |\ifinner|. They tell you whether \TeX\ is in (restricted)
+% horizontal or (internal) vertical or in (nondisplay) mathematical mode. For
+% example, true |\ifhmode| and true |\ifinner| indicate restricted horizontal
+% mode, which means that you are in a |\hbox|. The typical user doesn't care
+% about such modes; \TeX/\LaTeX\ manages all this. But since you're reading the
+% developer's guide, we discuss the analogue for the \packagename{listings}
+% package now. It uses modes to distinguish comments from strings, `comment
+% lines' from `single comments', and so on.
+%
+% The package is in `no mode' before reading the source code. In the phase of
+% initialization it goes to `processing mode'. Afterwards the mode depends on
+% the actual source code. For example, consider the line
+% \begin{verbatim}
+%    "string" // comment\end{verbatim}
+% and assume \texttt{language=C++}. Reading the string delimiter, the package
+% enters `string mode' and processes the string. The matching closing delimiter
+% leaves the mode, i.e.\ switches back to the general `processing mode'. Coming
+% to the two slashes, the package detects a comment line; it therefore enters
+% `comment line mode' and outputs the slashes. Usually this mode lasts to the
+% end of line.
+%
+% But with \texttt{textcl=true} the \aspectname{escape} aspect immediately
+% leaves `comment line mode', interrupts the current mode sequence, and enters
+% `\TeX\ comment line mode'. At the end of line we reenter the previous mode
+% sequence `no mode' $\to$ 'processing mode'. This escape to \LaTeX\ works
+% since `no mode' implies that \TeX's characters and catcodes are present,
+% whereas `processing mode' means that \packagename{listings}' characters and
+% catcodes are active.
+%
+% \begin{table}[htbp]
+% \caption{Internal modes}\label{dDefinedInternalModes}
+% \def\lsttabspace{\hspace*{1em}\hfill}
+% \begin{tabular}{@{}lp{0.56\linewidth}@{}}
+% aspect\lsttabspace\meta{mode name} & Usage/We are processing \ldots\\
+% \noalign{\smallskip}
+% kernel\lsttabspace |\lst@nomode| &
+%       If this mode is active, \TeX's `character table' is present; the other
+%       implication is not true. Any other mode \emph{may} imply that catcodes
+%       and\nobreak/\allowbreak or definitions of characters are changed.
+% \\
+%       \lsttabspace |\lst@Pmode| &
+%       is a general processing mode. If active we are processing a listing,
+%       but haven't entered a more special mode.
+% \\
+%       \lsttabspace |\lst@GPmode| &
+%       general purpose mode for language definitions.
+% \\
+% \aspectname{pod}\lsttabspace |\lst@PODmode| &
+%       \ldots~a POD---Perl specific.
+% \\
+% \aspectname{escape}\lsttabspace |\lst@TeXLmode| &
+%       \ldots~a comment line, but \TeX's character table is present---except
+%       the EOL character, which is needed to terminate this mode.
+% \\
+%       \lsttabspace |\lst@TeXmode| &
+%       indicates that \TeX's character table is present (except one user
+%       specified character, which is needed to terminate this mode).
+% \\
+% \aspectname{directives}\lsttabspace |\lst@CDmode| &
+%       indicates that the current line began with a compiler directive.
+% \\
+% \aspectname{keywordcomments}\lsttabspace |\lst@KCmode| &
+%       \ldots~a keyword comment.
+% \\
+%       \lsttabspace |\lst@KCSmode| &
+%       \ldots~a keyword comment which can be terminated by a semicolon only.
+% \\
+% \aspectname{html}\lsttabspace |\lst@insidemode| &
+%       Active if we are between \texttt{<} and \texttt{>}.
+% \\
+% \aspectname{make}\lsttabspace |\lst@makemode| &
+%       Used to indicate a keyword.
+% \end{tabular}
+% \end{table}
+% Table \ref{dDefinedInternalModes} lists all static modes and which aspects
+% they belong to. Most features use dynamically created mode numbers, for
+% example all strings and comments. Each aspect may define its own mode(s)
+% simply by allocating it/\allowbreak them inside the aspect definition.
+% \begin{syntax}
+% \item[0.19] |\lst@NewMode|\meta{mode \textup(control sequence\textup)}
+%
+%       defines a new static mode, which is a nonnegative integer assigned to
+%       \meta{mode}. \meta{mode} should have the prefix \texttt{lst@} and
+%       suffix \texttt{mode}.
+%
+% \item[0.21] |\lst@UseDynamicMode|\marg{token\textup(s\textup)}
+%
+%       inserts a dynamic mode number as argument to the token(s).
+%
+%       This macro cannot be used to get a mode number when an aspect is
+%       loaded or defined. It can only be used every listing in the process
+%       of initialization, e.g.~to define comments when the character table
+%       is selected.
+%
+% \item[0.19,,changed] |\lst@EnterMode|\meta{mode}\marg{start tokens}
+%
+%       opens a group level, enters the mode, and executes \meta{start tokens}.
+%
+%       Use |\lst@modetrue| in \meta{start tokens} to prohibit future mode
+%       changes---except leaving the mode, of course. You must test yourself
+%       whether you're allowed to enter, see below.
+%
+% \item[0.19] |\lst@LeaveMode|
+%
+%       returns to the previous mode by closing a group level if and only if
+%       the current mode isn't |\lst@nomode| already. You must test yourself
+%       whether you're allowed to leave a mode, see below.
+%
+%\iffalse
+% \item[0.19] |\lst@LeaveAllModes|
+%
+%       returns to |\lst@nomode|.
+%       This is some kind of emergency macro, so don't use it!
+%\fi
+%
+% \item[0.19] |\lst@InterruptModes|
+% \item[0.19] |\lst@ReenterModes|
+%
+%       The first command returns to |\lst@nomode|, but saves the current mode
+%       sequence on a special stack. Afterwards the second macro returns to the
+%       previous mode. In between these commands you may enter any mode you
+%       want. In particular you can interrupt modes, enter some modes, and say
+%       `interrupt modes' again. Then two re-enters will take you back in front
+%       of the first `interrupt modes'.
+%
+%       Remember that |\lst@nomode| implies that \TeX's character table is
+%       active.
+% \end{syntax}
+% Some variables show the internal state of processing. You are allowed to read
+% them, but \emph{direct write access is prohibited}. Note: |\lst@ifmode| is
+% \emph{not} obsolete since there is no relation between the boolean and the
+% current mode. It will happen that we enter a mode without setting
+% |\lst@ifmode| true, and we'll set it true without assigning any mode!
+% \begin{syntax}
+% \item[0.18,,counter] |\lst@mode|
+%
+%       keeps the current mode number. Use |\ifnum\lst@mode=|\meta{mode name}
+%       to test against a mode. Don't modify the counter directly!
+%
+% \item[0.18,,boolean] |\lst@ifmode|
+%
+%       No mode change is allowed if this boolean is true---except leaving the
+%       current mode. Use |\lst@modetrue| to modify this variable, but do it
+%       only in \meta{start tokens}.
+%
+% \item[1.0,,boolean] |\lst@ifLmode|
+%
+%       Indicates whether the current mode ends at end of line.
+% \end{syntax}
+%
+%
+% \subsection{Hooks}\label{dHooks}
+%
+% Several problems arise if you want to define an aspect.
+% You should and/or must
+%   (a) find additional functionality (of general interest) and implement it,
+%   (b) create the user interface, and
+%   (c) interface with the \packagename{listings} package, i.e.~find correct
+%       hooks and insert appropriate \TeX\ material.
+% (a) is out of the scope of this developer's guide. The commands |\lstKV@...|
+% in section \ref{dHowToDefineLstAspects} might help you with (b). Here now we
+% describe all hooks of the \packagename{listings} package.
+%
+% All hooks are executed inside an overall group. This group starts somewhere
+% near the beginning and ends somewhere at the end of each listing. Don't make
+% any other assumptions on grouping. So define variables globally if it's
+% necessary---and be alert of side effects if you don't use your own groups.
+% \begin{syntax}
+% \item \hookname{AfterBeginComment}
+%
+%       is executed after the package has entered comment mode.
+%       The starting delimiter is usually typeset when the hook is called.
+%
+% \item \hookname{BoxUnsafe}
+%
+%       Contains all material to deactivate all commands and registers which
+%       are possibly unsafe inside |\hbox|. It is used whenever the package
+%       makes a box around a listing and for \packagename{fancyvrb} support.
+%
+% \item \hookname{DeInit}
+%
+%       Called at the very end of a listing but before closing the box from
+%       \hookname{BoxUnsafe} or ending a float.
+%
+% \item \hookname{DetectKeywords}
+%
+%       This \hookname{Output} subhook is executed if and only if mode changes
+%       are allowed, i.e.~if and only if the package doesn't process a comment,
+%       string, and so on---see section \ref{dInternalModes}.
+%
+% \item \hookname{DisplayStyle}
+%
+%       deactivates/activates features for displaystyle listings.
+%
+% \item \hookname{EmptyStyle}
+%
+%       Executed to select the `empty' style---except the user has redefined
+%       the style.
+%
+% \item \hookname{EndGroup}
+%
+%       Executed whenever the package closes a group, e.g.~at end of comment or
+%       string.
+%
+% \item \hookname{EOL}
+%
+%       Called at each end of \emph{input} line, right before
+%       \hookname{InitVarsEOL}.
+%
+% \item \hookname{EveryLine}
+%
+%       Executed at the beginning of each \emph{output} line, i.e.~more than
+%       once for broken lines. This hook must not change the horizontal or
+%       vertical position.
+%
+% \item \hookname{EveryPar}
+%
+%       Executed once for each input line when the output starts. This hook
+%       must not change the horizontal or vertical position.
+%
+%^^A \item \hookname{ExcludeDelims}
+%^^A
+%^^A       Executed by the \keyname{excludedelims} key before the excluded
+%^^A       delimiters are determined.
+%^^A
+% \item \hookname{ExitVars}
+%
+%       Executed right before \hookname{DeInit}.
+%
+% \item \hookname{FontAdjust}
+%
+%       adjusts font specific internal values (currently |\lst@width| only).
+%
+% \item \hookname{Init}
+%
+%       Executed once each listing to initialize things before the character
+%       table is changed. It is called after \hookname{PreInit} and before
+%       \hookname{InitVars}.
+%
+% \item \hookname{InitVars}
+%
+%       Called to init variables each listing.
+%
+% \item \hookname{InitVarsBOL}
+%
+%       initializes variables at the beginning of each input line.
+%
+% \item \hookname{InitVarsEOL}
+%
+%       updates variables at the end of each input line.
+%
+% \item \hookname{ModeTrue}
+%
+%       executed by the package when mode changes become illegal.
+%       Here keyword detection is switched off for comments and strings.
+%
+% \item \hookname{OnEmptyLine}
+%
+%       executed \emph{before} the package outputs an empty line.
+%
+% \item \hookname{OnNewLine}
+%
+%       executed \emph{before} the package starts one or more new lines,
+%       i.e.~before saying |\par\noindent\hbox{}| (roughly speaking).
+%
+% \item \hookname{Output}
+%
+%       Called before an identifier is printed.
+%       If you want a special printing style, modify |\lst@thestyle|.
+%
+% \item \hookname{OutputBox}
+%
+%       used inside each output box. Currently it is only used to make the
+%       package work together with Lambda---hopefully.
+%
+% \item \hookname{OutputOther}
+%
+%       Called before other character strings are printed.
+%       If you want a special printing style, modify |\lst@thestyle|.
+%
+% \item \hookname{PostOutput}
+%
+%       Called after printing an identifier or any other output unit.
+%
+% \item \hookname{PostTrackKeywords}
+%
+%       is a very special \hookname{Init} subhook to insert keyword tests and
+%       define keywords on demand.
+%       This hook is called after \hookname{TrackKeywords}.
+%
+% \item \hookname{PreInit}
+%
+%       Called right before \hookname{Init} hook.
+%
+% \item \hookname{PreSet}
+%
+%       Each typesetting command/environment calls this hook to initialize
+%       internals before any user supplied key is set.
+%
+% \item \hookname{SelectCharTable}
+%
+%       is executed after the package has selected the standard character
+%       table. Aspects adjust the character table here and define string and
+%       comment delimiters, and such.
+%
+% \item \hookname{SetFormat}
+%
+%       Called before internal assignments for setting a format are made.
+%       This hook determines which parameters are reset every format selection.
+%
+% \item \hookname{SetStyle}
+%
+%       Called before internal assignments for setting a style are made.
+%       This hook determines which parameters are reset every style selection.
+%
+% \item \hookname{SetLanguage}
+%
+%       Called before internal assignments for setting a language are made.
+%       This hook determines which parameters are reset every language
+%       selection.
+%
+% \item \hookname{TextStyle}
+%
+%       deactivates/activates features for textstyle listings.
+%
+% \item \hookname{TrackKeywords}
+%
+%       is a very special \hookname{Init} subhook to insert keyword tests and
+%       define keywords on demand.
+%       This hook is called before \hookname{PostTrackKeywords}.
+% \end{syntax}
+%
+%
+% \subsection{Character tables}\label{dCharacterTables}
+%
+% Now you know how a car looks like, and you can get a driving license if you
+% take some practice. But you will have difficulties if you want to make heavy
+% alterations to the car. So let's take a closer look and come to the most
+% difficult part: the engine. We'll have a look at the big picture and fill in
+% the details step by step. For our purpose it's good to override \TeX's
+% character table. First we define a standard character table which contains
+% \begin{itemize}
+% \item letters: characters identifiers are out of,
+% \item digits: characters for identifiers or numerical constants,
+% \item spaces: characters treated as blank spaces,
+% \item tabulators: characters treated as tabulators,
+% \item form feeds: characters treated as form feed characters, and
+% \item others: all other characters.
+% \end{itemize}
+% This character table is altered depending on the current programming language.
+% We may define string and comment delimiters or other special characters.
+% Table \ref{rStdCharTable} on page \pageref{rStdCharTable} shows the standard
+% character table. It can be modified with the keys \keyname{alsoletter},
+% \keyname{alsodigit}, and \keyname{alsoother}.
+%
+% How do these `classes' work together? Let's say that the current character
+% string is `|tr|'. Then letter `|y|' simply appends the letter and we get
+% `|try|'. The next nonletter (and nondigit) causes the output of the
+% characters. Then we collect all coming nonletters until reaching a letter
+% again. This causes the output of the nonletters, and so on. Internally each
+% character becomes active in the sense of \TeX\ and is defined to do the right
+% thing, e.g.~we say
+% \begin{verbatim}
+%    \def A{\lst@ProcessLetter A}\end{verbatim}
+% where the first `|A|' is active and the second has letter catcode 11.
+% The macro |\lst@ProcessLetter| gets one token and treats it as a letter.
+% The following macros exist, where the last three get no explicit argument.
+% \begin{syntax}
+% \item[0.18] |\lst@ProcessLetter| \meta{spec.\ token}
+% \item[0.18] |\lst@ProcessDigit| \meta{spec.\ token}
+% \item[0.18] |\lst@ProcessOther| \meta{spec.\ token}
+% \item[0.18] |\lst@ProcessTabulator|
+% \item[0.18] |\lst@ProcessSpace|
+% \item[0.20] |\lst@ProcessFormFeed|
+% \end{syntax}
+% \meta{spec.\ token} is supposed to do two things. Usually it expands to
+% a printable version of the character. But if |\lst@UM| is equivalent to
+% |\@empty|, \meta{spec.\ token} must expand to a \emph{character token}.
+% For example, the sharp usually expands to |\#|, which is defined via
+% |\chardef| and is not a character token. But if |\lst@UM| is equivalent to
+% |\@empty|, the sharp expands to the character `|#|' (catcode 12). Note:
+% \emph{Changes to} |\lst@UM| \emph{must be locally.}  However, there should
+% be no need to do such basic things yourself. The \packagename{listings}
+% package provides advanced macros which use that feature,
+% e.g.~|\lst@InstallKeywords| in section \ref{dKeywordsAndWorkingIdentifiers}.
+%
+% \begin{syntax}
+% \item[0.18] |\lst@Def|\marg{character code}\meta{parameter text}\marg{definition}
+% \item[0.18] |\lst@Let|\marg{character code}\meta{token}
+%
+%       defines the specified character respectively assigns \meta{token}.
+%       The catcode table if not affected. Be careful if your definition has
+%       parameters: it is not safe to read more than one character ahead.
+%       Moreover, the argument can be \emph{arbitrary}; somtimes it's the next
+%       source code character, sometimes it's some code of the
+%       \packagename{listings} package, e.g.~|\relax|, |\@empty|, |\else|,
+%       |\fi|, and so on. Therefore don't use \TeX's ord-operator |`| on such
+%       an argument, e.g.~don't write |\ifnum`#1=65| to test against `|A|'.
+%
+%       |\lst@Def| and |\lst@Let| are relatively slow. The real definition of
+%       the standard character table differs from the following example, but it
+%       could begin with
+% \begin{verbatim}
+%    \lst@Def{9}{\lst@ProcessTabulator}
+%    \lst@Def{32}{\lst@ProcessSpace}
+%    \lst@Def{48}{\lst@ProcessDigit 0}
+%    \lst@Def{65}{\lst@ProcessLetter A}\end{verbatim}
+%
+%\iffalse
+% \item[0.20] |\lst@activecharstrue|
+% \item[0.20] |\lst@activecharsfalse|
+%
+%       control whether selecting the character table also makes all characters
+%       active (standard/extended). This is usually true and therefore default.
+%       Only the \packagename{fancyvrb} interface sets it locally false.
+%\fi
+% \end{syntax}
+% That's enough for the moment. Section \ref{dUsefulInternalDefinitions}
+% presents advanced definitions to manipulate the character table, in
+% particular how to add new comment or string types.
+%
+%
+% \subsection{On the output}
+%
+% The \packagename{listings} package uses some variables to keep the output
+% data. Write access is not recommended. Let's start with the easy ones.
+% \begin{syntax}
+% \item[0.17,,data] |\lst@lastother|
+%
+%       equals \meta{spec.\ token} version of the last processed
+%       nonidentifier-character. Since programming languages redefine the
+%       standard character table, we use the original \meta{spec.\ token}.
+%       For example, if a double quote was processed last, |\lst@lastother|
+%       is not equivalent to the macro which enters and leaves string mode.
+%       It's equivalent to |\lstum@"|, where |"| belongs to the control
+%       sequence. Remember that \meta{spec.\ token} expands either to a
+%       printable or to a token character.
+%
+%       |\lst@lastother| is equivalent to |\@empty| if such a character is not
+%       available, e.g.~at the beginning of a line. Sometimes an indentifier
+%       has already been printed after processing the last `other' character,
+%       i.e.~the character is far, far away. In this case |\lst@lastother|
+%       equals |\relax|.
+%
+% \item[0.17] |\lst@outputspace|
+%
+%       Use this predefined \meta{spec.\ token} (obviously for character code
+%       32) to test against |\lst@lastother|.
+%
+% \item[0.20] |\lstum@backslash|
+%
+%       Use this predefined \meta{spec.\ token} (for character code 92) to test
+%       against |\lst@lastother|. In the replacement text for |\lst@Def| one
+%       could write |\ifx| |\lst@lastother| |\lstum@backslash| \ldots\ to test
+%       whether the last character has been a backslash.
+%
+% \item[0.20] |\lst@SaveOutputDef|\marg{character code}\meta{macro}
+%
+%       Stores the \meta{spec.\ token} corresponding to \meta{character code}
+%       in \meta{macro}. This is the only safe way to get a correct meaning to
+%       test against |\lst@lastother|, for example
+%           |\lst@SaveOutputDef{"5C}\lstum@backslash|.
+%
+%       You'll get a ``runaway argument'' error if \meta{character code} is not
+%       between 33 and 126 (inclusive).
+% \end{syntax}
+% Now let's turn to the macros dealing a bit more with the output data and
+% state.
+% \begin{syntax}
+% \item[1.0] |\lst@XPrintToken|
+%
+%       outputs the current character string and resets it. This macro keeps
+%       track of all variables described here.
+%
+% \item[0.18,,token] |\lst@token|
+%
+%       contains the current character string. Each `character' usually
+%       expands to its printable version, but it must expand to a character
+%       token if |\lst@UM| is equivalent to |\@empty|.
+%
+% \item[0.12,,counter] |\lst@length|
+%
+%       is the length of the current character string.
+%
+% \item[0.12,,dimension] |\lst@width|
+%
+%       is the width of a single character box.
+%
+% \item[0.20,,global dimension] |\lst@currlwidth|
+%
+%       is the width of so far printed line.
+%
+% \item[0.18,,global counter] |\lst@column|
+% \item[0.12,,global counter] |\lst@pos| (nonpositive)
+%
+%       |\lst@column|$-$|\lst@pos| is the length of the so far printed line.
+%       We use two counters since this simplifies tabulator handling:
+%       |\lst@pos| is a nonpositive representative of `length of so far
+%       printed line' modulo \keyname{tabsize}.
+%       It's usually not the biggest nonpositive representative.
+%
+% \item[0.20] |\lst@CalcColumn|
+%
+%       |\@tempcnta| gets |\lst@column| $-$ |\lst@pos| $+$ |\lst@length|.
+%       This is the current column number minus one, or the current column
+%       number zero based.
+%
+% \item[0.18,,global dimension] |\lst@lostspace|
+%
+%       equals `lost' space: desired current line width minus real line width.
+%       Whenever this dimension is positive the flexible column format can use
+%       this space to fix the column alignment.
+% \end{syntax}
+%
+%
+% \section{Package extensions}\label{dPackageExtensions}
+%
+%
+% \subsection{Keywords and working identifiers}\label{dKeywordsAndWorkingIdentifiers}
+%
+% The \aspectname{keywords} aspect defines two main macros. Their respective
+% syntax is shown on the left. On the right you'll find examples how the
+% package actually defines some keys.
+% \begin{syntax}
+%   \item[0.21] \cs{lst@InstallFamily}
+%
+%     \marg{prefix}\syntaxfill \texttt k\\
+%     \marg{name}\syntaxfill |{keywords}|\\
+%     \marg{style name}\syntaxfill |{keywordstyle}|\\
+%     \marg{style init}\syntaxfill |\bfseries|\\
+%     \marg{default style name}\syntaxfill |{keywordstyle}|\\
+%     \marg{working procedure}\syntaxfill |{}|\\
+%     \meta{\alternative{l,o}}\syntaxfill |l|\\
+%     \meta{\alternative{d,o}}\syntaxfill |d|
+%
+%     installs either a keyword or `working' class of identifiers according
+%     to whether \meta{working procedure} is empty.
+%
+%     The three keys \meta{name}, \keyname{more}\meta{name} and
+%     \keyname{delete}\meta{name}, and if not empty \meta{style name} are
+%     defined. The first order member of the latter one is initialized with
+%     \meta{style init} if not equivalent to |\relax|. If the user leaves a
+%     class style undefined, \meta{default style name} is used instead.
+%     Thus, make sure that this style is always defined. In the example,
+%     the first order keywordstyle is set to |\bfseries| and is the default
+%     for all other classes.
+%
+%     If \meta{working procedure} is not empty, this code is executed when
+%     reaching such an (user defined) identifier. \meta{working procedure}
+%     takes exactly one argument, namely the class number to which the
+%     actual identifier belongs to. If the code uses variables and requires
+%     values from previous calls, you must define these variables
+%     |\global|ly. It's not sure whether working procedures are executed
+%     inside a (separate) group or not.
+%
+%     \texttt l indicates a language key, i.e.~the lists are reset every
+%     language selection. \texttt o stands for `other' key.  The keyword
+%     respectively working test is either installed at the
+%     \hookname{DetectKeyword} or \hookname{Output} hook according to
+%     \meta{\alternative{d,o}}.
+%
+%   \item[0.20] \cs{lst@InstallKeywords}
+%
+%     \marg{prefix}\syntaxfill \texttt{cs}\\
+%     \marg{name}\syntaxfill |{texcs}|\\
+%     \marg{style name}\syntaxfill |{texcsstyle}|\\
+%     \marg{style init}\syntaxfill |\relax|\\
+%     \marg{default style name}\syntaxfill |{keywordstyle}|\\
+%     \marg{working procedure}\syntaxfill see below\\
+%     \meta{\alternative{l,o}}\syntaxfill |l|\\
+%     \meta{\alternative{d,o}}\syntaxfill |d|
+%
+%     Same parameters, same functionality with one execption. The macro
+%     installs exactly one keyword class and not a whole family. Therefore
+%     the argument to \meta{working procedure} is constant (currently
+%     empty).
+%
+%     The working procedure of the example reads as
+%     follows.\vspace*{-.5\baselineskip}
+% \begin{verbatim}
+%    {\ifx\lst@lastother\lstum@backslash
+%         \let\lst@thestyle\lst@texcsstyle
+%     \fi}\end{verbatim}
+%    % \vspace*{-.5\baselineskip}
+% What does this procedure do? First of all it is called only if a keyword
+% from the user supplied list (or language definition) is found.  The
+% procedure now checks for a preceding backslash and sets the output style
+% accordingly.
+%
+% \iffalse
+% \item[0.20] |\lst@InstallTest|\marg{prefix}\syntaxbreak
+%   |\lst@|\meta{name}|@list||\lst@|\meta{name}~|\lst@g|\meta{name}|@list|^^A
+%   |\lst@g|\meta{name}\syntaxbreak
+%   |\lst@g|\meta{name}|@sty|~\meta{\alternative{w,s}}\meta{\alternative{d,o}}
+%
+%   installs a `working identifier' test or keyword style depending on
+%   \meta{\alternative{w,s}}. |\lst@g|\meta{name}|@sty| contains the
+%   working procedure or style macro. Note that the behaviour of the tests
+%   depends on the \texttt{savemem} option.  The keyword respectively
+%   working test is either installed at the \hookname{DetectKeyword} or
+%   \hookname{Output} hook according to \meta{\alternative{d,o}}.
+%
+%   ^^A Either each call of this macro or each different \meta{prefix}
+%   inserts ^^A another test (depending on the \texttt{savemem} option).
+%
+%   |\lst@|\meta{name} contains the current identifier list and
+%   |\lst@|\meta{name}|@list| a `|\lst@|\meta{$n_i$}|\lst@g|\meta{$n_i$}'
+%   sequence of currently used classes. If no other classes are used, this
+%   equals |\lst@|\meta{name}|\lst@g|\meta{name}. The global versions
+%   |\lst@g|\ldots\ are used to keep track of the keywords.  (This
+%   description needs improvement.)
+% \fi
+% \end{syntax}
+%
+%
+% \subsection{Delimiters}
+%
+% We describe two stages: adding a new delimiter type to an existing class of
+% delimiters and writing a new class. Each class has its name; currently exist
+% \texttt{Comment}, \texttt{String}, and \texttt{Delim}. As you know, the
+% latter and the first both provide the type \texttt l, but there is no string
+% which starts with the given delimiter and ends at end of line. So we'll add
+% it now!
+%
+% First of all we extend the list of string types by
+% \begin{verbatim}
+%    \lst@AddTo\lst@stringtypes{,l}\end{verbatim}
+% Then we must provide the macro which takes the user supplied delimiter and
+% makes appropriate definitions. The command name consists of the prefix
+% |\lst@|, the delimiter name, |DM| for using dynamic modes, and |@| followed
+% by the type.
+% \begin{verbatim}
+%    \gdef\lst@StringDM@l#1#2\@empty#3#4#5{%
+%        \lst@CArg #2\relax\lst@DefDelimB{}{}{}#3{#1}{#5\lst@Lmodetrue}}\end{verbatim}
+% You can put these three lines into a \texttt{.sty}-file or surround them by
+% |\makeatletter| and |\makeatother| in the preamble of a document.
+% And that's all!
+%{\makeatletter
+%\lst@AddTo\lst@stringtypes{,l}
+%\gdef\lst@StringDM@l#1#2\@empty#3#4#5{^^A
+%   \lst@CArg #2\relax\lst@DefDelimB{}{}{}#3{#1}{#5\lst@Lmodetrue}}
+%}
+% \begin{lstsample}{}{}
+%    \lstset{string=[l]//}
+%    \begin{lstlisting}
+%    // This is a string.
+%    This isn't a string.
+%    \end{lstlisting}
+% \end{lstsample}
+% You want more details, of course. Let's begin with the arguments.
+% \begin{itemize}
+% \item The first argument \emph{after} |\@empty| is used to start the
+%       delimiter. It's provided by the delimiter class.
+% \item The second argument \emph{after} |\@empty| is used to end the
+%       delimiter. It's also provided by the delimiter class. We didn't
+%       need it in the example, see the explanation below.
+% \item The third argument \emph{after} |\@empty| is
+%       \marg{style}\meta{start tokens}.
+%       This with a preceding |\def\lst@currstyle| is used as argument to
+%       |\lst@EnterMode|. The delimiter class also provides it. In the
+%       example we `extended' |#5| by |\lst@Lmodetrue| (line mode true).
+%       The mode automatically ends at end of line, so we didn't need the
+%       end-delimiter argument.
+% \end{itemize}
+% And now for the other arguments. In case of dynamic modes, the first argument
+% is the mode number. Then follow the user supplied  delimiter(s) whose number
+% must match the remaining arguments up to |\@empty|. For non-dynamic modes,
+% you must either allocate a static mode yourself or use a predefined mode
+% number. The delimiters then start with the first argument.
+%
+% Eventually let's look at the replacement text of the macro. The sequence
+% |\lst@CArg #2\relax| puts two required arguments after |\lst@DefDelimB|.
+% The syntax of the latter macro is
+% \begin{syntax}
+% \item[1.0] \cs{lst@DefDelimB}
+%
+%   |{|\meta{1st}\meta{2nd}\marg{rest}|}|\syntaxfill |{//{}}|\\
+%   \meta{save 1st}\syntaxfill |\lst@c/0|\\
+%   \marg{execute}\syntaxfill|{}|\\
+%   \marg{delim~exe~modetrue}\syntaxfill|{}|\\
+%   \marg{delim~exe~modefalse}\syntaxfill|{}|\\
+%   \meta{start-delimiter macro}\syntaxfill|#3|\\
+%   \meta{mode number}\syntaxfill |{#1}|\\
+%   |{|\marg{style}\meta{start tokens}|}|\syntaxfill |{#5\lst@Lmodetrue}|
+%
+%       defines \meta{1st}\meta{2nd}\meta{rest} as starting-delimiter.
+%       \meta{execute} is executed when the package comes to \meta{1st}.
+%       \meta{delim~exe~modetrue} and \meta{delim~exe~modefalse} are
+%       executed only if the whole delimiter \meta{1st}\meta{2nd}\meta{rest}
+%       is found. Exactly one of them is called depending on |\lst@ifmode|.
+%
+%       By default the package enters the mode if the delimiter is found
+%       \emph{and} |\lst@ifmode| is false. Internally we make an appropriate
+%       definition of |\lst@bnext|, which can be gobbled by placing
+%       |\@gobblethree| at the very end of \meta{delim exe modefalse}.
+%       One can provide an own definition (and gobble the default).
+%
+%       \meta{save 1st} must be an undefined macro and is used internally to
+%       store the previous meaning of \meta{1st}. The arguments \meta{2nd}
+%       and/or \meta{rest} are empty if the delimiter has strictly less than
+%       three characters. All characters of \meta{1st}\meta{2nd}\meta{rest}
+%       must already be active (if not empty).
+%       That's not a problem since the macro |\lst@CArgX| does this job.
+%
+% \item[1.0] \cs{lst@DefDelimE}
+%
+%   |{|\meta{1st}\meta{2nd}\marg{rest}|}|\\
+%   \meta{save 1st}\\
+%   \marg{execute}\\
+%   \marg{delim~exe~modetrue}\\
+%   \marg{delim~exe~modefalse}\\
+%   \meta{end-delimiter macro}\\
+%   \meta{mode number}
+%
+%       Ditto for ending-delimiter with slight differences:
+%       \meta{delim~exe~modetrue} and \meta{delim~exe~modefalse} are executed
+%       depending on whether |\lst@mode| equals \meta{mode}.
+%
+%       The package ends the mode if the delimiter is found and |\lst@mode|
+%       equals \meta{mode}. Internally we make an appropriate definition of
+%       |\lst@enext| (not |\lst@bnext|), which can be gobbled by placing
+%       |\@gobblethree| at the very end of \meta{delim exe modetrue}.
+%
+% \item[1.0] \cs{lst@DefDelimBE}
+%
+%   followed by the same eight arguments as for |\lst@DefDelimB| and \ldots\\
+%   \meta{end-delimiter macro}
+%
+%       This is a combination of |\lst@DefDelimB| and |\lst@DefDelimE| for the
+%       case of starting and ending delimiter being the same.
+% \end{syntax}
+% We finish the first stage by examining two easy examples.
+% \texttt d-type strings are defined by
+% \begin{verbatim}
+%    \gdef\lst@StringDM@d#1#2\@empty#3#4#5{%
+%        \lst@CArg #2\relax\lst@DefDelimBE{}{}{}#3{#1}{#5}#4}\end{verbatim}
+% (and an entry in the list of string types).
+% Not a big deal. Ditto \texttt d-type comments:
+% \begin{verbatim}
+%    \gdef\lst@CommentDM@s#1#2#3\@empty#4#5#6{%
+%        \lst@CArg #2\relax\lst@DefDelimB{}{}{}#4{#1}{#6}%
+%        \lst@CArg #3\relax\lst@DefDelimE{}{}{}#5{#1}}\end{verbatim}
+% Here we just need to use both |\lst@DefDelimB| and |\lst@DefDelimE|.
+% \goodbreak
+%
+% So let's get to the second stage. For illustration, here's the definition of
+% the \texttt{Delim} class. The respective first argument to the service macro
+% makes it delete all delimiters of the class, add the delimiter, or delete
+% the particular delimiter only.
+% \begin{verbatim}
+%    \lst@Key{delim}\relax{\lst@DelimKey\@empty{#1}}
+%    \lst@Key{moredelim}\relax{\lst@DelimKey\relax{#1}}
+%    \lst@Key{deletedelim}\relax{\lst@DelimKey\@nil{#1}}\end{verbatim}
+% The service macro itself calls another macro with appropriate arguments.
+% \begin{verbatim}
+%    \gdef\lst@DelimKey#1#2{%
+%        \lst@Delim{}#2\relax{Delim}\lst@delimtypes #1%
+%                    {\lst@BeginDelim\lst@EndDelim}
+%            i\@empty{\lst@BeginIDelim\lst@EndIDelim}}\end{verbatim}
+% We have to look at those arguments. Above you can see the actual arguments
+% for the \texttt{Delim} class, below are the \texttt{Comment} class ones.
+% Note that the user supplied value covers the second and third line of
+% arguments.
+% \begin{syntax}
+%   \item[0.21,,changed] \cs{lst@Delim}
+%
+%     \meta{default style macro}\syntaxfill \cs{lst@commentstyle}\\ \relax
+%     [\texttt*[\texttt*]]\texttt[\meta{type}\texttt][\texttt[\meta{style}^^A
+%     \texttt][\texttt[\meta{type option}\texttt]]]\\
+%     \meta{delimiter\textup(s\textup)}\cs{relax}\syntaxfill|#2|\cs{relax}\\
+%     \marg{delimiter name}\syntaxfill|{Comment}|\\
+%     \meta{delimiter types macro}\syntaxfill\texttt{\cs{lst@commenttypes}}\\
+%     \alternative{\cs{@empty},\cs{@nil},\cs{relax}}\syntaxfill|#1|\\
+%     \marg{begin- and end-delim macro}\syntaxfill|{|\cs{lst@BeginComment}^^A
+%     \cs{lst@EndComment}|}|\\
+%     \meta{extra prefix}\syntaxfill |i|\\
+%     \meta{extra conversion}\syntaxfill |\@empty|\\
+%     \marg{begin- and end-delim macro}\syntaxfill|{|\cs{lst@BeginIComment}^^A
+%     \cs{lst@EndIComment}|}|
+%
+%     Most arguments should be clear. We'll discuss the last four. Both
+%     \marg{begin- and end-delim macro} must contain exactly two control
+%     sequences, which are given to |\lst@|\meta{name}[|DM|]|@|\meta{type}
+%     to begin and end a delimiter. These are the arguments |#3| and |#4|
+%     in our first example of |\lst@StringDM@l|. Depending on whether the
+%     user chosen type starts with \meta{extra prefix}, the first two or
+%     the last control sequences are used.
+%
+%     By default the package takes the delimiter(s), makes the characters
+%     active, and places them after
+%     |\lst@|\meta{name}[|DM|]|@|\meta{type}. If the user type starts with
+%     \meta{extra prefix}, \meta{extra conversion} might change the
+%     definition of |\lst@next| to choose a different conversion. The
+%     default is equivalent to |\lst@XConvert| with |\lst@false|.
+%
+%     Note that \meta{type} never starts with \meta{extra prefix} since it
+%     is discarded. The functionality must be fully implemented by choosing
+%     a different \marg{begin- and end-delim macro} pair.
+% \end{syntax}
+% You might need to know the syntaxes of the \meta{begin- and end-delim macro}s.
+% They are called as follows.
+% \begin{syntax}
+% \item[0.21] |\lst@Begin|\meta{whatever}
+%
+%   \marg{mode}
+%   |{|\marg{style}\meta{start tokens}|}|
+%   \meta{delimiter}|\@empty|
+%
+% \item[0.21] |\lst@End|\meta{whatever}
+%
+%   \marg{mode}
+%   \meta{delimiter}|\@empty|
+% \end{syntax}
+% The existing macros are internally defined in terms of |\lst@DelimOpen| and
+% |\lst@DelimClose|, see the implementation.
+%
+%
+% \subsection{Getting the kernel run}
+%
+% If you want new pretty-printing environments, you should be happy with
+% section \ref{rEnvironments}. New commands like |\lstinline| or
+% |\lstinputlisting| are more difficult. Roughly speaking you must follow
+% these steps.
+% \begin{enumerate}
+% \item Open a group to make all changes local.
+% \item \meta{Do whatever you want.}
+% \item Call |\lsthk@PreSet| in any case.
+% \item Now you \emph{might } want to (but need not) use |\lstset| to set some
+%       new values.
+% \item \meta{Do whatever you want.}
+% \item Execute |\lst@Init\relax| to finish initialization.
+% \item \meta{Do whatever you want.}
+% \item Eventually comes the source code, which is processed by the kernel.
+%       You must ensure that the characters are either not already read or all
+%       active. Moreover \emph{you} must install a way to detect the end of the
+%       source code. If you've reached the end, you must \ldots
+% \item \ldots\ call |\lst@DeInit| to shutdown the kernel safely.
+% \item \meta{Do whatever you want.}
+% \item Close the group from the beginning.
+% \end{enumerate}
+% For example, consider the |\lstinline| command in case of being not inside an
+% argument. Then the steps are as follows.
+% \begin{enumerate}
+% \item |\leavevmode\bgroup| opens a group.
+% \item |\def\lst@boxpos{b}| `baseline' aligns the listing.
+% \item |\lsthk@PreSet|
+% \item |\lstset{flexiblecolumns,#1}| (|#1| is the user provided
+%       key=value list)
+% \item |\lsthk@TextStyle| deactivates all features not safe here.
+% \item |\lst@Init\relax|
+% \item |\lst@Def{`#1}{\lst@DeInit\egroup}| installs the `end inline'
+%       detection, where |#1| is the next character after |\lstinline|.
+%       Moreover chr(13) is redefined to end the fragment in the same way but
+%       also issues an error message.
+% \item Now comes the source code and \ldots
+% \item \ldots\ |\lst@DeInit| (from |\lst@Def| above) ends the code snippet
+%       correctly.
+% \item Nothing.
+% \item |\egroup| (also from |\lst@Def|) closes the group.
+% \end{enumerate}
+% The real definition is different since we allow source code inside arguments.
+% Read also section \ref{iTheInputCommand} if you really want to write
+% pretty-printing commands.
+%
+%
+% \section{Useful internal definitions}\label{dUsefulInternalDefinitions}
+%
+% This section requires an update.
+%
+%
+% \subsection{General purpose macros}\label{dGeneralPurposeMacros}
+%
+% \begin{syntax}
+%   \item[0.19] |\lst@AddTo|\meta{macro}\marg{\TeX~material}
+%
+%     adds \meta{\TeX~material} globally to the contents of \meta{macro}.
+%
+%   \item[0.20] |\lst@Extend|\meta{macro}\marg{\TeX~material}
+%
+%     calls |\lst@AddTo| after the first token of \meta{\TeX~material} is
+%     |\expand|ed|after|. For example, |\lst@Extend \a \b| merges the
+%     contents of the two macros and stores it globally in |\a|.
+%
+%   \item[0.19] |\lst@lAddTo|\meta{macro}\marg{\TeX~material}
+%   \item[0.20] |\lst@lExtend|\meta{macro}\marg{\TeX~material}
+%
+%     are local versions of |\lst@AddTo| and |\lst@Extend|.
+%
+%   \item[0.18] |\lst@DeleteKeysIn|\meta{macro}\meta{macro \textup(keys to
+%     remove\textup)}
+%
+%     Both macros contain a comma separated list of keys (or keywords). All
+%     keys appearing in the second macro are removed (locally) from the
+%     first.
+%
+%   \item[0.19] |\lst@ReplaceIn|\meta{macro}\meta{macro \textup(containing
+%     replacement list\textup)}
+%   \item[0.20] |\lst@ReplaceInArg|\meta{macro}\marg{replacement list}
+%
+%     The replacement list has the form
+%     $a_1b_1$\ldots$a_nb_n$, where each $a_i$ and
+%     $b_i$ is a character sequence (enclosed in braces if necessary) and
+%     may contain macros, but the first token of
+%     $b_i$ must not be equivalent to |\@empty|. Each sequence
+%     $a_i$ inside the first macro is (locally) replaced by
+%     $b_i$.  The suffix |Arg| refers to the \emph{braced} second argument
+%     instead of a (nonbraced) macro. It's a hint that we get the `real'
+%     argument and not a `pointer' to the argument.
+%
+%   \item[0.20] |\lst@IfSubstring|\marg{character
+%     sequence}\meta{macro}\marg{then}\marg{else}
+%
+%     \meta{then} is executed if \meta{character sequence} is a substring
+%     of the contents of \meta{macro}. Otherwise \meta{else} is called.
+%
+%   \item[0.12] |\lst@IfOneOf|\meta{character
+%     sequence}|\relax|\meta{macro}\marg{then}\marg{else}
+%
+%     |\relax| terminates the first parameter here since it is faster than
+%     enclosing it in braces. \meta{macro} contains a comma separated list
+%     of identifiers. If the character sequence is one of these
+%     indentifiers, \meta{then} is executed, and otherwise \meta{else}.
+%
+%   \item[0.21] |\lst@Swap|\marg{tok1}\marg{tok2}
+%
+%     changes places of the following two tokens or arguments
+%     \emph{without} inserting braces. For example, |\lst@Swap{abc}{def}|
+%     expands to |defabc|.
+%
+%   \item[0.18] |\lst@IfNextChars|\meta{macro}\marg{then}\marg{else}
+%   \item[0.19] |\lst@IfNextCharsArg|\marg{character
+%     sequence}\marg{then}\marg{else}
+%
+%     Both macros execute either \meta{then} or \meta{else} according to
+%     whether the given character sequence respectively the contents of the
+%     given macro is found (after the three arguments). Note an important
+%     difference between these macros and \LaTeX's |\@ifnextchar|: We
+%     remove the characters behind the arguments until it is possible to
+%     decide which part must be executed. However, we save these characters
+%     in the macro |\lst@eaten|, so they can be inserted using \meta{then}
+%     or \meta{else}.
+%
+%   \item[0.19] |\lst@IfNextCharActive|\marg{then}\marg{else}
+%
+%     executes \meta{then} if next character is active, and \meta{else}
+%     otherwise.
+%
+%   \item[0.20] |\lst@DefActive|\meta{macro}\marg{character sequence}
+%
+%     stores the character sequence in \meta{macro}, but all characters
+%     become active. The string \emph{must not} contain a begin group, end
+%     group or escape character (|{}\|); it may contain a left brace, right
+%     brace or backslash with other meaning (= catcode). This command would
+%     be quite surplus if \meta{character sequence} is not already read by
+%     \TeX\ since such catcodes can be changed easily. It is explicitly
+%     allowed that the charcaters have been read, e.g.~in
+%     |\def\test{\lst@DefActive\temp{ABC}}|!
+%
+%     Note that this macro changes |\lccode|s 0--9 without restoring them.
+%
+%   \item[0.20] |\lst@DefOther|\meta{macro}\marg{character sequence}
+%
+%     stores \meta{character sequence} in \meta{macro}, but all characters
+%     have catcode 12. Moreover all spaces are removed and control
+%     sequences are converted to their name without preceding
+%     backslash. For example, |\{ Chip \}| leads to |{Chip}| where all
+%     catcodes are 12---internally the primitive |\meaning| is used.
+%
+%     \iffalse
+%   \item[0.19] |\lst@MakeActive|\marg{character sequence}
+%
+%     stores the character sequence in |\lst@arg| and has the same
+%     restrictions as |\lst@DefActive|. If fact, the latter definition uses
+%     this macro here.  \fi
+% \end{syntax}
+%
+%
+% \subsection{Character tables manipulated}\label{dCharacterTablesManipulated}
+%
+% \begin{syntax}
+%   \item[0.20] |\lst@SaveDef|\marg{character code}\meta{macro}
+%
+%     Saves the current definition of the specified character in
+%     \meta{macro}. You should always save a character definition before
+%     you redefine it! And use the saved version instead of writing
+%     directly |\lst@Process|\ldots---the character could already be
+%     redefined and thus not equivalent to its standard definition.
+%
+%   \item[0.20] |\lst@DefSaveDef|\marg{character
+%     code}\meta{macro}\meta{parameter text}\marg{definition}
+%   \item[0.20] |\lst@LetSaveDef|\marg{character
+%     code}\meta{macro}\meta{token}
+%
+%     combine |\lst@SaveDef| and |\lst@Def| respectively |\lst@Let|.
+% \end{syntax}
+% Of course I shouldn't forget to mention \emph{where} to alter the character
+% table. Hook material at \hookname{SelectCharTable} makes permanent changes,
+% i.e.~it effects all languages. The following two keys can be used in any
+% language definition and effects the particular language only.
+% \begin{syntax}
+% \item[0.20] |SelectCharTable=|\meta{\TeX\ code}
+% \item[0.20] |MoreSelectCharTable=|\meta{\TeX\ code}
+%
+%       uses \meta{\TeX\ code} (additionally) to select the character table.
+%       The code is executed after the standard character table is selected,
+%       but possibly before other aspects make more changes. Since previous
+%       meanings are always saved and executed inside the new definition, this
+%       should be harmless.
+% \end{syntax}
+% Here come two rather useless examples. Each point (full stop) will cause a
+% message `|.|' on the terminal and in the |.log| file if language |useless| is
+% active:
+% \begin{verbatim}
+%   \lstdefinelanguage{useless}
+%       {SelectCharTable=\lst@DefSaveDef{46}% save chr(46) ...
+%            \lsts@point             % ... in \lsts@point and ...
+%            {\message{.}\lsts@point}% ... use new definition
+%       }\end{verbatim}
+% If you want to count points, you could write
+% \begin{verbatim}
+%   \newcount\lst@points % \global
+%   \lst@AddToHook{Init}{\global\lst@points\z@}
+%   \lst@AddToHook{DeInit}{\message{Number of points: \the\lst@points}}
+%   \lstdefinelanguage[2]{useless}
+%       {SelectCharTable=\lst@DefSaveDef{46}\lsts@point
+%            {\global\advance\lst@points\@ne \lsts@point}
+%       }\end{verbatim}
+% |% \global| indicates that the allocated counter is used globally. We zero
+% the counter at the beginning of each listing, display a message about the
+% current value at the end of a listing, and each processed point advances the
+% counter by one.
+%
+% \begin{syntax}
+%   \item[0.21] |\lst@CArg|\meta{active characters}|\relax|\meta{macro}
+%
+%     The string of active characters is split into \meta{1st}, \meta{2nd},
+%     and \marg{rest}. If one doesn't exist, an empty argument is
+%     used. Then \meta{macro} is called with
+%     |{|\meta{1st}\meta{2nd}\marg{rest}|}| plus a yet undefined control
+%     sequence \meta{save 1st}. This macro is intended to hold the current
+%     definition of \meta{1st}, so \meta{1st} can be redefined without
+%     loosing information.
+%
+%   \item[0.19] |\lst@CArgX|\meta{characters}|\relax|\meta{macro}
+%
+%     makes \meta{characters} active before calling |\lst@CArg|.
+%
+%   \item[0.21] |\lst@CDef{|\meta{1st}\meta{2nd}\marg{rest}|}|\meta{save
+%     1st}\marg{execute}\marg{pre}\marg{post}
+%
+%     should be used in connection with |\lst@CArg| or |\lst@CArgX|,
+%     i.e.~as \meta{macro} there. \meta{1st}, \meta{2nd}, and \meta{rest}
+%     must be active characters and \meta{save 1st} must be an undefined
+%     control sequence.
+%
+%     Whenever the package reaches the character \meta{1st} (in a listing),
+%     \meta{execute} is executed. If the package detects the whole string
+%     \meta{1st}\meta{2nd}\meta{rest}, we additionally execute \meta{pre},
+%     then the string, and finally \meta{post}.
+%
+%   \item[0.21] |\lst@CDefX|\meta{1st}\meta{2nd}\marg{rest}\meta{save
+%     1st}\marg{execute}\marg{pre}\marg{post}
+%
+%     Ditto except that we execute \meta{pre} and \meta{post} without the
+%     original string if we reach \meta{1st}\meta{2nd}\meta{rest}.  This
+%     means that the string is replaced by \meta{pre}\meta{post} (with
+%     preceding \meta{execute}).
+% \end{syntax}
+% As the final example, here's the definition of |\lst@DefDelimB|.
+% \begin{verbatim}
+%    \gdef\lst@DefDelimB#1#2#3#4#5#6#7#8{%
+%        \lst@CDef{#1}#2%
+%            {#3}%
+%            {\let\lst@bnext\lst@CArgEmpty
+%             \lst@ifmode #4\else
+%                 #5%
+%                 \def\lst@bnext{#6{#7}{#8}}%
+%             \fi
+%             \lst@bnext}%
+%            \@empty}\end{verbatim}
+% You got it?
+%
+%
+% \part{Implementation}
+%
+%
+% \CheckSum{12377}
+%^^A
+%^^A Don't index TeX-primitives.
+%^^A
+% \DoNotIndex{\advance,\afterassignment,\aftergroup,\batchmode,\begingroup}
+% \DoNotIndex{\box,\catcode,\char,\chardef,\closeout,\copy,\count,\csname,\def}
+% \DoNotIndex{\dimen,\discretionary,\divide,\dp,\edef,\else,\end,\endcsname}
+% \DoNotIndex{\endgroup,\endinput,\endlinechar,\escapechar,\everypar}
+% \DoNotIndex{\expandafter,\fi,\gdef,\global,\globaldefs,\hbadness,\hbox}
+% \DoNotIndex{\hrulefill,\hss,\ht}
+% \DoNotIndex{\if,\ifdim,\iffalse,\ifhmode,\ifinner,\ifnum,\ifodd,\iftrue}
+% \DoNotIndex{\ifvoid,\ifx,\ignorespaces,\immediate,\input,\jobname,\kern}
+% \DoNotIndex{\lccode,\leftskip,\let,\long,\lower,\lowercase,\meaning,\message}
+% \DoNotIndex{\multiply,\muskip,\noexpand,\noindent,\openout,\par,\parfillskip}
+% \DoNotIndex{\parshape,\parskip,\raise,\read,\relax,\rightskip,\setbox,\skip}
+% \DoNotIndex{\string,\the,\toks,\uppercase,\vbox,\vcenter,\vrule,\vtop,\wd}
+% \DoNotIndex{\write,\xdef}
+%
+%^^A
+%^^A Don't index LaTeX's private definitions.
+%^^A
+% \DoNotIndex{\@@end,\@@par,\@M,\@arabic,\@circlefnt,\@currentlabel}
+% \DoNotIndex{\@currenvir,\@depth,\@doendpe,\@dottedtocline,\@eha,\@ehc}
+% \DoNotIndex{\@empty,\@firstofone,\@firstoftwo,\@float,\@for,\@getcirc}
+% \DoNotIndex{\@gobble,\@gobbletwo,\@halfwidth,\@height,\@ifnextchar}
+% \DoNotIndex{\@ifundefined,\@ignoretrue,\@makecaption,\@makeother,\@namedef}
+% \DoNotIndex{\@ne,\@noligs,\@notprerr,\@onlypreamble,\@secondoftwo,\@spaces}
+% \DoNotIndex{\@starttoc,\@totalleftmargin,\@undefined,\@whilenum}
+% \DoNotIndex{\@wholewidth,\@width}
+% \DoNotIndex{\c@chapter,\c@figure,\c@page,\end@float,\f@family,\filename@area}
+% \DoNotIndex{\filename@base,\filename@ext,\filename@parse,\if@twoside}
+% \DoNotIndex{\l@ngrel@x,\m@ne,\new@command,\nfss@catcodes,\tw@,\thr@@}
+% \DoNotIndex{\z@,\zap@space}
+%
+%^^A
+%^^A Don't index LaTeX's package definitions.
+%^^A
+% \DoNotIndex{\AtEndOfPackage}
+% \DoNotIndex{\CurrentOption,\DeclareOption,\IfFileExists,\InputIfFileExists}
+% \DoNotIndex{\MessageBreak,\NeedsTeXFormat,\PackageError,\PackageWarning}
+% \DoNotIndex{\ProcessOptions,\ProvidesFile,\ProvidesPackage,\RequirePackage}
+%
+%^^A
+%^^A Don't index LaTeX's public definitions.
+%^^A
+% \DoNotIndex{\abovecaptionskip,\active,\addcontentsline,\addtocounter,\begin}
+% \DoNotIndex{\belowcaptionskip,\bfseries,\bgroup,\bigbreak,\chapter}
+% \DoNotIndex{\contentsname,\do,\egroup,\footnotesize,\index,\itshape}
+% \DoNotIndex{\linewidth,\llap,\makeatletter,\newbox,\newcommand,\newcount}
+% \DoNotIndex{\newcounter,\newdimen,\newtoks,\newwrite,\nointerlineskip}
+% \DoNotIndex{\normalbaselines,\normalfont,\numberline,\pretolerance,\protect}
+% \DoNotIndex{\qquad,\refstepcounter,\removelastskip,\renewcommand,\rlap}
+% \DoNotIndex{\small,\smallbreak,\smallskipamount,\smash,\space,\strut}
+% \DoNotIndex{\strutbox,\tableofcontents,\textasciicircum,\textasciitilde}
+% \DoNotIndex{\textasteriskcentered,\textbackslash,\textbar,\textbraceleft}
+% \DoNotIndex{\textbraceright,\textdollar,\textendash,\textgreater,\textless}
+% \DoNotIndex{\textunderscore,\textvisiblespace,\thechapter,\ttdefault}
+% \DoNotIndex{\ttfamily,\typeout,\value,\vphantom}
+%
+%^^A
+%^^A Don't index definitions from other packages.
+%^^A
+% \DoNotIndex{\MakePercentComment,\MakePercentIgnore}
+%
+%^^A
+%^^A Don't index 0.19 definitions.
+%^^A
+% \DoNotIndex{\listlistingsname,\listoflistings,\lstbox,\lstbox@}
+% \DoNotIndex{\lstlanguage@}
+%
+%^^A
+%^^A Don't index 0.20 subdefinitions.
+%^^A
+% \DoNotIndex{\lst@ATH@,\lst@BOLGobble@,\lst@BOLGobble@@,\lst@CArg@,\lst@CArg@@}
+% \DoNotIndex{\lst@CBC@,\lst@CBC@@,\lst@CCECUse@,\lst@CCPutMacro@,\lst@DefLang@}
+% \DoNotIndex{\lst@DefLang@@,\lst@DefOther@,\lst@DeleteKeysIn@,\lst@Escape@}
+% \DoNotIndex{\lstframe@,\lst@frameH@,\lst@frameL@,\lst@frameR@}
+% \DoNotIndex{\lst@FillFixed@,\lst@FindAlias@,\lst@FVConvert@}
+% \DoNotIndex{\lst@IfNextChars@,\lst@IfNextChars@@,\lst@InsideConvert@}
+% \DoNotIndex{\lst@InstallKeywords@,\lst@Key@,\lst@KeywordTestI@}
+% \DoNotIndex{\lst@MakeActive@,\lst@MakeMoreKeywords@}
+% \DoNotIndex{\lst@RC@,\lst@RC@@,\lst@ReplaceIn@,\lst@ReplaceInput@}
+% \DoNotIndex{\lst@ReportAllocs@,\lst@SKS@,\lst@SKS@@,\lst@UBC@}
+% \DoNotIndex{\lst@WorkingTestI@,\lstalias@,\lstalias@@,\lstalso@}
+% \DoNotIndex{\lstdefinestyle@,\lstenv@BOLGobble@@}
+% \DoNotIndex{\lstenv@ProcessJ@,\lstinline@,\lstKV@OptArg@,\lstKV@SetIf@}
+% \DoNotIndex{\lstlang@,\lstnewenvironment@,\lst@outputpos,\lstset@}
+%
+%
+% \section{Overture}
+%
+% \paragraph{Registers}
+% For each aspect, the required numbers of registers are listed in section
+% \lstref{dPackageLoading}. Furthermore, the \packagename{keyval} package
+% allocates one token register. The macros, boxes and counters
+% |\@temp|\ldots|a|/|b|, the dimensions |\@tempdim|\ldots, and the macro
+% |\@gtempa| are also used, see the index.
+%
+% \paragraph{Naming conventions}
+% Let's begin with definitions for the user. All these public macros have
+% lower case letters and contain |lst|. Private macros and variables use the
+% following prefixes (not up-to-date?):
+% \begin{itemize}
+% \item |\lst@| for a general macro or variable,
+% \item |\lstenv@| if it is defined for the listing environment,
+% \item |\lsts@| for |s|aved character meanings,
+% \item |\lsthk@|\meta{name of hook} holds hook material,
+% \item |\lst|\meta{prefix}|@| for various kinds of keywords and working
+%       identifiers.
+% \item |\lstlang@|\meta{language}|@|\meta{dialect} contains a language and
+% \item |\lststy@|\meta{the style} contains style definition,
+% \item |\lstpatch@|\meta{aspect} to patch an aspect,
+%
+% \item |\lsta@|\meta{language}|$|\meta{dialect} contains alias,
+% \item |\lsta@|\meta{language} contains alias for all dialects of a language,
+% \item |\lstdd@|\meta{language} contains default dialect of a language
+%       (if present).
+% \end{itemize}
+% To distinguish procedure-like macros from data-macros, the name of procedure
+% macros use upper case letters with each beginning word, e.g.~|\lst@AddTo|.
+% A macro with suffix |@| is the main working-procedure for another definition,
+% for example |\lstMakeShortInline@| does the main work for |\lstMakeShortInline|.
+%
+% \paragraph{Preamble}
+% All files generated from this \texttt{listings.dtx} will get a header.
+%    \begin{macrocode}
+%<*kernel|misc>
+%% Please read the software license in listings.dtx or listings.pdf.
+%%
+%% (w)(c) 1996--2004 Carsten Heinz and/or any other author listed
+%% elsewhere in this file.
+%% (c) 2006 Brooks Moses
+%% (c) 2013- Jobst Hoffmann
+%%
+%% Send comments and ideas on the package, error reports and additional
+%% programming languages to Jobst Hoffmann at <j.hoffmann@fh-aachen.de>.
+%%
+%</kernel|misc>
+%    \end{macrocode}
+%
+% \paragraph{Identification}
+% All files will have same date and version.
+%    \begin{macrocode}
+%<*kernel|misc|doc>
+\def\filedate{2019/02/27}
+\def\fileversion{1.8b}
+%</kernel|misc|doc>
+%    \end{macrocode}
+% What we need and who we are.
+%    \begin{macrocode}
+%<*kernel>
+\NeedsTeXFormat{LaTeX2e}
+\AtEndOfPackage{\ProvidesPackage{listings}
+             [\filedate\space\fileversion\space(Carsten Heinz)]}
+%    \end{macrocode}
+% \begin{macro}{\lst@CheckVersion}
+% can be used by the various driver files to guarantee the correct version.
+%    \begin{macrocode}
+\def\lst@CheckVersion#1{\edef\reserved@a{#1}%
+    \ifx\lst@version\reserved@a \expandafter\@gobble
+                          \else \expandafter\@firstofone \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\let\lst@version\fileversion
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+% For example by the miscellaneous file
+%    \begin{macrocode}
+%<*misc>
+\ProvidesFile{lstmisc.sty}
+             [\filedate\space\fileversion\space(Carsten Heinz)]
+\lst@CheckVersion\fileversion
+    {\typeout{^^J%
+     ***^^J%
+     *** This file requires `listings.sty' version \fileversion.^^J%
+     *** You have a serious problem, so I'm exiting ...^^J%
+     ***^^J}%
+     \batchmode \@@end}
+%</misc>
+%    \end{macrocode}
+% or by the dummy patch.
+%    \begin{macrocode}
+%<*patch>
+\ProvidesFile{lstpatch.sty}
+             [\filedate\space\fileversion\space(Carsten Heinz)]
+\lst@CheckVersion\lst@version{}
+%</patch>
+%    \end{macrocode}
+%    \begin{macrocode}
+%<*doc>
+\ProvidesPackage{lstdoc}
+             [\filedate\space\fileversion\space(Carsten Heinz)]
+%</doc>
+%    \end{macrocode}
+%
+% \paragraph{Category codes}
+% We define two macros to ensure correct catcodes when we input other files of
+% the \packagename{listings} package.
+%
+% \begin{macro}{\lst@InputCatcodes}
+% |@| and |"| become letters. Tabulators and EOLs are ignored; this avoids
+% unwanted spaces---in the case I've forgotten a comment character.
+%    \begin{macrocode}
+%<*kernel>
+\def\lst@InputCatcodes{%
+    \makeatletter \catcode`\"12%
+    \catcode`\^^@\active
+    \catcode`\^^I9%
+    \catcode`\^^L9%
+    \catcode`\^^M9%
+    \catcode`\%14%
+    \catcode`\~\active}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@RestoreCatcodes}
+% To load the kernel, we will change some catcodes and lccodes. We restore them
+% at the end of package loading. \lsthelper{Dr.~Jobst~Hoffmann}{2000/11/17}
+% {incompatibility with typehtml package} reported an incompatibility with the
+% \packagename{typehtml} package, which is resolved by |\lccode`\/`\/| below.
+%    \begin{macrocode}
+\def\lst@RestoreCatcodes#1{%
+    \ifx\relax#1\else
+        \noexpand\catcode`\noexpand#1\the\catcode`#1\relax
+        \expandafter\lst@RestoreCatcodes
+    \fi}
+\edef\lst@RestoreCatcodes{%
+    \noexpand\lccode`\noexpand\/`\noexpand\/%
+    \lst@RestoreCatcodes\"\^^I\^^M\~\^^@\relax
+    \catcode12\active}
+%    \end{macrocode}
+% Now we are ready for
+%    \begin{macrocode}
+\lst@InputCatcodes
+\AtEndOfPackage{\lst@RestoreCatcodes}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+% \paragraph{Statistics}
+% \begin{macro}{\lst@GetAllocs}
+% \begin{macro}{\lst@ReportAllocs}
+% are used to show the allocated registers.
+%    \begin{macrocode}
+%<*info>
+\def\lst@GetAllocs{%
+    \edef\lst@allocs{%
+        0\noexpand\count\the\count10,1\noexpand\dimen\the\count11,%
+        2\noexpand\skip\the\count12,3\noexpand\muskip\the\count13,%
+        4\noexpand\box\the\count14,5\noexpand\toks\the\count15,%
+        6\noexpand\read\the\count16,7\noexpand\write\the\count17}}
+\def\lst@ReportAllocs{%
+    \message{^^JAllocs:}\def\lst@temp{none}%
+    \expandafter\lst@ReportAllocs@\lst@allocs,\z@\relax\z@,}
+\def\lst@ReportAllocs@#1#2#3,{%
+    \ifx#2\relax \message{\lst@temp^^J}\else
+        \@tempcnta\count1#1\relax \advance\@tempcnta -#3\relax
+        \ifnum\@tempcnta=\z@\else
+            \let\lst@temp\@empty
+            \message{\the\@tempcnta \string#2,}%
+        \fi
+        \expandafter\lst@ReportAllocs@
+    \fi}
+\lst@GetAllocs
+%    \end{macrocode}
+% \end{macro}\end{macro}
+% \begingroup
+%    \begin{macrocode}
+%</info>
+%    \end{macrocode}
+% \endgroup
+%
+% \paragraph{Miscellaneous}
+% \begin{macro}{\@lst}
+% Just a definition to save memory space.
+%    \begin{macrocode}
+%<*kernel>
+\def\@lst{lst}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \section{General problems}
+%
+% All definitions in this section belong to the kernel.
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+%
+%
+%^^A \subsection{Quick `if parameter empty'}
+%^^A
+%^^A There are many situations where you have to look whether a macro parameter is empty.
+%^^A We have at least two possibilities to test |#1|, for example:
+%^^A \begin{center}
+%^^A \begin{minipage}{0.35\linewidth}
+%^^A \begin{verbatim}
+%^^A\def\test{#1}%
+%^^A\ifx \test\empty
+%^^A        % #1 is empty
+%^^A\else
+%^^A        % #1 is not empty
+%^^A\fi\end{verbatim}
+%^^A \end{minipage}
+%^^A \hskip2em\vrule\hskip2em
+%^^A \begin{minipage}{0.35\linewidth}
+%^^A \begin{verbatim}
+%^^A\ifx \empty#1\empty
+%^^A        % #1 is empty
+%^^A\else
+%^^A        % #1 is not empty
+%^^A\fi\end{verbatim}
+%^^A \end{minipage}
+%^^A \end{center}
+%^^A where |\empty| is defined by |\def\empty{}|, of course.
+%^^A The left variant should be clear and works in any case.
+%^^A The right-hand side works correct if and only if the first token of |#1| is
+%^^A not equivalent to |\empty|.
+%^^A This granted, the |\ifx| is true if and only if |#1| is empty (since |\empty|
+%^^A left from |#1| is (not) compared with |\empty| on the right).
+%^^A The two |\empty|s might be replaced by any other macro, which is not
+%^^A equivalent to the first token of the argument.
+%^^A But the definition of that macro shouldn't be too complex since this would
+%^^A slow down the |\ifx|.
+%^^A The right example needs about $45\%$ of the left's time.
+%^^A Note that this \TeX{}nique lost its importance from version 0.18 on and that
+%^^A other packages use |!| or |\relax| instead of |\empty|, for example.
+%^^A
+%^^A This \TeX nique is described in ``The \TeX book'' on page 376.
+%
+%
+% \subsection{Substring tests}\label{iSubstringTests}
+%
+% \lstset{language=TeX,gobble=4,xleftmargin=20pt,columns=[l]fullflexible,^^A
+%   mathescape,keywordstyle=\ttfamily,texcsstyle=\bfseries}
+% \let\texverb\lstinline
+% \lstnewenvironment{texcode}[1][]{\lstset{#1}}{}
+% \lstset{keywords={def,key}}
+%
+% It's easy to decide whether a given character sequence is a substring of
+% another string. For example, for the substring \texverb|def| we could say
+% \begin{texcode}
+%   \def \lst@temp#1def#2\relax{%
+%       \ifx \@empty#2\@empty
+%               % "def" is not a substring
+%       \else
+%               % "def" is a substring
+%       \fi}
+%
+%   \lst@temp $\meta{another\ string}$def\relax
+% \end{texcode}
+% When \TeX\ passes the arguments |#1| and |#2|, the second is empty if
+% and only if \texverb|def| is not a substring. Without the additional
+% \texverb|def\relax|, one would get a ``runaway argument'' error if
+% \meta{another string} doesn't contain \texverb|def|.
+%
+% We use substring tests mainly in the special case of an identifier and a
+% comma separated list of keys or keywords:
+% \begin{texcode}[keywords=key]
+%   \def \lst@temp#1,key,#2\relax{%
+%       \ifx \@empty#2\@empty
+%               % `key' is not a keyword
+%       \else
+%               % `key' is a keyword
+%       \fi}
+%
+%   \lst@temp,$\meta{list\ of\ keywords}$,key,\relax
+% \end{texcode}
+% This works very well and is quite fast. But we can reduce run time in the
+% case that \texttt{key} is a keyword. Then |#2| takes the rest of the string,
+% namely all keywords after \texttt{key}.
+% Since \TeX\ inserts |#2| between the \texverb|\@empty|s, it must drop all of
+% |#2| except the first character---which is compared with \texverb|\@empty|.
+% We can redirect this rest to a third parameter:
+% \begin{texcode}[keywords=key]
+%   \def \lst@temp#1,key,#2#3\relax{%
+%       \ifx \@empty#2%
+%               % "key" is not a keyword
+%       \else
+%               % "key" is a keyword
+%       \fi}
+%
+%   \lst@temp,$\meta{list\ of\ keywords}$,key,\@empty\relax
+% \end{texcode}
+% That's a bit faster and an improvement for version 0.20.
+%
+% \begin{macro}{\lst@IfSubstring}
+% The implementation should be clear from the discussion above.
+%    \begin{macrocode}
+\def\lst@IfSubstring#1#2{%
+    \def\lst@temp##1#1##2##3\relax{%
+        \ifx \@empty##2\expandafter\@secondoftwo
+                 \else \expandafter\@firstoftwo \fi}%
+    \expandafter\lst@temp#2#1\@empty\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfOneOf}
+% Ditto.
+%    \begin{macrocode}
+\def\lst@IfOneOf#1\relax#2{%
+    \def\lst@temp##1,#1,##2##3\relax{%
+        \ifx \@empty##2\expandafter\@secondoftwo
+                 \else \expandafter\@firstoftwo \fi}%
+    \expandafter\lst@temp\expandafter,#2,#1,\@empty\relax}
+%    \end{macrocode}
+% \end{macro}
+% \begin{REMOVED}
+% One day, if there is need for a case insensitive key(word) test again, we
+% can use two |\uppercase|s to normalize the first parameter:
+%    \begin{verbatim}
+%\def\lst@IfOneOfInsensitive#1\relax#2{%
+%    \uppercase{\def\lst@temp##1,#1},##2##3\relax{%
+%        \ifx \@empty##2\expandafter\@secondoftwo
+%                 \else \expandafter\@firstoftwo \fi}%
+%    \uppercase{%
+%        \expandafter\lst@temp\expandafter,#2,#1},\@empty\relax}\end{verbatim}
+% Here we assume that macro |#2| already contains capital characters only, see
+% the definition of |\lst@MakeMacroUppercase| at the very end of section
+% \ref{iMakingTests}. If we \emph{must not} assume that, we could simply
+% insert an |\expandafter| between the second |\uppercase| and the following
+% brace. But this slows down the tests!
+% \end{REMOVED}
+%
+% \begin{macro}{\lst@DeleteKeysIn}
+% The submacro does the main work; we only need to expand the second
+% macro---the list of keys to remove---and append the terminator |\relax|.
+%    \begin{macrocode}
+\def\lst@DeleteKeysIn#1#2{%
+    \expandafter\lst@DeleteKeysIn@\expandafter#1#2,\relax,}
+%    \end{macrocode}
+% `Replacing' the very last |\lst@DeleteKeysIn@| by |\lst@RemoveCommas|
+% terminates the loop here. Note: The |\@empty| after |#2| ensures that this
+% macro also works if |#2| is empty.
+%    \begin{macrocode}
+\def\lst@DeleteKeysIn@#1#2,{%
+    \ifx\relax#2\@empty
+        \expandafter\@firstoftwo\expandafter\lst@RemoveCommas
+    \else
+        \ifx\@empty#2\@empty\else
+%    \end{macrocode}
+% If we haven't reached the end of the list and if the key is not empty, we
+% define a temporary macro which removes all appearances.
+%    \begin{macrocode}
+            \def\lst@temp##1,#2,##2{%
+                ##1%
+                \ifx\@empty##2\@empty\else
+                    \expandafter\lst@temp\expandafter,%
+                \fi ##2}%
+            \edef#1{\expandafter\lst@temp\expandafter,#1,#2,\@empty}%
+        \fi
+    \fi
+    \lst@DeleteKeysIn@#1}
+%    \end{macrocode}
+% \end{macro}
+% \begin{OLDDEF}
+% The following modification needs about $50\%$ more run time.
+% It doesn't use |\edef| and thus also works with |\{| inside |#1|.
+% However, we don't need that at the moment.
+%    \begin{verbatim}
+%            \def\lst@temp##1,#2,##2{%
+%                \ifx\@empty##2%
+%                    \lst@lAddTo#1{##1}%
+%                \else
+%                    \lst@lAddTo#1{,##1}%
+%                    \expandafter\lst@temp\expandafter,%
+%                \fi ##2}%
+%            \let\@tempa#1\let#1\@empty
+%            \expandafter\lst@temp\expandafter,\@tempa,#2,\@empty\end{verbatim}
+% \end{OLDDEF}
+%
+% \begin{macro}{\lst@RemoveCommas}
+% The macro drops commas at the beginning and assigns the new value to |#1|.
+%    \begin{macrocode}
+\def\lst@RemoveCommas#1{\edef#1{\expandafter\lst@RC@#1\@empty}}
+\def\lst@RC@#1{\ifx,#1\expandafter\lst@RC@ \else #1\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{OLDDEF}
+% The following version works with |\{| inside the macro |#1|.
+%    \begin{verbatim}
+%\def\lst@RemoveCommas#1{\expandafter\lst@RC@#1\@empty #1}
+%\def\lst@RC@#1{%
+%    \ifx,#1\expandafter\lst@RC@
+%      \else\expandafter\lst@RC@@\expandafter#1\fi}
+%\def\lst@RC@@#1\@empty#2{\def#2{#1}}\end{verbatim}
+% \end{OLDDEF}
+%
+% \begin{macro}{\lst@ReplaceIn}
+% \begin{macro}{\lst@ReplaceInArg}
+% These macros are similar to |\lst@DeleteKeysIn|, except that \ldots
+%    \begin{macrocode}
+\def\lst@ReplaceIn#1#2{%
+    \expandafter\lst@ReplaceIn@\expandafter#1#2\@empty\@empty}
+\def\lst@ReplaceInArg#1#2{\lst@ReplaceIn@#1#2\@empty\@empty}
+%    \end{macrocode}
+% \ldots\space we replace |#2| by |#3| instead of |,#2,| by a single comma
+% (which removed the key |#2| above).
+%    \begin{macrocode}
+\def\lst@ReplaceIn@#1#2#3{%
+    \ifx\@empty#3\relax\else
+        \def\lst@temp##1#2##2{%
+            \ifx\@empty##2%
+                \lst@lAddTo#1{##1}%
+            \else
+                \lst@lAddTo#1{##1#3}\expandafter\lst@temp
+            \fi ##2}%
+        \let\@tempa#1\let#1\@empty
+        \expandafter\lst@temp\@tempa#2\@empty
+        \expandafter\lst@ReplaceIn@\expandafter#1%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsection{Flow of control}
+%
+% \begin{macro}{\@gobblethree}
+% is defined if and only if undefined.
+%    \begin{macrocode}
+\providecommand*\@gobblethree[3]{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@GobbleNil}
+%    \begin{macrocode}
+\def\lst@GobbleNil#1\@nil{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Swap}
+% is just this:
+%    \begin{macrocode}
+\def\lst@Swap#1#2{#2#1}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@if}
+% \begin{macro}{\lst@true}
+% \begin{macro}{\lst@false}
+% A general |\if| for temporary use.
+%    \begin{macrocode}
+\def\lst@true{\let\lst@if\iftrue}
+\def\lst@false{\let\lst@if\iffalse}
+\lst@false
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfNextCharsArg}
+% is quite easy: We define a macro and call |\lst@IfNextChars|.
+%    \begin{macrocode}
+\def\lst@IfNextCharsArg#1{%
+    \def\lst@tofind{#1}\lst@IfNextChars\lst@tofind}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfNextChars}
+% We save the arguments and start a loop.
+%    \begin{macrocode}
+\def\lst@IfNextChars#1#2#3{%
+    \let\lst@tofind#1\def\@tempa{#2}\def\@tempb{#3}%
+    \let\lst@eaten\@empty \lst@IfNextChars@}
+%    \end{macrocode}
+% Expand the characters we are looking for.
+%    \begin{macrocode}
+\def\lst@IfNextChars@{\expandafter\lst@IfNextChars@@\lst@tofind\relax}
+%    \end{macrocode}
+% Now we can refine |\lst@tofind| and append the input character |#3| to
+% |\lst@eaten|.
+%    \begin{macrocode}
+\def\lst@IfNextChars@@#1#2\relax#3{%
+    \def\lst@tofind{#2}\lst@lAddTo\lst@eaten{#3}%
+    \ifx#1#3%
+%    \end{macrocode}
+% If characters are the same, we either call |\@tempa| or continue the test.
+%    \begin{macrocode}
+        \ifx\lst@tofind\@empty
+            \let\lst@next\@tempa
+        \else
+            \let\lst@next\lst@IfNextChars@
+        \fi
+        \expandafter\lst@next
+    \else
+%    \end{macrocode}
+% If the characters are different, we call |\@tempb|.
+%    \begin{macrocode}
+        \expandafter\@tempb
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfNextCharActive}
+% We compare the character |#3| with its active version |\lowercase{~}|.
+% Note that the right brace between |\ifx~| and |#3| ends the |\lowercase|.
+% The |\endgroup| restores the |\lccode|.
+%    \begin{macrocode}
+\def\lst@IfNextCharActive#1#2#3{%
+    \begingroup \lccode`\~=`#3\lowercase{\endgroup
+    \ifx~}#3%
+        \def\lst@next{#1}%
+    \else
+        \def\lst@next{#2}%
+    \fi \lst@next #3}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@for}
+% A for-loop with expansion of the loop-variable.  This was improved due to
+% a suggestion by \lsthelper{Hendri~Adriaens}{2006/03/31}{speedup of
+% \lst@for}.
+%    \begin{macrocode}
+\def\lst@for#1\do#2{%
+  \def\lst@forbody##1{#2}%
+  \def\@tempa{#1}%
+  \ifx\@tempa\@empty\else\expandafter\lst@f@r#1,\@nil,\fi
+}
+\def\lst@f@r#1,{%
+  \def\@tempa{#1}%
+  \ifx\@tempa\@nnil\else\lst@forbody{#1}\expandafter\lst@f@r\fi
+}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Catcode changes}\label{iCatcodeChanges}
+%
+% A character gets its catcode right after reading it and \TeX\ has no
+% primitive command to change attached catcodes. However, we can replace these
+% characters by characters with same ASCII codes and different catcodes.
+% It's not the same but suffices since the result is the same.
+% Here we treat the very special case that all characters become active.
+% If we want \texverb|\lst@arg| to contain an active version of the character
+% |#1|, a prototype macro could be
+% \begin{texcode}
+%   \def\lst@MakeActive#1{\lccode`\~=`#1\lowercase{\def\lst@arg{~}}}
+% \end{texcode}
+% The |\lowercase| changes the ASCII code of |~| to the one of |#1| since we
+% have said that |#1| is the lower case version of |~|.
+% Fortunately the |\lowercase| doesn't change the catcode, so we have an active
+% version of |#1|.
+% Note that |~| is usually active.
+%
+% \begin{macro}{\lst@MakeActive}
+% We won't do this character by character.
+% To increase speed we change nine characters at the same time (if nine
+% characters are left).
+% \begin{TODO}
+% This was introduced when the delimiters were converted each listings. Now
+% this conversion is done only each language selection. So we might want to
+% implement a character by character conversion again to decrease the memory
+% usage.
+% \end{TODO}
+% We get the argument, empty |\lst@arg| and begin a loop.
+%    \begin{macrocode}
+\def\lst@MakeActive#1{%
+    \let\lst@temp\@empty \lst@MakeActive@#1%
+    \relax\relax\relax\relax\relax\relax\relax\relax\relax}
+%    \end{macrocode}
+% There are nine |\relax|es since |\lst@MakeActive@| has nine parameters and we
+% don't want any problems in the case that |#1| is empty.
+% We need nine active characters now instead of a single |~|.
+% We make these catcode changes local and define the coming macro |\global|.
+%    \begin{macrocode}
+\begingroup
+\catcode`\^^@=\active \catcode`\^^A=\active \catcode`\^^B=\active
+\catcode`\^^C=\active \catcode`\^^D=\active \catcode`\^^E=\active
+\catcode`\^^F=\active \catcode`\^^G=\active \catcode`\^^H=\active
+%    \end{macrocode}
+% First we |\let| the next operation be |\relax|.
+% This aborts our loop for processing all characters (default and possibly
+% changed later).
+% Then we look if we have at least one character.
+% If this is not the case, the loop terminates and all is done.
+%    \begin{macrocode}
+\gdef\lst@MakeActive@#1#2#3#4#5#6#7#8#9{\let\lst@next\relax
+    \ifx#1\relax
+    \else \lccode`\^^@=`#1%
+%    \end{macrocode}
+% Otherwise we say that |^^@|=chr(0) is the lower case version of the first
+% character.
+% Then we test the second character.
+% If there is none, we append the lower case |^^@| to |\lst@temp|.
+% Otherwise we say that |^^A|=chr(1) is the lower case version of the second
+% character and we test the next argument, and so on.
+%    \begin{macrocode}
+    \ifx#2\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@}}%
+    \else \lccode`\^^A=`#2%
+    \ifx#3\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A}}%
+    \else \lccode`\^^B=`#3%
+    \ifx#4\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B}}%
+    \else \lccode`\^^C=`#4%
+    \ifx#5\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C}}%
+    \else \lccode`\^^D=`#5%
+    \ifx#6\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D}}%
+    \else \lccode`\^^E=`#6%
+    \ifx#7\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D^^E}}%
+    \else \lccode`\^^F=`#7%
+    \ifx#8\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D^^E^^F}}%
+    \else \lccode`\^^G=`#8%
+    \ifx#9\relax
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D^^E^^F^^G}}%
+%    \end{macrocode}
+% If nine characters are present, we append (lower case versions of) nine
+% active characters and call this macro again via redefining |\lst@next|.
+%    \begin{macrocode}
+    \else \lccode`\^^H=`#9%
+        \lowercase{\lst@lAddTo\lst@temp{^^@^^A^^B^^C^^D^^E^^F^^G^^H}}%
+        \let\lst@next\lst@MakeActive@
+    \fi \fi \fi \fi \fi \fi \fi \fi \fi
+    \lst@next}
+\endgroup
+%    \end{macrocode}
+% This |\endgroup| restores the catcodes of chr(0)--chr(8), but not the
+% catcodes of the characters inside |\lst@MakeActive@| since they are already
+% read.
+%
+% Note: A conversion from an arbitrary `catcode--character code' table back to
+% \TeX's catcodes is possible if we test against the character codes (either
+% via |\ifnum| or |\ifcase|).
+% But control sequences and begin and end group characters definitely need
+% some special treatment.
+% However I haven't checked the details.
+% So just ignore this and don't bother me for this note. :\,--\,)
+% \end{macro}
+%
+% \begin{macro}{\lst@DefActive}
+% An easy application of |\lst@MakeActive|.
+%    \begin{macrocode}
+\def\lst@DefActive#1#2{\lst@MakeActive{#2}\let#1\lst@temp}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefOther}
+% We use the fact that |\meaning| produces catcode 12 characters except spaces
+% stay spaces. |\escapechar| is modified locally to suppress the output of an
+% escape character. Finally we remove spaces via \LaTeX's |\zap@space|, which
+% was proposed by \lsthelper{Rolf~Niepraschk}{1997/04/24}{use \zap@space}---not
+% in this context, but that doesn't matter.
+%    \begin{macrocode}
+\def\lst@DefOther#1#2{%
+    \begingroup \def#1{#2}\escapechar\m@ne \expandafter\endgroup
+    \expandafter\lst@DefOther@\meaning#1\relax#1}
+\def\lst@DefOther@#1>#2\relax#3{\edef#3{\zap@space#2 \@empty}}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+%\ifhyper
+% \subsection{Applications to \ref*{iCatcodeChanges}}\label{iApplicationsTo}
+%\else
+% \subsection{Applications to \ref{iCatcodeChanges}}\label{iApplicationsTo}
+%\fi
+%
+% If an environment is used inside an argument, the listing is already read and
+% we can do nothing to preserve the catcodes.
+% However, under certain circumstances the environment can be used inside an
+% argument---that's at least what I've said in the User's guide.
+% And now I have to work for it coming true.
+% Moreover we define an analogous conversion macro for the
+% \packagename{fancyvrb} mode.
+% \begin{syntax}
+% \item[0.19] |\lst@InsideConvert{|\meta{\TeX\ material \textup(already read\textup)}|}|
+%
+%       \emph{appends} a verbatim version of the argument to |\lst@arg|, but all
+%       appended characters are active. Since it's not a character to character
+%       conversion, `verbatim' needs to be explained. All characters can be
+%       typed in as they are except |\|, |{|, |}| and |%|. If you want one of
+%       these, you must write |\\|, |\{|, |\}| and |\%| instead.
+%       If two spaces should follow each other, the second (third, fourth,
+%       \ldots) space must be entered with a preceding backslash.
+%
+% \item[0.19] |\lst@XConvert{|\meta{\TeX\ material \textup(already read\textup)}|}|
+%
+%       \emph{appends} a `verbatim' version of the argument to |\lst@arg|.
+%       Here \TeX\ material is allowed to be put inside argument braces like
+%       |{(*}{*)}|. The contents of these arguments are converted, the braces
+%       stay as curly braces.
+%
+%       If |\lst@if| is true, each second argument is treated differently.
+%       Only the first character (of the delimiter) becomes active.
+% \end{syntax}
+%
+% \begin{macro}{\lst@InsideConvert}
+% If \texttt{mathescape} is not on, we call (near the end of this definition) a
+% submacro similar to |\zap@space| to replace single spaces by active spaces.
+% Otherwise we check whether the code contains a pair |$...$| and call the
+% appropriate macro.
+%    \begin{macrocode}
+\def\lst@InsideConvert#1{%
+   \lst@ifmathescape
+      \lst@InsideConvert@e#1$\@nil
+      \lst@if
+         \lst@InsideConvert@ey#1\@nil
+      \else
+         \lst@InsideConvert@#1 \@empty
+         \expandafter\@gobbletwo
+      \fi
+      \expandafter\lst@next
+   \else
+      \lst@InsideConvert@#1 \@empty
+   \fi}
+\begingroup \lccode`\~=`\ \relax \lowercase{%
+%    \end{macrocode}
+% We make |#1| active and append these characters (plus an active space) to
+% |\lst@arg|.
+% If we haven't found the end |\@empty| of the input, we continue the process.
+%    \begin{macrocode}
+\gdef\lst@InsideConvert@#1 #2{%
+    \lst@MakeActive{#1}%
+    \ifx\@empty#2%
+        \lst@lExtend\lst@arg{\lst@temp}%
+    \else
+        \lst@lExtend\lst@arg{\lst@temp~}%
+        \expandafter\lst@InsideConvert@
+    \fi #2}
+%    \end{macrocode}
+% Finally we end the |\lowercase| and close a group.
+%    \begin{macrocode}
+}\endgroup
+%    \end{macrocode}
+% The next definition has been used above to check for |$...$| and the following
+% one keeps the math contents from being converted. This feature was requested by
+% \lsthelper{Dr.~Jobst~Hoffmann}{}{}.
+%    \begin{macrocode}
+\def\lst@InsideConvert@e#1$#2\@nil{%
+   \ifx\@empty#2\@empty \lst@false \else \lst@true \fi}
+\def\lst@InsideConvert@ey#1$#2$#3\@nil{%
+   \lst@InsideConvert@#1 \@empty
+   \lst@lAddTo\lst@arg{%
+      \lst@ifdropinput\else
+         \lst@TrackNewLines\lst@OutputLostSpace \lst@XPrintToken
+         \setbox\@tempboxa=\hbox\bgroup$\lst@escapebegin
+         #2%
+         \lst@escapeend$\egroup \lst@CalcLostSpaceAndOutput
+         \lst@whitespacefalse
+      \fi}%
+   \def\lst@next{\lst@InsideConvert{#3}}%
+}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@XConvert}
+% Check for an argument \ldots
+%    \begin{macrocode}
+\def\lst@XConvert{\@ifnextchar\bgroup \lst@XConvertArg\lst@XConvert@}
+%    \end{macrocode}
+% \ldots, convert the argument, add it together with group delimiters to
+% |\lst@arg|, and we continue the conversion.
+%    \begin{macrocode}
+\def\lst@XConvertArg#1{%
+    {\lst@false \let\lst@arg\@empty
+     \lst@XConvert#1\@nil
+     \global\let\@gtempa\lst@arg}%
+    \lst@lExtend\lst@arg{\expandafter{\@gtempa}}%
+    \lst@XConvertNext}
+%    \end{macrocode}
+% Having no |\bgroup|, we look whether we've found the end of the input, and
+% convert one token ((non)active character or control sequence) and continue.
+%    \begin{macrocode}
+\def\lst@XConvert@#1{%
+    \ifx\@nil#1\else
+        \begingroup\lccode`\~=`#1\lowercase{\endgroup
+        \lst@lAddTo\lst@arg~}%
+        \expandafter\lst@XConvertNext
+    \fi}
+\def\lst@XConvertNext{%
+    \lst@if \expandafter\lst@XConvertX
+      \else \expandafter\lst@XConvert \fi}
+%    \end{macrocode}
+% Now we make only the first character active.
+%    \begin{macrocode}
+\def\lst@XConvertX#1{%
+    \ifx\@nil#1\else
+        \lst@XConvertX@#1\relax
+        \expandafter\lst@XConvert
+    \fi}
+\def\lst@XConvertX@#1#2\relax{%
+    \begingroup\lccode`\~=`#1\lowercase{\endgroup
+    \lst@XCConvertX@@~}{#2}}
+\def\lst@XCConvertX@@#1#2{\lst@lAddTo\lst@arg{{#1#2}}}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Driver file handling*}
+%
+% The \packagename{listings} package is split into several driver files,
+% miscellaneous (= aspect) files, and one kernel file.
+% All these files can be loaded partially and on demand---except the kernel
+% which provides this functionality.
+% \begin{syntax}
+%   \item[0.21] |\lst@Require|\marg{name}\marg{prefix}\marg{feature
+%     list}\meta{alias}\meta{file list macro}
+%
+%     tries to load all items of \meta{feature list} from the files listed
+%     in \meta{file list macro}.  Each item has the form
+%     [\oarg{sub}]\meta{feature}.  |\lst@if| equals |\iftrue| if and only
+%     if all items were loadable.
+%
+%     The macro \meta{alias} gets an item as argument and must define
+%     appropriate versions of |\lst@oalias| and |\lst@malias|. In fact the
+%     feature associated with these definitions is loaded. You can use
+%     \meta{alias}=|\lst@NoAlias| for no substitution.
+%
+%     \meta{prefix} identifies the type internally and \meta{name} is used
+%     for messages.
+%
+%     For example, |\lstloadaspects| uses the following arguments where
+%     |#1| is the list of aspects: |{aspects}|\allowbreak|a|\allowbreak
+%     |{#1}|\allowbreak|\lst@NoAlias|\allowbreak|\lstaspectfiles|.
+%
+%   \item[0.20] |\lst@DefDriver|\marg{name}\marg{prefix}\meta{interface
+%     macro}|\if|\alternative{true,false}
+%
+%   \item[0.21]
+%     |\lst@IfRequired|\oarg{sub}\marg{feature}\marg{then}\marg{else}
+%
+%     is used inside a driver file by the aspect, language, or whatever
+%     else defining commands. \meta{then} is executed if and only if
+%     \oarg{sub}\marg{feature} has been requested via |\lst@Require|.
+%     Otherwise \meta{else} is executed---which is also the case for
+%     subsequent calls with the same \oarg{sub}\marg{feature}.
+%
+%     \meta{then} and \meta{else} may use |\lst@prefix| (read access only).
+%
+%     |\lst@BeginAspect| in section \ref{iAspectCommands} and
+%     |\lst@DefDriver| serve as examples.
+% \end{syntax}
+%
+% \begin{macro}{\lst@Require}
+% Initialize variables (if required items aren't empty), \ldots
+%    \begin{macrocode}
+\def\lst@Require#1#2#3#4#5{%
+    \begingroup
+    \aftergroup\lst@true
+    \ifx\@empty#3\@empty\else
+        \def\lst@prefix{#2}\let\lst@require\@empty
+%    \end{macrocode}
+% \ldots\space and for each nonempty item: determine alias and add it to
+% |\lst@require| if it isn't loaded.
+%    \begin{macrocode}
+        \edef\lst@temp{\expandafter\zap@space#3 \@empty}%
+        \lst@for\lst@temp\do{%
+          \ifx\@empty##1\@empty\else \lstKV@OptArg[]{##1}{%
+            #4[####1]{####2}%
+            \@ifundefined{\@lst\lst@prefix @\lst@malias $\lst@oalias}%
+            {\edef\lst@require{\lst@require,\lst@malias $\lst@oalias}}%
+            {}}%
+          \fi}%
+%    \end{macrocode}
+% Init things and input files if and as long as it is necessary.
+%    \begin{macrocode}
+        \global\let\lst@loadaspects\@empty
+        \lst@InputCatcodes
+        \ifx\lst@require\@empty\else
+            \lst@for{#5}\do{%
+                \ifx\lst@require\@empty\else
+                    \InputIfFileExists{##1}{}{}%
+                \fi}%
+        \fi
+%    \end{macrocode}
+% Issue error and call |\lst@false| (after closing the local group) if some
+% items weren't loadable.
+%    \begin{macrocode}
+        \ifx\lst@require\@empty\else
+            \PackageError{Listings}{Couldn't load requested #1}%
+            {The following #1s weren't loadable:^^J\@spaces
+             \lst@require^^JThis may cause errors in the sequel.}%
+            \aftergroup\lst@false
+        \fi
+%    \end{macrocode}
+% Request aspects.
+%    \begin{macrocode}
+        \ifx\lst@loadaspects\@empty\else
+            \lst@RequireAspects\lst@loadaspects
+        \fi
+    \fi
+    \endgroup}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfRequired}
+% uses |\lst@IfOneOf| and adds some code to \meta{then} part:
+% delete the now loaded item from the list and define
+% |\lst|\meta{prefix}|@|\meta{feature}|$|\meta{sub}.
+%    \begin{macrocode}
+\def\lst@IfRequired[#1]#2{%
+    \lst@NormedDef\lst@temp{[#1]#2}%
+    \expandafter\lst@IfRequired@\lst@temp\relax}
+\def\lst@IfRequired@[#1]#2\relax#3{%
+    \lst@IfOneOf #2$#1\relax\lst@require
+        {\lst@DeleteKeysIn@\lst@require#2$#1,\relax,%
+         \global\expandafter\let
+             \csname\@lst\lst@prefix @#2$#1\endcsname\@empty
+         #3}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@require}
+%    \begin{macrocode}
+\let\lst@require\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@NoAlias}
+% just defines |\lst@oalias| and |\lst@malias|.
+%    \begin{macrocode}
+\def\lst@NoAlias[#1]#2{%
+    \lst@NormedDef\lst@oalias{#1}\lst@NormedDef\lst@malias{#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LAS}
+%    \begin{macrocode}
+\gdef\lst@LAS#1#2#3#4#5#6#7{%
+    \lst@Require{#1}{#2}{#3}#4#5%
+    #4#3%
+    \@ifundefined{lst#2@\lst@malias$\lst@oalias}%
+        {\PackageError{Listings}%
+         {#1 \ifx\@empty\lst@oalias\else \lst@oalias\space of \fi
+          \lst@malias\space undefined}%
+         {The #1 is not loadable. \@ehc}}%
+        {#6\csname\@lst#2@\lst@malias $\lst@oalias\endcsname #7}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@RequireAspects}
+% \begin{macro}{\lstloadaspects}
+% make use of the just developped definitions.
+%    \begin{macrocode}
+\def\lst@RequireAspects#1{%
+    \lst@Require{aspect}{asp}{#1}\lst@NoAlias\lstaspectfiles}
+\let\lstloadaspects\lst@RequireAspects
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lstaspectfiles}
+% This macro is defined if and only if it's undefined yet.
+%    \begin{macrocode}
+\@ifundefined{lstaspectfiles}
+    {\newcommand\lstaspectfiles{lstmisc0.sty,lstmisc.sty}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDriver}
+% Test the next character and reinsert the arguments.
+%    \begin{macrocode}
+\gdef\lst@DefDriver#1#2#3#4{%
+    \@ifnextchar[{\lst@DefDriver@{#1}{#2}#3#4}%
+                 {\lst@DefDriver@{#1}{#2}#3#4[]}}
+%    \end{macrocode}
+% We set |\lst@if| locally true if the item has been requested.
+%    \begin{macrocode}
+\gdef\lst@DefDriver@#1#2#3#4[#5]#6{%
+    \def\lst@name{#1}\let\lst@if#4%
+    \lst@NormedDef\lst@driver{\@lst#2@#6$#5}%
+    \lst@IfRequired[#5]{#6}{\begingroup \lst@true}%
+                           {\begingroup}%
+    \lst@setcatcodes
+    \@ifnextchar[{\lst@XDefDriver{#1}#3}{\lst@DefDriver@@#3}}
+%    \end{macrocode}
+% Note that |\lst@XDefDriver| takes optional `base' arguments, but eventually
+% calls |\lst@DefDriver@@|. We define the item (in case of need), and
+% |\endgroup| resets some catcodes and |\lst@if|, i.e.~|\lst@XXDefDriver| knows
+% whether called by a public or internal command.
+%    \begin{macrocode}
+\gdef\lst@DefDriver@@#1#2{%
+    \lst@if
+        \global\@namedef{\lst@driver}{#1{#2}}%
+    \fi
+    \endgroup
+    \@ifnextchar[\lst@XXDefDriver\@empty}
+%    \end{macrocode}
+% We get the aspect argument, and (if not empty) load the aspects immediately
+% if called by a public command or extend the list of required aspects or
+% simply ignore the argument if the item leaves undefined.
+%    \begin{macrocode}
+\gdef\lst@XXDefDriver[#1]{%
+    \ifx\@empty#1\@empty\else
+        \lst@if
+            \lstloadaspects{#1}%
+        \else
+            \@ifundefined{\lst@driver}{}%
+            {\xdef\lst@loadaspects{\lst@loadaspects,#1}}%
+        \fi
+    \fi}
+%    \end{macrocode}
+% We insert an additional `also'key=value pair.
+%    \begin{macrocode}
+\gdef\lst@XDefDriver#1#2[#3]#4#5{\lst@DefDriver@@#2{also#1=[#3]#4,#5}}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Aspect commands}\label{iAspectCommands}
+%
+% This section contains commands used in defining `\lst-aspects'.
+% \begin{macro}{\lst@UserCommand}
+% is mainly equivalent to |\gdef|.
+%    \begin{macrocode}
+%<!info>\let\lst@UserCommand\gdef
+%<info>\def\lst@UserCommand#1{\message{\string#1,}\gdef#1}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginAspect}
+% A straight-forward implementation:
+%    \begin{macrocode}
+\newcommand*\lst@BeginAspect[2][]{%
+    \def\lst@curraspect{#2}%
+    \ifx \lst@curraspect\@empty
+        \expandafter\lst@GobbleAspect
+    \else
+%    \end{macrocode}
+% If \meta{aspect name} is not empty, there are certain other conditions not to
+% define the aspect (as described in section \ref{dHowToDefineLstAspects}).
+%    \begin{macrocode}
+%<!info>        \let\lst@next\@empty
+%<info>        \def\lst@next{%
+%<info>            \message{^^JDefine lst-aspect `#2':}\lst@GetAllocs}%
+        \lst@IfRequired[]{#2}%
+            {\lst@RequireAspects{#1}%
+             \lst@if\else \let\lst@next\lst@GobbleAspect \fi}%
+            {\let\lst@next\lst@GobbleAspect}%
+        \expandafter\lst@next
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndAspect}
+% finishes an aspect definition.
+%    \begin{macrocode}
+\def\lst@EndAspect{%
+    \csname\@lst patch@\lst@curraspect\endcsname
+%<info>    \lst@ReportAllocs
+    \let\lst@curraspect\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@GobbleAspect}
+% drops all code up to the next |\lst@EndAspect|.
+%    \begin{macrocode}
+\long\def\lst@GobbleAspect#1\lst@EndAspect{\let\lst@curraspect\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Key}
+% The command simply defines the key. But we must take care of an optional
+% parameter and the initialization argument |#2|.
+%    \begin{macrocode}
+\def\lst@Key#1#2{%
+%<info>    \message{#1,}%
+    \@ifnextchar[{\lstKV@def{#1}{#2}}%
+                 {\def\lst@temp{\lst@Key@{#1}{#2}}
+                  \afterassignment\lst@temp
+                  \global\@namedef{KV@\@lst @#1}####1}}
+%    \end{macrocode}
+% Now comes a renamed and modified copy from a \packagename{keyval} macro:
+% We need global key definitions.
+%    \begin{macrocode}
+\def\lstKV@def#1#2[#3]{%
+    \global\@namedef{KV@\@lst @#1@default\expandafter}\expandafter
+        {\csname KV@\@lst @#1\endcsname{#3}}%
+    \def\lst@temp{\lst@Key@{#1}{#2}}\afterassignment\lst@temp
+    \global\@namedef{KV@\@lst @#1}##1}
+%    \end{macrocode}
+% We initialize the key if the first token of |#2| is not |\relax|.
+%    \begin{macrocode}
+\def\lst@Key@#1#2{%
+    \ifx\relax#2\@empty\else
+        \begingroup \globaldefs\@ne
+        \csname KV@\@lst @#1\endcsname{#2}%
+        \endgroup
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@UseHook}
+% is very, very, \ldots, very (hundreds of times) easy.
+%    \begin{macrocode}
+\def\lst@UseHook#1{\csname\@lst hk@#1\endcsname}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@AddToHook}
+% \begin{macro}{\lst@AddToHookExe}
+% \begin{macro}{\lst@AddToHookAtTop}
+% All use the same submacro.
+%    \begin{macrocode}
+\def\lst@AddToHook{\lst@ATH@\iffalse\lst@AddTo}
+\def\lst@AddToHookExe{\lst@ATH@\iftrue\lst@AddTo}
+\def\lst@AddToHookAtTop{\lst@ATH@\iffalse\lst@AddToAtTop}
+%    \end{macrocode}
+% If and only if the boolean value is true, the hook material is executed
+% globally.
+%    \begin{macrocode}
+\long\def\lst@ATH@#1#2#3#4{%
+    \@ifundefined{\@lst hk@#3}{%
+%<info>        \message{^^Jnew hook `#3',^^J}%
+        \expandafter\gdef\csname\@lst hk@#3\endcsname{}}{}%
+    \expandafter#2\csname\@lst hk@#3\endcsname{#4}%
+    \def\lst@temp{#4}%
+    #1% \iftrue|false
+        \begingroup \globaldefs\@ne \lst@temp \endgroup
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@AddTo}
+% Note that the definition is global!
+%    \begin{macrocode}
+\long\def\lst@AddTo#1#2{%
+    \expandafter\gdef\expandafter#1\expandafter{#1#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@AddToAtTop}
+% We need a couple of |\expandafter|s now. Simply note that we have\\
+%   {\small\hspace*{2em}|\expandafter\gdef\expandafter#1\expandafter{\lst@temp|
+%    $\langle$\textit{contents of }|#1|$\rangle$|}|}\\
+% after the `first phase' of expansion.
+%    \begin{macrocode}
+\def\lst@AddToAtTop#1#2{\def\lst@temp{#2}%
+    \expandafter\expandafter\expandafter\gdef
+    \expandafter\expandafter\expandafter#1%
+    \expandafter\expandafter\expandafter{\expandafter\lst@temp#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@lAddTo}
+% A local version of |\lst@AddTo| \ldots
+%    \begin{macrocode}
+\def\lst@lAddTo#1#2{\expandafter\def\expandafter#1\expandafter{#1#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Extend}
+% \begin{macro}{\lst@lExtend}
+% \ldots\space and here we expand the first token of the second argument first.
+%    \begin{macrocode}
+\def\lst@Extend#1#2{%
+    \expandafter\lst@AddTo\expandafter#1\expandafter{#2}}
+\def\lst@lExtend#1#2{%
+    \expandafter\lst@lAddTo\expandafter#1\expandafter{#2}}
+%    \end{macrocode}
+% \begin{TODO}
+% This should never be changed to
+%    \begin{verbatim}
+%    \def\lst@Extend#1{%
+%        \expandafter\lst@AddTo\expandafter#1\expandafter}
+%    \def\lst@lExtend#1{%
+%        \expandafter\lst@lAddTo\expandafter#1}\end{verbatim}
+% The first is not equivalent in case that the second argument is a single
+% (= non-braced) control sequence, and the second isn't in case of a braced
+% second argument.
+% \end{TODO}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsection{Interfacing with \textsf{keyval}}
+%
+% The \packagename{keyval} package passes the value via the one and only
+% paramater |#1| to the definition part of the key macro. The following
+% commands may be used to analyse the value. Note that we need at least version
+% 1.10 of the \packagename{keyval} package. Note also that the package removes
+% a naming conflict with AMS classes---reported by \lsthelper{Ralf~Quast}
+% {1998/01/08}{\keywords conflicts with AMS classes}.
+% \begingroup
+%    \begin{macrocode}
+\RequirePackage{keyval}[1997/11/10]
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lstKV@TwoArg}
+% \begin{macro}{\lstKV@ThreeArg}
+% \begin{macro}{\lstKV@FourArg}
+% Define temporary macros and call with given arguments |#1|. We add empty
+% arguments for the case that the user doesn't provide enough.
+%    \begin{macrocode}
+\def\lstKV@TwoArg#1#2{\gdef\@gtempa##1##2{#2}\@gtempa#1{}{}}
+\def\lstKV@ThreeArg#1#2{\gdef\@gtempa##1##2##3{#2}\@gtempa#1{}{}{}}
+\def\lstKV@FourArg#1#2{\gdef\@gtempa##1##2##3##4{#2}\@gtempa#1{}{}{}{}}
+%    \end{macrocode}
+% There's one question: What are the global definitions good for? |\lst@Key|
+% might set |\globaldefs| to one and possibly calls this macro. That's the
+% reason why we use global definitions here and below.
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@OptArg}
+% We define the temporary macro |\@gtempa| and insert default argument if
+% necessary.
+%    \begin{macrocode}
+\def\lstKV@OptArg[#1]#2#3{%
+    \gdef\@gtempa[##1]##2{#3}\lstKV@OptArg@{#1}#2\@}
+\def\lstKV@OptArg@#1{\@ifnextchar[\lstKV@OptArg@@{\lstKV@OptArg@@[#1]}}
+\def\lstKV@OptArg@@[#1]#2\@{\@gtempa[#1]{#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@XOptArg}
+% Here |#3| is already a definition with at least two parameters whose first
+% is enclosed in brackets.
+%    \begin{macrocode}
+\def\lstKV@XOptArg[#1]#2#3{%
+    \global\let\@gtempa#3\lstKV@OptArg@{#1}#2\@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@CSTwoArg}
+% Just define temporary macro and call it.
+%    \begin{macrocode}
+\def\lstKV@CSTwoArg#1#2{%
+    \gdef\@gtempa##1,##2,##3\relax{#2}%
+    \@gtempa#1,,\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@SetIf}
+% We simply test the lower case first character of |#1|.
+%    \begin{macrocode}
+\def\lstKV@SetIf#1{\lstKV@SetIf@#1\relax}
+\def\lstKV@SetIf@#1#2\relax#3{\lowercase{%
+    \expandafter\let\expandafter#3%
+        \csname if\ifx #1t}true\else false\fi\endcsname}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstKV@SwitchCases}
+% is implemented as a substring test. The original version used an |&|,
+% which produced a bug---see p.~\pageref{gAmpersand}.
+%    \begin{macrocode}
+\def\lstKV@SwitchCases#1#2#3{%
+    \def\lst@temp##1\\#1:##2\\##3##4\@nil{%
+        \ifx\@empty##3%
+            #3%
+        \else
+            ##2%
+        \fi
+    }%
+    \lst@temp\\#2\\#1:\\\@empty\@nil}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstset}
+% Finally this main user interface macro.
+% We change catcodes for reading the argument.
+%    \begin{macrocode}
+\lst@UserCommand\lstset{\begingroup \lst@setcatcodes \lstset@}
+\def\lstset@#1{\endgroup \ifx\@empty#1\@empty\else\setkeys{lst}{#1}\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@setcatcodes}
+% contains all catcode changes for |\lstset|. The equal-sign has been added
+% after a bug report by \lsthelper{Bekir~Karaoglu}{2003/09/16}{keyval problems
+% with [turkish]{babel}}---babel's active equal sign clashes with keyval's
+% usage. |\catcode`\"=12\relax| has been removed after a bug report by
+% \lsthelper{Heiko~Bauke}{2004/06/27}{listings und ngerman}\,---\,hopefully
+% this introduces no other bugs.
+%    \begin{macrocode}
+\def\lst@setcatcodes{\makeatletter \catcode`\==12\relax}
+%    \end{macrocode}
+% \begin{TODO}
+% Change more catcodes?
+% \end{TODO}
+% \end{macro}
+%
+%
+% \subsection{Internal modes}
+%
+% \begin{macro}{\lst@NewMode}
+% We simply use |\chardef| for a mode definition. The counter |\lst@mode|
+% mainly keeps the current mode number. But it is also used to advance the
+% number in the macro |\lst@newmode|---we don't waste another counter.
+%    \begin{macrocode}
+\def\lst@NewMode#1{%
+    \ifx\@undefined#1%
+        \lst@mode\lst@newmode\relax \advance\lst@mode\@ne
+        \xdef\lst@newmode{\the\lst@mode}%
+        \global\chardef#1=\lst@mode
+        \lst@mode\lst@nomode
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@mode}
+% \begin{macro}{\lst@nomode}
+% We allocate the counter and the first mode.
+%    \begin{macrocode}
+\newcount\lst@mode
+\def\lst@newmode{\m@ne}% init
+\lst@NewMode\lst@nomode % init (of \lst@mode :-)
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@UseDynamicMode}
+% For dynamic modes we must not use the counter |\lst@mode| (since possibly
+% already valued). |\lst@dynamicmode| substitutes |\lst@newmode| and is a local
+% definition here, \ldots
+%    \begin{macrocode}
+\def\lst@UseDynamicMode{%
+    \@tempcnta\lst@dynamicmode\relax \advance\@tempcnta\@ne
+    \edef\lst@dynamicmode{\the\@tempcnta}%
+    \expandafter\lst@Swap\expandafter{\expandafter{\lst@dynamicmode}}}
+%    \end{macrocode}
+% \ldots\ initialized each listing with the current `value' of |\lst@newmode|.
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}{\let\lst@dynamicmode\lst@newmode}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EnterMode}
+% Each mode opens a group level, stores the mode number and execute mode
+% specific tokens. Moreover we keep all these changes in mind (locally) and
+% adjust internal variables if the user wants it.
+%    \begin{macrocode}
+\def\lst@EnterMode#1#2{%
+    \bgroup \lst@mode=#1\relax #2%
+    \lst@FontAdjust
+    \lst@lAddTo\lst@entermodes{\lst@EnterMode{#1}{#2}}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}{\let\lst@entermodes\@empty}
+\let\lst@entermodes\@empty % init
+%    \end{macrocode}
+% The initialization has been added after a bug report from
+% \lsthelper{Herfried~Karl~Wagner}{2002/05/11}{undefined control sequence
+% \lst@entermodes}.
+% \end{macro}
+%
+% \begin{macro}{\lst@LeaveMode}
+% We simply close the group and call |\lsthk@EndGroup| if and only if the
+% current mode is not |\lst@nomode|.
+%    \begin{macrocode}
+\def\lst@LeaveMode{%
+    \ifnum\lst@mode=\lst@nomode\else
+        \egroup \expandafter\lsthk@EndGroup
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{EndGroup}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InterruptModes}
+% We put the current mode sequence on a stack and leave all modes.
+%    \begin{macrocode}
+\def\lst@InterruptModes{%
+    \lst@Extend\lst@modestack{\expandafter{\lst@entermodes}}%
+    \lst@LeaveAllModes}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}{\global\let\lst@modestack\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ReenterModes}
+% If the stack is not empty, we leave all modes and pop the topmost element
+% (which is the last element of |\lst@modestack|).
+%    \begin{macrocode}
+\def\lst@ReenterModes{%
+    \ifx\lst@modestack\@empty\else
+        \lst@LeaveAllModes
+        \global\let\@gtempa\lst@modestack
+        \global\let\lst@modestack\@empty
+        \expandafter\lst@ReenterModes@\@gtempa\relax
+    \fi}
+\def\lst@ReenterModes@#1#2{%
+    \ifx\relax#2\@empty
+%    \end{macrocode}
+% If we've reached |\relax|, we've also found the last element: we execute |#1|
+% and gobble |{#2}|=|{\relax}| after |\fi|.
+%    \begin{macrocode}
+        \gdef\@gtempa##1{#1}%
+        \expandafter\@gtempa
+    \else
+%    \end{macrocode}
+% Otherwise we just add the element to |\lst@modestack| and continue the loop.
+%    \begin{macrocode}
+        \lst@AddTo\lst@modestack{{#1}}%
+        \expandafter\lst@ReenterModes@
+    \fi
+    {#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LeaveAllModes}
+% Leaving all modes means closing groups until the mode equals |\lst@nomode|.
+%    \begin{macrocode}
+\def\lst@LeaveAllModes{%
+    \ifnum\lst@mode=\lst@nomode
+        \expandafter\lsthk@EndGroup
+    \else
+        \expandafter\egroup\expandafter\lst@LeaveAllModes
+    \fi}
+%    \end{macrocode}
+% We need that macro to end a listing correctly.
+%    \begin{macrocode}
+\lst@AddToHook{ExitVars}{\lst@LeaveAllModes}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Pmode}
+% \begin{macro}{\lst@GPmode}
+% The `processing' and the general purpose mode.
+%    \begin{macrocode}
+\lst@NewMode\lst@Pmode
+\lst@NewMode\lst@GPmode
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@modetrue}
+% The usual macro to value a boolean except that we also execute a hook.
+%    \begin{macrocode}
+\def\lst@modetrue{\let\lst@ifmode\iftrue \lsthk@ModeTrue}
+\let\lst@ifmode\iffalse % init
+\lst@AddToHook{ModeTrue}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifLmode}
+% Comment lines use a static mode. It terminates at end of line.
+%    \begin{macrocode}
+\def\lst@Lmodetrue{\let\lst@ifLmode\iftrue}
+\let\lst@ifLmode\iffalse % init
+\lst@AddToHook{EOL}{\@whilesw \lst@ifLmode\fi \lst@LeaveMode}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Diverse helpers}
+%
+% \begin{macro}{\lst@NormedDef}
+% works like |\def| (without any parameters!) but normalizes the replacement
+% text by making all characters lower case and stripping off spaces.
+%    \begin{macrocode}
+\def\lst@NormedDef#1#2{\lowercase{\edef#1{\zap@space#2 \@empty}}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@NormedNameDef}
+% works like |\global\@namedef| (again without any parameters!) but normalizes
+% both the macro name and the replacement text.
+%    \begin{macrocode}
+\def\lst@NormedNameDef#1#2{%
+    \lowercase{\edef\lst@temp{\zap@space#1 \@empty}%
+    \expandafter\xdef\csname\lst@temp\endcsname{\zap@space#2 \@empty}}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@GetFreeMacro}
+% Initialize |\@tempcnta| and |\lst@freemacro|, \ldots
+%    \begin{macrocode}
+\def\lst@GetFreeMacro#1{%
+    \@tempcnta\z@ \def\lst@freemacro{#1\the\@tempcnta}%
+    \lst@GFM@}
+%    \end{macrocode}
+% \ldots\space and either build the control sequence or advance the counter and
+% continue.
+%    \begin{macrocode}
+\def\lst@GFM@{%
+    \expandafter\ifx \csname\lst@freemacro\endcsname \relax
+        \edef\lst@freemacro{\csname\lst@freemacro\endcsname}%
+    \else
+        \advance\@tempcnta\@ne
+        \expandafter\lst@GFM@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@gtempboxa}
+%    \begin{macrocode}
+\newbox\lst@gtempboxa
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \section{Doing output}
+%
+%
+% \subsection{Basic registers and keys}
+%
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+%
+% \paragraph{The current character string}
+% is kept in a token register and a counter holds its length.
+% Here we define the macros to put characters into the output queue.
+%
+% \begin{macro}{\lst@token}
+% \begin{macro}{\lst@length}
+% are allocated here. Quite a useful comment, isn't it?
+%    \begin{macrocode}
+\newtoks\lst@token \newcount\lst@length
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@ResetToken}
+% \begin{macro}{\lst@lastother}
+% The two registers get empty respectively zero at the beginning of each line.
+% After receiving a report from \lsthelper{Claus~Atzenbeck}{1999/11/24}{HTML:
+% output unit repeated after >}---I removed such a bug many times---I decided
+% to reset these registers in the \hookname{EndGroup} hook, too.
+%    \begin{macrocode}
+\def\lst@ResetToken{\lst@token{}\lst@length\z@}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{InitVarsBOL}{\lst@ResetToken \let\lst@lastother\@empty}
+\lst@AddToHook{EndGroup}{\lst@ResetToken \let\lst@lastother\@empty}
+%    \end{macrocode}
+% The macro |\lst@lastother| will be equivalent to the last `other' character,
+% which leads us to |\lst@ifletter|.
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifletter}
+% indicates whether the token contains an identifier or other characters.
+%    \begin{macrocode}
+\def\lst@lettertrue{\let\lst@ifletter\iftrue}
+\def\lst@letterfalse{\let\lst@ifletter\iffalse}
+\lst@AddToHook{InitVars}{\lst@letterfalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Append}
+% puts the argument into the output queue.
+%    \begin{macrocode}
+\def\lst@Append#1{\advance\lst@length\@ne
+                  \lst@token=\expandafter{\the\lst@token#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@AppendOther}
+% Depending on the current state, we first output the character string as an
+% identifier. Then we save the `argument' via |\futurelet| and call the macro
+% |\lst@Append| to do the rest.
+%    \begin{macrocode}
+\def\lst@AppendOther{%
+    \lst@ifletter \lst@Output\lst@letterfalse \fi
+    \futurelet\lst@lastother\lst@Append}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@AppendLetter}
+% We output a non-identifier string if necessary and call |\lst@Append|.
+%    \begin{macrocode}
+\def\lst@AppendLetter{%
+    \lst@ifletter\else \lst@OutputOther\lst@lettertrue \fi
+    \lst@Append}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@SaveToken}
+% \begin{macro}{\lst@RestoreToken}
+% If a group end appears and ruins the character string, we can use these
+% macros to save and restore the contents. |\lst@thestyle| is the current
+% printing style and must be saved and restored, too.
+%    \begin{macrocode}
+\def\lst@SaveToken{%
+    \global\let\lst@gthestyle\lst@thestyle
+    \global\let\lst@glastother\lst@lastother
+    \xdef\lst@RestoreToken{\noexpand\lst@token{\the\lst@token}%
+                           \noexpand\lst@length\the\lst@length\relax
+                           \noexpand\let\noexpand\lst@thestyle
+                                        \noexpand\lst@gthestyle
+                           \noexpand\let\noexpand\lst@lastother
+                                        \noexpand\lst@glastother}}
+%    \end{macrocode}
+% Now -- that means after a bug report by \lsthelper{Rolf~Niepraschk}
+% {2002/04/12}{\RequirePackage is missing keywordstyle when near the top of
+% a page} -- |\lst@lastother| is also saved and restored.
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfLastOtherOneOf}
+% Finally, this obvious implementation.
+%    \begin{macrocode}
+\def\lst@IfLastOtherOneOf#1{\lst@IfLastOtherOneOf@ #1\relax}
+\def\lst@IfLastOtherOneOf@#1{%
+    \ifx #1\relax
+        \expandafter\@secondoftwo
+    \else
+        \ifx\lst@lastother#1%
+            \lst@IfLastOtherOneOf@t
+        \else
+            \expandafter\expandafter\expandafter\lst@IfLastOtherOneOf@
+        \fi
+    \fi}
+\def\lst@IfLastOtherOneOf@t#1\fi\fi#2\relax{\fi\fi\@firstoftwo}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{The current position}
+% is either the dimension |\lst@currlwidth|, which is the horizontal position
+% without taking the current character string into account, or it's the current
+% column starting with number 0. This is |\lst@column| $-$ |\lst@pos| $+$
+% |\lst@length|. Moreover we have |\lst@lostspace| which is the difference
+% between the current and the desired line width. We define macros to insert
+% this lost space.
+%
+% \begin{macro}{\lst@currlwidth}
+% \begin{macro}{\lst@column}
+% \begin{macro}{\lst@pos}
+% the current line width and two counters.
+%    \begin{macrocode}
+\newdimen\lst@currlwidth % \global
+\newcount\lst@column \newcount\lst@pos % \global
+\lst@AddToHook{InitVarsBOL}
+    {\global\lst@currlwidth\z@ \global\lst@pos\z@ \global\lst@column\z@}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@CalcColumn}
+% sets |\@tempcnta| to the current column.
+% Note that |\lst@pos| will be nonpositive.
+%    \begin{macrocode}
+\def\lst@CalcColumn{%
+            \@tempcnta\lst@column
+    \advance\@tempcnta\lst@length
+    \advance\@tempcnta-\lst@pos}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@lostspace}
+% Whenever this dimension is positive we can insert space. A negative `lost
+% space' means that the printed line is wider than expected.
+%    \begin{macrocode}
+\newdimen\lst@lostspace % \global
+\lst@AddToHook{InitVarsBOL}{\global\lst@lostspace\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@UseLostSpace}
+% We insert space and reset it if and only if |\lst@lostspace| is positive.
+%    \begin{macrocode}
+\def\lst@UseLostSpace{\ifdim\lst@lostspace>\z@ \lst@InsertLostSpace \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InsertLostSpace}
+% \begin{macro}{\lst@InsertHalfLostSpace}
+% Ditto, but insert even if negative. |\lst@Kern| will be defined very soon.
+%    \begin{macrocode}
+\def\lst@InsertLostSpace{%
+    \lst@Kern\lst@lostspace \global\lst@lostspace\z@}
+\def\lst@InsertHalfLostSpace{%
+    \global\lst@lostspace.5\lst@lostspace \lst@Kern\lst@lostspace}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%
+% \paragraph{Column widths}
+% Here we deal with the width of a single column, which equals the width of a
+% single character box. Keep in mind that there are fixed and flexible column
+% formats.
+%
+% \begin{macro}{\lst@width}
+% \begin{lstkey}{basewidth}
+% \keyname{basewidth} assigns the values to macros and tests whether they are
+% negative.
+%    \begin{macrocode}
+\newdimen\lst@width
+\lst@Key{basewidth}{0.6em,0.45em}{\lstKV@CSTwoArg{#1}%
+    {\def\lst@widthfixed{##1}\def\lst@widthflexible{##2}%
+     \ifx\lst@widthflexible\@empty
+         \let\lst@widthflexible\lst@widthfixed
+     \fi
+     \def\lst@temp{\PackageError{Listings}%
+                                {Negative value(s) treated as zero}%
+                                \@ehc}%
+     \let\lst@error\@empty
+     \ifdim \lst@widthfixed<\z@
+         \let\lst@error\lst@temp \let\lst@widthfixed\z@
+     \fi
+     \ifdim \lst@widthflexible<\z@
+         \let\lst@error\lst@temp \let\lst@widthflexible\z@
+     \fi
+     \lst@error}}
+%    \end{macrocode}
+% We set the dimension in a special hook.
+%    \begin{macrocode}
+\lst@AddToHook{FontAdjust}
+    {\lst@width=\lst@ifflexible\lst@widthflexible
+                          \else\lst@widthfixed\fi \relax}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{macro}
+%
+% \begin{lstkey}{fontadjust}
+% \begin{macro}{\lst@FontAdjust}
+% This hook is controlled by a switch and is always executed at
+% \hookname{InitVars}.
+%    \begin{macrocode}
+\lst@Key{fontadjust}{false}[t]{\lstKV@SetIf{#1}\lst@iffontadjust}
+\def\lst@FontAdjust{\lst@iffontadjust \lsthk@FontAdjust \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}{\lsthk@FontAdjust}
+%    \end{macrocode}
+% \end{macro}
+% \end{lstkey}
+%
+%
+% \subsection{Low- and mid-level output}
+%
+% \paragraph{Doing the output}
+% means putting the character string into a box register, updating all internal
+% data, and eventually giving the box to \TeX.
+%
+% \begin{macro}{\lst@OutputBox}
+% \begin{macro}{\lst@alloverstyle}
+% The lowest level is the output of a box register.
+% Here we use |\box#1| as argument to |\lst@alloverstyle|.
+%    \begin{macrocode}
+\def\lst@OutputBox#1{\lst@alloverstyle{\box#1}}
+%    \end{macrocode}
+% \begin{ALTERNATIVE}
+% Instead of |\global\advance\lst@currlwidth| |\wd|\meta{box number} in
+% both definitions |\lst@Kern| and |\lst@CalcLostSpaceAndOutput|, we could
+% also advance the dimension here. But I decided not to do so since it
+% simplifies possible redefinitions of |\lst@OutputBox|: we need not to care
+% about |\lst@currlwidth|.
+% \end{ALTERNATIVE}
+%    \begin{macrocode}
+\def\lst@alloverstyle#1{#1}% init
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@Kern}
+% has been used to insert `lost space'.
+% It must not use |\@tempboxa| since that \ldots
+%    \begin{macrocode}
+\def\lst@Kern#1{%
+    \setbox\z@\hbox{{\lst@currstyle{\kern#1}}}%
+    \global\advance\lst@currlwidth \wd\z@
+    \lst@OutputBox\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CalcLostSpaceAndOutput}
+% \ldots\space is used here.
+% We keep track of |\lst@lostspace|, |\lst@currlwidth| and |\lst@pos|.
+%    \begin{macrocode}
+\def\lst@CalcLostSpaceAndOutput{%
+    \global\advance\lst@lostspace \lst@length\lst@width
+    \global\advance\lst@lostspace-\wd\@tempboxa
+    \global\advance\lst@currlwidth \wd\@tempboxa
+    \global\advance\lst@pos -\lst@length
+%    \end{macrocode}
+% Before |\@tempboxa| is output, we insert space if there is enough lost space.
+% This possibly invokes |\lst@Kern| via `insert half lost space', which is the
+% reason for why we mustn't use |\@tempboxa| above. By redefinition we prevent
+% |\lst@OutputBox| from using any special style in |\lst@Kern|.
+%    \begin{macrocode}
+    \setbox\@tempboxa\hbox{\let\lst@OutputBox\box
+        \ifdim\lst@lostspace>\z@ \lst@leftinsert \fi
+        \box\@tempboxa
+        \ifdim\lst@lostspace>\z@ \lst@rightinsert \fi}%
+%    \end{macrocode}
+% Finally we can output the new box.
+%    \begin{macrocode}
+    \lst@OutputBox\@tempboxa \lsthk@PostOutput}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{PostOutput}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@OutputToken}
+% Now comes a mid-level definition.
+% Here we use |\lst@token| to set |\@tempboxa| and eventually output the box.
+% We take care of font adjustment and special output styles.
+% Yet unknown macros are defined in the following subsections.
+%    \begin{macrocode}
+\def\lst@OutputToken{%
+    \lst@TrackNewLines \lst@OutputLostSpace
+    \lst@ifgobbledws
+        \lst@gobbledwhitespacefalse
+        \lst@@discretionary
+    \fi
+    \lst@CheckMerge
+    {\lst@thestyle{\lst@FontAdjust
+     \setbox\@tempboxa\lst@hbox
+        {\lsthk@OutputBox
+         \lst@lefthss
+         \expandafter\lst@FillOutputBox\the\lst@token\@empty
+         \lst@righthss}%
+     \lst@CalcLostSpaceAndOutput}}%
+    \lst@ResetToken}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{OutputBox}{}% init
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\lst@gobbledwhitespacetrue{\global\let\lst@ifgobbledws\iftrue}
+\def\lst@gobbledwhitespacefalse{\global\let\lst@ifgobbledws\iffalse}
+\lst@AddToHookExe{InitBOL}{\lst@gobbledwhitespacefalse}% init
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{Delaying the output}
+% means saving the character string somewhere and pushing it back when
+% neccessary. We may also attach the string to the next output box without
+% affecting style detection: both will be printed in the style of the upcoming
+% output. We will call this `merging'.
+%
+% \begin{macro}{\lst@Delay}
+% \begin{macro}{\lst@Merge}
+% To delay or merge |#1|, we process it as usual and simply save the state
+% in macros. For delayed characters we also need the currently `active'
+% output routine. Both definitions first check whether there are already
+% delayed or `merged' characters.
+%    \begin{macrocode}
+\def\lst@Delay#1{%
+    \lst@CheckDelay
+    #1%
+    \lst@GetOutputMacro\lst@delayedoutput
+    \edef\lst@delayed{\the\lst@token}%
+    \edef\lst@delayedlength{\the\lst@length}%
+    \lst@ResetToken}
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\lst@Merge#1{%
+    \lst@CheckMerge
+    #1%
+    \edef\lst@merged{\the\lst@token}%
+    \edef\lst@mergedlength{\the\lst@length}%
+    \lst@ResetToken}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@MergeToken}
+% Here we put the things together again.
+%    \begin{macrocode}
+\def\lst@MergeToken#1#2{%
+    \advance\lst@length#2%
+    \lst@lExtend#1{\the\lst@token}%
+    \expandafter\lst@token\expandafter{#1}%
+    \let#1\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CheckDelay}
+% We need to print delayed characters. The mode depends on the current output
+% macro. If it equals the saved definition, we put the delayed characters in
+% front of the character string (we merge them) since there has been no
+% letter-to-other or other-to-letter leap. Otherwise we locally reset the
+% current character string, merge this empty string with the delayed one,
+% and output it.
+%    \begin{macrocode}
+\def\lst@CheckDelay{%
+    \ifx\lst@delayed\@empty\else
+        \lst@GetOutputMacro\@gtempa
+        \ifx\lst@delayedoutput\@gtempa
+            \lst@MergeToken\lst@delayed\lst@delayedlength
+        \else
+            {\lst@ResetToken
+             \lst@MergeToken\lst@delayed\lst@delayedlength
+             \lst@delayedoutput}%
+            \let\lst@delayed\@empty
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CheckMerge}
+% All this is easier for |\lst@merged|.
+%    \begin{macrocode}
+\def\lst@CheckMerge{%
+    \ifx\lst@merged\@empty\else
+        \lst@MergeToken\lst@merged\lst@mergedlength
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\let\lst@delayed\@empty % init
+\let\lst@merged\@empty % init
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Column formats}
+%
+% It's time to deal with fixed and flexible column modes.
+% A couple of open definitions are now filled in.
+%
+% \begin{macro}{\lst@column@fixed}
+% switches to the fixed column format. The definitions here control how the
+% output of the above definitions looks like.
+%    \begin{macrocode}
+\def\lst@column@fixed{%
+    \lst@flexiblefalse
+    \lst@width\lst@widthfixed\relax
+    \let\lst@OutputLostSpace\lst@UseLostSpace
+    \let\lst@FillOutputBox\lst@FillFixed
+    \let\lst@hss\hss
+    \def\lst@hbox{\hbox to\lst@length\lst@width}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@FillFixed}
+% Filling up a fixed mode box is easy.
+%    \begin{macrocode}
+\def\lst@FillFixed#1{#1\lst@FillFixed@}
+%    \end{macrocode}
+% While not reaching the end (|\@empty| from above), we insert dynamic space,
+% output the argument and call the submacro again.
+%    \begin{macrocode}
+\def\lst@FillFixed@#1{%
+    \ifx\@empty#1\else \lst@hss#1\expandafter\lst@FillFixed@ \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@column@flexible}
+% The first flexible format.
+%    \begin{macrocode}
+\def\lst@column@flexible{%
+    \lst@flexibletrue
+    \lst@width\lst@widthflexible\relax
+    \let\lst@OutputLostSpace\lst@UseLostSpace
+    \let\lst@FillOutputBox\@empty
+    \let\lst@hss\@empty
+    \let\lst@hbox\hbox}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@column@fullflexible}
+% This column format inserts no lost space except at the beginning of a line.
+%    \begin{macrocode}
+\def\lst@column@fullflexible{%
+    \lst@column@flexible
+    \def\lst@OutputLostSpace{\lst@ifnewline \lst@UseLostSpace\fi}%
+    \let\lst@leftinsert\@empty
+    \let\lst@rightinsert\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@column@spaceflexible}
+% This column format only inserts lost space by stretching (invisible)
+% existing spaces; it does not insert lost space between identifiers
+% and other characters where the original does not have a space.  It
+% was suggested by \lsthelper{Andrei~Alexandrescu}{2007-02-26}{-}.
+%    \begin{macrocode}
+\def\lst@column@spaceflexible{%
+    \lst@column@flexible
+    \def\lst@OutputLostSpace{%
+      \lst@ifwhitespace
+        \ifx\lst@outputspace\lst@visiblespace
+        \else
+          \lst@UseLostSpace
+        \fi
+      \else
+        \lst@ifnewline \lst@UseLostSpace\fi
+      \fi}%
+    \let\lst@leftinsert\@empty
+    \let\lst@rightinsert\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% Thus, we have the column formats. Now we define macros to use them.
+%
+% \begin{macro}{\lst@outputpos}
+% This macro sets the `output-box-positioning' parameter (the old key
+% \keyname{outputpos}). We test for |l|, |c| and |r|.
+% The fixed formats use |\lst@lefthss| and |\lst@righthss|, whereas the
+% flexibles need |\lst@leftinsert| and |\lst@rightinsert|.
+%    \begin{macrocode}
+\def\lst@outputpos#1#2\relax{%
+    \def\lst@lefthss{\lst@hss}\let\lst@righthss\lst@lefthss
+    \let\lst@rightinsert\lst@InsertLostSpace
+    \ifx #1c%
+        \let\lst@leftinsert\lst@InsertHalfLostSpace
+    \else\ifx #1r%
+        \let\lst@righthss\@empty
+        \let\lst@leftinsert\lst@InsertLostSpace
+        \let\lst@rightinsert\@empty
+    \else
+        \let\lst@lefthss\@empty
+        \let\lst@leftinsert\@empty
+        \ifx #1l\else \PackageWarning{Listings}%
+            {Unknown positioning for output boxes}%
+        \fi
+    \fi\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifflexible}
+% indicates the column mode but does not distinguish between different fixed
+% or flexible modes.
+%    \begin{macrocode}
+\def\lst@flexibletrue{\let\lst@ifflexible\iftrue}
+\def\lst@flexiblefalse{\let\lst@ifflexible\iffalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{columns}
+% This is done here: check optional parameter and then build the control
+% sequence of the column format.
+%    \begin{macrocode}
+\lst@Key{columns}{[c]fixed}{\lstKV@OptArg[]{#1}{%
+    \ifx\@empty##1\@empty\else \lst@outputpos##1\relax\relax \fi
+    \expandafter\let\expandafter\lst@arg
+                                \csname\@lst @column@##2\endcsname
+%    \end{macrocode}
+% We issue a warning or save the definition for later.
+%    \begin{macrocode}
+    \lst@arg
+    \ifx\lst@arg\relax
+        \PackageWarning{Listings}{Unknown column format `##2'}%
+    \else
+        \lst@ifflexible
+            \let\lst@columnsflexible\lst@arg
+        \else
+            \let\lst@columnsfixed\lst@arg
+        \fi
+    \fi}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\let\lst@columnsfixed\lst@column@fixed % init
+\let\lst@columnsflexible\lst@column@flexible % init
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{flexiblecolumns}
+% Nothing else but a key to switch between the last flexible and fixed mode.
+%    \begin{macrocode}
+\lst@Key{flexiblecolumns}\relax[t]{%
+    \lstKV@SetIf{#1}\lst@ifflexible
+    \lst@ifflexible \lst@columnsflexible
+              \else \lst@columnsfixed \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+%
+% \subsection{New lines}
+%
+% \begin{macro}{\lst@newlines}
+% This counter holds the number of `new lines' (cr+lf) we have to perform.
+%    \begin{macrocode}
+\newcount\lst@newlines
+\lst@AddToHook{InitVars}{\global\lst@newlines\z@}
+\lst@AddToHook{InitVarsBOL}{\global\advance\lst@newlines\@ne}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@NewLine}
+% This is how we start a new line: begin new paragraph and output an empty
+% box. If low-level definition |\lst@OutputBox| just gobbles the box , we
+% don't start a new line. This is used to drop the whole output.
+%    \begin{macrocode}
+\def\lst@NewLine{%
+    \ifx\lst@OutputBox\@gobble\else
+        \par\noindent \hbox{}%
+    \fi
+    \global\advance\lst@newlines\m@ne
+    \lst@newlinetrue}
+%    \end{macrocode}
+% Define |\lst@newlinetrue| and reset if after output.
+%    \begin{macrocode}
+\def\lst@newlinetrue{\global\let\lst@ifnewline\iftrue}
+\lst@AddToHookExe{PostOutput}{\global\let\lst@ifnewline\iffalse}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@TrackNewLines}
+% If |\lst@newlines| is positive, we execute the hook and insert the
+% new lines.
+%    \begin{macrocode}
+\def\lst@TrackNewLines{%
+    \ifnum\lst@newlines>\z@
+        \lsthk@OnNewLine
+        \lst@DoNewLines
+    \fi}
+\lst@AddToHook{OnNewLine}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{emptylines}
+% \lsthelper{Adam~Prugel-Bennett}{2001/02/19}{spacing of empty lines} asked for
+% such a key---if I didn't misunderstood him. We check for the optional star
+% and set |\lst@maxempty| and switch.
+%    \begin{macrocode}
+\lst@Key{emptylines}\maxdimen{%
+    \@ifstar{\lst@true\@tempcnta\@gobble#1\relax\lst@GobbleNil}%
+            {\lst@false\@tempcnta#1\relax\lst@GobbleNil}#1\@nil
+    \advance\@tempcnta\@ne
+    \edef\lst@maxempty{\the\@tempcnta\relax}%
+    \let\lst@ifpreservenumber\lst@if}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DoNewLines}
+% First we take care of |\lst@maxempty| and then of the remaining empty lines.
+%    \begin{macrocode}
+\def\lst@DoNewLines{
+    \@whilenum\lst@newlines>\lst@maxempty \do
+        {\lst@ifpreservenumber
+            \lsthk@OnEmptyLine
+            \global\advance\c@lstnumber\lst@advancelstnum
+         \fi
+         \global\advance\lst@newlines\m@ne}%
+    \@whilenum \lst@newlines>\@ne \do
+        {\lsthk@OnEmptyLine \lst@NewLine}%
+    \ifnum\lst@newlines>\z@ \lst@NewLine \fi}
+\lst@AddToHook{OnEmptyLine}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{High-level output}
+%
+% \begin{lstkey}{identifierstyle}
+% A simple key.
+%    \begin{macrocode}
+\lst@Key{identifierstyle}{}{\def\lst@identifierstyle{#1}}
+\lst@AddToHook{EmptyStyle}{\let\lst@identifierstyle\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@GotoTabStop}
+% Here we look whether the line already contains printed characters.
+% If true, we output a box with the width of a blank space.
+%    \begin{macrocode}
+\def\lst@GotoTabStop{%
+    \ifnum\lst@newlines=\z@
+        \setbox\@tempboxa\hbox{\lst@outputspace}%
+        \setbox\@tempboxa\hbox to\wd\@tempboxa{{\lst@currstyle{\hss}}}%
+        \lst@CalcLostSpaceAndOutput
+%    \end{macrocode}
+% It's probably not clear why it is sufficient to output a single space to go
+% to the next tabulator stop. Just note that the space lost by this process is
+% `lost space' in the sense above and therefore will be inserted before the
+% next characters are output.
+%    \begin{macrocode}
+    \else
+%    \end{macrocode}
+% Otherwise (no printed characters) we only need to advance |\lst@lostspace|,
+% which is inserted by |\lst@OutputToken| above, and update the column.
+%    \begin{macrocode}
+        \global\advance\lst@lostspace \lst@length\lst@width
+        \global\advance\lst@column\lst@length \lst@length\z@
+    \fi}
+%    \end{macrocode}
+% Note that this version works also in flexible column mode.
+% In fact, it's mainly the flexible version of \packagename{listings} 0.20.
+% \begin{TODO}
+% Use |\lst@ifnewline| instead of |\ifnum\lst@newlines=\z@|?
+% \end{TODO}
+% \end{macro}
+%
+% \begin{macro}{\lst@OutputOther}
+% becomes easy with the previous definitions.
+%    \begin{macrocode}
+\def\lst@OutputOther{%
+    \lst@CheckDelay
+    \ifnum\lst@length=\z@\else
+        \let\lst@thestyle\lst@currstyle
+        \lsthk@OutputOther
+        \lst@OutputToken
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{OutputOther}{}% init
+\let\lst@currstyle\relax % init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Output}
+% We might use identifier style as default.
+%    \begin{macrocode}
+\def\lst@Output{%
+    \lst@CheckDelay
+    \ifnum\lst@length=\z@\else
+        \ifx\lst@currstyle\relax
+            \let\lst@thestyle\lst@identifierstyle
+        \else
+            \let\lst@thestyle\lst@currstyle
+        \fi
+        \lsthk@Output
+        \lst@OutputToken
+    \fi
+    \let\lst@lastother\relax}
+%    \end{macrocode}
+% Note that |\lst@lastother| becomes equivalent to |\relax| and not equivalent
+% to |\@empty| as everywhere else. I don't know whether this will be important
+% in the future or not.
+%    \begin{macrocode}
+\lst@AddToHook{Output}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@GetOutputMacro}
+% Just saves the output macro to be used.
+%    \begin{macrocode}
+\def\lst@GetOutputMacro#1{%
+    \lst@ifletter \global\let#1\lst@Output
+            \else \global\let#1\lst@OutputOther\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@PrintToken}
+% outputs the current character string in letter or nonletter mode.
+%    \begin{macrocode}
+\def\lst@PrintToken{%
+    \lst@ifletter \lst@Output \lst@letterfalse
+            \else \lst@OutputOther \let\lst@lastother\@empty \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@XPrintToken}
+% is a special definition to print also merged characters.
+%    \begin{macrocode}
+\def\lst@XPrintToken{%
+    \lst@PrintToken \lst@CheckMerge
+    \ifnum\lst@length=\z@\else \lst@PrintToken \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Dropping the whole output}
+%
+% \begin{macro}{\lst@BeginDropOutput}
+% It's sometimes useful to process a part of a listing as usual, but to drop
+% the output. This macro does the main work and gets one argument, namely the
+% internal mode it enters. We save |\lst@newlines|, restore it |\aftergroup|
+% and redefine one macro, namely |\lst@OutputBox|. After a bug report from
+% \lsthelper{Gunther~Schmidl}{2002/02/27}{collapsing empty lines don't work
+% with printpod=false}
+%    \begin{macrocode}
+\def\lst@BeginDropOutput#1{%
+    \xdef\lst@BDOnewlines{\the\lst@newlines}%
+    \global\let\lst@BDOifnewline\lst@ifnewline
+    \lst@EnterMode{#1}%
+        {\lst@modetrue
+         \let\lst@OutputBox\@gobble
+         \aftergroup\lst@BDORestore}}
+%    \end{macrocode}
+% Restoring the date is quite easy:
+%    \begin{macrocode}
+\def\lst@BDORestore{%
+    \global\lst@newlines\lst@BDOnewlines
+    \global\let\lst@ifnewline\lst@BDOifnewline}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndDropOutput}
+% is equivalent to |\lst@LeaveMode|.
+%    \begin{macrocode}
+\let\lst@EndDropOutput\lst@LeaveMode
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Writing to an external file}
+%
+% \begin{aspect}{writefile}
+% Now it would be good to know something about character classes since we need
+% to access the true input characters, for example a tabulator and not the
+% spaces it `expands' to.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{writefile}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@WF}
+% \begin{macro}{\lst@WFtoken}
+% The contents of the token will be written to file.
+%    \begin{macrocode}
+\newtoks\lst@WFtoken % global
+\lst@AddToHook{InitVarsBOL}{\global\lst@WFtoken{}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\newwrite\lst@WF
+\global\let\lst@WFifopen\iffalse % init
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@WFWriteToFile}
+% To do this, we have to expand the contents and then expand this via |\edef|.
+% Empty |\lst@UM| ensures that special characters (underscore, dollar, etc.)
+% are written correctly.
+%    \begin{macrocode}
+\gdef\lst@WFWriteToFile{%
+  \begingroup
+   \let\lst@UM\@empty
+   \expandafter\edef\expandafter\lst@temp\expandafter{\the\lst@WFtoken}%
+   \immediate\write\lst@WF{\lst@temp}%
+  \endgroup
+  \global\lst@WFtoken{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@WFAppend}
+% Similar to |\lst@Append| but uses |\lst@WFtoken|.
+%    \begin{macrocode}
+\gdef\lst@WFAppend#1{%
+    \global\lst@WFtoken=\expandafter{\the\lst@WFtoken#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginWriteFile}
+% \begin{macro}{\lst@BeginAlsoWriteFile}
+% use different macros for |\lst@OutputBox| (not) to drop the output.
+%    \begin{macrocode}
+\gdef\lst@BeginWriteFile{\lst@WFBegin\@gobble}
+\gdef\lst@BeginAlsoWriteFile{\lst@WFBegin\lst@OutputBox}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@WFBegin}
+% Here \ldots
+%    \begin{macrocode}
+\begingroup \catcode`\^^I=11
+\gdef\lst@WFBegin#1#2{%
+    \begingroup
+    \let\lst@OutputBox#1%
+%    \end{macrocode}
+% \ldots\space we have to update |\lst@WFtoken| and \ldots
+%    \begin{macrocode}
+    \def\lst@Append##1{%
+        \advance\lst@length\@ne
+        \expandafter\lst@token\expandafter{\the\lst@token##1}%
+        \ifx ##1\lst@outputspace \else
+            \lst@WFAppend##1%
+        \fi}%
+    \lst@lAddTo\lst@PreGotoTabStop{\lst@WFAppend{^^I}}%
+    \lst@lAddTo\lst@ProcessSpace{\lst@WFAppend{ }}%
+%    \end{macrocode}
+% \ldots\space need different `EOL' and `DeInit' definitions to write the
+% token register to file.
+%    \begin{macrocode}
+    \let\lst@DeInit\lst@WFDeInit
+    \let\lst@MProcessListing\lst@WFMProcessListing
+%    \end{macrocode}
+% Finally we open the file if necessary.
+%    \begin{macrocode}
+    \lst@WFifopen\else
+        \immediate\openout\lst@WF=#2\relax
+        \global\let\lst@WFifopen\iftrue
+        \@gobbletwo\fi\fi
+    \fi}
+\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndWriteFile}
+% closes the file and restores original definitions.
+%    \begin{macrocode}
+\gdef\lst@EndWriteFile{%
+    \immediate\closeout\lst@WF \endgroup
+    \global\let\lst@WFifopen\iffalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@WFMProcessListing}
+% \begin{macro}{\lst@WFDeInit}
+% write additionally |\lst@WFtoken| to external file.
+%    \begin{macrocode}
+\global\let\lst@WFMProcessListing\lst@MProcessListing
+\global\let\lst@WFDeInit\lst@DeInit
+\lst@AddToAtTop\lst@WFMProcessListing{\lst@WFWriteToFile}
+\lst@AddToAtTop\lst@WFDeInit{%
+    \ifnum\lst@length=\z@\else \lst@WFWriteToFile \fi}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \section{Character classes}\label{iCharacterClasses}
+%
+% In this section, we define how the basic character classes do behave, before
+% turning over to the selection of character tables and how to specialize
+% characters.
+%
+%
+% \subsection{Letters, digits and others}
+%
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@ProcessLetter}
+% We put the letter, which is not a whitespace, into the output queue.
+%    \begin{macrocode}
+\def\lst@ProcessLetter{\lst@whitespacefalse \lst@AppendLetter}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ProcessOther}
+% Ditto.
+%    \begin{macrocode}
+\def\lst@ProcessOther{\lst@whitespacefalse \lst@AppendOther}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ProcessDigit}
+% A digit appends the character to the current character string. But we must
+% use the right macro. This allows digits to be part of an identifier or
+% a numerical constant.
+%    \begin{macrocode}
+\def\lst@ProcessDigit{%
+    \lst@whitespacefalse
+    \lst@ifletter \expandafter\lst@AppendLetter
+            \else \expandafter\lst@AppendOther\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifwhitespace}
+% indicates whether the last processed character has been white space.
+%    \begin{macrocode}
+\def\lst@whitespacetrue{\global\let\lst@ifwhitespace\iftrue}
+\def\lst@whitespacefalse{\global\let\lst@ifwhitespace\iffalse}
+\lst@AddToHook{InitVarsBOL}{\lst@whitespacetrue}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Whitespaces}
+%
+% Here we have to take care of two things: dropping empty lines at the end of
+% a listing and the different column formats. Both use |\lst@lostspace|. Lines
+% containing only tabulators and spaces should be viewed as empty. In order to
+% achieve this, tabulators and spaces at the beginning of a line don't output
+% any characters but advance |\lst@lostspace|. Whenever this dimension is
+% positive we insert that space before the character string is output. Thus,
+% if there are only tabulators and spaces, the line is `empty' since we
+% haven't done any output.
+%
+% We have to do more for flexible columns. Whitespaces can fix the column
+% alignment: if the real line is wider than expected, a tabulator is at least
+% one space wide; all remaining space fixes the alignment. If there are two or
+% more space characters, at least one is printed; the others fix the column
+% alignment.
+%
+%
+% \paragraph{Tabulators}
+% are processed in three stages. You have already seen the last stage
+% |\lst@GotoTabStop|. The other two calculate the necessary width and take care
+% of visible tabulators and spaces.
+%
+% \begin{lstkey}{tabsize}
+% We check for a legal argument before saving it. Default tabsize is 8 as
+% proposed by \lsthelper{Rolf~Niepraschk}{1997/04/24}{tabsize=8}.
+%    \begin{macrocode}
+\lst@Key{tabsize}{8}
+    {\ifnum#1>\z@ \def\lst@tabsize{#1}\else
+         \PackageError{Listings}{Strict positive integer expected}%
+         {You can't use `#1' as tabsize. \@ehc}%
+     \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{showtabs}
+% \begin{lstkey}{tab}
+% Two more user keys for tab control.
+%    \begin{macrocode}
+\lst@Key{showtabs}f[t]{\lstKV@SetIf{#1}\lst@ifshowtabs}
+\lst@Key{tab}{\kern.06em\hbox{\vrule\@height.3ex}%
+              \hrulefill\hbox{\vrule\@height.3ex}}
+    {\def\lst@tab{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@ProcessTabulator}
+% A tabulator outputs the preceding characters, which decrements |\lst@pos| by
+% the number of printed characters.
+%    \begin{macrocode}
+\def\lst@ProcessTabulator{%
+    \lst@XPrintToken \lst@whitespacetrue
+%    \end{macrocode}
+% Then we calculate how many columns we need to reach the next tabulator stop:
+% we add |\lst@tabsize| until |\lst@pos| is strict positive. In other words,
+% |\lst@pos| is the column modulo |tabsize| and we're looking for a positive
+% representative. We assign it to |\lst@length| and reset |\lst@pos| in the
+% submacro.
+%    \begin{macrocode}
+    \global\advance\lst@column -\lst@pos
+    \@whilenum \lst@pos<\@ne \do
+        {\global\advance\lst@pos\lst@tabsize}%
+    \lst@length\lst@pos
+    \lst@PreGotoTabStop}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@PreGotoTabStop}
+% Visible tabs print |\lst@tab|.
+%    \begin{macrocode}
+\def\lst@PreGotoTabStop{%
+    \lst@ifshowtabs
+        \lst@TrackNewLines
+        \setbox\@tempboxa\hbox to\lst@length\lst@width
+            {{\lst@currstyle{\hss\lst@tab}}}%
+        \lst@CalcLostSpaceAndOutput
+    \else
+%    \end{macrocode}
+% If we are advised to keep spaces, we insert the correct number of them.
+%    \begin{macrocode}
+        \lst@ifkeepspaces
+            \@tempcnta\lst@length \lst@length\z@
+            \@whilenum \@tempcnta>\z@ \do
+                {\lst@AppendOther\lst@outputspace
+                 \advance\@tempcnta\m@ne}%
+            \lst@OutputOther
+        \else
+            \lst@GotoTabStop
+        \fi
+    \fi
+    \lst@length\z@ \global\lst@pos\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{Spaces}
+% are implemented as described at the beginning of this subsection. But first
+% we define some user keys.
+%
+% \begin{macro}{\lst@outputspace}
+% \begin{macro}{\lst@visiblespace}
+% The first macro is a default definition, \ldots
+%    \begin{macrocode}
+\def\lst@outputspace{\ }
+\def\lst@visiblespace{\lst@ttfamily{\char32}\textvisiblespace}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{showspaces}
+% \begin{lstkey}{keepspaces}
+% \ldots\space which is modified on user's request.
+%    \begin{macrocode}
+\lst@Key{showspaces}{false}[t]{\lstKV@SetIf{#1}\lst@ifshowspaces}
+\lst@Key{keepspaces}{false}[t]{\lstKV@SetIf{#1}\lst@ifkeepspaces}
+\lst@AddToHook{Init}
+    {\lst@ifshowspaces
+         \let\lst@outputspace\lst@visiblespace
+         \lst@keepspacestrue
+     \fi}
+\def\lst@keepspacestrue{\let\lst@ifkeepspaces\iftrue}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@ProcessSpace}
+% We look whether spaces fix the column alignment or not. In the latter case
+% we append a space; otherwise \ldots
+% \lsthelper{Andrei~Alexandrescu}{2007/02/27}{-} tested the |spaceflexible|
+% column setting and found a bug that resulted from |\lst@PrintToken| and
+% |\lst@whitespacetrue| being out of order here.
+%    \begin{macrocode}
+\def\lst@ProcessSpace{%
+    \lst@ifkeepspaces
+        \lst@PrintToken
+        \lst@whitespacetrue
+        \lst@AppendOther\lst@outputspace
+        \lst@PrintToken
+    \else \ifnum\lst@newlines=\z@
+%    \end{macrocode}
+% \ldots\space we append a `special space' if the line isn't empty.
+%    \begin{macrocode}
+        \lst@AppendSpecialSpace
+    \else \ifnum\lst@length=\z@
+%    \end{macrocode}
+% If the line is empty, we check whether there are characters in the output
+% queue. If there are no characters we just advance |\lst@lostspace|.
+% Otherwise we append the space.
+%    \begin{macrocode}
+            \global\advance\lst@lostspace\lst@width
+            \global\advance\lst@pos\m@ne
+            \lst@whitespacetrue
+        \else
+            \lst@AppendSpecialSpace
+        \fi
+    \fi \fi}
+%    \end{macrocode}
+% Note that this version works for fixed and flexible column output.
+% \end{macro}
+%
+% \begin{macro}{\lst@AppendSpecialSpace}
+% If there are at least two white spaces, we output preceding characters and
+% advance |\lst@lostspace| to avoid alignment problems. Otherwise we append
+% a space to the current character string.  Also, |\lst@whitespacetrue| has
+% been moved after |\lst@PrintToken| so that the token-printer can correctly
+% check whether it is printing whitespace or not; this was preventing the
+% |spaceflexible| column setting from working correctly.
+%    \begin{macrocode}
+\def\lst@AppendSpecialSpace{%
+    \lst@ifwhitespace
+        \lst@PrintToken
+        \global\advance\lst@lostspace\lst@width
+        \global\advance\lst@pos\m@ne
+        \lst@gobbledwhitespacetrue
+    \else
+        \lst@PrintToken
+        \lst@whitespacetrue
+        \lst@AppendOther\lst@outputspace
+        \lst@PrintToken
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{Form feeds}
+% has been introduced after communication with
+% \lsthelper{Jan~Braun}{1998/04/27}{formfeed}.
+%
+% \begin{lstkey}{formfeed}
+% let the user make adjustments.
+%    \begin{macrocode}
+\lst@Key{formfeed}{\bigbreak}{\def\lst@formfeed{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@ProcessFormFeed}
+% Here we execute some macros according to whether a new line has already
+% begun or not. No |\lst@EOLUpdate| is used in the else branch
+% anymore---\lsthelper{Kalle~Tuulos}{2001/01/14}{form feed gobbles following
+% output unit} sent the bug report.
+%    \begin{macrocode}
+\def\lst@ProcessFormFeed{%
+    \lst@XPrintToken
+    \ifnum\lst@newlines=\z@
+        \lst@EOLUpdate \lsthk@InitVarsBOL
+    \fi
+    \lst@formfeed
+    \lst@whitespacetrue}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Character tables}\label{iCharacterTables}
+%
+%
+% \subsubsection{The standard table}
+%
+% The standard character table is selected by |\lst@SelectStdCharTable|, which
+% expands to a token sequence
+%    \ldots|\def| |A{\lst@ProcessLetter| |A}|\ldots\space
+% where the first A is active and the second has catcode 12. We use the
+% following macros to build the character table.
+% \begin{syntax}
+%   \item[0.19] |\lst@CCPut|\meta{class
+%     macro}\meta{$c_1$}\ldots\meta{$c_k$}|\z@|
+%
+%     extends the standard character table by the characters with codes
+%     \meta{$c_1$}\ldots\meta{$c_k$} making each character use \meta{class
+%     macro}. All these characters must be printable via
+%     |\char|\meta{$c_i$}.
+%
+%   \item[0.20]
+%     |\lst@CCPutMacro|\meta{class$_1$}\meta{$c_1$}\meta{definition$_1$}^^A
+%     \ldots|\@empty\z@\@empty|
+%
+%     also extends the standard character table: the character
+%     \meta{$c_i$} will use
+%     \meta{class$_i$} and is printed via
+%     \meta{definition$_i$}.  These definitions must be \meta{spec. token}s
+%     in the sense of section \ref{dCharacterTables}.
+% \end{syntax}
+%
+% \begin{macro}{\lst@Def}
+% \begin{macro}{\lst@Let}
+% For speed we won't use these helpers too often.
+%    \begin{macrocode}
+\def\lst@Def#1{\lccode`\~=#1\lowercase{\def~}}
+\def\lst@Let#1{\lccode`\~=#1\lowercase{\let~}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begingroup
+% The definition of the space below doesn't hurt anything. But other aspects,
+% for example \aspectname{lineshape} and \aspectname{formats}, redefine also
+% the macro |\space|. Now, if \LaTeX\ calls |\try@load@fontshape|, the |.log|
+% messages would show some strange things since \LaTeX\ uses |\space| in these
+% messages. The following addition ensures that |\space| expands to a space
+% and not to something different. This was one more bug reported by
+% \lsthelper{Denis~Girou}{1999/09/16}{bad font info message with breaklines}.
+%    \begin{macrocode}
+\lst@AddToAtTop{\try@load@fontshape}{\def\space{ }}
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lst@SelectStdCharTable}
+% The first three standard characters. |\lst@Let| has been replaced by
+% |\lst@Def| after a bug report from \lsthelper{Chris~Edwards}{2002/02/15}
+% {tabulators show up with firstline>1}.
+%    \begin{macrocode}
+\def\lst@SelectStdCharTable{%
+    \lst@Def{9}{\lst@ProcessTabulator}%
+    \lst@Def{12}{\lst@ProcessFormFeed}%
+    \lst@Def{32}{\lst@ProcessSpace}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CCPut}
+% The first argument gives the character class, then follow the
+% codes.
+%
+% \lsthelper{Joseph~Wright}{2016/04/04}{unguarded setting of |lccode|}
+% pointed to a bug which came up on TeX StackExchange
+% (|http://tex.stackexchange.com/questions/302437/textcase-lstings-and-tilde|). Other
+% than in |\lst@CCPutMacro| the |\lccode| settings weren't local and caused
+% the error.
+%    \begin{macrocode}
+\def\lst@CCPut#1#2{%
+    \ifnum#2=\z@
+        \expandafter\@gobbletwo
+    \else
+        \begingroup\lccode`\~=#2\lccode`\/=#2\lowercase{\endgroup\lst@CCPut@~{#1/}}%
+    \fi
+    \lst@CCPut#1}
+\def\lst@CCPut@#1#2{\lst@lAddTo\lst@SelectStdCharTable{\def#1{#2}}}
+%    \end{macrocode}
+% Now we insert more standard characters.
+%    \begin{macrocode}
+\lst@CCPut \lst@ProcessOther
+    {"21}{"22}{"28}{"29}{"2B}{"2C}{"2E}{"2F}
+    {"3A}{"3B}{"3D}{"3F}{"5B}{"5D}
+    \z@
+\lst@CCPut \lst@ProcessDigit
+    {"30}{"31}{"32}{"33}{"34}{"35}{"36}{"37}{"38}{"39}
+    \z@
+\lst@CCPut \lst@ProcessLetter
+    {"40}{"41}{"42}{"43}{"44}{"45}{"46}{"47}
+    {"48}{"49}{"4A}{"4B}{"4C}{"4D}{"4E}{"4F}
+    {"50}{"51}{"52}{"53}{"54}{"55}{"56}{"57}
+    {"58}{"59}{"5A}
+         {"61}{"62}{"63}{"64}{"65}{"66}{"67}
+    {"68}{"69}{"6A}{"6B}{"6C}{"6D}{"6E}{"6F}
+    {"70}{"71}{"72}{"73}{"74}{"75}{"76}{"77}
+    {"78}{"79}{"7A}
+    \z@
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CCPutMacro}
+% Now we come to a delicate point. The characters not inserted yet aren't
+% printable (|_|, |$|, \ldots) or aren't printed well (|*|, |-|, \ldots) if we
+% enter these characters. Thus we use proper macros to print the characters.
+% Works perfectly. The problem is that the current character string is
+% printable for speed, for example |_| is already replaced by a macro version,
+% but the new keyword tests need the original characters.
+%
+% The solution: We define |\def _{\lst@ProcessLetter\lst@um_}| where the first
+% underscore is active and the second belongs to the control sequence.
+% Moreover we have |\def\lst@um_{\lst@UM _}| where the second underscore has
+% the usual meaning. Now the keyword tests can access the original character
+% simply by making |\lst@UM| empty. The default definition gets the following
+% token and builds the control sequence |\lst@um_@|, which we'll define to
+% print the character. Easy, isn't it?^^A ;-)
+%
+% The following definition does all this for us. The first parameter gives the
+% character class, the second the character code, and the last the definition
+% which actually prints the character. We build the names |\lst@um_| and
+% |\lst@um_@| and give them to a submacro.
+%    \begin{macrocode}
+\def\lst@CCPutMacro#1#2#3{%
+    \ifnum#2=\z@ \else
+        \begingroup\lccode`\~=#2\relax \lccode`\/=#2\relax
+        \lowercase{\endgroup\expandafter\lst@CCPutMacro@
+            \csname\@lst @um/\expandafter\endcsname
+            \csname\@lst @um/@\endcsname /~}#1{#3}%
+        \expandafter\lst@CCPutMacro
+    \fi}
+%    \end{macrocode}
+% The arguments are now |\lst@um_|, |\lst@um_@|, nonactive character, active
+% character, character class and printing definition. We add |\def _{|
+% |\lst@ProcessLetter| |\lst@um_}| to |\lst@SelectStdCharTable| (and similarly
+% other special characters), define |\def\lst@um_{\lst@UM _}| and |\lst@um_@|.
+%    \begin{macrocode}
+\def\lst@CCPutMacro@#1#2#3#4#5#6{%
+    \lst@lAddTo\lst@SelectStdCharTable{\def#4{#5#1}}%
+    \def#1{\lst@UM#3}%
+    \def#2{#6}}
+%    \end{macrocode}
+% The default definition of |\lst@UM|:
+%    \begin{macrocode}
+\def\lst@UM#1{\csname\@lst @um#1@\endcsname}
+%    \end{macrocode}
+% And all remaining standard characters.
+%    \begin{macrocode}
+\lst@CCPutMacro
+    \lst@ProcessOther {"23}\#
+    \lst@ProcessLetter{"24}\textdollar
+    \lst@ProcessOther {"25}\%
+    \lst@ProcessOther {"26}\&
+    \lst@ProcessOther {"27}{\lst@ifupquote \textquotesingle
+                                     \else \char39\relax \fi}
+    \lst@ProcessOther {"2A}{\lst@ttfamily*\textasteriskcentered}
+    \lst@ProcessOther {"2D}{\lst@ttfamily{-{}}{$-$}}
+    \lst@ProcessOther {"3C}{\lst@ttfamily<\textless}
+    \lst@ProcessOther {"3E}{\lst@ttfamily>\textgreater}
+    \lst@ProcessOther {"5C}{\lst@ttfamily{\char92}\textbackslash}
+    \lst@ProcessOther {"5E}\textasciicircum
+    \lst@ProcessLetter{"5F}{\lst@ttfamily{\char95}\textunderscore}
+    \lst@ProcessOther {"60}{\lst@ifupquote \textasciigrave
+                                     \else \char96\relax \fi}
+    \lst@ProcessOther {"7B}{\lst@ttfamily{\char123}\textbraceleft}
+    \lst@ProcessOther {"7C}{\lst@ttfamily|\textbar}
+    \lst@ProcessOther {"7D}{\lst@ttfamily{\char125}\textbraceright}
+    \lst@ProcessOther {"7E}\textasciitilde
+    \lst@ProcessOther {"7F}-
+    \@empty\z@\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ttfamily}
+% What is this ominous macro? It prints either the first or the second
+% argument. In |\ttfamily| it ensures that |----| is typeset |----| and not
+% $-$$-$$-$$-$ as in version 0.17. Bug encountered by
+% \lsthelper{Dr.~Jobst~Hoffmann}{1998/03/30}{|\lst@minus| and |\ttfamily|}.
+% Furthermore I added |\relax| after receiving an error report from
+% \lsthelper{Magnus~Lewis-Smith}{1999/08/06}{! Bad character code (920).}
+%    \begin{macrocode}
+\def\lst@ttfamily#1#2{\ifx\f@family\ttdefault#1\relax\else#2\fi}
+%    \end{macrocode}
+% |\ttdefault| is defined |\long|, so the |\ifx| doesn't work since |\f@family|
+% isn't |\long|! We go around this problem by redefining |\ttdefault| locally:
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\edef\ttdefault{\ttdefault}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{upquote}
+% is used above to decide which quote to print. We print an error message if
+% the necessary \packagename{textcomp} commands are not available. This key
+% has been added after an email from \lsthelper{Frank~Mittelbach}{2003/06/18}
+% {listings and upquote}.
+%    \begin{macrocode}
+\lst@Key{upquote}{false}[t]{\lstKV@SetIf{#1}\lst@ifupquote
+    \lst@ifupquote
+       \@ifundefined{textasciigrave}%
+          {\let\KV@lst@upquote\@gobble
+           \lstKV@SetIf f\lst@ifupquote \@gobble\fi
+           \PackageError{Listings}{Option `upquote' requires `textcomp'
+            package.\MessageBreak The option has been disabled}%
+          {Add \string\usepackage{textcomp} to your preamble.}}%
+          {}%
+    \fi}
+%    \end{macrocode}
+% If an \packagename{upquote} package is loaded, the \keyname{upquote} option
+% is enabled by default.
+%    \begin{macrocode}
+\AtBeginDocument{%
+  \@ifpackageloaded{upquote}{\RequirePackage{textcomp}%
+                             \lstset{upquote}}{}%
+  \@ifpackageloaded{upquote2}{\lstset{upquote}}{}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@ifactivechars}
+% A simple switch.
+%    \begin{macrocode}
+\def\lst@activecharstrue{\let\lst@ifactivechars\iftrue}
+\def\lst@activecharsfalse{\let\lst@ifactivechars\iffalse}
+\lst@activecharstrue
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@SelectCharTable}
+% We select the standard character table and switch to active catcodes.
+%    \begin{macrocode}
+\def\lst@SelectCharTable{%
+    \lst@SelectStdCharTable
+    \lst@ifactivechars
+        \catcode9\active \catcode12\active \catcode13\active
+        \@tempcnta=32\relax
+        \@whilenum\@tempcnta<128\do
+            {\catcode\@tempcnta\active\advance\@tempcnta\@ne}%
+    \fi
+    \lst@ifec \lst@DefEC \fi
+%    \end{macrocode}
+% The following line and the according macros below have been added after a
+% bug report from \lsthelper{Fr\'ed\'eric~Boulanger}{2001/02/27}{ligatures}.
+% The assignment to |\do@noligs| was changed to |\do| after a bug report from
+% \lsthelper{Peter~Ruckdeschel}{2002/04/12}{problems with simultanous use of
+% seminar.sty and listings.sty}. This bugfix was kindly provided by
+% \lsthelper{Timothy~Van~Zandt}{2002/04/13}{Re: ...}.
+%    \begin{macrocode}
+    \let\do\lst@do@noligs \verbatim@nolig@list
+%    \end{macrocode}
+% There are two ways to adjust the standard table: inside the hook or with
+% |\lst@DeveloperSCT|. We use these macros and initialize the backslash if
+% necessary. |\lst@DefRange| has been moved outside the hook after a bug report
+% by \lsthelper{Michael~Bachmann}{2004/07/21}{Keine label-Referenzierung
+% m\"oglich...}.
+%    \begin{macrocode}
+    \lsthk@SelectCharTable
+    \lst@DeveloperSCT
+    \lst@DefRange
+    \ifx\lst@Backslash\relax\else
+        \lst@LetSaveDef{"5C}\lsts@backslash\lst@Backslash
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{SelectCharTable}
+% \begin{lstkey}{MoreSelectCharTable}
+% The keys to adjust |\lst@DeveloperSCT|.
+%    \begin{macrocode}
+\lst@Key{SelectCharTable}{}{\def\lst@DeveloperSCT{#1}}
+\lst@Key{MoreSelectCharTable}\relax{\lst@lAddTo\lst@DeveloperSCT{#1}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SetLanguage}{\let\lst@DeveloperSCT\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@do@noligs}
+% To prevent ligatures, this macro inserts the token |\lst@NoLig| in front of
+% |\lst@Process|\meta{whatever}\meta{spec.~token}. This is done by
+% |\verbatim@nolig@list| for certain characters. Note that the submacro is
+% a special kind of a local |\lst@AddToAtTop|. The submacro definition was
+% fixed thanks to \lsthelper{Peter~Bartke}{2002/04/10}{bad `noligs' handling}.
+%    \begin{macrocode}
+\def\lst@do@noligs#1{%
+    \begingroup \lccode`\~=`#1\lowercase{\endgroup
+    \lst@do@noligs@~}}
+\def\lst@do@noligs@#1{%
+    \expandafter\expandafter\expandafter\def
+    \expandafter\expandafter\expandafter#1%
+    \expandafter\expandafter\expandafter{\expandafter\lst@NoLig#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@NoLig}
+% When this extra macro is processed, it adds |\lst@nolig| to the output queue
+% without increasing its length. For keyword detection this must expand to
+% nothing if |\lst@UM| is empty.
+%    \begin{macrocode}
+\def\lst@NoLig{\advance\lst@length\m@ne \lst@Append\lst@nolig}
+\def\lst@nolig{\lst@UM\@empty}%
+%    \end{macrocode}
+% But the usual meaning of |\lst@UM| builds the following control sequence,
+% which prevents ligatures in the manner of \LaTeX's |\do@noligs|.
+%    \begin{macrocode}
+\@namedef{\@lst @um@}{\leavevmode\kern\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@SaveOutputDef}
+% To get the \meta{spec.~token} meaning of character |#1|, we look for |\def|
+% `active character |#1|' in |\lst@SelectStdCharTable|, get the replacement
+% text, strip off the character class via |\@gobble|, and assign the meaning.
+% Note that you get a ``runaway argument'' error if an illegal \meta{character
+% code}=|#1| is used.
+%    \begin{macrocode}
+\def\lst@SaveOutputDef#1#2{%
+    \begingroup \lccode`\~=#1\relax \lowercase{\endgroup
+    \def\lst@temp##1\def~##2##3\relax}{%
+        \global\expandafter\let\expandafter#2\@gobble##2\relax}%
+    \expandafter\lst@temp\lst@SelectStdCharTable\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstum@backslash}
+% A commonly used character.
+%    \begin{macrocode}
+\lst@SaveOutputDef{"5C}\lstum@backslash
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsubsection{National characters}
+%
+% \begin{lstkey}{extendedchars}
+% The user key to activate extended characters 128--255.
+%    \begin{macrocode}
+\lst@Key{extendedchars}{true}[t]{\lstKV@SetIf{#1}\lst@ifec}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DefEC}
+% Currently each character in the range 128--255 is treated as a letter.
+%    \begin{macrocode}
+\def\lst@DefEC{%
+    \lst@CCECUse \lst@ProcessLetter
+      ^^80^^81^^82^^83^^84^^85^^86^^87^^88^^89^^8a^^8b^^8c^^8d^^8e^^8f%
+      ^^90^^91^^92^^93^^94^^95^^96^^97^^98^^99^^9a^^9b^^9c^^9d^^9e^^9f%
+      ^^a0^^a1^^a2^^a3^^a4^^a5^^a6^^a7^^a8^^a9^^aa^^ab^^ac^^ad^^ae^^af%
+      ^^b0^^b1^^b2^^b3^^b4^^b5^^b6^^b7^^b8^^b9^^ba^^bb^^bc^^bd^^be^^bf%
+      ^^c0^^c1^^c2^^c3^^c4^^c5^^c6^^c7^^c8^^c9^^ca^^cb^^cc^^cd^^ce^^cf%
+      ^^d0^^d1^^d2^^d3^^d4^^d5^^d6^^d7^^d8^^d9^^da^^db^^dc^^dd^^de^^df%
+      ^^e0^^e1^^e2^^e3^^e4^^e5^^e6^^e7^^e8^^e9^^ea^^eb^^ec^^ed^^ee^^ef%
+      ^^f0^^f1^^f2^^f3^^f4^^f5^^f6^^f7^^f8^^f9^^fa^^fb^^fc^^fd^^fe^^ff%
+      ^^00}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CCECUse}
+% Reaching end of list (|^^00|) we terminate the loop.
+% Otherwise we do the same as in |\lst@CCPut| if the character is not active.
+% But if the character is active, we save the meaning before redefinition.
+%    \begin{macrocode}
+\def\lst@CCECUse#1#2{%
+    \ifnum`#2=\z@
+        \expandafter\@gobbletwo
+    \else
+        \ifnum\catcode`#2=\active
+            \lccode`\~=`#2\lccode`\/=`#2\lowercase{\lst@CCECUse@#1~/}%
+        \else
+            \lst@ifactivechars \catcode`#2=\active \fi
+            \lccode`\~=`#2\lccode`\/=`#2\lowercase{\def~{#1/}}%
+        \fi
+    \fi
+    \lst@CCECUse#1}
+%    \end{macrocode}
+% We save the meaning as mentioned. Here we must also use the `|\lst@UM|
+% construction' since extended characters could often appear in words =
+% identifiers. Bug reported by \lsthelper{Denis~Girou}{1999/07/26}
+% {incompatibility with inputenc}.
+%    \begin{macrocode}
+\def\lst@CCECUse@#1#2#3{%
+    \expandafter\def\csname\@lst @EC#3\endcsname{\lst@UM#3}%
+    \expandafter\let\csname\@lst @um#3@\endcsname #2%
+    \edef#2{\noexpand#1%
+            \expandafter\noexpand\csname\@lst @EC#3\endcsname}}
+%    \end{macrocode}
+% \lsthelper{Daniel~Gerigk}{2001/10/25}{extendedchars do not work} and
+% \lsthelper{Heiko~Oberdiek}{2001/10/26}{extendedchars do not work: um@\#3@
+% must be @um\#3@} reported an error and a solution, respectively.
+% \end{macro}
+%
+%
+% \subsubsection{Catcode problems}
+%
+% \begin{macro}{\lst@nfss@catcodes}
+% \lsthelper{Anders~Edenbrandt}{1997/04/22}{preload of .fd files} found a bug
+% with \texttt{.fd}-files. Since we change catcodes and these files are read
+% on demand, we must reset the catcodes before the files are input. We use a
+% local redefinition of |\nfss@catcodes|.
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+    {\let\lsts@nfss@catcodes\nfss@catcodes
+     \let\nfss@catcodes\lst@nfss@catcodes}
+%    \end{macrocode}
+% The |&|-character had turned into |\&| after a bug report by \lsthelper
+% {David~Aspinall}{2003/07/17}{loading of .fd file inside tabular produces
+% error}.
+%    \begin{macrocode}
+\def\lst@nfss@catcodes{%
+    \lst@makeletter
+        ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\relax
+    \@makeother (\@makeother )\@makeother ,\@makeother :\@makeother\&%
+    \@makeother 0\@makeother 1\@makeother 2\@makeother 3\@makeother 4%
+    \@makeother 5\@makeother 6\@makeother 7\@makeother 8\@makeother 9%
+    \@makeother =\lsts@nfss@catcodes}
+%    \end{macrocode}
+% The investigation of a bug reported by \lsthelper{Christian~Gudrian}
+% {2000/11/16}{problems with mathpple} showed that the equal sign needs
+% to have `other' catcode, as assigned above.
+% \lsthelper{Svend~Tollak~Munkejord}{2002/04/17}{package incompatible with
+%  Lucida .fd files} reported problems with Lucida .fd-files, while
+% \lsthelper{Heiko~Oberdiek}{2002/04/17}{Re: listings fails with Lucida
+% font} analysed the bug, which above led to the line starting with
+% |\@makeaother (|.
+%
+% The name of |\lst@makeletter| is an imitation of \LaTeX's |\@makeother|.
+%    \begin{macrocode}
+\def\lst@makeletter#1{%
+    \ifx\relax#1\else\catcode`#111\relax \expandafter\lst@makeletter\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{useoutput}
+% \begin{macro}{\output}
+% Another problem was first reported by \lsthelper{Marcin~Kasperski}
+% {1999/04/28}{listings spoil toc}. It is also catcode related and
+% \lsthelper{Donald~Arseneau}{1999/05/13}{comp.text.tex Re: delayed write and
+% catcode changes} let me understand it. The point is that \TeX\ seems to use
+% the \emph{currently} active catcode table when it writes non-|\immediate|
+% |\write|s to file and not the catcodes involved when \emph{reading} the
+% characters.
+% So a section heading |\L a| was written |\La| if a listing was split on two
+% pages since a non-standard catcode table was in use when writing |\La| to
+% file, the previously attached catcodes do not matter. One more bug was that
+% accents in page headings or footers were lost when a listing was split on
+% two pages. \lsthelper{Denis~Girou}{1999/08/03}{Accents lost in heading if
+% listing split on two pages} found this latter bug. A similar problem with
+% the tilde was reported by \lsthelper{Thorsten~Vitt}{2001/06/25}{fancyhdr +
+% listings crossing pages ==> ~ in header, not space}.
+%
+% We can choose between three possibilities.
+% \lsthelper{Donald~Arseneau}{2006/09/14}{cannot select output routine 1}
+% noted a bug here in the |\ifcase| argument.
+%    \begin{macrocode}
+\lst@Key{useoutput}{2}{\edef\lst@useoutput{\ifcase0#1 0\or 1\else 2\fi}}
+%    \end{macrocode}
+% The first does not modify the existing output routine.
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+{\edef\lst@OrgOutput{\the\output}%
+\ifcase\lst@useoutput\relax
+\or
+%    \end{macrocode}
+% The second possibility is as follows: We interrupt the current modes---in
+% particular |\lst@Pmode| with modified catcode table---, call the original
+% output routine and reenter the mode. This must be done with a little care.
+% First we have to close the group which \TeX\ opens at the beginning of the
+% output routine. A single |\egroup| gives an `unbalanced output routine'
+% error. But |\expandafter\egroup| works. Again it was
+% \lsthelper{Donald~Arseneau}{2001/01/10}{comp.text.tex Re: \output puzzle}
+% who gave the explaination: The |\expandafter| set the token type of |\bgroup|
+% to |backed_up|, which prevents \TeX's from recovering from an unbalanced
+% output routine. \lsthelper{Heiko~Oberdiek}{2001/01/05}{comp.text.tex Re:
+% \output puzzle} reported that |\csname| |egroup||\endcsname| does the trick,
+% too.
+%
+% However, since \TeX\ checks the contents of |\box| 255 when we close the
+% group (`output routine didn't use all of |\box| 255'), we have to save it
+% temporaryly.
+%    \begin{macrocode}
+ \output{\global\setbox\lst@gtempboxa\box\@cclv
+         \expandafter\egroup
+%    \end{macrocode}
+% Now we can interrupt the mode, but we have to save the current character
+% string and the current style.
+%    \begin{macrocode}
+         \lst@SaveToken
+     \lst@InterruptModes
+%    \end{macrocode}
+% We restore the contents, use the original output routine, and \ldots
+%    \begin{macrocode}
+     \setbox\@cclv\box\lst@gtempboxa
+     \bgroup\lst@OrgOutput\egroup
+%    \end{macrocode}
+% \ldots\space open a group matching the |}| which \TeX\ inserts at the end of
+% the output routine. We reenter modes and restore the character string and
+% style |\aftergroup|. Moreover we need to reset |\pagegoal|---added after a
+% bug report by \lsthelper{Jochen~Schneider}{2002/03/09}{de.comp.text.tex:
+% Problem mit Listings-Paket 1.0-Beta; unmotivated pagebreak with preceding
+% float}.
+%    \begin{macrocode}
+     \bgroup
+     \aftergroup\pagegoal\aftergroup\vsize
+     \aftergroup\lst@ReenterModes\aftergroup\lst@RestoreToken}%
+\else
+%    \end{macrocode}
+% The third option is to restore all catcodes and meanings inside a modified
+% output routine and to call the original routine afterwards.
+%    \begin{macrocode}
+ \output{\lst@RestoreOrigCatcodes
+         \lst@ifec \lst@RestoreOrigExtendedCatcodes \fi
+         \lst@OrgOutput}%
+\fi}
+%    \end{macrocode}
+% Note that this output routine isn't used too often. It is executed only if
+% it's possible that a listing is split on two pages: if a listing ends at
+% the bottom or begins at the top of a page, or if a listing is really split.
+% \end{macro}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@GetChars}
+% \begin{macro}{\lst@ScanChars}
+% \begin{lstkey}{rescanchars}
+% To make the third |\output|-option work, we have to scan the catcodes and
+% also the meanings of active characters:
+%    \begin{macrocode}
+\def\lst@GetChars#1#2#3{%
+    \let#1\@empty
+    \@tempcnta#2\relax \@tempcntb#3\relax
+    \loop \ifnum\@tempcnta<\@tempcntb\relax
+        \lst@lExtend#1{\expandafter\catcode\the\@tempcnta=}%
+        \lst@lExtend#1{\the\catcode\@tempcnta\relax}%
+        \ifnum\the\catcode\@tempcnta=\active
+            \begingroup\lccode`\~=\@tempcnta
+            \lowercase{\endgroup
+            \lst@lExtend#1{\expandafter\let\expandafter~\csname
+                                    lstecs@\the\@tempcnta\endcsname}%
+            \expandafter\let\csname lstecs@\the\@tempcnta\endcsname~}%
+        \fi
+        \advance\@tempcnta\@ne
+    \repeat}
+%    \end{macrocode}
+% As per a bug report by \lsthelper{Benjamin~Lings}{2004/10/15}%
+% {\usepackage{xy,listings} yields: "Forbidden control sequence...."}, we
+% deactivate |\outer| definition of |^^L| temporarily (inside and outside
+% of |\lst@ScanChars|) and restore the catcode at end of package via the
+% |\lst@RestoreCatcodes| command.
+%    \begin{macrocode}
+\begingroup \catcode12=\active\let^^L\@empty
+\gdef\lst@ScanChars{%
+  \let\lsts@ssL^^L%
+  \def^^L{\par}%
+    \lst@GetChars\lst@RestoreOrigCatcodes\@ne {128}%
+  \let^^L\lsts@ssL
+    \lst@GetChars\lst@RestoreOrigExtendedCatcodes{128}{256}}
+\endgroup
+%    \end{macrocode}
+% The scan can be issued by hand and at the beginning of a document.
+%    \begin{macrocode}
+\lst@Key{rescanchars}\relax{\lst@ScanChars}
+\AtBeginDocument{\lst@ScanChars}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsubsection{Adjusting the table}
+%
+% We begin with modifiers for the basic character classes.
+%
+% \begin{lstkey}{alsoletter}
+% \begin{lstkey}{alsodigit}
+% \begin{lstkey}{alsoother}
+% The macros |\lst@also|\ldots\space will hold |\def|\meta{char}|{|\ldots|}|
+% sequences, which adjusts the standard character table.
+%    \begin{macrocode}
+\lst@Key{alsoletter}\relax{%
+    \lst@DoAlso{#1}\lst@alsoletter\lst@ProcessLetter}
+\lst@Key{alsodigit}\relax{%
+    \lst@DoAlso{#1}\lst@alsodigit\lst@ProcessDigit}
+\lst@Key{alsoother}\relax{%
+    \lst@DoAlso{#1}\lst@alsoother\lst@ProcessOther}
+%    \end{macrocode}
+% This is done at \hookname{SelectCharTable} and every language selection
+% the macros get empty.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}
+    {\lst@alsoother \lst@alsodigit \lst@alsoletter}
+\lst@AddToHookExe{SetLanguage}% init
+    {\let\lst@alsoletter\@empty
+     \let\lst@alsodigit\@empty
+     \let\lst@alsoother\@empty}
+%    \end{macrocode}
+% The service macro starts a loop and \ldots
+%    \begin{macrocode}
+\def\lst@DoAlso#1#2#3{%
+    \lst@DefOther\lst@arg{#1}\let#2\@empty
+    \expandafter\lst@DoAlso@\expandafter#2\expandafter#3\lst@arg\relax}
+\def\lst@DoAlso@#1#2#3{%
+    \ifx\relax#3\expandafter\@gobblethree \else
+%    \end{macrocode}
+% \ldots\space while not reaching |\relax| we use the \TeX nique from
+% |\lst@SaveOutputDef| to replace the class by |#2|. Eventually we append
+% the new definition to |#1|.
+%    \begin{macrocode}
+        \begingroup \lccode`\~=`#3\relax \lowercase{\endgroup
+        \def\lst@temp##1\def~##2##3\relax{%
+            \edef\lst@arg{\def\noexpand~{\noexpand#2\expandafter
+                                         \noexpand\@gobble##2}}}}%
+        \expandafter\lst@temp\lst@SelectStdCharTable\relax
+        \lst@lExtend#1{\lst@arg}%
+    \fi
+    \lst@DoAlso@#1#2}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@SaveDef}
+% \begin{macro}{\lst@DefSaveDef}
+% \begin{macro}{\lst@LetSaveDef}
+% These macros can be used in language definitions to make special changes.
+% They save the definition and define or assign a new one.
+%    \begin{macrocode}
+\def\lst@SaveDef#1#2{%
+    \begingroup \lccode`\~=#1\relax \lowercase{\endgroup\let#2~}}
+\def\lst@DefSaveDef#1#2{%
+    \begingroup \lccode`\~=#1\relax \lowercase{\endgroup\let#2~\def~}}
+\def\lst@LetSaveDef#1#2{%
+    \begingroup \lccode`\~=#1\relax \lowercase{\endgroup\let#2~\let~}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% Now we get to the more powerful definitions.
+%
+% \begin{macro}{\lst@CDef}
+% Here we unfold the first parameter \meta{1st}\marg{2nd}\marg{rest} and say
+% that this input string is `replaced' by \meta{save 1st}\marg{2nd}^^A
+% \marg{rest}---plus \meta{execute}, \meta{pre}, and \meta{post}. This main
+% work is done by |\lst@CDefIt|.
+%    \begin{macrocode}
+\def\lst@CDef#1{\lst@CDef@#1}
+\def\lst@CDef@#1#2#3#4{\lst@CDefIt#1{#2}{#3}{#4#2#3}#4}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CDefX}
+% drops the input string.
+%    \begin{macrocode}
+\def\lst@CDefX#1{\lst@CDefX@#1}
+\def\lst@CDefX@#1#2#3{\lst@CDefIt#1{#2}{#3}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CDefIt}
+% is the main working procedure for the previous macros. It redefines the
+% sequence |#1#2#3| of characters. At least |#1| must be active; the other two
+% arguments might be empty, not equivalent to empty!
+%    \begin{macrocode}
+\def\lst@CDefIt#1#2#3#4#5#6#7#8{%
+    \ifx\@empty#2\@empty
+%    \end{macrocode}
+% For a single character we just execute the arguments in the correct order.
+% You might want to go back to section \ref{dCharacterTablesManipulated} to
+% look them up.
+%    \begin{macrocode}
+        \def#1{#6\def\lst@next{#7#4#8}\lst@next}%
+    \else \ifx\@empty#3\@empty
+%    \end{macrocode}
+% For a two character sequence we test whether \meta{pre} and \meta{post}
+% must be executed.
+%    \begin{macrocode}
+        \def#1##1{%
+            #6%
+            \ifx##1#2\def\lst@next{#7#4#8}\else
+                     \def\lst@next{#5##1}\fi
+            \lst@next}%
+    \else
+%    \end{macrocode}
+% We do the same for an arbitrary character sequence---except that we have to
+% use |\lst@IfNextCharsArg| instead of |\ifx|\ldots|\fi|.
+%    \begin{macrocode}
+        \def#1{%
+            #6%
+            \lst@IfNextCharsArg{#2#3}{#7#4#8}%
+                                     {\expandafter#5\lst@eaten}}%
+    \fi \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CArgX}
+% We make |#1#2| active and call |\lst@CArg|.
+%    \begin{macrocode}
+\def\lst@CArgX#1#2\relax{%
+    \lst@DefActive\lst@arg{#1#2}%
+    \expandafter\lst@CArg\lst@arg\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CArg}
+% arranges the first two arguments for |\lst@CDef|[|X|]. We get an undefined
+% macro and use |\@empty\@empty\relax| as delimiter for the submacro.
+%    \begin{macrocode}
+\def\lst@CArg#1#2\relax{%
+    \lccode`\/=`#1\lowercase{\def\lst@temp{/}}%
+    \lst@GetFreeMacro{lst@c\lst@temp}%
+    \expandafter\lst@CArg@\lst@freemacro#1#2\@empty\@empty\relax}
+%    \end{macrocode}
+% Save meaning of \meta{1st}=|#2| in \meta{save 1st}=|#1| and call the macro
+% |#6| with correct arguments. From version 1.0 on, |#2|, |#3| and |#4|
+% (respectively empty arguments) are tied together with group braces.
+% This allows us to save two arguments in other definitions, for example in
+% |\lst@DefDelimB|.
+%    \begin{macrocode}
+\def\lst@CArg@#1#2#3#4\@empty#5\relax#6{%
+    \let#1#2%
+    \ifx\@empty#3\@empty
+        \def\lst@next{#6{#2{}{}}}%
+    \else
+        \def\lst@next{#6{#2#3{#4}}}%
+    \fi
+    \lst@next #1}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CArgEmpty}
+% `executes' an |\@empty|-delimited argument. We will use it for the delimiters.
+%    \begin{macrocode}
+\def\lst@CArgEmpty#1\@empty{#1}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Delimiters}
+%
+% Here we start with general definitions common to all delimiters.
+%
+% \begin{lstkey}{excludedelims}
+% controls which delimiters are not printed in \meta{whatever}style. We just
+% define |\lst@ifex|\meta{whatever} to be true. Such switches are set false
+% in the \hookname{ExcludeDelims} hook and are handled by the individual
+% delimiters.
+%    \begin{macrocode}
+\lst@Key{excludedelims}\relax
+    {\lsthk@ExcludeDelims \lst@NormedDef\lst@temp{#1}%
+     \expandafter\lst@for\lst@temp\do
+     {\expandafter\let\csname\@lst @ifex##1\endcsname\iftrue}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DelimPrint}
+% And this macro might help in doing so. |#1| is |\lst@ifex|\meta{whatever}
+% (plus |\else|) or just |\iffalse|, and |#2| will be the delimiter. The
+% temporary mode change ensures that the characters can't end the current
+% delimiter or start a new one.
+%    \begin{macrocode}
+\def\lst@DelimPrint#1#2{%
+    #1%
+      \begingroup
+        \lst@mode\lst@nomode \lst@modetrue
+        #2\lst@XPrintToken
+      \endgroup
+      \lst@ResetToken
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DelimOpen}
+% We print preceding characters and the delimiter, enter the appropriate mode,
+% print the delimiter again, and execute |#3|. In fact, the arguments |#1| and
+% |#2| will ensure that the delimiter is printed only once.
+%    \begin{macrocode}
+\def\lst@DelimOpen#1#2#3#4#5#6\@empty{%
+    \lst@TrackNewLines \lst@XPrintToken
+    \lst@DelimPrint#1{#6}%
+    \lst@EnterMode{#4}{\def\lst@currstyle#5}%
+    \lst@DelimPrint{#1#2}{#6}%
+    #3}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DelimClose}
+% is the same in reverse order.
+%    \begin{macrocode}
+\def\lst@DelimClose#1#2#3\@empty{%
+    \lst@TrackNewLines \lst@XPrintToken
+    \lst@DelimPrint{#1#2}{#3}%
+    \lst@LeaveMode
+    \lst@DelimPrint{#1}{#3}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginDelim}
+% \begin{macro}{\lst@EndDelim}
+% These definitions are applications of |\lst@DelimOpen| and |\lst@DelimClose|:
+% the delimiters have the same style as the delimited text.
+%    \begin{macrocode}
+\def\lst@BeginDelim{\lst@DelimOpen\iffalse\else{}}
+\def\lst@EndDelim{\lst@DelimClose\iffalse\else}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginIDelim}
+% \begin{macro}{\lst@EndIDelim}
+% Another application: no delimiter is printed.
+%    \begin{macrocode}
+\def\lst@BeginIDelim{\lst@DelimOpen\iffalse{}{}}
+\def\lst@EndIDelim{\lst@DelimClose\iffalse{}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDelims}
+% This macro defines all delimiters and is therefore reset every language
+% selection.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}{\lst@DefDelims}
+\lst@AddToHookExe{SetLanguage}{\let\lst@DefDelims\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim}
+% First we set default values: no |\lst@modetrue|, cumulative style, and no
+% argument to |\lst@Delim|[|DM|]|@|\meta{type}.
+%    \begin{macrocode}
+\def\lst@Delim#1{%
+    \lst@false \let\lst@cumulative\@empty \let\lst@arg\@empty
+%    \end{macrocode}
+% These are the correct settings for the double-star-form, so we immediately
+% call the submacro in this case. Otherwise we either just suppress cumulative
+% style, or even indicate the usage of |\lst@modetrue| with |\lst@true|.
+%    \begin{macrocode}
+    \@ifstar{\@ifstar{\lst@Delim@{#1}}%
+                     {\let\lst@cumulative\relax
+                      \lst@Delim@{#1}}}%
+            {\lst@true\lst@Delim@{#1}}}
+%    \end{macrocode}
+% The type argument is saved for later use. We check against the optional
+% \meta{style} argument using |#1| as default, define |\lst@delimstyle| and
+% look for the optional \meta{type option}, which is just saved in |\lst@arg|.
+%    \begin{macrocode}
+\def\lst@Delim@#1[#2]{%
+    \gdef\lst@delimtype{#2}%
+    \@ifnextchar[\lst@Delim@sty
+                 {\lst@Delim@sty[#1]}}
+\def\lst@Delim@sty[#1]{%
+    \def\lst@delimstyle{#1}%
+    \ifx\@empty#1\@empty\else
+        \lst@Delim@sty@ #1\@nil
+    \fi
+    \@ifnextchar[\lst@Delim@option
+                 \lst@Delim@delim}
+\def\lst@Delim@option[#1]{\def\lst@arg{[#1]}\lst@Delim@delim}
+%    \end{macrocode}
+% |[| and |]| in the replacement text above have been added after a bug report
+% by \lsthelper{Stephen~Reindl}{2002/05/28}{\inaccessible using Cobol}.
+%
+% The definition of |\lst@delimstyle| depends on whether the first token is a
+% control sequence. Here we possibly build |\lst@|\meta{style}.
+%    \begin{macrocode}
+\def\lst@Delim@sty@#1#2\@nil{%
+    \if\relax\noexpand#1\else
+        \edef\lst@delimstyle{\expandafter\noexpand
+                             \csname\@lst @\lst@delimstyle\endcsname}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim@delim}
+% Eventually this macro is called. First we might need to delete a bunch of
+% delimiters. If there is no delimiter, we might delete a subclass.
+%    \begin{macrocode}
+\def\lst@Delim@delim#1\relax#2#3#4#5#6#7#8{%
+    \ifx #4\@empty \lst@Delim@delall{#2}\fi
+    \ifx\@empty#1\@empty
+        \ifx #4\@nil
+            \@ifundefined{\@lst @#2DM@\lst@delimtype}%
+                {\lst@Delim@delall{#2@\lst@delimtype}}%
+                {\lst@Delim@delall{#2DM@\lst@delimtype}}%
+        \fi
+    \else
+%    \end{macrocode}
+% If the delimiter is not empty, we convert the delimiter and append it to
+% |\lst@arg|. Ditto |\lst@Begin|\ldots, |\lst@End|\ldots, and the style and
+% mode selection.
+%    \begin{macrocode}
+        \expandafter\lst@Delim@args\expandafter
+            {\lst@delimtype}{#1}{#5}#6{#7}{#8}#4%
+%    \end{macrocode}
+% If the type is known, we either choose dynamic or static mode and use the
+% contents of |\lst@arg| as arguments. All this is put into |\lst@delim|.
+%    \begin{macrocode}
+        \let\lst@delim\@empty
+        \expandafter\lst@IfOneOf\lst@delimtype\relax#3%
+        {\@ifundefined{\@lst @#2DM@\lst@delimtype}%
+             {\lst@lExtend\lst@delim{\csname\@lst @#2@\lst@delimtype
+                                     \expandafter\endcsname\lst@arg}}%
+             {\lst@lExtend\lst@delim{\expandafter\lst@UseDynamicMode
+                                     \csname\@lst @#2DM@\lst@delimtype
+                                     \expandafter\endcsname\lst@arg}}%
+%    \end{macrocode}
+% Now, depending on the mode |#4| we either remove this particular delimiter or
+% append it to all current ones.
+%    \begin{macrocode}
+         \ifx #4\@nil
+             \let\lst@temp\lst@DefDelims \let\lst@DefDelims\@empty
+             \expandafter\lst@Delim@del\lst@temp\@empty\@nil\@nil\@nil
+         \else
+             \lst@lExtend\lst@DefDelims\lst@delim
+         \fi}%
+%    \end{macrocode}
+% An unknown type issues an error.
+%    \begin{macrocode}
+        {\PackageError{Listings}{Illegal type `\lst@delimtype'}%
+                                {#2 types are #3.}}%
+     \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim@args}
+% Now let's look how we add the arguments to |\lst@arg|. First we initialize
+% the conversion just to make all characters active. But if the first character
+% of the type equals |#4|, \ldots
+%    \begin{macrocode}
+\def\lst@Delim@args#1#2#3#4#5#6#7{%
+    \begingroup
+    \lst@false \let\lst@next\lst@XConvert
+%    \end{macrocode}
+% \ldots\ we remove that character from |\lst@delimtype|, and |#5| might select
+% a different conversion setting or macro.
+%    \begin{macrocode}
+    \@ifnextchar #4{\xdef\lst@delimtype{\expandafter\@gobble
+                                        \lst@delimtype}%
+                    #5\lst@next#2\@nil
+                    \lst@lAddTo\lst@arg{\@empty#6}%
+                    \lst@GobbleNil}%
+%    \end{macrocode}
+% Since we are in the `special' case above, we've also added the special
+% |\lst@Begin|\ldots\space and |\lst@End|\ldots\space macros to |\lst@arg|
+% (and |\@empty| as a brake for the delimiter). No special task must be done
+% if the characters are not equal.
+%    \begin{macrocode}
+                   {\lst@next#2\@nil
+                    \lst@lAddTo\lst@arg{\@empty#3}%
+                    \lst@GobbleNil}%
+                 #1\@nil
+%    \end{macrocode}
+% We always transfer the arguments to the outside of the group and append the
+% style and mode selection if and only if we're not deleting a delimiter.
+% Therefor we expand the delimiter style.
+%    \begin{macrocode}
+    \global\let\@gtempa\lst@arg
+    \endgroup
+    \let\lst@arg\@gtempa
+    \ifx #7\@nil\else
+        \expandafter\lst@Delim@args@\expandafter{\lst@delimstyle}%
+    \fi}
+%    \end{macrocode}
+% Recall that the style is `selected' by |\def\lst@currstyle#5|, and this
+% `argument' |#5| is to be added now. Depending on the settings at the very
+% beginning, we use either |{\meta{style}}\lst@modetrue|---which selects the
+% style and deactivates keyword detection---, or |{}\meta{style}|---which
+% defines an empty style macro and executes the style for cumulative styles---,
+% or |{\meta{style}|---which just defines the style macro. Note that we have to
+% use two extra group levels below: one is discarded directly by |\lst@lAddTo|
+% and the other by |\lst@Delim|[|DM|]|@|\meta{type}.
+%    \begin{macrocode}
+\def\lst@Delim@args@#1{%
+    \lst@if
+        \lst@lAddTo\lst@arg{{{#1}\lst@modetrue}}%
+    \else
+        \ifx\lst@cumulative\@empty
+            \lst@lAddTo\lst@arg{{{}#1}}%
+        \else
+            \lst@lAddTo\lst@arg{{{#1}}}%
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim@del}
+% To delete a particular delimiter, we iterate down the list of delimiters and
+% compare the current item with the user supplied.
+%    \begin{macrocode}
+\def\lst@Delim@del#1\@empty#2#3#4{%
+    \ifx #2\@nil\else
+        \def\lst@temp{#1\@empty#2#3}%
+        \ifx\lst@temp\lst@delim\else
+            \lst@lAddTo\lst@DefDelims{#1\@empty#2#3{#4}}%
+        \fi
+        \expandafter\lst@Delim@del
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Delim@delall}
+% To delete a whole class of delimiters, we first expand the control sequence
+% name, init some other data, and call a submacro to do the work.
+%    \begin{macrocode}
+\def\lst@Delim@delall#1{%
+    \begingroup
+    \edef\lst@delim{\expandafter\string\csname\@lst @#1\endcsname}%
+    \lst@false \global\let\@gtempa\@empty
+    \expandafter\lst@Delim@delall@\lst@DefDelims\@empty
+    \endgroup
+    \let\lst@DefDelims\@gtempa}
+%    \end{macrocode}
+% We first discard a preceding |\lst@UseDynamicMode|.
+%    \begin{macrocode}
+\def\lst@Delim@delall@#1{%
+    \ifx #1\@empty\else
+        \ifx #1\lst@UseDynamicMode
+            \lst@true
+            \let\lst@next\lst@Delim@delall@do
+        \else
+            \def\lst@next{\lst@Delim@delall@do#1}%
+        \fi
+        \expandafter\lst@next
+    \fi}
+%    \end{macrocode}
+% Then we can check whether (the following) |\lst@|\meta{delimiter name}\ldots\
+% matches the delimiter class given by |\lst@delim|.
+%    \begin{macrocode}
+\def\lst@Delim@delall@do#1#2\@empty#3#4#5{%
+    \expandafter\lst@IfSubstring\expandafter{\lst@delim}{\string#1}%
+      {}%
+      {\lst@if \lst@AddTo\@gtempa\lst@UseDynamicMode \fi
+       \lst@AddTo\@gtempa{#1#2\@empty#3#4{#5}}}%
+    \lst@false \lst@Delim@delall@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDelimB}
+% Here we put the arguments together to fit |\lst@CDef|. Note that the very
+% last argument |\@empty| to |\lst@CDef| is a brake for |\lst@CArgEmpty|
+% and |\lst@DelimOpen|.
+%    \begin{macrocode}
+\gdef\lst@DefDelimB#1#2#3#4#5#6#7#8{%
+    \lst@CDef{#1}#2%
+        {#3}%
+        {\let\lst@bnext\lst@CArgEmpty
+         \lst@ifmode #4\else
+             #5%
+             \def\lst@bnext{#6{#7}{#8}}%
+         \fi
+         \lst@bnext}%
+        \@empty}
+%    \end{macrocode}
+% After a bug report from \lsthelper{Vespe~Savikko}{2000/11/06}{bad output of
+% doc-strings if HTML and Python are loaded} I added braces around |#7|.
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDelimE}
+% The  |\ifnum #7=\lst@mode| in the 5th line ensures that the delimiters
+% match each other.
+%    \begin{macrocode}
+\gdef\lst@DefDelimE#1#2#3#4#5#6#7{%
+    \lst@CDef{#1}#2%
+        {#3}%
+        {\let\lst@enext\lst@CArgEmpty
+         \ifnum #7=\lst@mode%
+             #4%
+             \let\lst@enext#6%
+         \else
+             #5%
+         \fi
+         \lst@enext}%
+        \@empty}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\let\lst@bnext\relax \let\lst@enext\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefDelimBE}
+% This service macro will actually define all string delimiters.
+%    \begin{macrocode}
+\gdef\lst@DefDelimBE#1#2#3#4#5#6#7#8#9{%
+    \lst@CDef{#1}#2%
+        {#3}%
+        {\let\lst@bnext\lst@CArgEmpty
+         \ifnum #7=\lst@mode
+             #4%
+             \let\lst@bnext#9%
+         \else
+             \lst@ifmode\else
+                 #5%
+                 \def\lst@bnext{#6{#7}{#8}}%
+             \fi
+         \fi
+         \lst@bnext}%
+        \@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@delimtypes}
+% is the list of general delimiter types.
+%    \begin{macrocode}
+\gdef\lst@delimtypes{s,l}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DelimKey}
+% We just put together the arguments for |\lst@Delim|.
+%    \begin{macrocode}
+\gdef\lst@DelimKey#1#2{%
+    \lst@Delim{}#2\relax
+        {Delim}\lst@delimtypes #1%
+                {\lst@BeginDelim\lst@EndDelim}
+        i\@empty{\lst@BeginIDelim\lst@EndIDelim}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{delim}
+% \begin{lstkey}{moredelim}
+% \begin{lstkey}{deletedelim}
+% all use |\lst@DelimKey|.
+%    \begin{macrocode}
+\lst@Key{delim}\relax{\lst@DelimKey\@empty{#1}}
+\lst@Key{moredelim}\relax{\lst@DelimKey\relax{#1}}
+\lst@Key{deletedelim}\relax{\lst@DelimKey\@nil{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DelimDM@l}
+% \begin{macro}{\lst@DelimDM@s}
+% Nohting special here.
+%    \begin{macrocode}
+\gdef\lst@DelimDM@l#1#2\@empty#3#4#5{%
+    \lst@CArg #2\relax\lst@DefDelimB{}{}{}#3{#1}{#5\lst@Lmodetrue}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@DelimDM@s#1#2#3\@empty#4#5#6{%
+    \lst@CArg #2\relax\lst@DefDelimB{}{}{}#4{#1}{#6}%
+    \lst@CArg #3\relax\lst@DefDelimE{}{}{}#5{#1}}
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsubsection{Strings}
+%
+% \begin{aspect}{strings}
+% Just starting a new aspect.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{strings}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@stringtypes}
+% is the list of \ldots\space string types?
+%    \begin{macrocode}
+\gdef\lst@stringtypes{d,b,m,bd,db,s}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@StringKey}
+% We just put together the arguments for |\lst@Delim|.
+%    \begin{macrocode}
+\gdef\lst@StringKey#1#2{%
+    \lst@Delim\lst@stringstyle #2\relax
+        {String}\lst@stringtypes #1%
+                     {\lst@BeginString\lst@EndString}%
+        \@@end\@empty{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{string}
+% \begin{lstkey}{morestring}
+% \begin{lstkey}{deletestring}
+% all use |\lst@StringKey|.
+%    \begin{macrocode}
+\lst@Key{string}\relax{\lst@StringKey\@empty{#1}}
+\lst@Key{morestring}\relax{\lst@StringKey\relax{#1}}
+\lst@Key{deletestring}\relax{\lst@StringKey\@nil{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{stringstyle}
+% You shouldn't need comments on the following two lines, do you?
+%    \begin{macrocode}
+\lst@Key{stringstyle}{}{\def\lst@stringstyle{#1}}
+\lst@AddToHook{EmptyStyle}{\let\lst@stringstyle\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{showstringspaces}
+% Thanks to \lsthelper{Knut~M\"uller}{1997/04/28}{\blankstringtrue} for
+% reporting problems with |\blankstringtrue| (now |showstringspaces=false|).
+% The problem has gone.
+%    \begin{macrocode}
+\lst@Key{showstringspaces}t[t]{\lstKV@SetIf{#1}\lst@ifshowstringspaces}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BeginString}
+% Note that the tokens after |\lst@DelimOpen| are arguments! The only special
+% here is that we switch to `keepspaces' after starting a string, if necessary.
+% A bug reported by \lsthelper{Vespe~Savikko}{2000/09/27}{stringstyle used also
+% on previous other characters} has gone due to the use of |\lst@DelimOpen|.
+%    \begin{macrocode}
+\gdef\lst@BeginString{%
+    \lst@DelimOpen
+        \lst@ifexstrings\else
+        {\lst@ifshowstringspaces
+             \lst@keepspacestrue
+             \let\lst@outputspace\lst@visiblespace
+         \fi}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHookExe{ExcludeDelims}{\let\lst@ifexstrings\iffalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndString}
+% Again the two tokens following |\lst@DelimClose| are arguments.
+%    \begin{macrocode}
+\gdef\lst@EndString{\lst@DelimClose\lst@ifexstrings\else}
+%    \end{macrocode}
+% \end{macro}
+%
+% And now all the |\lst@StringDM@|\meta{type} definitions.
+%
+% \begin{macro}{\lst@StringDM@d}
+% `d' means no extra work.; the first three arguments after |\lst@DefDelimBE|
+% are left empty. The others are used to start and end the string.
+%    \begin{macrocode}
+\gdef\lst@StringDM@d#1#2\@empty#3#4#5{%
+    \lst@CArg #2\relax\lst@DefDelimBE{}{}{}#3{#1}{#5}#4}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@StringDM@b}
+% The |\lst@ifletter|\ldots|\fi| has been inserted after bug reports by
+% \lsthelper{Daniel~Gerigk}{2001/10/25}{improper strings in C++} and
+% \lsthelper{Peter~Bartke}{2001/11/01}{improper strings in C++}. If the last
+% other character is a backslash (4th line), we gobble the `end string' token
+% sequence.
+%    \begin{macrocode}
+\gdef\lst@StringDM@b#1#2\@empty#3#4#5{%
+    \let\lst@ifbstring\iftrue
+    \lst@CArg #2\relax\lst@DefDelimBE
+       {\lst@ifletter \lst@Output \lst@letterfalse \fi}%
+       {\ifx\lst@lastother\lstum@backslash
+            \expandafter\@gobblethree
+        \fi}{}#3{#1}{#5}#4}
+%    \end{macrocode}
+%    \begin{macrocode}
+\global\let\lst@ifbstring\iffalse % init
+%    \end{macrocode}
+% \lsthelper{Heiko~Heil}{2002/02/08}{string '\\' does not finish after the
+% delimiter} reported problems with double backslashes. So:
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}{%
+    \lst@ifbstring
+        \lst@CArgX \\\\\relax \lst@CDefX{}%
+           {\lst@ProcessOther\lstum@backslash
+            \lst@ProcessOther\lstum@backslash
+            \let\lst@lastother\relax}%
+           {}%
+    \fi}
+%    \end{macrocode}
+% The reset of |\lst@lastother| has been added after a bug reports by
+% \lsthelper{Hermann~H\"uttler}{2002/10/05}{C++-string "... \\" does not
+% end with second double quote} and \lsthelper{Dan~Luecking}{2003/01/15}
+% {string "\\" doesn't end after the second quote}.
+% \end{macro}
+%
+% \begin{macro}{\lst@StringDM@bd}
+% \begin{macro}{\lst@StringDM@db}
+% are just the same and the same as |\lst@StringDM@b|.
+%    \begin{macrocode}
+\global\let\lst@StringDM@bd\lst@StringDM@b
+\global\let\lst@StringDM@db\lst@StringDM@bd
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{macro}{\lst@StringDM@m}
+% is for Matlab. We enter string mode only if the last character is not in
+% the following list of exceptional characters: letters, digits, period,
+% quote, right parenthesis, right bracket, and right brace. The first list
+% has been extended after bug reports from \lsthelper{Christian~Kindinger}
+% {2002/03/??}{]' starts a string in Matlab}, \lsthelper{Benjamin~Schubert}
+% {2003/02/05}{.' starts a string in Matlab}, and \lsthelper{Stefan~Stoll}
+% {2003/02/18}{any of 0123456789\}' plus quote start a string in Matlab}.
+%    \begin{macrocode}
+\gdef\lst@StringDM@m#1#2\@empty#3#4#5{%
+    \lst@CArg #2\relax\lst@DefDelimBE{}{}%
+        {\let\lst@next\@gobblethree
+         \lst@ifletter\else
+             \lst@IfLastOtherOneOf{)].0123456789\lstum@rbrace'}%
+                 {}%
+                 {\let\lst@next\@empty}%
+         \fi
+         \lst@next}#3{#1}{#5}#4}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@StringDM@s}
+% is for string-delimited strings, just as for comments.  This is needed
+% for Ruby, and possibly other languages.
+%    \begin{macrocode}
+\gdef\lst@StringDM@s#1#2#3\@empty#4#5#6{%
+    \lst@CArg #2\relax\lst@DefDelimB{}{}{}#4{#1}{#6}%
+    \lst@CArg #3\relax\lst@DefDelimE{}{}{}#5{#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstum@rbrace}
+% This has been used above.
+%    \begin{macrocode}
+\lst@SaveOutputDef{"7D}\lstum@rbrace
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \begin{aspect}{mf}
+% For MetaFont and MetaPost we now define macros to print the input-filenames
+% in stringstyle.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{mf}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@mfinputmode}
+% \begin{macro}{\lst@String@mf}
+%    \begin{macrocode}
+\lst@AddTo\lst@stringtypes{,mf}
+\lst@NewMode\lst@mfinputmode
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@String@mf#1\@empty#2#3#4{%
+  \lst@CArg #1\relax\lst@DefDelimB
+       {}{}{\lst@ifletter \expandafter\@gobblethree \fi}%
+       \lst@BeginStringMFinput\lst@mfinputmode{#4\lst@Lmodetrue}%
+  \@ifundefined{lsts@semicolon}%
+  {\lst@DefSaveDef{`\;}\lsts@semicolon{% ; and space end the filename
+      \ifnum\lst@mode=\lst@mfinputmode
+          \lst@XPrintToken
+          \expandafter\lst@LeaveMode
+      \fi
+      \lsts@semicolon}%
+   \lst@DefSaveDef{`\ }\lsts@space{%
+      \ifnum\lst@mode=\lst@mfinputmode
+          \lst@XPrintToken
+          \expandafter\lst@LeaveMode
+      \fi
+      \lsts@space}%
+  }{}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginStringMFinput}
+% It remains to define this macro. In contrast to |\lst@PrintDelim|, we don't
+% use |\lst@modetrue| to allow keyword detection here.
+%    \begin{macrocode}
+\gdef\lst@BeginStringMFinput#1#2#3\@empty{%
+    \lst@TrackNewLines \lst@XPrintToken
+      \begingroup
+        \lst@mode\lst@nomode
+        #3\lst@XPrintToken
+      \endgroup
+      \lst@ResetToken
+    \lst@EnterMode{#1}{\def\lst@currstyle#2}%
+    \lst@ifshowstringspaces
+         \lst@keepspacestrue
+         \let\lst@outputspace\lst@visiblespace
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsubsection{Comments}
+%
+% \begin{aspect}{comments}
+% That's what we are working on.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{comments}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@commentmode}
+% is a general purpose mode for comments.
+%    \begin{macrocode}
+\lst@NewMode\lst@commentmode
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@commenttypes}
+% Via \keyname{comment} available comment types: \textbf line, \textbf fixed
+% column, \textbf single, and \textbf nested and all with
+% preceding \textbf i for invisible comments.
+%    \begin{macrocode}
+\gdef\lst@commenttypes{l,f,s,n}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CommentKey}
+% We just put together the arguments for |\lst@Delim|.
+%    \begin{macrocode}
+\gdef\lst@CommentKey#1#2{%
+    \lst@Delim\lst@commentstyle #2\relax
+        {Comment}\lst@commenttypes #1%
+                {\lst@BeginComment\lst@EndComment}%
+        i\@empty{\lst@BeginInvisible\lst@EndInvisible}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{comment}
+% \begin{lstkey}{morecomment}
+% \begin{lstkey}{deletecomment}
+% The keys are easy since defined in terms of |\lst@CommentKey|.
+%    \begin{macrocode}
+\lst@Key{comment}\relax{\lst@CommentKey\@empty{#1}}
+\lst@Key{morecomment}\relax{\lst@CommentKey\relax{#1}}
+\lst@Key{deletecomment}\relax{\lst@CommentKey\@nil{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{commentstyle}
+% Any hints necessary?
+%    \begin{macrocode}
+\lst@Key{commentstyle}{}{\def\lst@commentstyle{#1}}
+\lst@AddToHook{EmptyStyle}{\let\lst@commentstyle\itshape}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BeginComment}
+% \begin{macro}{\lst@EndComment}
+% Once more the three tokens following |\lst@DelimOpen| are arguments.
+%    \begin{macrocode}
+\gdef\lst@BeginComment{%
+    \lst@DelimOpen
+        \lst@ifexcomments\else
+        \lsthk@AfterBeginComment}
+%    \end{macrocode}
+% Ditto.
+%    \begin{macrocode}
+\gdef\lst@EndComment{\lst@DelimClose\lst@ifexcomments\else}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{AfterBeginComment}{}
+\lst@AddToHookExe{ExcludeDelims}{\let\lst@ifexcomments\iffalse}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginInvisible}
+% \begin{macro}{\lst@EndInvisible}
+% Print preceding characters and begin dropping the output.
+%    \begin{macrocode}
+\gdef\lst@BeginInvisible#1#2#3\@empty{%
+    \lst@TrackNewLines \lst@XPrintToken
+    \lst@BeginDropOutput{#1}}
+%    \end{macrocode}
+% Don't print the delimiter and end dropping the output.
+%    \begin{macrocode}
+\gdef\lst@EndInvisible#1\@empty{\lst@EndDropOutput}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% Now we provide all |\lst@Comment|[|DM|]|@|\meta{type} macros.
+%
+% \begin{macro}{\lst@CommentDM@l}
+% is easy---thanks to |\lst@CArg| and |\lst@DefDelimB|. Note that the
+% `end comment' argument |#4| is not used here.
+%    \begin{macrocode}
+\gdef\lst@CommentDM@l#1#2\@empty#3#4#5{%
+    \lst@CArg #2\relax\lst@DefDelimB{}{}{}#3{#1}{#5\lst@Lmodetrue}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CommentDM@f}
+% is slightly more work. First we provide the number of preceding columns.
+%    \begin{macrocode}
+\gdef\lst@CommentDM@f#1{%
+    \@ifnextchar[{\lst@Comment@@f{#1}}%
+                 {\lst@Comment@@f{#1}[0]}}
+%    \end{macrocode}
+% We define the comment in the same way as above, but we enter comment mode
+% if and only if the character is in column |#2| (counting from zero).
+%    \begin{macrocode}
+\gdef\lst@Comment@@f#1[#2]#3\@empty#4#5#6{%
+    \lst@CArg #3\relax\lst@DefDelimB{}{}%
+        {\lst@CalcColumn
+         \ifnum #2=\@tempcnta\else
+             \expandafter\@gobblethree
+         \fi}%
+        #4{#1}{#6\lst@Lmodetrue}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CommentDM@s}
+% Nothing special here.
+%    \begin{macrocode}
+\gdef\lst@CommentDM@s#1#2#3\@empty#4#5#6{%
+    \lst@CArg #2\relax\lst@DefDelimB{}{}{}#4{#1}{#6}%
+    \lst@CArg #3\relax\lst@DefDelimE{}{}{}#5{#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@CommentDM@n}
+% We either give an error message or define the nested comment.
+%    \begin{macrocode}
+\gdef\lst@CommentDM@n#1#2#3\@empty#4#5#6{%
+    \ifx\@empty#3\@empty\else
+        \def\@tempa{#2}\def\@tempb{#3}%
+        \ifx\@tempa\@tempb
+            \PackageError{Listings}{Identical delimiters}%
+            {These delimiters make no sense with nested comments.}%
+        \else
+            \lst@CArg #2\relax\lst@DefDelimB
+                {}%
+%    \end{macrocode}
+% Note that the following |\@gobble| eats an |\else| from |\lst@DefDelimB|.
+%    \begin{macrocode}
+                {\ifnum\lst@mode=#1\relax \expandafter\@gobble \fi}%
+                {}#4{#1}{#6}%
+            \lst@CArg #3\relax\lst@DefDelimE{}{}{}#5{#1}%
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsubsection{PODs}
+%
+% \begin{aspect}{pod}
+% PODs are defined as a separate aspect.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{pod}
+%    \end{macrocode}
+%
+% \begin{lstkey}{printpod}
+% \begin{lstkey}{podcomment}
+% We begin with the user keys, which I introduced after communication with
+% \lsthelper{Michael~Piotrowski}{1997/11/11}{printpod}.
+%    \begin{macrocode}
+\lst@Key{printpod}{false}[t]{\lstKV@SetIf{#1}\lst@ifprintpod}
+\lst@Key{podcomment}{false}[t]{\lstKV@SetIf{#1}\lst@ifpodcomment}
+\lst@AddToHookExe{SetLanguage}{\let\lst@ifpodcomment\iffalse}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@PODmode}
+% is the static mode for PODs.
+%    \begin{macrocode}
+\lst@NewMode\lst@PODmode
+%    \end{macrocode}
+% \end{macro}
+%
+% We adjust some characters if the user has selected |podcomment=true|.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}
+    {\lst@ifpodcomment
+         \lst@CArgX =\relax\lst@DefDelimB{}{}%
+%    \end{macrocode}
+% The following code is executed if we've found an equality sign and haven't
+% entered a mode (in fact if mode changes are allowed): We `begin drop output'
+% and gobble the usual begin of comment sequence (via |\@gobblethree|) if PODs
+% aren't be printed. Moreover we gobble it if the current column number is not
+% zero---|\@tempcnta| is valued below.
+%    \begin{macrocode}
+           {\ifnum\@tempcnta=\z@
+                \lst@ifprintpod\else
+                    \def\lst@bnext{\lst@BeginDropOutput\lst@PODmode}%
+                    \expandafter\expandafter\expandafter\@gobblethree
+                \fi
+            \else
+               \expandafter\@gobblethree
+            \fi}%
+           \lst@BeginComment\lst@PODmode{{\lst@commentstyle}}%
+%    \end{macrocode}
+% If we come to |=|, we calculate the current column number (zero based).
+%    \begin{macrocode}
+         \lst@CArgX =cut\^^M\relax\lst@DefDelimE
+           {\lst@CalcColumn}%
+%    \end{macrocode}
+% If there is additionally |cut|+EOL and if we are in |\lst@PODmode| but not in
+% column one, we must gobble the `end comment sequence'.
+%    \begin{macrocode}
+           {\ifnum\@tempcnta=\z@\else
+                \expandafter\@gobblethree
+            \fi}%
+           {}%
+           \lst@EndComment\lst@PODmode
+     \fi}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsubsection{Tags}
+%
+% \begin{aspect}{html}
+% Support for HTML and other `markup languages'.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{html}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@tagtypes}
+% Again we begin with the list of tag types. It's rather short.
+%    \begin{macrocode}
+\gdef\lst@tagtypes{s}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@TagKey}
+% Again we just put together the arguments for |\lst@Delim| and \ldots
+%    \begin{macrocode}
+\gdef\lst@TagKey#1#2{%
+    \lst@Delim\lst@tagstyle #2\relax
+        {Tag}\lst@tagtypes #1%
+                     {\lst@BeginTag\lst@EndTag}%
+        \@@end\@empty{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{tag}
+% \ldots\ we use the definition here.
+%    \begin{macrocode}
+\lst@Key{tag}\relax{\lst@TagKey\@empty{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{tagstyle}
+% You shouldn't need comments on the following two lines, do you?
+%    \begin{macrocode}
+\lst@Key{tagstyle}{}{\def\lst@tagstyle{#1}}
+\lst@AddToHook{EmptyStyle}{\let\lst@tagstyle\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BeginTag}
+% The special things here are: (1) We activate keyword detection inside tags
+% and (2) we initialize the switch |\lst@iffirstintag| if necessary.
+%    \begin{macrocode}
+\gdef\lst@BeginTag{%
+    \lst@DelimOpen
+        \lst@ifextags\else
+        {\let\lst@ifkeywords\iftrue
+         \lst@ifmarkfirstintag \lst@firstintagtrue \fi}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHookExe{ExcludeDelims}{\let\lst@ifextags\iffalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndTag}
+% is just like the other |\lst@End|\meta{whatever} definitions.
+%    \begin{macrocode}
+\gdef\lst@EndTag{\lst@DelimClose\lst@ifextags\else}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{usekeywordsintag}
+% \begin{lstkey}{markfirstintag}
+% The second key has already been `used'.
+%    \begin{macrocode}
+\lst@Key{usekeywordsintag}t[t]{\lstKV@SetIf{#1}\lst@ifusekeysintag}
+\lst@Key{markfirstintag}f[t]{\lstKV@SetIf{#1}\lst@ifmarkfirstintag}
+%    \end{macrocode}
+% For this, we install a (global) switch, \ldots
+%    \begin{macrocode}
+\gdef\lst@firstintagtrue{\global\let\lst@iffirstintag\iftrue}
+\global\let\lst@iffirstintag\iffalse
+%    \end{macrocode}
+% \ldots\ which is reset by the output of an identifier but not by other
+% output.
+%    \begin{macrocode}
+\lst@AddToHook{PostOutput}{\lst@tagresetfirst}
+\lst@AddToHook{Output}
+    {\gdef\lst@tagresetfirst{\global\let\lst@iffirstintag\iffalse}}
+\lst@AddToHook{OutputOther}{\gdef\lst@tagresetfirst{}}
+%    \end{macrocode}
+% Now we only need to test against this switch in the \hookname{Output} hook.
+%    \begin{macrocode}
+\lst@AddToHook{Output}
+    {\ifnum\lst@mode=\lst@tagmode
+         \lst@iffirstintag \let\lst@thestyle\lst@gkeywords@sty \fi
+%    \end{macrocode}
+% Moreover we check here, whether the keyword style is always to be used.
+%    \begin{macrocode}
+         \lst@ifusekeysintag\else \let\lst@thestyle\lst@gkeywords@sty\fi
+     \fi}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@tagmode}
+% We allocate the mode and \ldots
+%    \begin{macrocode}
+\lst@NewMode\lst@tagmode
+%    \end{macrocode}
+% deactivate keyword detection if any tag delimiter is defined (see below).
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\global\let\lst@ifnotag\iftrue}
+\lst@AddToHook{SelectCharTable}{\let\lst@ifkeywords\lst@ifnotag}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Tag@s}
+% The definition of the one and only delimiter type is not that interesting.
+% Compared with the others we set |\lst@ifnotag| and enter tag mode only if
+% we aren't in tag mode.
+%    \begin{macrocode}
+\gdef\lst@Tag@s#1#2\@empty#3#4#5{%
+    \global\let\lst@ifnotag\iffalse
+    \lst@CArg #1\relax\lst@DefDelimB {}{}%
+        {\ifnum\lst@mode=\lst@tagmode \expandafter\@gobblethree \fi}%
+        #3\lst@tagmode{#5}%
+    \lst@CArg #2\relax\lst@DefDelimE {}{}{}#4\lst@tagmode}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@BeginCDATA}
+% This macro is used by the XML language definition.
+%    \begin{macrocode}
+\gdef\lst@BeginCDATA#1\@empty{%
+    \lst@TrackNewLines \lst@PrintToken
+    \lst@EnterMode\lst@GPmode{}\let\lst@ifmode\iffalse
+    \lst@mode\lst@tagmode #1\lst@mode\lst@GPmode\relax\lst@modetrue}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Replacing input}
+%
+% \begingroup
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lst@ReplaceInput}
+% is defined in terms of |\lst@CArgX| and |\lst@CDefX|.
+%    \begin{macrocode}
+\def\lst@ReplaceInput#1{\lst@CArgX #1\relax\lst@CDefX{}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{literate}
+% \lsthelper{Jason~Alexander}{1999/03/10}{literate programming} asked for
+% something like that. The key looks for a star and saves the argument.
+%    \begin{macrocode}
+\def\lst@Literatekey#1\@nil@{\let\lst@ifxliterate\lst@if
+                             \def\lst@literate{#1}}
+\lst@Key{literate}{}{\@ifstar{\lst@true \lst@Literatekey}
+                             {\lst@false\lst@Literatekey}#1\@nil@}
+\lst@AddToHook{SelectCharTable}
+    {\ifx\lst@literate\@empty\else
+         \expandafter\lst@Literate\lst@literate{}\relax\z@
+     \fi}
+%    \end{macrocode}
+% Internally we don't make use of the `replace input' feature any more.
+%^^A We print the preceding text, assign token and length, and output it.
+%    \begin{macrocode}
+\def\lst@Literate#1#2#3{%
+    \ifx\relax#2\@empty\else
+        \lst@CArgX #1\relax\lst@CDef
+            {}
+            {\let\lst@next\@empty
+             \lst@ifxliterate
+                \lst@ifmode \let\lst@next\lst@CArgEmpty \fi
+             \fi
+             \ifx\lst@next\@empty
+                 \ifx\lst@OutputBox\@gobble\else
+                   \lst@XPrintToken \let\lst@scanmode\lst@scan@m
+                   \lst@token{#2}\lst@length#3\relax
+                   \lst@XPrintToken
+                 \fi
+                 \let\lst@next\lst@CArgEmptyGobble
+             \fi
+             \lst@next}%
+            \@empty
+        \expandafter\lst@Literate
+    \fi}
+\def\lst@CArgEmptyGobble#1\@empty{}
+%    \end{macrocode}
+% Note that we check |\lst@OutputBox| for being |\@gobble|. This is due to
+% a bug report by \lsthelper{Jared~Warren}{2003/07/10}{literate replacement
+% produces "ghosts"}.
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BeginDropInput}
+% We deactivate all `process' macros. |\lst@modetrue| does this for all
+% up-coming string delimiters, comments, and so on.
+%    \begin{macrocode}
+\def\lst@BeginDropInput#1{%
+    \lst@EnterMode{#1}%
+    {\lst@modetrue
+     \let\lst@OutputBox\@gobble
+     \let\lst@ifdropinput\iftrue
+     \let\lst@ProcessLetter\@gobble
+     \let\lst@ProcessDigit\@gobble
+     \let\lst@ProcessOther\@gobble
+     \let\lst@ProcessSpace\@empty
+     \let\lst@ProcessTabulator\@empty
+     \let\lst@ProcessFormFeed\@empty}}
+\let\lst@ifdropinput\iffalse % init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begingroup
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \endgroup
+%
+%
+% \subsection{Escaping to \LaTeX}
+%
+% \begin{aspect}{escape}
+% We now define the \ldots\ damned \ldots\ the aspect has escaped!
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{escape}
+%    \end{macrocode}
+%
+% \begin{lstkey}{texcl}
+% Communication with \lsthelper{J\"orn~Wilms}{1997/07/07}{\TeX\ comments} is
+% responsible for this key. The definition and the first hooks are easy.
+%    \begin{macrocode}
+\lst@Key{texcl}{false}[t]{\lstKV@SetIf{#1}\lst@iftexcl}
+\lst@AddToHook{TextStyle}{\let\lst@iftexcl\iffalse}
+\lst@AddToHook{EOL}
+    {\ifnum\lst@mode=\lst@TeXLmode
+         \expandafter\lst@escapeend
+         \expandafter\lst@LeaveAllModes
+         \expandafter\lst@ReenterModes
+     \fi}
+%    \end{macrocode}
+% If the user wants \TeX\ comment lines, we print the comment separator and
+% interrupt the normal processing.
+%    \begin{macrocode}
+\lst@AddToHook{AfterBeginComment}
+    {\lst@iftexcl \lst@ifLmode \lst@ifdropinput\else
+         \lst@PrintToken
+         \lst@LeaveMode \lst@InterruptModes
+         \lst@EnterMode{\lst@TeXLmode}{\lst@modetrue\lst@commentstyle}%
+         \expandafter\expandafter\expandafter\lst@escapebegin
+     \fi \fi \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@NewMode\lst@TeXLmode
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@ActiveCDefX}
+% Same as |\lst@CDefX| but we both make |#1| active and assign a new catcode.
+%    \begin{macrocode}
+\gdef\lst@ActiveCDefX#1{\lst@ActiveCDefX@#1}
+\gdef\lst@ActiveCDefX@#1#2#3{
+    \catcode`#1\active\lccode`\~=`#1%
+    \lowercase{\lst@CDefIt~}{#2}{#3}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@Escape}
+% gets four arguments all in all. The first and second are the `begin' and
+% `end' escape sequences, the third is executed when the escape starts, and the
+% fourth right before ending it. We use the same mechanism as for \TeX\ comment
+% lines. The |\lst@ifdropinput| test has been added after a bug report by
+% \lsthelper{Michael~Weber}{2002/03/26}{escape on lines < firstline corrupts
+% output}.  The |\lst@newlines\z@| was added due to a bug report by
+% \lsthelper{Frank~Atanassow}{2004/10/07}{space after mathescape is not
+% preserved}.
+%    \begin{macrocode}
+\gdef\lst@Escape#1#2#3#4{%
+    \lst@CArgX #1\relax\lst@CDefX
+        {}%
+        {\lst@ifdropinput\else
+         \lst@TrackNewLines\lst@OutputLostSpace \lst@XPrintToken
+         \lst@InterruptModes
+         \lst@EnterMode{\lst@TeXmode}{\lst@modetrue}%
+%    \end{macrocode}
+% Now we must define the character sequence to end the escape.
+%    \begin{macrocode}
+         \ifx\^^M#2%
+             \lst@CArg #2\relax\lst@ActiveCDefX
+                 {}%
+                 {\lst@escapeend #4\lst@LeaveAllModes\lst@ReenterModes}%
+                 {\lst@MProcessListing}%
+         \else
+             \lst@CArg #2\relax\lst@ActiveCDefX
+                 {}%
+                 {\lst@escapeend #4\lst@LeaveAllModes\lst@ReenterModes
+                  \lst@newlines\z@ \lst@whitespacefalse}%
+                 {}%
+         \fi
+         #3\lst@escapebegin
+         \fi}%
+        {}}
+%    \end{macrocode}
+% The |\lst@whitespacefalse| above was added after a bug report from
+% \lsthelper{Martin~Steffen}{2001/04/07}{mathescape drops subsequent space}.
+%    \begin{macrocode}
+\lst@NewMode\lst@TeXmode
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{escapebegin}
+% \begin{lstkey}{escapeend}
+% The keys simply store the arguments.
+%    \begin{macrocode}
+\lst@Key{escapebegin}{}{\def\lst@escapebegin{#1}}
+\lst@Key{escapeend}{}{\def\lst@escapeend{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{escapechar}
+% The introduction of this key is due to a communication with \lsthelper
+% {Rui~Oliveira}{1998/06/05}{escape characters}. We define |\lst@DefEsc| and
+% execute it after selecting the standard character table.
+%    \begin{macrocode}
+\lst@Key{escapechar}{}
+    {\ifx\@empty#1\@empty
+         \let\lst@DefEsc\relax
+     \else
+         \def\lst@DefEsc{\lst@Escape{#1}{#1}{}{}}%
+     \fi}
+\lst@AddToHook{TextStyle}{\let\lst@DefEsc\@empty}
+\lst@AddToHook{SelectCharTable}{\lst@DefEsc}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{escapeinside}
+% Nearly the same.
+%    \begin{macrocode}
+\lst@Key{escapeinside}{}{\lstKV@TwoArg{#1}%
+    {\let\lst@DefEsc\@empty
+     \ifx\@empty##1@empty\else \ifx\@empty##2\@empty\else
+         \def\lst@DefEsc{\lst@Escape{##1}{##2}{}{}}%
+     \fi\fi}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{mathescape}
+% This is a switch and checked after character table selection. We use
+% |\lst@Escape| with math shifts as arguments, but all inside |\hbox|
+% to determine the correct width.
+%    \begin{macrocode}
+\lst@Key{mathescape}{false}[t]{\lstKV@SetIf{#1}\lst@ifmathescape}
+\lst@AddToHook{SelectCharTable}
+    {\lst@ifmathescape \lst@Escape{\$}{\$}%
+        {\setbox\@tempboxa=\hbox\bgroup$}%
+        {$\egroup \lst@CalcLostSpaceAndOutput}\fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \section{Keywords}
+%
+%
+% \subsection{Making tests}\label{iMakingTests}
+%
+% \begin{aspect}{keywords}
+% We begin a new and very important aspect.
+% First of all we need to initialize some variables in order to work around a
+% bug reported by \lsthelper{Beat~Birkhofer}{2001/06/15}{savemem doesn't work}.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{keywords}
+%    \end{macrocode}
+%    \begin{macrocode}
+\global\let\lst@ifsensitive\iftrue % init
+\global\let\lst@ifsensitivedefed\iffalse % init % \global
+%    \end{macrocode}
+% All keyword tests take the following three arguments.
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@|\meta{name}|@list| (a list of macros which contain the keywords)
+% \item |\lst@g|\meta{name}|@sty| (global style macro)
+% \end{macroargs}
+% We begin with non memory-saving tests.
+% \begingroup
+%    \begin{macrocode}
+\lst@ifsavemem\else
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lst@KeywordTest}
+% Fast keyword tests take advance of the |\lst@UM| construction in section
+% \ref{iCharacterTables}. If |\lst@UM| is empty, all `use macro' characters
+% expand to their original characters. Since |\lst|\meta{prefix}|@|\meta{keyword}
+% will be equivalent to the appropriate style, we only need to build the control
+% sequence |\lst|\meta{prefix}|@|\meta{current token} and assign it to
+% |\lst@thestyle|.
+%    \begin{macrocode}
+\gdef\lst@KeywordTest#1#2#3{%
+    \begingroup \let\lst@UM\@empty
+    \global\expandafter\let\expandafter\@gtempa
+        \csname\@lst#1@\the\lst@token\endcsname
+    \endgroup
+    \ifx\@gtempa\relax\else
+        \let\lst@thestyle\@gtempa
+    \fi}
+%    \end{macrocode}
+% Note that we need neither |#2| nor |#3| here.
+% \end{macro}
+%
+% \begin{macro}{\lst@KEYWORDTEST}
+% Case insensitive tests make the current character string upper case and give
+% it to a submacro similar to |\lst@KeywordTest|.
+%    \begin{macrocode}
+\gdef\lst@KEYWORDTEST{%
+    \uppercase\expandafter{\expandafter
+        \lst@KEYWORDTEST@\the\lst@token}\relax}
+\gdef\lst@KEYWORDTEST@#1\relax#2#3#4{%
+    \begingroup \let\lst@UM\@empty
+    \global\expandafter\let\expandafter\@gtempa
+        \csname\@lst#2@#1\endcsname
+    \endgroup
+    \ifx\@gtempa\relax\else
+        \let\lst@thestyle\@gtempa
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@WorkingTest}
+% \begin{macro}{\lst@WORKINGTEST}
+% The same except that |\lst|\meta{prefix}|@|\meta{current token} might be
+% a working procedure; it is executed.
+%    \begin{macrocode}
+\gdef\lst@WorkingTest#1#2#3{%
+    \begingroup \let\lst@UM\@empty
+    \global\expandafter\let\expandafter\@gtempa
+        \csname\@lst#1@\the\lst@token\endcsname
+    \endgroup
+    \@gtempa}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@WORKINGTEST{%
+    \uppercase\expandafter{\expandafter
+        \lst@WORKINGTEST@\the\lst@token}\relax}
+\gdef\lst@WORKINGTEST@#1\relax#2#3#4{%
+    \begingroup \let\lst@UM\@empty
+    \global\expandafter\let\expandafter\@gtempa
+        \csname\@lst#2@#1\endcsname
+    \endgroup
+    \@gtempa}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@DefineKeywords}
+% Eventually we need macros which define and undefine
+% |\lst|\meta{prefix}|@|\meta{keyword}. Here the arguments are
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@|\meta{name} (a keyword list)
+% \item |\lst@g|\meta{name}|@sty|
+% \end{macroargs}
+% We make the keywords upper case if necessary, \ldots
+%    \begin{macrocode}
+\gdef\lst@DefineKeywords#1#2#3{%
+    \lst@ifsensitive
+        \def\lst@next{\lst@for#2}%
+    \else
+        \def\lst@next{\uppercase\expandafter{\expandafter\lst@for#2}}%
+    \fi
+    \lst@next\do
+%    \end{macrocode}
+% \ldots\space iterate through the list, and make
+% |\lst|\meta{prefix}|@|\meta{keyword} (if undefined) equivalent to
+% |\lst@g|\meta{name}|@sty| which is possibly a working macro.
+%    \begin{macrocode}
+    {\expandafter\ifx\csname\@lst#1@##1\endcsname\relax
+        \global\expandafter\let\csname\@lst#1@##1\endcsname#3%
+     \fi}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@UndefineKeywords}
+% We make the keywords upper case if necessary, \ldots
+%    \begin{macrocode}
+\gdef\lst@UndefineKeywords#1#2#3{%
+    \lst@ifsensitivedefed
+        \def\lst@next{\lst@for#2}%
+    \else
+        \def\lst@next{\uppercase\expandafter{\expandafter\lst@for#2}}%
+    \fi
+    \lst@next\do
+%    \end{macrocode}
+% \ldots\space iterate through the list, and `undefine'
+% |\lst|\meta{prefix}|@|\meta{keyword} if it's equivalent to
+% |\lst@g|\meta{name}|@sty|.
+%    \begin{macrocode}
+    {\expandafter\ifx\csname\@lst#1@##1\endcsname#3%
+        \global\expandafter\let\csname\@lst#1@##1\endcsname\relax
+     \fi}}
+%    \end{macrocode}
+% Thanks to \lsthelper{Magnus~Lewis-Smith}{1999/09/08}{keywords do not
+% undefine} a wrong |#2| in the replacement text could be changed to |#3|.
+% \end{macro}
+%
+% \begingroup
+% And now memory-saving tests.
+%    \begin{macrocode}
+\fi
+\lst@ifsavemem
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{macro}{\lst@IfOneOutOf}
+% The definition here is similar to |\lst@IfOneOf|, but its second argument
+% is a |\lst@|\meta{name}|@list|. Therefore we test a list of macros here.
+%    \begin{macrocode}
+\gdef\lst@IfOneOutOf#1\relax#2{%
+    \def\lst@temp##1,#1,##2##3\relax{%
+        \ifx\@empty##2\else \expandafter\lst@IOOOfirst \fi}%
+    \def\lst@next{\lst@IfOneOutOf@#1\relax}%
+    \expandafter\lst@next#2\relax\relax}
+%    \end{macrocode}
+% We either execute the \meta{else} part or make the next test.
+%    \begin{macrocode}
+\gdef\lst@IfOneOutOf@#1\relax#2#3{%
+    \ifx#2\relax
+        \expandafter\@secondoftwo
+    \else
+        \expandafter\lst@temp\expandafter,#2,#1,\@empty\relax
+        \expandafter\lst@next
+    \fi}
+\ifx\iffalse\else\fi
+\gdef\lst@IOOOfirst#1\relax#2#3{\fi#2}
+%    \end{macrocode}
+% The line |\ifx\iffalse\else\fi| balances the |\fi| inside |\lst@IOOOfirst|.
+% \end{macro}
+%
+% \begin{macro}{\lst@IFONEOUTOF}
+% As in |\lst@IFONEOF| we need two |\uppercase|s here.
+%    \begin{macrocode}
+\gdef\lst@IFONEOUTOF#1\relax#2{%
+    \uppercase{\def\lst@temp##1,#1},##2##3\relax{%
+        \ifx\@empty##2\else \expandafter\lst@IOOOfirst \fi}%
+    \def\lst@next{\lst@IFONEOUTOF@#1\relax}%
+    \expandafter\lst@next#2\relax}
+\gdef\lst@IFONEOUTOF@#1\relax#2#3{%
+    \ifx#2\relax
+        \expandafter\@secondoftwo
+    \else
+        \uppercase
+            {\expandafter\lst@temp\expandafter,#2,#1,\@empty\relax}%
+        \expandafter\lst@next
+    \fi}
+%    \end{macrocode}
+% Note: The third last line uses the fact that keyword lists (not the list
+% of keyword lists) are already made upper case if keywords are insensitive.
+% \end{macro}
+%
+% \begin{macro}{\lst@KWTest}
+% is a helper for the keyword and working identifier tests. We expand the
+% token and call |\lst@IfOneOf|. The tests below will append appropriate
+% \meta{then} and \meta{else} arguments.
+%    \begin{macrocode}
+\gdef\lst@KWTest{%
+    \begingroup \let\lst@UM\@empty
+    \expandafter\xdef\expandafter\@gtempa\expandafter{\the\lst@token}%
+    \endgroup
+    \expandafter\lst@IfOneOutOf\@gtempa\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@KeywordTest}
+% \begin{macro}{\lst@KEYWORDTEST}
+% are fairly easy now. Note that we don't need |#1|=\meta{prefix} here.
+%    \begin{macrocode}
+\gdef\lst@KeywordTest#1#2#3{\lst@KWTest #2{\let\lst@thestyle#3}{}}
+\global\let\lst@KEYWORDTEST\lst@KeywordTest
+%    \end{macrocode}
+% For case insensitive tests we assign the insensitive version to
+% |\lst@IfOneOutOf|. Thus we need no extra definition here.
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@WorkingTest}
+% \begin{macro}{\lst@WORKINGTEST}
+% Ditto.
+%    \begin{macrocode}
+\gdef\lst@WorkingTest#1#2#3{\lst@KWTest #2#3{}}
+\global\let\lst@WORKINGTEST\lst@WorkingTest
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begingroup
+%    \begin{macrocode}
+\fi
+%    \end{macrocode}
+% \endgroup
+%
+% \begin{lstkey}{sensitive}
+% is a switch, preset \texttt{true} every language selection.
+%    \begin{macrocode}
+\lst@Key{sensitive}\relax[t]{\lstKV@SetIf{#1}\lst@ifsensitive}
+\lst@AddToHook{SetLanguage}{\let\lst@ifsensitive\iftrue}
+%    \end{macrocode}
+% We select case insensitive definitions if necessary.
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+    {\lst@ifsensitive\else
+         \let\lst@KeywordTest\lst@KEYWORDTEST
+         \let\lst@WorkingTest\lst@WORKINGTEST
+         \let\lst@IfOneOutOf\lst@IFONEOUTOF
+     \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@MakeMacroUppercase}
+% makes the contents of |#1| (if defined) upper case.
+%    \begin{macrocode}
+\gdef\lst@MakeMacroUppercase#1{%
+    \ifx\@undefined#1\else \uppercase\expandafter
+        {\expandafter\def\expandafter#1\expandafter{#1}}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Installing tests}
+%
+% \begin{macro}{\lst@InstallTest}
+% The arguments are
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@|\meta{name}|@list|
+% \item |\lst@|\meta{name}
+% \item |\lst@g|\meta{name}|@list|
+% \item |\lst@g|\meta{name}
+% \item |\lst@g|\meta{name}|@sty|
+% \item \alternative{w,s} (working procedure or style)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \end{macroargs}
+% We just insert hook material. The tests will be inserted on demand.
+%    \begin{macrocode}
+\gdef\lst@InstallTest#1#2#3#4#5#6#7#8{%
+    \lst@AddToHook{TrackKeywords}{\lst@TrackKeywords{#1}#2#4#6#7#8}%
+    \lst@AddToHook{PostTrackKeywords}{\lst@PostTrackKeywords#2#3#4#5}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\lsthk@TrackKeywords\lsthk@PostTrackKeywords}
+\lst@AddToHook{TrackKeywords}
+    {\global\let\lst@DoDefineKeywords\@empty}% init
+\lst@AddToHook{PostTrackKeywords}
+    {\lst@DoDefineKeywords
+     \global\let\lst@DoDefineKeywords\@empty}% init
+%    \end{macrocode}
+% We have to detect the keywords somewhere.
+%    \begin{macrocode}
+\lst@AddToHook{Output}{\lst@ifkeywords \lsthk@DetectKeywords \fi}
+\lst@AddToHook{DetectKeywords}{}% init
+\lst@AddToHook{ModeTrue}{\let\lst@ifkeywords\iffalse}
+\lst@AddToHookExe{Init}{\let\lst@ifkeywords\iftrue}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InstallTestNow}
+% actually inserts a test.
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@|\meta{name}|@list|
+% \item |\lst@g|\meta{name}|@sty|
+% \item \alternative{w,s} (working procedure or style)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \end{macroargs}
+% For example, |#4#5|=|sd| will add
+%    |\lst@KeywordTest{|\meta{prefix}|}|
+%       |\lst@|\meta{name}|@list| |\lst@g|\meta{name}|@sty|
+% to the \hookname{DetectKeywords} hook.
+%    \begin{macrocode}
+\gdef\lst@InstallTestNow#1#2#3#4#5{%
+    \@ifundefined{\string#2#1}%
+    {\global\@namedef{\string#2#1}{}%
+     \edef\@tempa{%
+         \noexpand\lst@AddToHook{\ifx#5dDetectKeywords\else Output\fi}%
+         {\ifx #4w\noexpand\lst@WorkingTest
+             \else\noexpand\lst@KeywordTest \fi
+          {#1}\noexpand#2\noexpand#3}}%
+%    \end{macrocode}
+% If we are advised to save memory, we insert a test for each \meta{name}.
+% Otherwise we install the tests according to \meta{prefix}.
+%    \begin{macrocode}
+     \lst@ifsavemem
+         \@tempa
+     \else
+         \@ifundefined{\@lst#1@if@ins}%
+             {\@tempa \global\@namedef{\@lst#1@if@ins}{}}%
+             {}%
+     \fi}
+    {}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@TrackKeywords}
+% Now it gets a bit tricky. We expand the class list |\lst@|\meta{name}|@list|
+% behind |\lst@TK@{|\meta{prefix}|}||\lst@g|\meta{name}|@sty| and use two
+% |\relax|es as terminators. This will define the keywords of all the classes
+% as keywords of type \meta{prefix}. More details come soon.
+%    \begin{macrocode}
+\gdef\lst@TrackKeywords#1#2#3#4#5#6{%
+    \lst@false
+    \def\lst@arg{{#1}#4}%
+    \expandafter\expandafter\expandafter\lst@TK@
+        \expandafter\lst@arg#2\relax\relax
+%    \end{macrocode}
+% And nearly the same to undefine all out-dated keywords, which is necessary
+% only if we don't save memory.
+%    \begin{macrocode}
+    \lst@ifsavemem\else
+        \def\lst@arg{{#1}#4#2}%
+        \expandafter\expandafter\expandafter\lst@TK@@
+            \expandafter\lst@arg#3\relax\relax
+    \fi
+%    \end{macrocode}
+% Finally we install the keyword test if keywords changed, in particular if
+% they are defined the first time. Note that |\lst@InstallTestNow| inserts a
+% test only once.
+%    \begin{macrocode}
+    \lst@if \lst@InstallTestNow{#1}#2#4#5#6\fi}
+%    \end{macrocode}
+% Back to the current keywords. Global macros |\lst@g|\meta{id} contain
+% globally defined keywords, whereas |\lst@|\meta{id} conatin the true
+% keywords. This way we can keep track of the keywords: If keywords or
+% \keyname{sensitive} changed, we undefine the old (= globally defined)
+% keywords and define the true ones. The arguments of |\lst@TK@| are
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@g|\meta{name}|@sty|
+% \item |\lst@|\meta{id}
+% \item |\lst@g|\meta{id}
+% \end{macroargs}
+% Thanks to \lsthelper{Holger~Arndt}{2004/05/27}{bad \lst@UndefineKeywords
+% \lst@DefineKeywords sequence if keyword crosses orders in two languages}
+% the definition of keywords is now delayed via |\lst@DoDefineKeywords|.
+%    \begin{macrocode}
+\gdef\lst@TK@#1#2#3#4{%
+  \ifx\lst@ifsensitive\lst@ifsensitivedefed
+    \ifx#3#4\else
+      \lst@true
+      \lst@ifsavemem\else
+          \lst@UndefineKeywords{#1}#4#2%
+          \lst@AddTo\lst@DoDefineKeywords{\lst@DefineKeywords{#1}#3#2}%
+      \fi
+    \fi
+  \else
+    \ifx#3\relax\else
+      \lst@true
+      \lst@ifsavemem\else
+          \lst@UndefineKeywords{#1}#4#2%
+          \lst@AddTo\lst@DoDefineKeywords{\lst@DefineKeywords{#1}#3#2}%
+      \fi
+    \fi
+  \fi
+%    \end{macrocode}
+% We don't define and undefine keywords if we try to save memory. But we
+% possibly need to make them upper case, which again wastes some memory.
+%    \begin{macrocode}
+  \lst@ifsavemem \ifx#3\relax\else
+      \lst@ifsensitive\else \lst@MakeMacroUppercase#3\fi
+  \fi \fi
+%    \end{macrocode}
+% Reaching the end of the class list, we end the loop.
+%    \begin{macrocode}
+  \ifx#3\relax
+      \expandafter\@gobblethree
+  \fi
+  \lst@TK@{#1}#2}
+%    \end{macrocode}
+% Here now we undefine the out-dated keywords. While not reaching the end of
+% the global list, we look whether the keyword class |#4#5| is still in use or
+% needs to be undefined. Our arguments are
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item |\lst@g|\meta{name}|@sty|
+% \item |\lst@|\meta{name}|@list|
+% \item |\lst@|\meta{id}
+% \item |\lst@g|\meta{id}
+% \end{macroargs}
+%    \begin{macrocode}
+\gdef\lst@TK@@#1#2#3#4#5{%
+    \ifx#4\relax
+        \expandafter\@gobblefour
+    \else
+        \lst@IfSubstring{#4#5}#3{}{\lst@UndefineKeywords{#1}#5#2}%
+    \fi
+    \lst@TK@@{#1}#2#3}
+%    \end{macrocode}
+% Keywords are up-to-date after \hookname{InitVars}.
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}
+    {\global\let\lst@ifsensitivedefed\lst@ifsensitive}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@PostTrackKeywords}
+% After updating all the keywords, the global keywords and the global list
+% become equivalent to the local ones.
+%    \begin{macrocode}
+\gdef\lst@PostTrackKeywords#1#2#3#4{%
+    \lst@ifsavemem\else
+        \global\let#3#1%
+        \global\let#4#2%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Classes and families}
+%
+% \begin{lstkey}{classoffset}
+% just stores the argument in a macro.
+%    \begin{macrocode}
+\lst@Key{classoffset}\z@{\def\lst@classoffset{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@InstallFamily}
+% Recall the parameters
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item \meta{name}
+% \item \meta{style name}
+% \item \meta{style init}
+% \item \meta{default style name}
+% \item \meta{working procedure}
+% \item \alternative{l,o} (language or other key)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \end{macroargs}
+% First we define the keys and the style key \meta{style name} if and only if
+% the name is not empty.
+%    \begin{macrocode}
+\gdef\lst@InstallFamily#1#2#3#4#5{%
+    \lst@Key{#2}\relax{\lst@UseFamily{#2}##1\relax\lst@MakeKeywords}%
+    \lst@Key{more#2}\relax
+        {\lst@UseFamily{#2}##1\relax\lst@MakeMoreKeywords}%
+    \lst@Key{delete#2}\relax
+        {\lst@UseFamily{#2}##1\relax\lst@DeleteKeywords}%
+    \ifx\@empty#3\@empty\else
+        \lst@Key{#3}{#4}{\lstKV@OptArg[\@ne]{##1}%
+            {\@tempcnta\lst@classoffset \advance\@tempcnta####1\relax
+             \@namedef{lst@#3\ifnum\@tempcnta=\@ne\else \the\@tempcnta
+                             \fi}{####2}}}%
+    \fi
+    \expandafter\lst@InstallFamily@
+        \csname\@lst @#2@data\expandafter\endcsname
+        \csname\@lst @#5\endcsname {#1}{#2}{#3}}
+%    \end{macrocode}
+% Now we check whether \meta{working procedure} is empty. Accordingly we use
+% \texttt working procedure or \texttt style in the `data' definition.
+% The working procedure is defined right here if necessary.
+%    \begin{macrocode}
+\gdef\lst@InstallFamily@#1#2#3#4#5#6#7#8{%
+    \gdef#1{{#3}{#4}{#5}#2#7}%
+    \long\def\lst@temp##1{#6}%
+    \ifx\lst@temp\@gobble
+        \lst@AddTo#1{s#8}%
+    \else
+        \lst@AddTo#1{w#8}%
+        \global\@namedef{lst@g#4@wp}##1{#6}%
+    \fi}
+%    \end{macrocode}
+% Nothing else is defined here, all the rest is done on demand.
+% \end{macro}
+%
+% \begin{macro}{\lst@UseFamily}
+% We look for the optional class number, provide this member, \ldots
+%    \begin{macrocode}
+\gdef\lst@UseFamily#1{%
+    \def\lst@family{#1}%
+    \@ifnextchar[\lst@UseFamily@{\lst@UseFamily@[\@ne]}}
+\gdef\lst@UseFamily@[#1]{%
+    \@tempcnta\lst@classoffset \advance\@tempcnta#1\relax
+    \lst@ProvideFamily\lst@family
+%    \end{macrocode}
+% \ldots\space and build the control sequences \ldots
+%    \begin{macrocode}
+    \lst@UseFamily@a
+        {\lst@family\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi}}
+\gdef\lst@UseFamily@a#1{%
+    \expandafter\lst@UseFamily@b
+       \csname\@lst @#1@list\expandafter\endcsname
+       \csname\@lst @#1\expandafter\endcsname
+       \csname\@lst @#1@also\expandafter\endcsname
+       \csname\@lst @g#1\endcsname}
+%    \end{macrocode}
+% \ldots\space required for |\lst@MakeKeywords| and |#6|.
+%    \begin{macrocode}
+\gdef\lst@UseFamily@b#1#2#3#4#5\relax#6{\lstKV@XOptArg[]{#5}#6#1#2#3#4}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ProvideFamily}
+% provides the member `|\the\@tempcnta|' of the family |#1|. We do nothing if
+% the member already exists. Otherwise we expand the data macro defined above.
+% Note that we don't use the counter if it equals one. Since a bug report by
+% \lsthelper{Kris~Luyten}{2002/08/03}{Undefined control sequence \lst@thestyle}
+% keyword families use the prefix |lstfam| instead of |lst|. The marker
+% |\lstfam@#1|\oarg{number} is defined globally since a bug report by
+% \lsthelper{Edsko~de~Vries}{2003/07/20}{bad keywords with language selections
+% only in optional arguments}.
+%    \begin{macrocode}
+\gdef\lst@ProvideFamily#1{%
+    \@ifundefined{lstfam@#1\ifnum\@tempcnta=\@ne\else\the\@tempcnta\fi}%
+    {\global\@namedef{lstfam@#1\ifnum\@tempcnta=\@ne\else
+                                        \the\@tempcnta\fi}{}%
+     \expandafter\expandafter\expandafter\lst@ProvideFamily@
+         \csname\@lst @#1@data\endcsname
+         {\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi}}%
+    {}}%
+%    \end{macrocode}
+% Now we have the following arguments
+% \begin{macroargs}
+% \item \meta{prefix}
+% \item \meta{name}
+% \item \meta{style name}
+% \item \meta{default style name}
+% \item \alternative{l,o} (language or other key)
+% \item \alternative{w,s} (working procedure or style)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \item |\ifnum\@tempcnta=\@ne\else \the\@tempcnta \fi|
+% \end{macroargs}
+% We define |\lst@g|\meta{name}\meta{number}|@sty| to call either
+% |\lst@g|\meta{name}|@wp| with the number as argument or
+% |\lst@|\meta{style name}\meta{number} where the number belongs to the control
+% sequence.
+%    \begin{macrocode}
+\gdef\lst@ProvideFamily@#1#2#3#4#5#6#7#8{%
+    \expandafter\xdef\csname\@lst @g#2#8@sty\endcsname
+    {\if #6w%
+         \expandafter\noexpand\csname\@lst @g#2@wp\endcsname{#8}%
+     \else
+         \expandafter\noexpand\csname\@lst @#3#8\endcsname
+     \fi}%
+%    \end{macrocode}
+% We ensure the existence of the style macro. This is done in the
+% \hookname{Init} hook by assigning the default style if necessary.
+%    \begin{macrocode}
+    \ifx\@empty#3\@empty\else
+        \edef\lst@temp{\noexpand\lst@AddToHook{Init}{%
+            \noexpand\lst@ProvideStyle\expandafter\noexpand
+                \csname\@lst @#3#8\endcsname\noexpand#4}}%
+        \lst@temp
+    \fi
+%    \end{macrocode}
+% We call a submacro to do the rest. It requires some control sequences.
+%    \begin{macrocode}
+    \expandafter\lst@ProvideFamily@@
+         \csname\@lst @#2#8@list\expandafter\endcsname
+         \csname\@lst @#2#8\expandafter\endcsname
+         \csname\@lst @#2#8@also\expandafter\endcsname
+         \csname\@lst @g#2#8@list\expandafter\endcsname
+         \csname\@lst @g#2#8\expandafter\endcsname
+         \csname\@lst @g#2#8@sty\expandafter\endcsname
+         {#1}#5#6#7}
+%    \end{macrocode}
+% Now we have (except that \meta{number} is possibly always missing)
+% \begin{macroargs}
+% \item |\lst@|\meta{name}\meta{number}|@list|
+% \item |\lst@|\meta{name}\meta{number}
+% \item |\lst@|\meta{name}\meta{number}|@also|
+% \item |\lst@g|\meta{name}\meta{number}|@list|
+% \item |\lst@g|\meta{name}\meta{number}
+% \item |\lst@g|\meta{name}\meta{number}|@sty|
+% \item \meta{prefix}
+% \item \alternative{l,o} (language or other key)
+% \item \alternative{w,s} (working procedure or style)
+% \item \alternative{d,o} (\hookname{DetectKeywords} or \hookname{Output} hook)
+% \end{macroargs}
+% Note that |#9| and `|#10|' are read by |\lst@InstallTest|. We initialize all
+% required `variables' (at \hookname{SetLanguage}) and install the test (which
+% definition is in fact also delayed).
+%    \begin{macrocode}
+\gdef\lst@ProvideFamily@@#1#2#3#4#5#6#7#8{%
+    \gdef#1{#2#5}\global\let#2\@empty \global\let#3\@empty % init
+    \gdef#4{#2#5}\global\let#5\@empty % init
+    \if #8l\relax
+        \lst@AddToHook{SetLanguage}{\def#1{#2#5}\let#2\@empty}%
+    \fi
+    \lst@InstallTest{#7}#1#2#4#5#6}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InstallKeywords}
+% Now we take advance of the optional argument construction above. Thus, we
+% just insert |[\@ne]| as \meta{number} in the definitions of the keys.
+%    \begin{macrocode}
+\gdef\lst@InstallKeywords#1#2#3#4#5{%
+    \lst@Key{#2}\relax
+        {\lst@UseFamily{#2}[\@ne]##1\relax\lst@MakeKeywords}%
+    \lst@Key{more#2}\relax
+        {\lst@UseFamily{#2}[\@ne]##1\relax\lst@MakeMoreKeywords}%
+    \lst@Key{delete#2}\relax
+        {\lst@UseFamily{#2}[\@ne]##1\relax\lst@DeleteKeywords}%
+    \ifx\@empty#3\@empty\else
+        \lst@Key{#3}{#4}{\@namedef{lst@#3}{##1}}%
+    \fi
+    \expandafter\lst@InstallFamily@
+        \csname\@lst @#2@data\expandafter\endcsname
+        \csname\@lst @#5\endcsname {#1}{#2}{#3}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ProvideStyle}
+% If the style macro |#1| is not defined, it becomes equivalent to |#2|.
+%    \begin{macrocode}
+\gdef\lst@ProvideStyle#1#2{%
+    \ifx#1\@undefined \let#1#2%
+    \else\ifx#1\relax \let#1#2\fi\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% Finally we define |\lst@MakeKeywords|, \ldots, |\lst@DeleteKeywords|.
+% We begin with two helper.
+%
+% \begin{macro}{\lst@BuildClassList}
+% After |#1| follows a comma separated list of keyword classes terminated by
+% |,\relax,|, e.g.~|keywords2,emph1,\relax,|. For each \meta{item} in this
+% list we \emph{append} the two macros |\lst@|\meta{item}|\lst@g|\meta{item}
+% to |#1|.
+%    \begin{macrocode}
+\gdef\lst@BuildClassList#1#2,{%
+    \ifx\relax#2\@empty\else
+        \ifx\@empty#2\@empty\else
+            \lst@lExtend#1{\csname\@lst @#2\expandafter\endcsname
+                           \csname\@lst @g#2\endcsname}%
+        \fi
+        \expandafter\lst@BuildClassList\expandafter#1
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DeleteClassesIn}
+% deletes pairs of tokens, namely the arguments |#2#3| to the submacro.
+%    \begin{macrocode}
+\gdef\lst@DeleteClassesIn#1#2{%
+    \expandafter\lst@DCI@\expandafter#1#2\relax\relax}
+\gdef\lst@DCI@#1#2#3{%
+    \ifx#2\relax
+        \expandafter\@gobbletwo
+    \else
+%    \end{macrocode}
+% If we haven't reached the end of the class list, we define a temporary macro
+% which removes all appearances.
+%    \begin{macrocode}
+        \def\lst@temp##1#2#3##2{%
+            \lst@lAddTo#1{##1}%
+            \ifx ##2\relax\else
+                \expandafter\lst@temp
+            \fi ##2}%
+        \let\@tempa#1\let#1\@empty
+        \expandafter\lst@temp\@tempa#2#3\relax
+    \fi
+    \lst@DCI@#1}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@MakeKeywords}
+% We empty some macros and make use of |\lst@MakeMoreKeywords|.
+% Note that this and the next two definitions have the following arguments:
+% \begin{macroargs}
+% \item class list (in brackets)
+% \item keyword list
+% \item |\lst@|\meta{name}|@list|
+% \item |\lst@|\meta{name}
+% \item |\lst@|\meta{name}|@also|
+% \item |\lst@g|\meta{name}
+% \end{macroargs}
+%    \begin{macrocode}
+\gdef\lst@MakeKeywords[#1]#2#3#4#5#6{%
+    \def#3{#4#6}\let#4\@empty \let#5\@empty
+    \lst@MakeMoreKeywords[#1]{#2}#3#4#5#6}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@MakeMoreKeywords}
+% We append classes and keywords.
+%    \begin{macrocode}
+\gdef\lst@MakeMoreKeywords[#1]#2#3#4#5#6{%
+    \lst@BuildClassList#3#1,\relax,%
+    \lst@DefOther\lst@temp{,#2}\lst@lExtend#4\lst@temp}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@DeleteKeywords}
+% We convert the keyword arguments via |\lst@MakeKeywords| and remove the
+% classes and keywords.
+%    \begin{macrocode}
+\gdef\lst@DeleteKeywords[#1]#2#3#4#5#6{%
+    \lst@MakeKeywords[#1]{#2}\@tempa\@tempb#5#6%
+    \lst@DeleteClassesIn#3\@tempa
+    \lst@DeleteKeysIn#4\@tempb}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Main families and classes}
+%
+%
+% \paragraph{Keywords}
+%
+% \begin{lstkey}{keywords}
+% Defining the keyword family gets very, very easy.
+%    \begin{macrocode}
+\lst@InstallFamily k{keywords}{keywordstyle}\bfseries{keywordstyle}{}ld
+%    \end{macrocode}
+% The following macro sets a keywordstyle, which \ldots
+%    \begin{macrocode}
+\gdef\lst@DefKeywordstyle#1#2\@nil@{%
+   \@namedef{lst@keywordstyle\ifnum\@tempcnta=\@ne\else\the\@tempcnta
+                             \fi}{#1#2}}%
+%    \end{macrocode}
+% \ldots\space is put together here. If we detect a star after the class
+% number, we insert code to make the keyword uppercase.
+%    \begin{macrocode}
+\lst@Key{keywordstyle}{\bfseries}{\lstKV@OptArg[\@ne]{#1}%
+  {\@tempcnta\lst@classoffset \advance\@tempcnta##1\relax
+   \@ifstar{\lst@DefKeywordstyle{\uppercase\expandafter{%
+                                 \expandafter\lst@token
+                                 \expandafter{\the\lst@token}}}}%
+           {\lst@DefKeywordstyle{}}##2\@nil@}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{ndkeywords}
+% Second order keywords use the same trick as |\lst@InstallKeywords|.
+%    \begin{macrocode}
+\lst@Key{ndkeywords}\relax
+    {\lst@UseFamily{keywords}[\tw@]#1\relax\lst@MakeKeywords}%
+\lst@Key{morendkeywords}\relax
+    {\lst@UseFamily{keywords}[\tw@]#1\relax\lst@MakeMoreKeywords}%
+\lst@Key{deletendkeywords}\relax
+    {\lst@UseFamily{keywords}[\tw@]#1\relax\lst@DeleteKeywords}%
+\lst@Key{ndkeywordstyle}\relax{\@namedef{lst@keywordstyle2}{#1}}%
+%    \end{macrocode}
+% \lsthelper{Dr.~Peter~Leibner}{1999/11/05}{undefined \lst@UseKeywords,
+% Illegal parameter number (##1)} reported two bugs: |\lst@UseKeywords| and
+% |##1| became |\lst@UseFamily| and |#1|.
+% \end{lstkey}
+%
+% \begin{lstkey}{keywordsprefix}
+% is implemented experimentally. The one and only prefix indicates its
+% presence by making |\lst@prefixkeyword| empty. We can catch this information
+% in the \keyname{Output} hook.
+%    \begin{macrocode}
+\lst@Key{keywordsprefix}\relax{\lst@DefActive\lst@keywordsprefix{#1}}
+\global\let\lst@keywordsprefix\@empty
+\lst@AddToHook{SelectCharTable}
+    {\ifx\lst@keywordsprefix\@empty\else
+         \expandafter\lst@CArg\lst@keywordsprefix\relax
+             \lst@CDef{}%
+                      {\lst@ifletter\else
+                           \global\let\lst@prefixkeyword\@empty
+                       \fi}%
+                      {}%
+     \fi}
+\lst@AddToHook{Init}{\global\let\lst@prefixkeyword\relax}
+\lst@AddToHook{Output}
+    {\ifx\lst@prefixkeyword\@empty
+         \let\lst@thestyle\lst@gkeywords@sty
+         \global\let\lst@prefixkeyword\relax
+     \fi}%
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{otherkeywords}
+% Thanks to \lsthelper{Bradford~Chamberlain}{2001/07/07}{otherkeywords={@,@^}
+% does not work} we now iterate down the list of `other keywords' and make each
+% active---instead of making the whole argument active. We append the active
+% token sequence to |\lst@otherkeywords| to define each `other' keyword.
+%    \begin{macrocode}
+\lst@Key{otherkeywords}{}{%
+    \let\lst@otherkeywords\@empty
+    \lst@for{#1}\do{%
+      \lst@MakeActive{##1}%
+      \lst@lExtend\lst@otherkeywords{%
+          \expandafter\lst@CArg\lst@temp\relax\lst@CDef
+              {}\lst@PrintOtherKeyword\@empty}}}
+\lst@AddToHook{SelectCharTable}{\lst@otherkeywords}
+%    \end{macrocode}
+% |\lst@PrintOtherkeyword| has been changed to |\lst@PrintOtherKeyword| after a
+% bug report by \lsthelper{Peter~Bartke}{2001/11/06}{undefined control sequence
+% \lst@PrintOtherkeyword}.
+% \end{lstkey}
+%
+% \begin{macro}{\lst@PrintOtherKeyword}
+% print preceding characters, prepare the output and typeset the argument in
+% keyword style. \lsthelper{James~Willans}{2004/07/23}{problem: otherkeywords}
+% reported problems when the output routine is invoked within |\begingroup| and
+% |\endgroup|. Now the definition is restructured.
+%    \begin{macrocode}
+\gdef\lst@PrintOtherKeyword#1\@empty{%
+    \lst@XPrintToken
+    \begingroup
+      \lst@modetrue \lsthk@TextStyle
+      \let\lst@ProcessDigit\lst@ProcessLetter
+      \let\lst@ProcessOther\lst@ProcessLetter
+      \lst@lettertrue
+      #1%
+	  \lst@SaveToken
+    \endgroup
+	\lst@RestoreToken
+	\global\let\lst@savedcurrstyle\lst@currstyle
+	\let\lst@currstyle\lst@gkeywords@sty
+    \lst@Output
+	\let\lst@currstyle\lst@savedcurrstyle}
+%    \end{macrocode}
+% \begin{TODO}
+% Which part of \hookname{TextStyle} hook is required? Is it required anymore,
+% i.e.after the restruction? Need to move it elsewhere?
+% \end{TODO}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \paragraph{The emphasize family}
+%
+% \begin{aspect}{emph}
+% is just one macro call here.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{emph}
+\lst@InstallFamily e{emph}{emphstyle}{}{emphstyle}{}od
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \paragraph{\TeX\ control sequences}
+%
+% \begin{aspect}{tex}
+% Here we check the last `other' processed token.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{tex}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@InstallFamily {cs}{texcs}{texcsstyle}\relax{keywordstyle}
+    {\ifx\lst@lastother\lstum@backslash
+         \expandafter\let\expandafter\lst@thestyle
+                         \csname lst@texcsstyle#1\endcsname
+     \fi}
+    ld
+%    \end{macrocode}
+% The style-key checks for the optional star (which must be in front of
+% the optional class argument).
+%    \begin{macrocode}
+\lst@Key{texcsstyle}\relax
+  {\@ifstar{\lst@true\lst@DefTexcsstyle}%
+           {\lst@false\lst@DefTexcsstyle}#1\@nil@}
+\gdef\lst@DefTexcsstyle#1\@nil@{%
+    \let\lst@iftexcsincludebs\lst@if
+    \lstKV@OptArg[\@ne]{#1}%
+    {\@tempcnta\lst@classoffset \advance\@tempcnta##1\relax
+     \@namedef{lst@texcsstyle\ifnum\@tempcnta=\@ne\else
+                                   \the\@tempcnta \fi}{##2}}}%
+\global\let\lst@iftexcsincludebs\iffalse
+%    \end{macrocode}
+% To make the backslash belong to the control sequence, it is merged with
+% the following token. This option was suggested by \lsthelper{Morten~H\o gholm}
+% {2004/07/16}{defining new (colored) texcs}.
+% \lsthelper{Christian~Schneider}{2006/09/08}{-} pointed out that the original
+% implementation was broken when the identifier was preceded by an ``other''
+% character.  To fix this (and other bugs), we first output whatever is in the
+% current token before merging.
+%    \begin{macrocode}
+\let\lst@iftexcsincludebs\iffalse
+\lst@AddToHook{SelectCharTable}
+{\lst@iftexcsincludebs \ifx\@empty\lst@texcs\else
+     \lst@DefSaveDef{`\\}\lsts@texcsbs
+      {\lst@ifletter
+           \lst@Output
+       \else
+           \lst@OutputOther
+       \fi
+       \lst@Merge\lsts@texcsbs}%
+ \fi \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \paragraph{Compiler directives}
+%
+% \begin{aspect}{directives}
+% \begin{lstkey}{directives}
+% First some usual stuff.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{directives}
+%    \end{macrocode}
+% The initialization of |\lst@directives| has been added after a bug report
+% from \lsthelper{Kris~Luyten}{2002/07/30}{Undefined control sequence
+% \lst@thestyle caused by undefined \lst@directives after loading C}.
+%    \begin{macrocode}
+\lst@NewMode\lst@CDmode
+\lst@AddToHook{EOL}{\ifnum\lst@mode=\lst@CDmode \lst@LeaveMode \fi}
+\lst@InstallKeywords{d}{directives}{directivestyle}\relax{keywordstyle}
+    {\ifnum\lst@mode=\lst@CDmode
+         \let\lst@thestyle\lst@directivestyle
+     \fi}
+    ld
+\global\let\lst@directives\@empty % init
+%    \end{macrocode}
+% Now we define a new delimiter for directives: We enter `directive mode'
+% only in the first column.
+%    \begin{macrocode}
+\lst@AddTo\lst@delimtypes{,directive}
+\gdef\lst@Delim@directive#1\@empty#2#3#4{%
+    \lst@CArg #1\relax\lst@DefDelimB
+        {\lst@CalcColumn}%
+        {}%
+        {\ifnum\@tempcnta=\z@
+             \def\lst@bnext{#2\lst@CDmode{#4\lst@Lmodetrue}%
+			                \let\lst@currstyle\lst@directivestyle}%
+		 \fi
+		 \@gobblethree}%
+        #2\lst@CDmode{#4\lst@Lmodetrue}}
+%    \end{macrocode}
+% We introduce a new string type (thanks to \lsthelper{R.~Isernhagen}
+% {1999/11/12}{float isn't keyword in #include <float>}), which \ldots
+%    \begin{macrocode}
+\lst@AddTo\lst@stringtypes{,directive}
+\gdef\lst@StringDM@directive#1#2#3\@empty{%
+    \lst@CArg #2\relax\lst@CDef
+        {}%
+%    \end{macrocode}
+% \ldots\space is active only in |\lst@CDmode|:
+%    \begin{macrocode}
+        {\let\lst@bnext\lst@CArgEmpty
+         \ifnum\lst@mode=\lst@CDmode
+             \def\lst@bnext{\lst@BeginString{#1}}%
+         \fi
+         \lst@bnext}%
+        \@empty
+    \lst@CArg #3\relax\lst@CDef
+        {}%
+        {\let\lst@enext\lst@CArgEmpty
+         \ifnum #1=\lst@mode
+             \let\lst@bnext\lst@EndString
+         \fi
+         \lst@bnext}%
+        \@empty}
+%    \end{macrocode}
+% \end{lstkey}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Keyword comments}
+%
+% \begin{aspect}{keywordcomments}
+% includes both comment types and is possibly split into this and |dkcs|.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords,comments]{keywordcomments}
+%    \end{macrocode}
+%
+% \begin{macro}{\lst@BeginKC}
+% \begin{macro}{\lst@BeginKCS}
+% Starting a keyword comment is easy, but: (1) The submacros are called
+% outside of two group levels, and \ldots
+%    \begin{macrocode}
+\lst@NewMode\lst@KCmode \lst@NewMode\lst@KCSmode
+\gdef\lst@BeginKC{\aftergroup\aftergroup\aftergroup\lst@BeginKC@}%
+\gdef\lst@BeginKC@{%
+    \lst@ResetToken
+    \lst@BeginComment\lst@KCmode{{\lst@commentstyle}\lst@modetrue}%
+                     \@empty}%
+\gdef\lst@BeginKCS{\aftergroup\aftergroup\aftergroup\lst@BeginKCS@}%
+\gdef\lst@BeginKCS@{%
+    \lst@ResetToken
+    \lst@BeginComment\lst@KCSmode{{\lst@commentstyle}\lst@modetrue}%
+                     \@empty}%
+%    \end{macrocode}
+% (2) we must ensure that the comment starts after printing the comment
+% delimiter since it could be a keyword. We assign |\lst@BeginKC|[|S|] to
+% |\lst@KCpost|, which is executed and reset in \hookname{PostOutput}.
+%    \begin{macrocode}
+\lst@AddToHook{PostOutput}{\lst@KCpost \global\let\lst@KCpost\@empty}
+\global\let\lst@KCpost\@empty % init
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndKC}
+% leaves the comment mode before the (temporaryly saved) comment delimiter is
+% printed.
+%    \begin{macrocode}
+\gdef\lst@EndKC{\lst@SaveToken \lst@LeaveMode \lst@RestoreToken
+    \let\lst@thestyle\lst@identifierstyle \lsthk@Output}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{keywordcomment}
+% The delimiters must be identical here, thus we use |\lst@KCmatch|. Note the
+% last argument |o| to |\lst@InstallKeywords|: The working test is installed
+% in the \hookname{Output} hook and not in \hookname{DetectKeywords}.
+% Otherwise we couldn't detect the ending delimiter since keyword detection is
+% done if and only if mode changes are allowed.
+%    \begin{macrocode}
+\lst@InstallKeywords{kc}{keywordcomment}{}\relax{}
+    {\ifnum\lst@mode=\lst@KCmode
+         \edef\lst@temp{\the\lst@token}%
+         \ifx\lst@temp\lst@KCmatch
+             \lst@EndKC
+         \fi
+     \else
+         \lst@ifmode\else
+             \xdef\lst@KCmatch{\the\lst@token}%
+             \global\let\lst@KCpost\lst@BeginKC
+         \fi
+     \fi}
+    lo
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{keywordcommentsemicolon}
+% The key simply stores the keywords. After a bug report by \lsthelper
+% {Norbert~Eisinger}{2002/11/26}{keywordcommentsemicolon active after
+% language change} the initialization in \hookname{SetLanguage} has been
+% added.
+%    \begin{macrocode}
+\lst@Key{keywordcommentsemicolon}{}{\lstKV@ThreeArg{#1}%
+    {\def\lst@KCAkeywordsB{##1}%
+     \def\lst@KCAkeywordsE{##2}%
+     \def\lst@KCBkeywordsB{##3}%
+     \def\lst@KCkeywords{##1##2##3}}}
+\lst@AddToHook{SetLanguage}{%
+    \let\lst@KCAkeywordsB\@empty \let\lst@KCAkeywordsE\@empty
+    \let\lst@KCBkeywordsB\@empty \let\lst@KCkeywords\@empty}
+%    \end{macrocode}
+% We define an appropriate semicolon if this keyword comment type is defined.
+% Appropriate means that we leave any keyword comment mode if active.
+% \lsthelper{Oldrich~Jedlicka}{2001/12/12}{keywordcomment(semicolon) fails}
+% reported a bug and provided the fix, the two |\@empty|s.
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}
+    {\ifx\lst@KCkeywords\@empty\else
+        \lst@DefSaveDef{`\;}\lsts@EKC
+            {\lst@XPrintToken
+             \ifnum\lst@mode=\lst@KCmode \lst@EndComment\@empty \else
+             \ifnum\lst@mode=\lst@KCSmode \lst@EndComment\@empty
+             \fi \fi
+             \lsts@EKC}%
+     \fi}
+%    \end{macrocode}
+% The `working identifier' macros enter respectively leave comment mode.
+%    \begin{macrocode}
+\gdef\lst@KCAWorkB{%
+    \lst@ifmode\else \global\let\lst@KCpost\lst@BeginKC \fi}
+\gdef\lst@KCBWorkB{%
+    \lst@ifmode\else \global\let\lst@KCpost\lst@BeginKCS \fi}
+\gdef\lst@KCAWorkE{\ifnum\lst@mode=\lst@KCmode \lst@EndKC \fi}
+%    \end{macrocode}
+% Now we install the tests and initialize the given macros.
+%    \begin{macrocode}
+\lst@ProvideFamily@@
+    \lst@KCAkeywordsB@list\lst@KCAkeywordsB \lst@KC@also
+    \lst@gKCAkeywordsB@list\lst@gKCAkeywordsB \lst@KCAWorkB
+    {kcb}owo % prefix, other key, working procedure, Output hook
+\lst@ProvideFamily@@
+    \lst@KCAkeywordsE@list\lst@KCAkeywordsE \lst@KC@also
+    \lst@gKCAkeywordsE@list\lst@gKCAkeywordsE \lst@KCAWorkE
+    {kce}owo
+\lst@ProvideFamily@@
+    \lst@KCBkeywordsB@list\lst@KCBkeywordsB \lst@KC@also
+    \lst@gKCBkeywordsB@list\lst@gKCBkeywordsB \lst@KCBWorkB
+    {kcs}owo
+%    \end{macrocode}
+% \end{lstkey}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Export of identifiers}
+%
+% \begin{aspect}{index}
+% \begin{macro}{\lstindexmacro}
+% One more `keyword' class.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{index}
+\lst@InstallFamily w{index}{indexstyle}\lstindexmacro{indexstyle}
+    {\csname\@lst @indexstyle#1\expandafter\endcsname
+         \expandafter{\the\lst@token}}
+    od
+\lst@UserCommand\lstindexmacro#1{\index{{\ttfamily#1}}}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{macro}
+% \end{aspect}
+%
+% \begin{aspect}{procnames}
+% \begin{lstkey}{procnamestyle}
+% \begin{lstkey}{procnamekeys}
+% \begin{lstkey}{indexprocnames}
+% The `idea' here is the usage of a global |\lst@ifprocname|, indicating a
+% preceding `procedure keyword'. All the other is known stuff.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{procnames}
+\gdef\lst@procnametrue{\global\let\lst@ifprocname\iftrue}
+\gdef\lst@procnamefalse{\global\let\lst@ifprocname\iffalse}
+\lst@AddToHook{Init}{\lst@procnamefalse}
+\lst@AddToHook{DetectKeywords}
+    {\lst@ifprocname
+         \let\lst@thestyle\lst@procnamestyle
+         \lst@ifindexproc \csname\@lst @gindex@sty\endcsname \fi
+         \lst@procnamefalse
+     \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{procnamestyle}{}{\def\lst@procnamestyle{#1}}
+\lst@Key{indexprocnames}{false}[t]{\lstKV@SetIf{#1}\lst@ifindexproc}
+\lst@AddToHook{Init}{\lst@ifindexproc \lst@indexproc \fi}
+\gdef\lst@indexproc{%
+    \@ifundefined{lst@indexstyle1}%
+        {\@namedef{lst@indexstyle1}##1{}}%
+        {}}
+%    \end{macrocode}
+% The default definition of |\lst@indexstyle| above has been moved outside the
+% hook after a bug report from \lsthelper{Ulrich~G.~Wortmann}{2002/01/22}
+% {procnames doesn't work}.
+%    \begin{macrocode}
+\lst@InstallKeywords w{procnamekeys}{}\relax{}
+    {\global\let\lst@PNpost\lst@procnametrue}
+    od
+\lst@AddToHook{PostOutput}{\lst@PNpost\global\let\lst@PNpost\@empty}
+\global\let\lst@PNpost\@empty % init
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{aspect}
+%
+%
+% \section{More aspects and keys}
+%
+% \begin{lstkey}{basicstyle}
+% \begin{lstkey}{inputencoding}
+% There is no better place to define these keys, I think.
+%    \begin{macrocode}
+%<*kernel>
+\lst@Key{basicstyle}\relax{\def\lst@basicstyle{#1}}
+\lst@Key{inputencoding}\relax{\def\lst@inputenc{#1}}
+\lst@AddToHook{Init}
+    {\lst@basicstyle
+     \ifx\lst@inputenc\@empty\else
+         \@ifundefined{inputencoding}{}%
+            {\inputencoding\lst@inputenc}%
+     \fi}
+\lst@AddToHookExe{EmptyStyle}
+    {\let\lst@basicstyle\@empty
+     \let\lst@inputenc\@empty}
+\lst@Key{multicols}{}{\@tempcnta=0#1\relax\def\lst@multicols{#1}}
+%</kernel>
+%    \end{macrocode}
+% Michael Niedermair asked for a key like \keyname{inputencoding}.
+% \end{lstkey}
+% \end{lstkey}
+%
+%
+% \subsection{Styles and languages}
+%
+% \begin{aspect}{style}
+% We begin with style definition and selection.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{style}
+%    \end{macrocode}
+%
+% \begin{macro}{\lststylefiles}
+% This macro is defined if and only if it's undefined yet.
+%    \begin{macrocode}
+\@ifundefined{lststylefiles}
+    {\lst@UserCommand\lststylefiles{lststy0.sty}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstdefinestyle}
+% \begin{macro}{\lst@definestyle}
+% \begin{macro}{\lst@DefStyle}
+% are defined in terms of |\lst@DefStyle|, which is defined via
+% |\lst@DefDriver|.
+%    \begin{macrocode}
+\lst@UserCommand\lstdefinestyle{\lst@DefStyle\iftrue}
+\lst@UserCommand\lst@definestyle{\lst@DefStyle\iffalse}
+\gdef\lst@DefStyle{\lst@DefDriver{style}{sty}\lstset}
+%    \end{macrocode}
+% The `empty' style calls the initial empty hook \hookname{EmptyStyle}.
+%    \begin{macrocode}
+\global\@namedef{lststy@$}{\lsthk@EmptyStyle}
+\lst@AddToHook{EmptyStyle}{}% init
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{style}
+% is an application of |\lst@LAS|. We just specify the hook and an empty
+% argument as `pre' and `post' code.
+%    \begin{macrocode}
+\lst@Key{style}\relax{%
+    \lst@LAS{style}{sty}{[]{#1}}\lst@NoAlias\lststylefiles
+        \lsthk@SetStyle
+        {}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SetStyle}{}% init
+%    \end{macrocode}
+% \end{lstkey}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+% \begin{aspect}{language}
+% Now we deal with commands used in defining and selecting programming
+% languages, in particular with aliases.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{language}
+%    \end{macrocode}
+%
+% \begin{macro}{\lstlanguagefiles}
+% This macro is defined if and only if it's undefined yet.
+%    \begin{macrocode}
+\@ifundefined{lstdriverfiles}
+    {\lst@UserCommand\lstlanguagefiles{lstlang0.sty}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstdefinelanguage}
+% \begin{macro}{\lst@definelanguage}
+% \begin{macro}{\lst@DefLang}
+% are defined in terms of |\lst@DefLang|, which is defined via
+% |\lst@DefDriver|.
+%    \begin{macrocode}
+\lst@UserCommand\lstdefinelanguage{\lst@DefLang\iftrue}
+\lst@UserCommand\lst@definelanguage{\lst@DefLang\iffalse}
+\gdef\lst@DefLang{\lst@DefDriver{language}{lang}\lstset}
+%    \end{macrocode}
+% Now we can provide the `empty' language.
+%    \begin{macrocode}
+\lstdefinelanguage{}{}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{language}
+% \begin{lstkey}{alsolanguage}
+% is mainly an application of |\lst@LAS|.
+%    \begin{macrocode}
+\lst@Key{language}\relax{\lstKV@OptArg[]{#1}%
+    {\lst@LAS{language}{lang}{[##1]{##2}}\lst@FindAlias\lstlanguagefiles
+         \lsthk@SetLanguage
+         {\lst@FindAlias[##1]{##2}%
+          \let\lst@language\lst@malias
+          \let\lst@dialect\lst@oalias}}}
+%    \end{macrocode}
+% Ditto, we simply don't execute |\lsthk@SetLanguage|.
+%    \begin{macrocode}
+\lst@Key{alsolanguage}\relax{\lstKV@OptArg[]{#1}%
+    {\lst@LAS{language}{lang}{[##1]{##2}}\lst@FindAlias\lstlanguagefiles
+         {}%
+         {\lst@FindAlias[##1]{##2}%
+          \let\lst@language\lst@malias
+          \let\lst@dialect\lst@oalias}}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SetLanguage}{}% init
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lstalias}
+% Now we concentrate on aliases and default dialects.
+% |\lsta@|\meta{language}|$|\meta{dialect} and |\lsta@|\meta{language} contain
+% the aliases of a particular dialect respectively a complete language.
+% We'll use a |$|-character to separate a language name from its dialect.
+% Thanks to \lsthelper{Walter~E.~Brown}{2004/02/25}{\lstalias
+% (+\lstdefinelanguage) fails} for reporting a problem with the argument
+% delimiter `[' in a previous definition of |\lstalias@|.
+%    \begin{macrocode}
+\lst@UserCommand\lstalias{\@ifnextchar[\lstalias@\lstalias@@}
+\gdef\lstalias@[#1]#2{\lstalias@b #2$#1}
+\gdef\lstalias@b#1[#2]#3{\lst@NormedNameDef{lsta@#1}{#3$#2}}
+\gdef\lstalias@@#1#2{\lst@NormedNameDef{lsta@#1}{#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{defaultdialect}
+% We simply store the dialect.
+%    \begin{macrocode}
+\lst@Key{defaultdialect}\relax
+    {\lstKV@OptArg[]{#1}{\lst@NormedNameDef{lstdd@##2}{##1}}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@FindAlias}
+% Now we have to find a language. First we test for a complete language alias,
+% then we set the default dialect if necessary.
+%    \begin{macrocode}
+\gdef\lst@FindAlias[#1]#2{%
+    \lst@NormedDef\lst@oalias{#1}%
+    \lst@NormedDef\lst@malias{#2}%
+    \@ifundefined{lsta@\lst@malias}{}%
+        {\edef\lst@malias{\csname\@lst a@\lst@malias\endcsname}}%
+%    \end{macrocode}
+%    \begin{macrocode}
+    \ifx\@empty\lst@oalias \@ifundefined{lstdd@\lst@malias}{}%
+        {\edef\lst@oalias{\csname\@lst dd@\lst@malias\endcsname}}%
+    \fi
+%    \end{macrocode}
+% Now we are ready for an alias of a single dialect.
+%    \begin{macrocode}
+    \edef\lst@temp{\lst@malias $\lst@oalias}%
+    \@ifundefined{lsta@\lst@temp}{}%
+        {\edef\lst@temp{\csname\@lst a@\lst@temp\endcsname}}%
+%    \end{macrocode}
+% Finally we again set the default dialect---for the case of a dialect alias.
+%    \begin{macrocode}
+    \expandafter\lst@FindAlias@\lst@temp $}
+\gdef\lst@FindAlias@#1$#2${%
+    \def\lst@malias{#1}\def\lst@oalias{#2}%
+    \ifx\@empty\lst@oalias \@ifundefined{lstdd@\lst@malias}{}%
+        {\edef\lst@oalias{\csname\@lst dd@\lst@malias\endcsname}}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@RequireLanguages}
+% This definition will be equivalent to |\lstloadlanguages|. We requested the
+% given list of languages and load additionally required aspects.
+%    \begin{macrocode}
+\gdef\lst@RequireLanguages#1{%
+    \lst@Require{language}{lang}{#1}\lst@FindAlias\lstlanguagefiles
+    \ifx\lst@loadaspects\@empty\else
+        \lst@RequireAspects\lst@loadaspects
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstloadlanguages}
+% is the same as |\lst@RequireLanguages|.
+%    \begin{macrocode}
+\global\let\lstloadlanguages\lst@RequireLanguages
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Format definitions*}
+%
+% \begin{aspect}{formats}
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{formats}
+%    \end{macrocode}
+%
+% \begin{macro}{\lstformatfiles}
+% This macro is defined if and only if it's undefined yet.
+%    \begin{macrocode}
+\@ifundefined{lstformatfiles}
+    {\lst@UserCommand\lstformatfiles{lstfmt0.sty}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstdefineformat}
+% \begin{macro}{\lst@defineformat}
+% \begin{macro}{\lst@DefFormat}
+% are defined in terms of |\lst@DefFormat|, which is defined via
+% |\lst@DefDriver|.
+%    \begin{macrocode}
+\lst@UserCommand\lstdefineformat{\lst@DefFormat\iftrue}
+\lst@UserCommand\lst@defineformat{\lst@DefFormat\iffalse}
+\gdef\lst@DefFormat{\lst@DefDriver{format}{fmt}\lst@UseFormat}
+%    \end{macrocode}
+% We provide the `empty' format.
+%    \begin{macrocode}
+\lstdefineformat{}{}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{format}
+% is an application of |\lst@LAS|. We just specify the hook as `pre' and an
+% empty argument as  `post' code.
+%    \begin{macrocode}
+\lst@Key{format}\relax{%
+    \lst@LAS{format}{fmt}{[]{#1}}\lst@NoAlias\lstformatfiles
+        \lsthk@SetFormat
+        {}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SetFormat}{\let\lst@fmtformat\@empty}% init
+%    \end{macrocode}
+% \end{lstkey}
+%
+%
+% \paragraph{Helpers}
+% Our goal is to define the yet unkown |\lst@UseFormat|. This definition
+% will parse the user supplied format. We start with some general macros.
+%
+% \begin{macro}{\lst@fmtSplit}
+% splits the content of the macro |#1| at |#2| in the preceding characters
+% |\lst@fmta| and the following ones |\lst@fmtb|. |\lst@if| is false if and
+% only if |#1| doesn't contain |#2|.
+%    \begin{macrocode}
+\gdef\lst@fmtSplit#1#2{%
+    \def\lst@temp##1#2##2\relax##3{%
+        \ifnum##3=\z@
+            \ifx\@empty##2\@empty
+                \lst@false
+                \let\lst@fmta#1%
+                \let\lst@fmtb\@empty
+            \else
+                \expandafter\lst@temp#1\relax\@ne
+            \fi
+        \else
+            \def\lst@fmta{##1}\def\lst@fmtb{##2}%
+        \fi}%
+    \lst@true
+    \expandafter\lst@temp#1#2\relax\z@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@IfNextCharWhitespace}
+% is defined in terms of |\lst@IfSubstring|.
+%    \begin{macrocode}
+\gdef\lst@IfNextCharWhitespace#1#2#3{%
+    \lst@IfSubstring#3\lst@whitespaces{#1}{#2}#3}
+%    \end{macrocode}
+% And here come all white space characters.
+%    \begin{macrocode}
+\begingroup
+\catcode`\^^I=12\catcode`\^^J=12\catcode`\^^M=12\catcode`\^^L=12\relax%
+\lst@DefActive\lst@whitespaces{\ ^^I^^J^^M}% add ^^L
+\global\let\lst@whitespaces\lst@whitespaces%
+\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtIfIdentifier}
+% tests the first character of |#1|
+%    \begin{macrocode}
+\gdef\lst@fmtIfIdentifier#1{%
+    \ifx\relax#1\@empty
+        \expandafter\@secondoftwo
+    \else
+        \expandafter\lst@fmtIfIdentifier@\expandafter#1%
+    \fi}
+%    \end{macrocode}
+% against the `letters' |_|, |@|, |A|,\ldots,|Z| and |a|,\ldots,|z|.
+%    \begin{macrocode}
+\gdef\lst@fmtIfIdentifier@#1#2\relax{%
+    \let\lst@next\@secondoftwo
+    \ifnum`#1=`_\else
+    \ifnum`#1<64\else
+    \ifnum`#1<91\let\lst@next\@firstoftwo\else
+    \ifnum`#1<97\else
+    \ifnum`#1<123\let\lst@next\@firstoftwo\else
+    \fi \fi \fi \fi \fi
+    \lst@next}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtIfNextCharIn}
+% is required for the optional \meta{exceptional characters}.
+% The implementation is easy---refer section \ref{iSubstringTests}.
+%    \begin{macrocode}
+\gdef\lst@fmtIfNextCharIn#1{%
+    \ifx\@empty#1\@empty \expandafter\@secondoftwo \else
+                         \def\lst@next{\lst@fmtIfNextCharIn@{#1}}%
+                         \expandafter\lst@next\fi}
+\gdef\lst@fmtIfNextCharIn@#1#2#3#4{%
+    \def\lst@temp##1#4##2##3\relax{%
+        \ifx \@empty##2\expandafter\@secondoftwo
+                 \else \expandafter\@firstoftwo \fi}%
+    \lst@temp#1#4\@empty\relax{#2}{#3}#4}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtCDef}
+% We need derivations of |\lst@CDef| and |\lst@CDefX|: we have to test the
+% next character against the sequence |#5| of exceptional characters.
+% These tests are inserted here.
+%    \begin{macrocode}
+\gdef\lst@fmtCDef#1{\lst@fmtCDef@#1}
+\gdef\lst@fmtCDef@#1#2#3#4#5#6#7{%
+    \lst@CDefIt#1{#2}{#3}%
+               {\lst@fmtIfNextCharIn{#5}{#4#2#3}{#6#4#2#3#7}}%
+               #4%
+               {}{}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtCDefX}
+% The same but `drop input'.
+%    \begin{macrocode}
+\gdef\lst@fmtCDefX#1{\lst@fmtCDefX@#1}
+\gdef\lst@fmtCDefX@#1#2#3#4#5#6#7{%
+    \let#4#1%
+    \ifx\@empty#2\@empty
+        \def#1{\lst@fmtIfNextCharIn{#5}{#4}{#6#7}}%
+    \else \ifx\@empty#3\@empty
+        \def#1##1{%
+            \ifx##1#2%
+                \def\lst@next{\lst@fmtIfNextCharIn{#5}{#4##1}%
+                                                      {#6#7}}%
+            \else
+                 \def\lst@next{#4##1}%
+            \fi
+            \lst@next}%
+    \else
+        \def#1{%
+            \lst@IfNextCharsArg{#2#3}%
+                {\lst@fmtIfNextCharIn{#5}{\expandafter#4\lst@eaten}%
+                                         {#6#7}}%
+                {\expandafter#4\lst@eaten}}%
+    \fi \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{The parser}
+% applies |\lst@fmtSplit| to cut a format definition into items, items into
+% `input' and `output', and `output' into `pre' and 'post'. This should be
+% clear if you are in touch with format definitions.
+%
+% \begin{macro}{\lst@UseFormat}
+% Now we can start with the parser.
+%    \begin{macrocode}
+\gdef\lst@UseFormat#1{%
+    \def\lst@fmtwhole{#1}%
+    \lst@UseFormat@}
+\gdef\lst@UseFormat@{%
+    \lst@fmtSplit\lst@fmtwhole,%
+%    \end{macrocode}
+% We assign the rest of the format definition, \ldots
+%    \begin{macrocode}
+    \let\lst@fmtwhole\lst@fmtb
+    \ifx\lst@fmta\@empty\else
+%    \end{macrocode}
+% \ldots\space split the item at the equal sign, and work on the item.
+%    \begin{macrocode}
+        \lst@fmtSplit\lst@fmta=%
+        \ifx\@empty\lst@fmta\else
+%    \end{macrocode}
+% \begin{TODO}
+% Insert |\let\lst@arg\@empty| |\expandafter\lst@XConvert\lst@fmtb\@nil|
+% |\let\lst@fmtb\lst@arg|.
+% \end{TODO}
+%    \begin{macrocode}
+            \expandafter\lstKV@XOptArg\expandafter[\expandafter]%
+                \expandafter{\lst@fmtb}\lst@UseFormat@b
+        \fi
+    \fi
+%    \end{macrocode}
+% Finally we process the next item if the rest is not empty.
+%    \begin{macrocode}
+    \ifx\lst@fmtwhole\@empty\else
+        \expandafter\lst@UseFormat@
+    \fi}
+%    \end{macrocode}
+% We make |\lst@fmtc| contain the preceding characters as a braced argument.
+% To add more arguments, we first split the replacement tokens at the control
+% sequence |\string|.
+%    \begin{macrocode}
+\gdef\lst@UseFormat@b[#1]#2{%
+    \def\lst@fmtc{{#1}}\lst@lExtend\lst@fmtc{\expandafter{\lst@fmta}}%
+    \def\lst@fmtb{#2}%
+    \lst@fmtSplit\lst@fmtb\string
+%    \end{macrocode}
+% We append an empty argument or |\lst@fmtPre| with `|\string|-preceding'
+% tokens as argument. We do the same for the tokens after |\string|.
+%    \begin{macrocode}
+    \ifx\@empty\lst@fmta
+        \lst@lAddTo\lst@fmtc{{}}%
+    \else
+        \lst@lExtend\lst@fmtc{\expandafter
+            {\expandafter\lst@fmtPre\expandafter{\lst@fmta}}}%
+    \fi
+    \ifx\@empty\lst@fmtb
+        \lst@lAddTo\lst@fmtc{{}}%
+    \else
+        \lst@lExtend\lst@fmtc{\expandafter
+            {\expandafter\lst@fmtPost\expandafter{\lst@fmtb}}}%
+    \fi
+%    \end{macrocode}
+% Eventually we extend |\lst@fmtformat| appropriately. Note that |\lst@if|
+% still indicates whether the replacement tokens contain |\string|.
+%    \begin{macrocode}
+    \expandafter\lst@UseFormat@c\lst@fmtc}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@UseFormat@c#1#2#3#4{%
+    \lst@fmtIfIdentifier#2\relax
+    {\lst@fmtIdentifier{#2}%
+     \lst@if\else \PackageWarning{Listings}%
+         {Cannot drop identifier in format definition}%
+     \fi}%
+    {\lst@if
+         \lst@lAddTo\lst@fmtformat{\lst@CArgX#2\relax\lst@fmtCDef}%
+     \else
+         \lst@lAddTo\lst@fmtformat{\lst@CArgX#2\relax\lst@fmtCDefX}%
+     \fi
+     \lst@DefActive\lst@fmtc{#1}%
+     \lst@lExtend\lst@fmtformat{\expandafter{\lst@fmtc}{#3}{#4}}}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}{\lst@fmtformat}
+\global\let\lst@fmtformat\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{The formatting}
+%
+% \begin{macro}{\lst@fmtPre}
+%    \begin{macrocode}
+\gdef\lst@fmtPre#1{%
+    \lst@PrintToken
+    \begingroup
+    \let\newline\lst@fmtEnsureNewLine
+    \let\space\lst@fmtEnsureSpace
+    \let\indent\lst@fmtIndent
+    \let\noindent\lst@fmtNoindent
+    #1%
+    \endgroup}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtPost}
+%    \begin{macrocode}
+\gdef\lst@fmtPost#1{%
+    \global\let\lst@fmtPostOutput\@empty
+    \begingroup
+    \def\newline{\lst@AddTo\lst@fmtPostOutput\lst@fmtEnsureNewLine}%
+    \def\space{\aftergroup\lst@fmtEnsurePostSpace}%
+    \def\indent{\lst@AddTo\lst@fmtPostOutput\lst@fmtIndent}%
+    \def\noindent{\lst@AddTo\lst@fmtPostOutput\lst@fmtNoindent}%
+    \aftergroup\lst@PrintToken
+    #1%
+    \endgroup}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\global\let\lst@fmtPostOutput\@empty}
+\lst@AddToHook{PostOutput}
+    {\lst@fmtPostOutput \global\let\lst@fmtPostOutput\@empty}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtEnsureSpace}
+% \begin{macro}{\lst@fmtEnsurePostSpace}
+%    \begin{macrocode}
+\gdef\lst@fmtEnsureSpace{%
+    \lst@ifwhitespace\else \expandafter\lst@ProcessSpace \fi}
+\gdef\lst@fmtEnsurePostSpace{%
+    \lst@IfNextCharWhitespace{}{\lst@ProcessSpace}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{lstkey}{fmtindent}
+% \begin{macro}{\lst@fmtIndent}
+% \begin{macro}{\lst@fmtNoindent}
+%    \begin{macrocode}
+\lst@Key{fmtindent}{20pt}{\def\lst@fmtindent{#1}}
+\newdimen\lst@fmtcurrindent
+\lst@AddToHook{InitVars}{\global\lst@fmtcurrindent\z@}
+\gdef\lst@fmtIndent{\global\advance\lst@fmtcurrindent\lst@fmtindent}
+\gdef\lst@fmtNoindent{\global\advance\lst@fmtcurrindent-\lst@fmtindent}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@fmtEnsureNewLine}
+%    \begin{macrocode}
+\gdef\lst@fmtEnsureNewLine{%
+    \global\advance\lst@newlines\@ne
+    \global\advance\lst@newlinesensured\@ne
+    \lst@fmtignoretrue}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToAtTop\lst@DoNewLines{%
+    \ifnum\lst@newlines>\lst@newlinesensured
+        \global\advance\lst@newlines-\lst@newlinesensured
+    \fi
+    \global\lst@newlinesensured\z@}
+\newcount\lst@newlinesensured % global
+\lst@AddToHook{Init}{\global\lst@newlinesensured\z@}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@fmtignoretrue{\let\lst@fmtifignore\iftrue}
+\gdef\lst@fmtignorefalse{\let\lst@fmtifignore\iffalse}
+\lst@AddToHook{InitVars}{\lst@fmtignorefalse}
+\lst@AddToHook{Output}{\lst@fmtignorefalse}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtUseLostSpace}
+%    \begin{macrocode}
+\gdef\lst@fmtUseLostSpace{%
+    \lst@ifnewline \kern\lst@fmtcurrindent \global\lst@lostspace\z@
+    \else
+        \lst@OldOLS
+    \fi}
+\lst@AddToHook{Init}
+    {\lst@true
+     \ifx\lst@fmtformat\@empty \ifx\lst@fmt\@empty \lst@false \fi\fi
+     \lst@if
+        \let\lst@OldOLS\lst@OutputLostSpace
+        \let\lst@OutputLostSpace\lst@fmtUseLostSpace
+        \let\lst@ProcessSpace\lst@fmtProcessSpace
+     \fi}
+%    \end{macrocode}
+% \begin{TODO}
+% This `lost space' doesn't use |\lst@alloverstyle| yet!
+% \end{TODO}
+% \end{macro}
+%
+% \begin{macro}{\lst@fmtProcessSpace}
+%    \begin{macrocode}
+\gdef\lst@fmtProcessSpace{%
+    \lst@ifletter
+        \lst@Output
+        \lst@fmtifignore\else
+            \lst@AppendOther\lst@outputspace
+        \fi
+    \else \lst@ifkeepspaces
+        \lst@AppendOther\lst@outputspace
+    \else \ifnum\lst@newlines=\z@
+        \lst@AppendSpecialSpace
+    \else \ifnum\lst@length=\z@
+            \global\advance\lst@lostspace\lst@width
+            \global\advance\lst@pos\m@ne
+        \else
+            \lst@AppendSpecialSpace
+        \fi
+    \fi \fi \fi
+    \lst@whitespacetrue}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \paragraph{Formatting identifiers}
+%
+% \begin{macro}{\lst@fmtIdentifier}
+% We install a (keyword) test for the `format identifiers'.
+%    \begin{macrocode}
+\lst@InstallTest{f}
+    \lst@fmt@list\lst@fmt \lst@gfmt@list\lst@gfmt
+    \lst@gfmt@wp
+    wd
+\gdef\lst@fmt@list{\lst@fmt\lst@gfmt}\global\let\lst@fmt\@empty
+\gdef\lst@gfmt@list{\lst@fmt\lst@gfmt}\global\let\lst@gfmt\@empty
+%    \end{macrocode}
+% The working procedure expands |\lst@fmt$|\meta{string} (and defines
+% |\lst@PrintToken| to do nothing).
+%    \begin{macrocode}
+\gdef\lst@gfmt@wp{%
+    \begingroup \let\lst@UM\@empty
+    \let\lst@PrintToken\@empty
+    \csname\@lst @fmt$\the\lst@token\endcsname
+    \endgroup}
+%    \end{macrocode}
+% This control sequence is probably defined as `working identifier'.
+%    \begin{macrocode}
+\gdef\lst@fmtIdentifier#1#2#3#4{%
+    \lst@DefOther\lst@fmta{#2}\edef\lst@fmt{\lst@fmt,\lst@fmta}%
+    \@namedef{\@lst @fmt$\lst@fmta}{#3#4}}
+%    \end{macrocode}
+% |\lst@fmt$|\meta{identifier} expands to a |\lst@fmtPre|/|\lst@fmtPost|
+% sequence defined by |#2| and |#3|.
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+%
+% \subsection{Line numbers}
+%
+% \begin{aspect}{labels}
+% \lsthelper{Rolf~Niepraschk}{1997/04/24}{line numbers} asked for line numbers.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{labels}
+%    \end{macrocode}
+%
+% \begin{lstkey}{numbers}
+% Depending on the argument we define |\lst@PlaceNumber| to print the line
+% number.
+%    \begin{macrocode}
+\lst@Key{numbers}{none}{%
+    \let\lst@PlaceNumber\@empty
+    \lstKV@SwitchCases{#1}%
+    {none:\\%
+     left:\def\lst@PlaceNumber{\llap{\normalfont
+                \lst@numberstyle{\thelstnumber}\kern\lst@numbersep}}\\%
+     right:\def\lst@PlaceNumber{\rlap{\normalfont
+                \kern\linewidth \kern\lst@numbersep
+                \lst@numberstyle{\thelstnumber}}}%
+    }{\PackageError{Listings}{Numbers #1 unknown}\@ehc}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{numberstyle}
+% \begin{lstkey}{numbersep}
+% \begin{lstkey}{stepnumber}
+% \begin{lstkey}{numberblanklines}
+% \begin{lstkey}{numberfirstline}
+% Definition of the keys.
+%    \begin{macrocode}
+\lst@Key{numberstyle}{}{\def\lst@numberstyle{#1}}
+\lst@Key{numbersep}{10pt}{\def\lst@numbersep{#1}}
+\lst@Key{stepnumber}{1}{\def\lst@stepnumber{#1\relax}}
+\lst@AddToHook{EmptyStyle}{\let\lst@stepnumber\@ne}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{numberblanklines}{true}[t]
+    {\lstKV@SetIf{#1}\lst@ifnumberblanklines}
+\lst@Key{numberfirstline}{f}[t]{\lstKV@SetIf{#1}\lst@ifnumberfirstline}
+\gdef\lst@numberfirstlinefalse{\let\lst@ifnumberfirstline\iffalse}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{firstnumber}
+% We select the first number according to the argument.
+%    \begin{macrocode}
+\lst@Key{firstnumber}{auto}{%
+    \lstKV@SwitchCases{#1}%
+    {auto:\let\lst@firstnumber\@undefined\\%
+     last:\let\lst@firstnumber\c@lstnumber
+    }{\def\lst@firstnumber{#1\relax}}}
+\lst@AddToHook{PreSet}{\let\lst@advancenumber\z@}
+%    \end{macrocode}
+% |\lst@firstnumber| now set to |\lst@lineno| instead of |\lst@firstline|,
+% as per changes in |lstpatch.sty| from 1.3b pertaining to linerange markers.
+%    \begin{macrocode}
+\lst@AddToHook{PreInit}
+    {\ifx\lst@firstnumber\@undefined
+         \def\lst@firstnumber{\lst@lineno}%
+     \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@SetFirstNumber}
+% \begin{macro}{\lst@SaveFirstNumber}
+% \lsthelper{Boris~Veytsman}{1998/03/25}{continue line numbering: a.c b.c a.c}
+% proposed to continue line numbers according to listing names. We define the
+% label number of the first printing line here. A bug reported by
+% \lsthelper{Jens~Schwarzer}{2001/05/29}{wrong line numbering of lstlisting
+% with first>1} has been removed by replacing |\@ne| by |\lst@firstline|.
+%    \begin{macrocode}
+\gdef\lst@SetFirstNumber{%
+    \ifx\lst@firstnumber\@undefined
+        \@tempcnta 0\csname\@lst no@\lst@intname\endcsname\relax
+        \ifnum\@tempcnta=\z@ \@tempcnta\lst@firstline
+                       \else \lst@nololtrue \fi
+        \advance\@tempcnta\lst@advancenumber
+        \edef\lst@firstnumber{\the\@tempcnta\relax}%
+    \fi}
+%    \end{macrocode}
+% The current label is stored in|\lstno@|\meta{name}. If the name is empty,
+% we use a space instead, which leaves |\lstno@| undefined.
+%    \begin{macrocode}
+\gdef\lst@SaveFirstNumber{%
+    \expandafter\xdef
+        \csname\@lst no\ifx\lst@intname\@empty @ \else @\lst@intname\fi
+        \endcsname{\the\c@lstnumber}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\c@lstnumber}
+% This counter keeps the current label number. We use it as current label to
+% make line numbers referenced by |\ref|. This was proposed by
+% \lsthelper{Boris~Veytsman}{1998/03/25}{make line numbers referenced via
+% \label and \ref}. We now use |\refstepcounter| to do the job---thanks to a
+% bug report from \lsthelper{Christian~Gudrian}{2000/11/13}{\ref{lst:line}
+% jumps to top of listing and not to the line}.
+%    \begin{macrocode}
+\newcounter{lstnumber}% \global
+\global\c@lstnumber\@ne % init
+\renewcommand*\thelstnumber{\@arabic\c@lstnumber}
+\lst@AddToHook{EveryPar}
+    {\global\advance\c@lstnumber\lst@advancelstnum
+     \global\advance\c@lstnumber\m@ne \refstepcounter{lstnumber}%
+     \lst@SkipOrPrintLabel}%
+\global\let\lst@advancelstnum\@ne
+%    \end{macrocode}
+% Note that the counter advances \emph{before} the label is printed and not
+% afterwards. Otherwise we have wrong references---reported by
+% \lsthelper{Gregory~Van~Vooren}{1999/06/04}{reference one unit too large}.
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\def\@currentlabel{\thelstnumber}}
+%    \end{macrocode}
+% The label number is initialized and we ensure correct line numbers for
+% continued listings.  An apparently-extraneous advancement of the line
+% number by \verb|-\lst@advancelstnum| when \texttt{firstnumber=last} is
+% specified was removed, following a bug report by \lsthelper{Joachim~Breitner}%
+% {2006/05/14}{failure to continue counting correctly}.
+%    \begin{macrocode}
+\lst@AddToHook{InitVars}
+    {\global\c@lstnumber\lst@firstnumber
+     \global\advance\c@lstnumber\lst@advancenumber
+     \global\advance\c@lstnumber-\lst@advancelstnum}
+\lst@AddToHook{ExitVars}
+    {\global\advance\c@lstnumber\lst@advancelstnum}
+%    \end{macrocode}
+% \lsthelper{Walter~E.~Brown}{2001/05/22}{pdftex 3.14159-14f warning:
+% destination with the same identifier} reported problems with pdftex and
+% \packagename{hyperref}. A bad default of |\theHlstlabel| was the reason.
+% \lsthelper{Heiko~Oberdiek}{2001/11/08}{pdftex warning: destination with
+% the same identifier} found another bug which was due to the localization
+% of |\lst@neglisting|. He also provided the following fix, replacing
+% |\thelstlisting| with the |\ifx| \ldots\ |\fi| construction.
+% \lsthelper{Ivo~Pletikosi\'c}{2015/08/18}{listings + hyperref, lstmisc.sty}
+% reported another problem with the redefinition of |\thelstlisting|.
+% \lsthelper{Heiko~Oberdiek}{2001/11/08}%
+% {http://tex.stackexchange.com/questions/261437/renewing-the-thelstlisting^^A
+% -command-when-hyperref-is-on}
+% again provided a fix: |\thelstlisting| must be replaced by |\theHlstlisting|.
+%    \begin{macrocode}
+\AtBeginDocument{%
+    \def\theHlstnumber{\ifx\lst@@caption\@empty \lst@neglisting
+                                          \else \theHlstlisting \fi
+                       .\thelstnumber}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@skipnumbers}
+% There are more things to do. We calculate how many lines must skip their
+% label. The formula is
+%	$$|\lst@skipnumbers|=
+%		\textrm{\emph{first printing line}}\bmod|\lst@stepnumber|.$$
+% Note that we use a nonpositive representative for |\lst@skipnumbers|.
+%    \begin{macrocode}
+\newcount\lst@skipnumbers % \global
+\lst@AddToHook{Init}
+    {\ifnum \z@>\lst@stepnumber
+         \let\lst@advancelstnum\m@ne
+         \edef\lst@stepnumber{-\lst@stepnumber}%
+     \fi
+     \ifnum \z@<\lst@stepnumber
+         \global\lst@skipnumbers\lst@firstnumber
+         \global\divide\lst@skipnumbers\lst@stepnumber
+         \global\multiply\lst@skipnumbers-\lst@stepnumber
+         \global\advance\lst@skipnumbers\lst@firstnumber
+         \ifnum\lst@skipnumbers>\z@
+             \global\advance\lst@skipnumbers -\lst@stepnumber
+         \fi
+%    \end{macrocode}
+% If |\lst@stepnumber| is zero, no line numbers are printed:
+%    \begin{macrocode}
+     \else
+         \let\lst@SkipOrPrintLabel\relax
+     \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@SkipOrPrintLabel}
+% But default is this. We use the fact that |\lst@skipnumbers| is nonpositive.
+% The counter advances every line and if that counter is zero, we print a line
+% number and decrement the counter by |\lst@stepnumber|.
+%    \begin{macrocode}
+\gdef\lst@SkipOrPrintLabel{%
+    \ifnum\lst@skipnumbers=\z@
+        \global\advance\lst@skipnumbers-\lst@stepnumber\relax
+        \lst@PlaceNumber
+        \lst@numberfirstlinefalse
+    \else
+%    \end{macrocode}
+% If the first line of a listing should get a number, it gets it here.
+%    \begin{macrocode}
+        \lst@ifnumberfirstline
+            \lst@PlaceNumber
+            \lst@numberfirstlinefalse
+        \fi
+    \fi
+    \global\advance\lst@skipnumbers\@ne}%
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{OnEmptyLine}{%
+    \lst@ifnumberblanklines\else \ifnum\lst@skipnumbers=\z@
+        \global\advance\lst@skipnumbers-\lst@stepnumber\relax
+    \fi\fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Line shape and line breaking}
+%
+% \begin{macro}{\lst@parshape}
+% We define a default version of |\lst@parshape| for the case that the
+% \aspectname{lineshape} aspect is not loaded. We use this parshape every line
+% (in fact every paragraph). Furthermore we must repeat the parshape if we
+% close a group level---or the shape is forgotten.
+%    \begin{macrocode}
+%<*kernel>
+\def\lst@parshape{\parshape\@ne \z@ \linewidth}
+\lst@AddToHookAtTop{EveryLine}{\lst@parshape}
+\lst@AddToHookAtTop{EndGroup}{\lst@parshape}
+%</kernel>
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{aspect}{lineshape}
+% Our first aspect in this section.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{lineshape}
+%    \end{macrocode}
+%
+% \begin{lstkey}{xleftmargin}
+% \begin{lstkey}{xrightmargin}
+% \begin{lstkey}{resetmargins}
+% \begin{lstkey}{linewidth}
+% Usual stuff.
+%    \begin{macrocode}
+\lst@Key{xleftmargin}{\z@}{\def\lst@xleftmargin{#1}}
+\lst@Key{xrightmargin}{\z@}{\def\lst@xrightmargin{#1}}
+\lst@Key{resetmargins}{false}[t]{\lstKV@SetIf{#1}\lst@ifresetmargins}
+%    \end{macrocode}
+% The margins become zero if we make an exact box around the listing.
+%    \begin{macrocode}
+\lst@AddToHook{BoxUnsafe}{\let\lst@xleftmargin\z@
+                          \let\lst@xrightmargin\z@}
+\lst@AddToHook{TextStyle}{%
+    \let\lst@xleftmargin\z@ \let\lst@xrightmargin\z@
+    \let\lst@ifresetmargins\iftrue}
+%    \end{macrocode}
+% Added above hook after bug report from \lsthelper{Magnus~Lewis-Smith}
+%{1999/08/06}{|\lstinline| indented} and \lsthelper{Jos\'e~Romildo~Malaquias}
+%{2000/08/22}{|\lstinline| indented (resetmargins)} respectively.
+%    \begin{macrocode}
+\lst@Key{linewidth}\linewidth{\def\lst@linewidth{#1}}
+\lst@AddToHook{PreInit}{\linewidth\lst@linewidth\relax}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@parshape}
+% The definition itself is easy.
+%    \begin{macrocode}
+\gdef\lst@parshape{%
+    \parshape\@ne \@totalleftmargin \linewidth}
+%    \end{macrocode}
+% We calculate the line width and (inner/outer) indent for a listing.
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+    {\lst@ifresetmargins
+         \advance\linewidth\@totalleftmargin
+         \advance\linewidth\rightmargin
+         \@totalleftmargin\z@
+     \fi
+     \advance\linewidth-\lst@xleftmargin
+     \advance\linewidth-\lst@xrightmargin
+     \advance\@totalleftmargin\lst@xleftmargin\relax}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{lineskip}
+% The introduction of this key is due to communication with
+% \lsthelper{Andreas~Bartelt}{1997/09/11}{problem with redefed \parskip;
+% \lstlineskip introduced}. Version 1.0 implements this feature by
+% redefining |\baselinestretch|.
+%    \begin{macrocode}
+\lst@Key{lineskip}{\z@}{\def\lst@lineskip{#1\relax}}
+\lst@AddToHook{Init}
+    {\parskip\z@
+     \ifdim\z@=\lst@lineskip\else
+         \@tempdima\baselineskip
+         \advance\@tempdima\lst@lineskip
+%    \end{macrocode}
+% The following three lines simulate the `bad' |\divide| |\@tempdima|
+% |\strip@pt| |\baselineskip| |\relax|. Thanks to \lsthelper{Peter~Bartke}
+% {2002/04/10}{bad use of \strip@pt} for the bug report.
+%    \begin{macrocode}
+         \multiply\@tempdima\@cclvi
+         \divide\@tempdima\baselineskip\relax
+         \multiply\@tempdima\@cclvi
+%    \end{macrocode}
+%    \begin{macrocode}
+         \edef\baselinestretch{\strip@pt\@tempdima}%
+         \selectfont
+     \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{breaklines}
+% \begin{lstkey}{breakindent}
+% \begin{lstkey}{breakautoindent}
+% \begin{lstkey}{breakatwhitespace}
+% \begin{lstkey}{prebreak}
+% \begin{lstkey}{postbreak}
+% As usual we have no problems in announcing more keys.
+% \keyname{breakatwhitespace} is due to \lsthelper{Javier~Bezos}{2003/09/23}
+% {breaklines breaks at odd places}. Unfortunately a previous definition of
+% that key was wrong as \lsthelper{Franz~Rinnerthaler}{2004/03/12}
+% {breakatwhitespace has no effect} and \lsthelper{Ulrike~Fischer}{2004/07/11}
+% {breakatwhitespace has no effect} reported.
+%    \begin{macrocode}
+\lst@Key{breaklines}{false}[t]{\lstKV@SetIf{#1}\lst@ifbreaklines}
+\lst@Key{breakindent}{20pt}{\def\lst@breakindent{#1}}
+\lst@Key{breakautoindent}{t}[t]{\lstKV@SetIf{#1}\lst@ifbreakautoindent}
+\lst@Key{breakatwhitespace}{false}[t]%
+    {\lstKV@SetIf{#1}\lst@ifbreakatwhitespace}
+\lst@Key{prebreak}{}{\def\lst@prebreak{#1}}
+\lst@Key{postbreak}{}{\def\lst@postbreak{#1}}
+%    \end{macrocode}
+% We assign some different macros and (if necessary) suppress ``underfull
+% |\hbox|'' messages (and use different pretolerance):
+%    \begin{macrocode}
+\lst@AddToHook{Init}
+    {\lst@ifbreaklines
+         \hbadness\@M \pretolerance\@M
+         \@rightskip\@flushglue \rightskip\@rightskip % \raggedright
+         \leftskip\z@skip \parindent\z@
+%    \end{macrocode}
+% A |\raggedright| above has been replaced by setting the values by hand after
+% a bug report from \lsthelper{Morten~H\o gholm}{2004/09/06}{ltugboat.cls and
+% listings}.
+%
+% We use the normal parshape and the calculated |\lst@breakshape| (see below).
+%    \begin{macrocode}
+         \def\lst@parshape{\parshape\tw@ \@totalleftmargin\linewidth
+                           \lst@breakshape}%
+     \else
+         \let\lst@discretionary\@empty
+     \fi}
+\lst@AddToHook{OnNewLine}
+    {\lst@ifbreaklines \lst@breakNewLine \fi}
+%    \end{macrocode}
+% \end{lstkey}\end{lstkey}\end{lstkey}\end{lstkey}
+% \end{lstkey}\end{lstkey}
+%
+% \begin{macro}{\lst@discretionary}
+% \begin{macro}{\lst@spacekern}
+% Here comes the whole magic: We set a discretionary break after each `output
+% unit'. However we redefine |\space| to be used inside |\discretionary| and
+% use \hookname{EveryLine} hook. After a bug report by \lsthelper{Carsten~Hamm}
+% {2002/04/19}{wrong frame rules with breaklines and xleftmargin>0pt} I've
+% added |\kern-\lst@xleftmargin|, which became |\kern-\@totalleftmargin| after
+% a bug report by \lsthelper{Christian~Kaiser}{2002/12/13}{wrong frame inside
+% itemize with breaklines=true}.
+%    \begin{macrocode}
+\gdef\lst@discretionary{%
+    \lst@ifbreakatwhitespace
+        \lst@ifwhitespace \lst@@discretionary \fi
+    \else
+        \lst@@discretionary
+    \fi}%
+\gdef\lst@@discretionary{%
+    \discretionary{\let\space\lst@spacekern\lst@prebreak}%
+                  {\llap{\lsthk@EveryLine
+                   \kern\lst@breakcurrindent \kern-\@totalleftmargin}%
+                   \let\space\lst@spacekern\lst@postbreak}{}}
+\lst@AddToHook{PostOutput}{\lst@discretionary}
+\gdef\lst@spacekern{\kern\lst@width}
+%    \end{macrocode}
+% \begin{ALTERNATIVE}
+% |\penalty\@M \hskip\z@ plus 1fil \penalty0\hskip\z@ plus-1fil| \emph{before}
+% each `output unit' (i.e.~before |\hbox{...}| in the output macros) also break
+% the lines as desired. But we wouldn't have |prebreak| and |postbreak|.
+% \end{ALTERNATIVE}
+% \end{macro}\end{macro}
+%
+% \begin{macro}{\lst@breakNewLine}
+% We use \keyname{breakindent}, and additionally the current line indention
+% (coming from white spaces at the beginning of the line) if `auto indent' is
+% on.
+%    \begin{macrocode}
+\gdef\lst@breakNewLine{%
+    \@tempdima\lst@breakindent\relax
+    \lst@ifbreakautoindent \advance\@tempdima\lst@lostspace \fi
+%    \end{macrocode}
+% Now we calculate the margin and line width of the wrapped part \ldots
+%    \begin{macrocode}
+    \@tempdimc-\@tempdima \advance\@tempdimc\linewidth
+                          \advance\@tempdima\@totalleftmargin
+%    \end{macrocode}
+% \ldots\space and store it in |\lst@breakshape|.
+%    \begin{macrocode}
+    \xdef\lst@breakshape{\noexpand\lst@breakcurrindent \the\@tempdimc}%
+    \xdef\lst@breakcurrindent{\the\@tempdima}}
+\global\let\lst@breakcurrindent\z@ % init
+%    \end{macrocode}
+% The initialization of |\lst@breakcurrindent| has been added after a bug
+% report by \lsthelper{Alvaro~Herrera}{2002/12/09}{`undefined control
+% sequence \lst@breakcurrindent' with fancyvrb and breaklines}.
+% \begin{TODO}
+% We could speed this up by allocating two global dimensions.
+% \end{TODO}
+% \end{macro}
+%
+% \begin{macro}{\lst@breakshape}
+% \lsthelper{Andreas~Deininger}{2000/08/25}{`breaklines,first>1' leads to
+% ``undefined control sequence'' error} reported a problem which is resolved
+% by providing a default break shape.
+%    \begin{macrocode}
+\gdef\lst@breakshape{\@totalleftmargin \linewidth}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@breakProcessOther}
+% is the same as |\lst@ProcessOther| except that it also outputs the current
+% token string. This inserts a potential linebreak point.
+% Only the closing parenthesis uses this macro yet.
+%    \begin{macrocode}
+\gdef\lst@breakProcessOther#1{\lst@ProcessOther#1\lst@OutputOther}
+\lst@AddToHook{SelectCharTable}
+    {\lst@ifbreaklines \lst@Def{`)}{\lst@breakProcessOther)}\fi}
+%    \end{macrocode}
+% A bug reported by \lsthelper{Gabriel~Tauro}{2001/04/18}{unexpected `)' if
+% the character appears before first printed line} has been removed by using
+% |\lst@ProcessOther| instead of |\lst@AppendOther|.
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Frames}
+%
+% \begin{aspect}{frames}
+% Another aspect.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[lineshape]{frames}
+%    \end{macrocode}
+%
+% \begin{lstkey}{framexleftmargin}
+% \begin{lstkey}{framexrightmargin}
+% \begin{lstkey}{framextopmargin}
+% \begin{lstkey}{framexbottommargin}
+% These keys just save the argument.
+%    \begin{macrocode}
+\lst@Key{framexleftmargin}{\z@}{\def\lst@framexleftmargin{#1}}
+\lst@Key{framexrightmargin}{\z@}{\def\lst@framexrightmargin{#1}}
+\lst@Key{framextopmargin}{\z@}{\def\lst@framextopmargin{#1}}
+\lst@Key{framexbottommargin}{\z@}{\def\lst@framexbottommargin{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{backgroundcolor}
+% \lsthelper{Ralf~Imh\"auser}{2000/01/08}{coloured background} inspired the
+% key \keyname{backgroundcolor}. All keys save the argument, and \ldots
+%    \begin{macrocode}
+\lst@Key{backgroundcolor}{}{\def\lst@bkgcolor{#1}}
+\lst@Key{fillcolor}{}{\def\lst@fillcolor{#1}}
+\lst@Key{rulecolor}{}{\def\lst@rulecolor{#1}}
+\lst@Key{rulesepcolor}{}{\def\lst@rulesepcolor{#1}}
+%    \end{macrocode}
+% \ldots\space some have default settings if they are empty.
+%    \begin{macrocode}
+\lst@AddToHook{Init}{%
+    \ifx\lst@fillcolor\@empty
+        \let\lst@fillcolor\lst@bkgcolor
+    \fi
+    \ifx\lst@rulesepcolor\@empty
+        \let\lst@rulesepcolor\lst@fillcolor
+    \fi}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{lstkey}{rulesep}
+% \begin{lstkey}{framerule}
+% \begin{lstkey}{framesep}
+% \begin{lstkey}{frameshape}
+% Another set of keys, which mainly save their respective argument.
+% \keyname{frameshape} capitalizes all letters, and checks whether at least one
+% round corner is specified. Eventually we define |\lst@frame| to be empty if
+% and only if there is no frameshape.
+%    \begin{macrocode}
+\lst@Key{rulesep}{2pt}{\def\lst@rulesep{#1}}
+\lst@Key{framerule}{.4pt}{\def\lst@framerulewidth{#1}}
+\lst@Key{framesep}{3pt}{\def\lst@frametextsep{#1}}
+\lst@Key{frameshape}{}{%
+    \let\lst@xrulecolor\@empty
+    \lstKV@FourArg{#1}%
+    {\uppercase{\def\lst@frametshape{##1}}%
+     \uppercase{\def\lst@framelshape{##2}}%
+     \uppercase{\def\lst@framershape{##3}}%
+     \uppercase{\def\lst@framebshape{##4}}%
+     \let\lst@ifframeround\iffalse
+     \lst@IfSubstring R\lst@frametshape{\let\lst@ifframeround\iftrue}{}%
+     \lst@IfSubstring R\lst@framebshape{\let\lst@ifframeround\iftrue}{}%
+     \def\lst@frame{##1##2##3##4}}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{lstkey}{frameround}
+% \begin{lstkey}{frame}
+% We have to do some conversion here.
+%    \begin{macrocode}
+\lst@Key{frameround}\relax
+    {\uppercase{\def\lst@frameround{#1}}%
+     \expandafter\lstframe@\lst@frameround ffff\relax}
+\global\let\lst@frameround\@empty
+%    \end{macrocode}
+% In case of an verbose argument, we use the |trbl|-subset replacement.
+%    \begin{macrocode}
+\lst@Key{frame}\relax{%
+    \let\lst@xrulecolor\@empty
+    \lstKV@SwitchCases{#1}%
+    {none:\let\lst@frame\@empty\\%
+     leftline:\def\lst@frame{l}\\%
+     topline:\def\lst@frame{t}\\%
+     bottomline:\def\lst@frame{b}\\%
+     lines:\def\lst@frame{tb}\\%
+     single:\def\lst@frame{trbl}\\%
+     shadowbox:\def\lst@frame{tRBl}%
+            \def\lst@xrulecolor{\lst@rulesepcolor}%
+            \def\lst@rulesep{\lst@frametextsep}%
+    }{\def\lst@frame{#1}}%
+    \expandafter\lstframe@\lst@frameround ffff\relax}
+%    \end{macrocode}
+% Adding |t|, |r|, |b|, and |l| in case of their upper case versions makes
+% later tests easier.
+%    \begin{macrocode}
+\gdef\lstframe@#1#2#3#4#5\relax{%
+    \lst@IfSubstring T\lst@frame{\edef\lst@frame{t\lst@frame}}{}%
+    \lst@IfSubstring R\lst@frame{\edef\lst@frame{r\lst@frame}}{}%
+    \lst@IfSubstring B\lst@frame{\edef\lst@frame{b\lst@frame}}{}%
+    \lst@IfSubstring L\lst@frame{\edef\lst@frame{l\lst@frame}}{}%
+%    \end{macrocode}
+% We now check top and bottom frame rules, \ldots
+%    \begin{macrocode}
+    \let\lst@frametshape\@empty \let\lst@framebshape\@empty
+    \lst@frameCheck
+        ltr\lst@framelshape\lst@frametshape\lst@framershape #4#1%
+    \lst@frameCheck
+        LTR\lst@framelshape\lst@frametshape\lst@framershape #4#1%
+    \lst@frameCheck
+        lbr\lst@framelshape\lst@framebshape\lst@framershape #3#2%
+    \lst@frameCheck
+        LBR\lst@framelshape\lst@framebshape\lst@framershape #3#2%
+%    \end{macrocode}
+% \ldots\space look for round corners \ldots
+%    \begin{macrocode}
+    \let\lst@ifframeround\iffalse
+    \lst@IfSubstring R\lst@frametshape{\let\lst@ifframeround\iftrue}{}%
+    \lst@IfSubstring R\lst@framebshape{\let\lst@ifframeround\iftrue}{}%
+%    \end{macrocode}
+% and define left and right frame shape.
+%    \begin{macrocode}
+    \let\lst@framelshape\@empty \let\lst@framershape\@empty
+    \lst@IfSubstring L\lst@frame
+        {\def\lst@framelshape{YY}}%
+        {\lst@IfSubstring l\lst@frame{\def\lst@framelshape{Y}}{}}%
+    \lst@IfSubstring R\lst@frame
+        {\def\lst@framershape{YY}}%
+        {\lst@IfSubstring r\lst@frame{\def\lst@framershape{Y}}{}}}
+%    \end{macrocode}
+% Now comes the macro used to define top and bottom frame shape.
+% It extends the macro |#5|.
+% The last two arguments show whether left and right corners are round.
+% |#4| and |#6| are temporary macros.
+% |#1#2#3| are the three characters we test for.
+%    \begin{macrocode}
+\gdef\lst@frameCheck#1#2#3#4#5#6#7#8{%
+    \lst@IfSubstring #1\lst@frame
+        {\if #7T\def#4{R}\else \def#4{Y}\fi}%
+        {\def#4{N}}%
+    \lst@IfSubstring #3\lst@frame
+        {\if #8T\def#6{R}\else \def#6{Y}\fi}%
+        {\def#6{N}}%
+    \lst@IfSubstring #2\lst@frame{\edef#5{#5#4Y#6}}{}}
+%    \end{macrocode}
+% For text style listings all frames and the background color are
+% deactivated -- added after bug reports by \lsthelper{Stephen~Reindl}%
+% {2002/06/04}{frames not deactivated for text style listings} and
+% \lsthelper{Thomas~ten~Cate}{2006/07/14}{inline listings get background
+% color after a line break}
+%    \begin{macrocode}
+\lst@AddToHook{TextStyle}
+   {\let\lst@frame\@empty
+    \let\lst@frametshape\@empty
+    \let\lst@framershape\@empty
+    \let\lst@framebshape\@empty
+    \let\lst@framelshape\@empty
+    \let\lst@bkgcolor\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% As per a bug report by \lsthelper{Ignacio~Fern\'andez~Galv\'an}{2006/07/26}%
+% {Frame with background color has slight hole on left side}, the small section
+% of background color to the left of the margin is now drawn before the left
+% side of the frame is drawn, so that they overlap correctly in Acrobat.
+%
+% \begin{macro}{\lst@frameMakeVBox}
+%    \begin{macrocode}
+\gdef\lst@frameMakeBoxV#1#2#3{%
+    \setbox#1\hbox{%
+      \color@begingroup \lst@rulecolor
+      \ifx\lst@framelshape\@empty
+      \else
+            \llap{%
+                \lst@frameBlock\lst@fillcolor\lst@frametextsep{#2}{#3}%
+                \kern\lst@framexleftmargin}%
+      \fi
+      \llap{\setbox\z@\hbox{\vrule\@width\z@\@height#2\@depth#3%
+                            \lst@frameL}%
+            \rlap{\lst@frameBlock\lst@rulesepcolor{\wd\z@}%
+                                                  {\ht\z@}{\dp\z@}}%
+            \box\z@
+            \kern\lst@frametextsep\relax
+            \kern\lst@framexleftmargin}%
+      \rlap{\kern-\lst@framexleftmargin
+                    \@tempdima\linewidth
+            \advance\@tempdima\lst@framexleftmargin
+            \advance\@tempdima\lst@framexrightmargin
+            \lst@frameBlock\lst@bkgcolor\@tempdima{#2}{#3}%
+            \ifx\lst@framershape\@empty
+                \kern\lst@frametextsep\relax
+            \else
+                \lst@frameBlock\lst@fillcolor\lst@frametextsep{#2}{#3}%
+            \fi
+            \setbox\z@\hbox{\vrule\@width\z@\@height#2\@depth#3%
+                            \lst@frameR}%
+            \rlap{\lst@frameBlock\lst@rulesepcolor{\wd\z@}%
+                                                  {\ht\z@}{\dp\z@}}%
+            \box\z@}%
+      \color@endgroup}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameBlock}
+%    \begin{macrocode}
+\gdef\lst@frameBlock#1#2#3#4{%
+    \color@begingroup
+      #1%
+      \setbox\z@\hbox{\vrule\@height#3\@depth#4%
+                      \ifx#1\@empty \@width\z@ \kern#2\relax
+                              \else \@width#2\relax \fi}%
+      \box\z@
+    \color@endgroup}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameR}
+% typesets right rules.
+% We only need to iterate through |\lst@framershape|.
+%    \begin{macrocode}
+\gdef\lst@frameR{%
+    \expandafter\lst@frameR@\lst@framershape\relax
+    \kern-\lst@rulesep}
+\gdef\lst@frameR@#1{%
+    \ifx\relax#1\@empty\else
+        \if #1Y\lst@framevrule \else \kern\lst@framerulewidth \fi
+        \kern\lst@rulesep
+        \expandafter\lst@frameR@b
+    \fi}
+\gdef\lst@frameR@b#1{%
+    \ifx\relax#1\@empty
+    \else
+        \if #1Y\color@begingroup
+               \lst@xrulecolor
+               \lst@framevrule
+               \color@endgroup
+        \else
+               \kern\lst@framerulewidth
+        \fi
+        \kern\lst@rulesep
+        \expandafter\lst@frameR@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameL}
+% Ditto left rules.
+%    \begin{macrocode}
+\gdef\lst@frameL{%
+    \kern-\lst@rulesep
+    \expandafter\lst@frameL@\lst@framelshape\relax}
+\gdef\lst@frameL@#1{%
+    \ifx\relax#1\@empty\else
+        \kern\lst@rulesep
+        \if#1Y\lst@framevrule \else \kern\lst@framerulewidth \fi
+        \expandafter\lst@frameL@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameH}
+% This is the central macro used to draw top and bottom frame rules.
+% The first argument is either |T| or |B| and the second contains the shape.
+% We use |\@tempcntb| as size counter.
+%    \begin{macrocode}
+\gdef\lst@frameH#1#2{%
+    \global\let\lst@framediml\z@ \global\let\lst@framedimr\z@
+    \setbox\z@\hbox{}\@tempcntb\z@
+    \expandafter\lst@frameH@\expandafter#1#2\relax\relax\relax
+            \@tempdimb\lst@frametextsep\relax
+    \advance\@tempdimb\lst@framerulewidth\relax
+            \@tempdimc-\@tempdimb
+    \advance\@tempdimc\ht\z@
+    \advance\@tempdimc\dp\z@
+    \setbox\z@=\hbox{%
+      \lst@frameHBkg\lst@fillcolor\@tempdimb\@firstoftwo
+      \if#1T\rlap{\raise\dp\@tempboxa\box\@tempboxa}%
+       \else\rlap{\lower\ht\@tempboxa\box\@tempboxa}\fi
+      \lst@frameHBkg\lst@rulesepcolor\@tempdimc\@secondoftwo
+      \advance\@tempdimb\ht\@tempboxa
+      \if#1T\rlap{\raise\lst@frametextsep\box\@tempboxa}%
+       \else\rlap{\lower\@tempdimb\box\@tempboxa}\fi
+      \rlap{\box\z@}%
+    }}
+\gdef\lst@frameH@#1#2#3#4{%
+    \ifx\relax#4\@empty\else
+        \lst@frameh \@tempcntb#1#2#3#4%
+        \advance\@tempcntb\@ne
+        \expandafter\lst@frameH@\expandafter#1%
+    \fi}
+\gdef\lst@frameHBkg#1#2#3{%
+    \setbox\@tempboxa\hbox{%
+        \kern-\lst@framexleftmargin
+        #3{\kern-\lst@framediml\relax}{\@tempdima\z@}%
+        \ifdim\lst@framediml>\@tempdimb
+            #3{\@tempdima\lst@framediml \advance\@tempdima-\@tempdimb
+               \lst@frameBlock\lst@rulesepcolor\@tempdima\@tempdimb\z@}%
+              {\kern-\lst@framediml
+               \advance\@tempdima\lst@framediml\relax}%
+        \fi
+        #3{\@tempdima\z@
+           \ifx\lst@framelshape\@empty\else
+               \advance\@tempdima\@tempdimb
+           \fi
+           \ifx\lst@framershape\@empty\else
+               \advance\@tempdima\@tempdimb
+           \fi}%
+          {\ifdim\lst@framedimr>\@tempdimb
+              \advance\@tempdima\lst@framedimr\relax
+           \fi}%
+        \advance\@tempdima\linewidth
+        \advance\@tempdima\lst@framexleftmargin
+        \advance\@tempdima\lst@framexrightmargin
+        \lst@frameBlock#1\@tempdima#2\z@
+        #3{\ifdim\lst@framedimr>\@tempdimb
+               \@tempdima-\@tempdimb
+               \advance\@tempdima\lst@framedimr\relax
+               \lst@frameBlock\lst@rulesepcolor\@tempdima\@tempdimb\z@
+           \fi}{}%
+        }}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameh}
+% This is the low-level macro used to draw top and bottom frame rules.
+% It \emph{adds} one rule plus corners to box 0.
+% The first parameter gives the size of the corners and the second is either
+% |T| or |B|.
+% |#3#4#5| is a left-to-right description of the frame and is in
+% $\{$\texttt{Y,N,R}$\}\times\{$\texttt{Y,N}$\}\times\{$\texttt{Y,N,R}$\}$.
+% We move to the correct horizontal position, set the left corner, the
+% horizontal line, and the right corner.
+%    \begin{macrocode}
+\gdef\lst@frameh#1#2#3#4#5{%
+    \lst@frameCalcDimA#1%
+    \lst@ifframeround \@getcirc\@tempdima \fi
+%    \end{macrocode}
+%    \begin{macrocode}
+    \setbox\z@\hbox{%
+      \begingroup
+      \setbox\z@\hbox{%
+        \kern-\lst@framexleftmargin
+        \color@begingroup
+        \ifnum#1=\z@ \lst@rulecolor \else \lst@xrulecolor \fi
+%    \end{macrocode}
+% |\lst@frameCorner| gets four arguments:
+% |\llap|, |TL| or |BL|, the corner type $\in\{$\texttt{Y,N,R}$\}$, and the
+% size |#1|.
+%    \begin{macrocode}
+        \lst@frameCornerX\llap{#2L}#3#1%
+        \ifdim\lst@framediml<\@tempdimb
+            \xdef\lst@framediml{\the\@tempdimb}%
+        \fi
+        \begingroup
+        \if#4Y\else \let\lst@framerulewidth\z@ \fi
+                \@tempdima\lst@framexleftmargin
+        \advance\@tempdima\lst@framexrightmargin
+        \advance\@tempdima\linewidth
+        \vrule\@width\@tempdima\@height\lst@framerulewidth \@depth\z@
+        \endgroup
+        \lst@frameCornerX\rlap{#2R}#5#1%
+        \ifdim\lst@framedimr<\@tempdimb
+            \xdef\lst@framedimr{\the\@tempdimb}%
+        \fi
+        \color@endgroup}%
+%    \end{macrocode}
+%    \begin{macrocode}
+      \if#2T\rlap{\raise\dp\z@\box\z@}%
+       \else\rlap{\lower\ht\z@\box\z@}\fi
+      \endgroup
+      \box\z@}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameCornerX}
+% typesets a single corner and returns |\@tempdimb|, the width of the corner.
+%    \begin{macrocode}
+\gdef\lst@frameCornerX#1#2#3#4{%
+    \setbox\@tempboxa\hbox{\csname\@lst @frame\if#3RR\fi #2\endcsname}%
+    \@tempdimb\wd\@tempboxa
+    \if #3R%
+        #1{\box\@tempboxa}%
+    \else
+        \if #3Y\expandafter#1\else
+               \@tempdimb\z@ \expandafter\vphantom \fi
+        {\box\@tempboxa}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameCalcDimA}
+% calculates an all over width; used by |\lst@frameh| and |\lst@frameInit|.
+%    \begin{macrocode}
+\gdef\lst@frameCalcDimA#1{%
+            \@tempdima\lst@rulesep
+    \advance\@tempdima\lst@framerulewidth
+    \multiply\@tempdima#1\relax
+    \advance\@tempdima\lst@frametextsep
+    \advance\@tempdima\lst@framerulewidth
+    \multiply\@tempdima\tw@}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameInit}
+% First we look which frame types we have on the left and on the right.
+% We speed up things if there are no vertical rules.
+%    \begin{macrocode}
+\lst@AddToHook{Init}{\lst@frameInit}
+\newbox\lst@framebox
+\gdef\lst@frameInit{%
+    \ifx\lst@framelshape\@empty \let\lst@frameL\@empty \fi
+    \ifx\lst@framershape\@empty \let\lst@frameR\@empty \fi
+    \def\lst@framevrule{\vrule\@width\lst@framerulewidth\relax}%
+%    \end{macrocode}
+% We adjust values to round corners if necessary.
+%    \begin{macrocode}
+    \lst@ifframeround
+        \lst@frameCalcDimA\z@ \@getcirc\@tempdima
+        \@tempdimb\@tempdima \divide\@tempdimb\tw@
+        \advance\@tempdimb -\@wholewidth
+        \edef\lst@frametextsep{\the\@tempdimb}%
+        \edef\lst@framerulewidth{\the\@wholewidth}%
+%    \end{macrocode}
+%    \begin{macrocode}
+        \lst@frameCalcDimA\@ne \@getcirc\@tempdima
+        \@tempdimb\@tempdima \divide\@tempdimb\tw@
+        \advance\@tempdimb -\tw@\@wholewidth
+        \advance\@tempdimb -\lst@frametextsep
+        \edef\lst@rulesep{\the\@tempdimb}%
+    \fi
+%    \end{macrocode}
+%    \begin{macrocode}
+    \lst@frameMakeBoxV\lst@framebox{\ht\strutbox}{\dp\strutbox}%
+    \def\lst@framelr{\copy\lst@framebox}%
+%    \end{macrocode}
+% Finally we typeset the rules (+ corners).
+% We possibly need to insert negative |\vskip| to remove space between
+% preceding text and top rule.
+% \begin{TODO}
+% Use |\vspace| instead of |\vskip|?
+% \end{TODO}
+%    \begin{macrocode}
+    \ifx\lst@frametshape\@empty\else
+        \lst@frameH T\lst@frametshape
+        \ifvoid\z@\else
+            \par\lst@parshape
+            \@tempdima-\baselineskip \advance\@tempdima\ht\z@
+            \ifdim\prevdepth<\@cclvi\p@\else
+                \advance\@tempdima\prevdepth
+            \fi
+            \ifdim\@tempdima<\z@
+                \vskip\@tempdima\vskip\lineskip
+            \fi
+            \noindent\box\z@\par
+            \lineskiplimit\maxdimen \lineskip\z@
+        \fi
+        \lst@frameSpreadV\lst@framextopmargin
+    \fi}
+%    \end{macrocode}
+% |\parshape\lst@parshape| ensures that the top rules correctly indented.
+% The bug was reported by \lsthelper{Marcin~Kasperski}{1999/04/28}{top rules
+% indented right inside itemize}.
+%
+% We typeset left and right rules every line.
+%    \begin{macrocode}
+\lst@AddToHook{EveryLine}{\lst@framelr}
+\global\let\lst@framelr\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameExit}
+% The rules at the bottom.
+%    \begin{macrocode}
+\lst@AddToHook{DeInit}
+    {\ifx\lst@framebshape\@empty\else \lst@frameExit \fi}
+\gdef\lst@frameExit{%
+    \lst@frameSpreadV\lst@framexbottommargin
+    \lst@frameH B\lst@framebshape
+    \ifvoid\z@\else
+        \everypar{}\par\lst@parshape\nointerlineskip\noindent\box\z@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameSpreadV}
+% sets rules for vertical spread.
+%    \begin{macrocode}
+\gdef\lst@frameSpreadV#1{%
+    \ifdim\z@=#1\else
+        \everypar{}\par\lst@parshape\nointerlineskip\noindent
+        \lst@frameMakeBoxV\z@{#1}{\z@}%
+        \box\z@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameTR}
+% \begin{macro}{\lst@frameBR}
+% \begin{macro}{\lst@frameBL}
+% \begin{macro}{\lst@frameTL}
+% These macros make a vertical and horizontal rule.
+% The implicit argument |\@tempdima| gives the size of two corners and is
+% provided by |\lst@frameh|.
+%    \begin{macrocode}
+\gdef\lst@frameTR{%
+    \vrule\@width.5\@tempdima\@height\lst@framerulewidth\@depth\z@
+    \kern-\lst@framerulewidth
+    \raise\lst@framerulewidth\hbox{%
+        \vrule\@width\lst@framerulewidth\@height\z@\@depth.5\@tempdima}}
+\gdef\lst@frameBR{%
+    \vrule\@width.5\@tempdima\@height\lst@framerulewidth\@depth\z@
+    \kern-\lst@framerulewidth
+    \vrule\@width\lst@framerulewidth\@height.5\@tempdima\@depth\z@}
+\gdef\lst@frameBL{%
+    \vrule\@width\lst@framerulewidth\@height.5\@tempdima\@depth\z@
+    \kern-\lst@framerulewidth
+    \vrule\@width.5\@tempdima\@height\lst@framerulewidth\@depth\z@}
+\gdef\lst@frameTL{%
+    \raise\lst@framerulewidth\hbox{%
+        \vrule\@width\lst@framerulewidth\@height\z@\@depth.5\@tempdima}%
+    \kern-\lst@framerulewidth
+    \vrule\@width.5\@tempdima\@height\lst@framerulewidth\@depth\z@}
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{macro}\end{macro}
+%
+% \begin{macro}{\lst@frameRoundT}
+% \begin{macro}{\lst@frameRoundB}
+% are helper macros to typeset round corners. We set height and depth to
+% the visible parts of the circle font.
+%    \begin{macrocode}
+\gdef\lst@frameRoundT{%
+    \setbox\@tempboxa\hbox{\@circlefnt\char\@tempcnta}%
+    \ht\@tempboxa\lst@framerulewidth
+    \box\@tempboxa}
+\gdef\lst@frameRoundB{%
+    \setbox\@tempboxa\hbox{\@circlefnt\char\@tempcnta}%
+    \dp\@tempboxa\z@
+    \box\@tempboxa}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@frameRTR}
+% \begin{macro}{\lst@frameRBR}
+% \begin{macro}{\lst@frameRBL}
+% \begin{macro}{\lst@frameRTL}
+% The round corners.
+%    \begin{macrocode}
+\gdef\lst@frameRTR{%
+    \hb@xt@.5\@tempdima{\kern-\lst@framerulewidth
+                           \kern.5\@tempdima \lst@frameRoundT \hss}}
+\gdef\lst@frameRBR{%
+    \hb@xt@.5\@tempdima{\kern-\lst@framerulewidth
+    \advance\@tempcnta\@ne \kern.5\@tempdima \lst@frameRoundB \hss}}
+\gdef\lst@frameRBL{%
+    \advance\@tempcnta\tw@ \lst@frameRoundB
+    \kern-.5\@tempdima}
+\gdef\lst@frameRTL{%
+    \advance\@tempcnta\thr@@\lst@frameRoundT
+    \kern-.5\@tempdima}
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{macro}\end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Macro use for make}
+%
+% \begin{aspect}{make}
+% \begin{macro}{\lst@makemode}
+% \begin{macro}{\lst@ifmakekey}
+% If we've entered the special mode for Make, we save whether the last
+% identifier has been a first order keyword.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{make}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@NewMode\lst@makemode
+\lst@AddToHook{Output}{%
+    \ifnum\lst@mode=\lst@makemode
+        \ifx\lst@thestyle\lst@gkeywords@sty
+            \lst@makekeytrue
+        \fi
+    \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@makekeytrue{\let\lst@ifmakekey\iftrue}
+\gdef\lst@makekeyfalse{\let\lst@ifmakekey\iffalse}
+\global\lst@makekeyfalse % init
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{lstkey}{makemacrouse}
+% adjusts the character table if necessary
+%    \begin{macrocode}
+\lst@Key{makemacrouse}f[t]{\lstKV@SetIf{#1}\lst@ifmakemacrouse}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@MakeSCT}
+% If `macro use' is on, the opening |$(| prints preceding characters, enters
+% the special mode and merges the two characters with the following output.
+%
+%    \begin{macrocode}
+\gdef\lst@MakeSCT{%
+    \lst@ifmakemacrouse
+        \lst@ReplaceInput{$(}{%
+            \lst@PrintToken
+            \lst@EnterMode\lst@makemode{\lst@makekeyfalse}%
+            \lst@Merge{\lst@ProcessOther\$\lst@ProcessOther(}}%
+%    \end{macrocode} ^^A $
+% The closing parenthesis tests for the mode and either processes |)| as usual
+% or outputs it right here (in keyword style if a keyword was between |$(| and
+% |)|).
+%    \begin{macrocode}
+        \lst@ReplaceInput{)}{%
+            \ifnum\lst@mode=\lst@makemode
+                \lst@PrintToken
+                \begingroup
+                    \lst@ProcessOther)%
+                    \lst@ifmakekey
+                        \let\lst@currstyle\lst@gkeywords@sty
+                    \fi
+                    \lst@OutputOther
+                \endgroup
+                \lst@LeaveMode
+            \else
+                \expandafter\lst@ProcessOther\expandafter)%
+            \fi}%
+%    \end{macrocode}
+% If \keyname{makemacrouse} is off then both |$(| are just `others'.
+%    \begin{macrocode}
+    \else
+        \lst@ReplaceInput{$(}{\lst@ProcessOther\$\lst@ProcessOther(}%
+    \fi}
+%    \end{macrocode} ^^A $
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \section{Typesetting a listing}
+%
+% \begingroup
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+% \endgroup
+% \begin{macro}{\lst@lineno}
+% \begin{lstkey}{print}
+% \begin{lstkey}{firstline}
+% \begin{lstkey}{lastline}
+% \begin{lstkey}{linerange}
+% The `current line' counter and three keys.
+%    \begin{macrocode}
+\newcount\lst@lineno % \global
+\lst@AddToHook{InitVars}{\global\lst@lineno\@ne}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{print}{true}[t]{\lstKV@SetIf{#1}\lst@ifprint}
+\lst@Key{firstline}\relax{\def\lst@firstline{#1\relax}}
+\lst@Key{lastline}\relax{\def\lst@lastline{#1\relax}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{PreSet}
+    {\let\lst@firstline\@ne \def\lst@lastline{9999999\relax}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}\end{lstkey}\end{lstkey}\end{macro}
+% The following code is just copied from the current development version, and
+% from the |lstpatch.sty| file that Carsten left in version 1.3b for doing
+% line ranges with numbers and range markers.
+%
+% First, the options that control the line-range handling.
+%    \begin{macrocode}
+\lst@Key{linerange}\relax{\lstKV@OptArg[]{#1}{%
+    \def\lst@interrange{##1}\def\lst@linerange{##2,}}}
+\lst@Key{rangeprefix}\relax{\def\lst@rangebeginprefix{#1}%
+                            \def\lst@rangeendprefix{#1}}
+\lst@Key{rangesuffix}\relax{\def\lst@rangebeginsuffix{#1}%
+                            \def\lst@rangeendsuffix{#1}}
+\lst@Key{rangebeginprefix}{}{\def\lst@rangebeginprefix{#1}}
+\lst@Key{rangebeginsuffix}{}{\def\lst@rangebeginsuffix{#1}}
+\lst@Key{rangeendprefix}{}{\def\lst@rangeendprefix{#1}}
+\lst@Key{rangeendsuffix}{}{\def\lst@rangeendsuffix{#1}}
+\lst@Key{includerangemarker}{true}[t]{\lstKV@SetIf{#1}\lst@ifincluderangemarker}
+\lst@AddToHook{PreSet}{\def\lst@firstline{1\relax}%
+                       \let\lst@linerange\@empty}
+\lst@AddToHook{Init}
+    {\ifx\lst@linerange\@empty
+         \edef\lst@linerange{{\lst@firstline}-{\lst@lastline},}%
+     \fi%
+     \lst@GetLineInterval}%
+\def\lst@GetLineInterval{\expandafter\lst@GLI\lst@linerange\@nil}
+\def\lst@GLI#1,#2\@nil{\def\lst@linerange{#2}\lst@GLI@#1--\@nil}
+\def\lst@GLI@#1-#2-#3\@nil{%
+    \lst@IfNumber{#1}%
+    {\ifx\@empty#1\@empty
+         \let\lst@firstline\@ne
+     \else
+         \def\lst@firstline{#1\relax}%
+     \fi
+     \ifx\@empty#3\@empty
+         \def\lst@lastline{9999999\relax}%
+     \else
+         \ifx\@empty#2\@empty
+             \let\lst@lastline\lst@firstline
+         \else
+             \def\lst@lastline{#2\relax}%
+         \fi
+     \fi}%
+%    \end{macrocode}
+%    If we've found a general marker, we set firstline and lastline to 9999999.
+%    This prevents (almost) anything from being printed for now.
+%    \begin{macrocode}
+    {\def\lst@firstline{9999999\relax}%
+     \let\lst@lastline\lst@firstline
+%    \end{macrocode}
+%    We add the prefixes and suffixes to the markers.
+%    \begin{macrocode}
+     \let\lst@rangebegin\lst@rangebeginprefix
+     \lst@AddTo\lst@rangebegin{#1}\lst@Extend\lst@rangebegin\lst@rangebeginsuffix
+     \ifx\@empty#3\@empty
+         \let\lst@rangeend\lst@rangeendprefix
+         \lst@AddTo\lst@rangeend{#1}\lst@Extend\lst@rangeend\lst@rangeendsuffix
+     \else
+         \ifx\@empty#2\@empty
+             \let\lst@rangeend\@empty
+         \else
+             \let\lst@rangeend\lst@rangeendprefix
+             \lst@AddTo\lst@rangeend{#2}\lst@Extend\lst@rangeend\lst@rangeendsuffix
+         \fi
+     \fi
+%    \end{macrocode}
+% The following definition will be executed in the
+% \hookname{SelectCharTable} hook and here right now if we are already
+% processing a listing.
+%    \begin{macrocode}
+     \global\def\lst@DefRange{\expandafter\lst@CArgX\lst@rangebegin\relax\lst@DefRangeB}%
+     \ifnum\lst@mode=\lst@Pmode \expandafter\lst@DefRange \fi}}
+%    \end{macrocode}
+%    |\lst@DefRange| is not inserted via a hook anymore. Instead it is now called
+%    directly from |\lst@SelectCharTable|. This was necessary to get rid of an
+%    interference with the escape-to-LaTeX-feature. The bug was reported by
+%    \lsthelper{Michael~Bachmann}{2004/07/21}{Keine label-Referenzierung
+%    m\"oglich...}. Another chance is due to the same bug: |\lst@DefRange| is
+%    redefined globally when the begin of code is found, see below. The bug was
+%    reported by \lsthelper{Tobias~Rapp}{2004/04/06}{undetected end of range if
+%    listing crosses page break} and \lsthelper{Markus~Luisser}{2004/08/13}{Bug mit
+%    'linerangemarker' in umgebrochenen listings}.
+%    \begin{macrocode}
+\lst@AddToHookExe{DeInit}{\global\let\lst@DefRange\@empty}
+%    \end{macrocode}
+%
+% Actually defining the marker (via |\lst@GLI@|, |\lst@DefRange|,
+% |\lst@CArgX| as seen above) is similar to |\lst@DefDelimB|---except that
+% we unfold the first parameter and use different \meta{execute},
+% \meta{pre}, and \meta{post} statements.
+%    \begin{macrocode}
+\def\lst@DefRangeB#1#2{\lst@DefRangeB@#1#2}
+\def\lst@DefRangeB@#1#2#3#4{%
+    \lst@CDef{#1{#2}{#3}}#4{}%
+    {\lst@ifincluderangemarker
+         \lst@LeaveMode
+         \let#1#4%
+         \lst@DefRangeEnd
+         \lst@InitLstNumber
+     \else
+         \@tempcnta\lst@lineno \advance\@tempcnta\@ne
+         \edef\lst@firstline{\the\@tempcnta\relax}%
+         \gdef\lst@OnceAtEOL{\let#1#4\lst@DefRangeEnd}%
+         \lst@InitLstNumber
+     \fi
+	 \global\let\lst@DefRange\lst@DefRangeEnd
+     \lst@CArgEmpty}%
+    \@empty}
+%    \end{macrocode}
+%
+% Modify labels and define |\lst@InitLstNumber| used above according to an
+% error reported by
+% \lsthelper{Omair-Inam~Abdul-Matin}{2004/05/10}{experimental linerange
+% feature does not work with firstnumber}.
+%    \begin{macrocode}
+\def\lstpatch@labels{%
+\gdef\lst@SetFirstNumber{%
+    \ifx\lst@firstnumber\@undefined
+        \@tempcnta 0\csname\@lst no@\lst@intname\endcsname\relax
+        \ifnum\@tempcnta=\z@ \else
+            \lst@nololtrue
+            \advance\@tempcnta\lst@advancenumber
+            \edef\lst@firstnumber{\the\@tempcnta\relax}%
+        \fi
+    \fi}%
+}
+\def\lst@InitLstNumber{%
+     \global\c@lstnumber\lst@firstnumber
+     \global\advance\c@lstnumber\lst@advancenumber
+     \global\advance\c@lstnumber-\lst@advancelstnum
+     \ifx \lst@firstnumber\c@lstnumber
+         \global\advance\c@lstnumber-\lst@advancelstnum
+     \fi%
+%    \end{macrocode}
+% \lsthelper{Byron~K.~Boulton}{2013/11/21}{line numbers off by one}
+% reported, that the line numbers are off by one, if they are displayed when
+% a linerange is given by patterns and |includerangemarker=false| is
+% set. Adding this test corrects this behaviour.
+%    \begin{macrocode}
+     \lst@ifincluderangemarker\else%
+         \global\advance\c@lstnumber by 1%
+     \fi%
+     }
+%    \end{macrocode}
+%
+%    The end-marker is defined if and only if it's not empty. The definition is
+%    similar to |\lst@DefDelimE|---with the above exceptions and except that we
+%    define the re-entry point |\lst@DefRangeE@@| as it is defined in the new
+%    version of |\lst@MProcessListing| above.
+%    \begin{macrocode}
+\def\lst@DefRangeEnd{%
+    \ifx\lst@rangeend\@empty\else
+        \expandafter\lst@CArgX\lst@rangeend\relax\lst@DefRangeE
+    \fi}
+\def\lst@DefRangeE#1#2{\lst@DefRangeE@#1#2}
+\def\lst@DefRangeE@#1#2#3#4{%
+    \lst@CDef{#1#2{#3}}#4{}%
+    {\let#1#4%
+     \edef\lst@lastline{\the\lst@lineno\relax}%
+     \lst@DefRangeE@@}%
+    \@empty}
+\def\lst@DefRangeE@@#1\@empty{%
+    \lst@ifincluderangemarker
+        #1\lst@XPrintToken
+    \fi
+    \lst@LeaveModeToPmode
+    \lst@BeginDropInput{\lst@Pmode}}
+\def\lst@LeaveModeToPmode{%
+    \ifnum\lst@mode=\lst@Pmode
+        \expandafter\lsthk@EndGroup
+    \else
+        \expandafter\egroup\expandafter\lst@LeaveModeToPmode
+    \fi}
+%    \end{macrocode}
+%
+%    Eventually we shouldn't forget to install |\lst@OnceAtEOL|, which must
+%    also be called in |\lst@MSkipToFirst|.
+%    \begin{macrocode}
+\lst@AddToHook{EOL}{\lst@OnceAtEOL\global\let\lst@OnceAtEOL\@empty}
+\gdef\lst@OnceAtEOL{}% Init
+\def\lst@MSkipToFirst{%
+    \global\advance\lst@lineno\@ne
+    \ifnum \lst@lineno=\lst@firstline
+        \def\lst@next{\lst@LeaveMode \global\lst@newlines\z@
+        \lst@OnceAtEOL \global\let\lst@OnceAtEOL\@empty
+        \lst@InitLstNumber % Added to work with modified \lsthk@PreInit.
+        \lsthk@InitVarsBOL
+        \lst@BOLGobble}%
+        \expandafter\lst@next
+    \fi}
+\def\lst@SkipToFirst{%
+    \ifnum \lst@lineno<\lst@firstline
+        \def\lst@next{\lst@BeginDropInput\lst@Pmode
+        \lst@Let{13}\lst@MSkipToFirst
+        \lst@Let{10}\lst@MSkipToFirst}%
+        \expandafter\lst@next
+    \else
+        \expandafter\lst@BOLGobble
+    \fi}
+%    \end{macrocode}
+%
+%    Finally the service macro |\lst@IfNumber|:
+%    \begin{macrocode}
+\def\lst@IfNumber#1{%
+    \ifx\@empty#1\@empty
+        \let\lst@next\@firstoftwo
+    \else
+        \lst@IfNumber@#1\@nil
+    \fi
+    \lst@next}
+\def\lst@IfNumber@#1#2\@nil{%
+    \let\lst@next\@secondoftwo
+    \ifnum`#1>47\relax \ifnum`#1>57\relax\else
+        \let\lst@next\@firstoftwo
+    \fi\fi}
+%    \end{macrocode}
+%
+% \begin{lstkey}{nolol}
+% is just a key here. We'll use it below, of course.
+%    \begin{macrocode}
+\lst@Key{nolol}{false}[t]{\lstKV@SetIf{#1}\lst@ifnolol}
+\def\lst@nololtrue{\let\lst@ifnolol\iftrue}
+\let\lst@ifnolol\iffalse % init
+%    \end{macrocode}
+% \end{lstkey}
+%
+%
+% \subsection{Floats, boxes and captions}
+%
+% \begin{lstkey}{captionpos}
+% \begin{lstkey}{abovecaptionskip}
+% \begin{lstkey}{belowcaptionskip}
+% \begin{lstkey}{label}
+% \begin{lstkey}{title}
+% \begin{lstkey}{caption}
+% Some keys and \ldots
+%    \begin{macrocode}
+\lst@Key{captionpos}{t}{\def\lst@captionpos{#1}}
+\lst@Key{abovecaptionskip}\smallskipamount{\def\lst@abovecaption{#1}}
+\lst@Key{belowcaptionskip}\smallskipamount{\def\lst@belowcaption{#1}}
+%    \end{macrocode}
+% \lsthelper{Rolf~Niepraschk}{2000/01/10}{key: title} proposed \keyname{title}.
+%    \begin{macrocode}
+\lst@Key{label}\relax{\def\lst@label{#1}}
+\lst@Key{title}\relax{\def\lst@title{#1}\let\lst@caption\relax}
+\lst@Key{caption}\relax{\lstKV@OptArg[{#1}]{#1}%
+    {\def\lst@caption{##2}\def\lst@@caption{##1}}%
+     \let\lst@title\@empty}
+\lst@AddToHookExe{TextStyle}
+    {\let\lst@caption\@empty \let\lst@@caption\@empty
+     \let\lst@title\@empty \let\lst@label\@empty}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\thelstlisting}
+% \begin{macro}{\lstlistingname}
+% \begin{lstkey}{numberbychapter}
+% \ldots\space and how the caption numbers look like. I switched to
+% |\@ifundefined| (instead of |\ifx| |\@undefined|) after an error report from
+% \lsthelper{Denis~Girou}{1999/07/26}{incompatible if hyperref loaded before
+% listings}.
+%
+% This is set |\AtBeginDocument| so that the user can specify whether or not
+% the counter should be reset at each chapter before the counter is defined,
+% using the |numberbychapter| key.
+%    \begin{macrocode}
+\AtBeginDocument{
+  \@ifundefined{thechapter}{\let\lst@ifnumberbychapter\iffalse}{}
+  \lst@ifnumberbychapter
+      \newcounter{lstlisting}[chapter]
+      \gdef\thelstlisting%
+           {\ifnum \c@chapter>\z@ \thechapter.\fi \@arabic\c@lstlisting}
+  \else
+      \newcounter{lstlisting}
+      \gdef\thelstlisting{\@arabic\c@lstlisting}
+  \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@UserCommand\lstlistingname{Listing}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{numberbychapter}{true}[t]{\lstKV@SetIf{#1}\lst@ifnumberbychapter}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@MakeCaption}
+% Before defining this macro, we ensure that some other control sequences
+% exist---\lsthelper{Adam~Prugel-Bennett}{2001/02/19}{\abovecaptionskip
+% undefined in slides.cls} reported problems with the slides document class.
+% In particular we allocate above- and belowcaption skip registers and define
+% |\@makecaption|, which is an exact copy of the definition in the article
+% class. To respect the LPPL: you should have a copy of this class on your
+% \TeX\ system or you can obtain a copy from the CTAN, e.g.~from the ftp-server
+% \texttt{ftp.dante.de}.
+%
+% Axel Sommerfeldt proposed a couple of improvements regarding captions and
+% titles. The first is to separate the definitions of the skip registers and
+% |\@makecaption|.
+%    \begin{macrocode}
+\@ifundefined{abovecaptionskip}
+{\newskip\abovecaptionskip
+ \newskip\belowcaptionskip}{}
+\@ifundefined{@makecaption}
+{\long\def\@makecaption#1#2{%
+   \vskip\abovecaptionskip
+   \sbox\@tempboxa{#1: #2}%
+   \ifdim \wd\@tempboxa >\hsize
+     #1: #2\par
+   \else
+     \global \@minipagefalse
+     \hb@xt@\hsize{\hfil\box\@tempboxa\hfil}%
+   \fi
+   \vskip\belowcaptionskip}%
+}{}
+%    \end{macrocode}
+% The introduction of |\fnum@lstlisting| is also due to Axel. Previously the
+% replacement text was used directly in |\lst@MakeCaption|. A |\noindent| has
+% been moved elsewhere and became |\@parboxrestore| after a bug report from
+% \lsthelper{Frank~Mittelbach}{2004/02/13}{Re: Info: Inkompatibilit\"at
+% zwischen caption und listings}.
+%    \begin{macrocode}
+\def\fnum@lstlisting{%
+  \lstlistingname
+  \ifx\lst@@caption\@empty\else~\thelstlisting\fi}%
+%    \end{macrocode}
+% Captions are set only for display style listings -- thanks to
+% \lsthelper{Peter~L\"offler}{2004/04/24}{pdfTeX warning (dest): name{figure.1}
+% has been referenced but does not exist} for reporting the bug and to
+% \lsthelper{Axel~Sommerfeldt}{2004/02/27}{Re: caption + listings + hyperref}
+% for analyzing the bug.
+% We |\refstepcounter| the listing counter if and only if |\lst@@caption| is
+% not empty. Otherwise we ensure correct hyper-references,
+% see |\lst@HRefStepCounter| below. We do this once a listing, namely at the
+% top.
+%    \begin{macrocode}
+\def\lst@MakeCaption#1{%
+  \lst@ifdisplaystyle
+    \ifx #1t%
+        \ifx\lst@@caption\@empty\expandafter\lst@HRefStepCounter \else
+                                \expandafter\refstepcounter
+        \fi {lstlisting}%
+        \ifx\lst@label\@empty\else \label{\lst@label}\fi
+%    \end{macrocode}
+% The following code has been moved here from the \hookname{Init} hook after
+% a bug report from \lsthelper{Rolf~Niepraschk}{2003/06/11}{pagebreak between
+% caption and listing}. Moreover the initialization of |\lst@name| et al have
+% been inserted here after a bug report from \lsthelper{Werner~Struckmann}
+% {2003/06/25}{undefined control sequence \lst@name}.
+% We make a `lol' entry if the name is neither empty nor a single space. But
+% we test |\lst@|(|@|)|caption| and |\lst@ifnolol| first.
+%    \begin{macrocode}
+        \let\lst@arg\lst@intname \lst@ReplaceIn\lst@arg\lst@filenamerpl
+        \global\let\lst@name\lst@arg \global\let\lstname\lst@name
+        \lst@ifnolol\else
+            \ifx\lst@@caption\@empty
+                \ifx\lst@caption\@empty
+                    \ifx\lst@intname\@empty \else \def\lst@temp{ }%
+                    \ifx\lst@intname\lst@temp \else
+                        \addcontentsline{lol}{lstlisting}\lst@name
+                    \fi\fi
+                \fi
+            \else
+                \addcontentsline{lol}{lstlisting}%
+                    {\protect\numberline{\thelstlisting}\lst@@caption}%
+            \fi
+         \fi
+     \fi
+%    \end{macrocode}
+% We make a caption if and only if the caption is not empty and the user
+% requested a caption at |#1| $\in\{\mathtt t,\mathtt b\}$. To disallow
+% pagebreaks between caption (or title) and a listing, we redefine the
+% primitive |\vskip| locally to insert |\nobreak|s. Note that we allow
+% pagebreaks in front of a `top-caption' and after a `bottom-caption'.
+% Also, the |\ignorespaces| in the |\@makecaption| call is added to match
+% what \LaTeX\ does in |\@caption|; the AMSbook class (and perhaps others)
+% assume this is present and attempt to strip it off when testing for an
+% empty caption, causing a bug noted by \lsthelper{Xiaobo~Peng}{2006/06/29}%
+% {captions not shown with amsbook class}.
+% \begin{TODO}
+% This redefinition is a brute force method. Is there a better one?
+% \end{TODO}
+%    \begin{macrocode}
+    \ifx\lst@caption\@empty\else
+        \lst@IfSubstring #1\lst@captionpos
+            {\begingroup \let\@@vskip\vskip
+             \def\vskip{\afterassignment\lst@vskip \@tempskipa}%
+             \def\lst@vskip{\nobreak\@@vskip\@tempskipa\nobreak}%
+             \par\@parboxrestore\normalsize\normalfont % \noindent (AS)
+             \ifx #1t\allowbreak \fi
+             \ifx\lst@title\@empty
+                 \lst@makecaption\fnum@lstlisting{\ignorespaces \lst@caption}
+             \else
+                 \lst@maketitle\lst@title % (AS)
+             \fi
+             \ifx #1b\allowbreak \fi
+             \endgroup}{}%
+    \fi
+  \fi}
+%    \end{macrocode}
+% I've inserted |\normalsize| after a bug report from
+% \lsthelper{Andreas~Matthias}{2000/01/04}{caption affected by basicstyle}
+% and moved it in front of |\@makecaption| after receiving another from
+% \lsthelper{Sonja~Weidmann}{2000/02/01}{listings and caption packages
+% not compatible}.
+% \end{macro}
+%
+% \begin{macro}{\lst@makecaption}
+% \begin{macro}{\lst@maketitle}
+% Axel proposed the first definition. The other two are default definitions.
+% They may be adjusted to make \packagename{listings} compatible with other
+% packages and classes.
+%    \begin{macrocode}
+\def\lst@makecaption{\@makecaption}
+\def\lst@maketitle{\@makecaption\lst@title@dropdelim}
+\def\lst@title@dropdelim#1{\ignorespaces}
+%    \end{macrocode}
+% The following \packagename{caption}(\packagename{2}) support comes also from
+% Axel.
+%    \begin{macrocode}
+\AtBeginDocument{%
+\@ifundefined{captionlabelfalse}{}{%
+  \def\lst@maketitle{\captionlabelfalse\@makecaption\@empty}}%
+\@ifundefined{caption@startrue}{}{%
+  \def\lst@maketitle{\caption@startrue\@makecaption\@empty}}%
+}
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{macro}{\lst@HRefStepCounter}
+% This macro sets the listing number to a negative value since the user
+% shouldn't refer to such a listing. If the \packagename{hyperref} package
+% is present, we use `lstlisting' (argument from above) to hyperref to.
+% The groups have been added to prevent other packages (namely
+% \packagename{tabularx}) from reading the locally changed counter
+% and writing it back globally. Thanks to \lsthelper{Michael~Niedermair}
+% {2001/09/18}{strange numbering of listings} for the report. Unfortunately
+% this localization led to another bug, see |\theHlstnumber|.
+%    \begin{macrocode}
+\def\lst@HRefStepCounter#1{%
+    \begingroup
+    \c@lstlisting\lst@neglisting
+    \advance\c@lstlisting\m@ne \xdef\lst@neglisting{\the\c@lstlisting}%
+    \ifx\hyper@refstepcounter\@undefined\else
+        \hyper@refstepcounter{#1}%
+    \fi
+    \endgroup}
+\gdef\lst@neglisting{\z@}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{boxpos}
+% \begin{macro}{\lst@boxtrue}
+% sets the vertical alignment of the (possibly) used box respectively indicates
+% that a box is used.
+%    \begin{macrocode}
+\lst@Key{boxpos}{c}{\def\lst@boxpos{#1}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\lst@boxtrue{\let\lst@ifbox\iftrue}
+\let\lst@ifbox\iffalse
+%    \end{macrocode}
+% \end{macro}\end{lstkey}
+%
+% \begin{lstkey}{float}
+% \begin{lstkey}{floatplacement}
+% Matthias Zenger asked for double-column floats, so I've inserted some code.
+% We first check for a star \ldots
+%    \begin{macrocode}
+\lst@Key{float}\relax[\lst@floatplacement]{%
+    \lstKV@SwitchCases{#1}%
+    {true:\let\lst@floatdefault\lst@floatplacement
+          \let\lst@float\lst@floatdefault\\%
+     false:\let\lst@floatdefault\relax
+           \let\lst@float\lst@floatdefault
+    }{\def\lst@next{\@ifstar{\let\lst@beginfloat\@dblfloat
+                             \let\lst@endfloat\end@dblfloat
+                             \lst@KFloat}%
+                            {\let\lst@beginfloat\@float
+                             \let\lst@endfloat\end@float
+                             \lst@KFloat}}
+      \edef\lst@float{#1}%
+      \expandafter\lst@next\lst@float\relax}}
+%    \end{macrocode}
+% \ldots\ and define |\lst@float|.
+%    \begin{macrocode}
+\def\lst@KFloat#1\relax{%
+    \ifx\@empty#1\@empty
+        \let\lst@float\lst@floatplacement
+    \else
+        \def\lst@float{#1}%
+    \fi}
+%    \end{macrocode}
+% The setting |\lst@AddToHook{PreSet}{\let\lst@float\relax}| has been
+% changed on request of \lsthelper{Tanguy~Fautr\'e}{2004/02/02}{listings
+% not following float directive?}. This also led to some adjustments above.
+%    \begin{macrocode}
+\lst@Key{floatplacement}{tbp}{\def\lst@floatplacement{#1}}
+\lst@AddToHook{PreSet}{\let\lst@float\lst@floatdefault}
+\lst@AddToHook{TextStyle}{\let\lst@float\relax}
+\let\lst@floatdefault\relax % init
+%    \end{macrocode}
+% |\lst@doendpe| is set according to |\lst@float| -- thanks to
+% \lsthelper{Andreas~Schmidt}{2004/05/15}{wrong spacing when a floating listing
+% follows \section} and \lsthelper{Heiko~Oberdiek}{2004/05/18}{dito}.
+%    \begin{macrocode}
+\lst@AddToHook{DeInit}{%
+    \ifx\lst@float\relax
+        \global\let\lst@doendpe\@doendpe
+    \else
+        \global\let\lst@doendpe\@empty
+    \fi}
+%    \end{macrocode}
+% The float type |\ftype@lstlisting| is set according to whether the
+% \packagename{float} package is loaded and whether \texttt{figure} and
+% \texttt{table} floats are defined. This is done at |\begin{document}| to
+% make the code independent of the order of package loading.
+%    \begin{macrocode}
+\AtBeginDocument{%
+\@ifundefined{c@float@type}%
+    {\edef\ftype@lstlisting{\ifx\c@figure\@undefined 1\else 4\fi}}
+    {\edef\ftype@lstlisting{\the\c@float@type}%
+     \addtocounter{float@type}{\value{float@type}}}%
+}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+%
+% \subsection{Init and EOL}
+%
+% \begin{lstkey}{aboveskip}
+% \begin{lstkey}{belowskip}
+% We define and initialize these keys and prevent extra spacing for `inline'
+% listings (in particular if \packagename{fancyvrb} interface is active,
+% problem reported by \lsthelper{Denis~Girou}{1999/08/03}{wrong spacing}).
+%    \begin{macrocode}
+\lst@Key{aboveskip}\medskipamount{\def\lst@aboveskip{#1}}
+\lst@Key{belowskip}\medskipamount{\def\lst@belowskip{#1}}
+\lst@AddToHook{TextStyle}
+    {\let\lst@aboveskip\z@ \let\lst@belowskip\z@}
+%    \end{macrocode}
+% \end{lstkey}\end{lstkey}
+%
+% \begin{lstkey}{everydisplay}
+% \begin{macro}{\lst@ifdisplaystyle}
+% Some things depend on display-style listings.
+%    \begin{macrocode}
+\lst@Key{everydisplay}{}{\def\lst@EveryDisplay{#1}}
+\lst@AddToHook{TextStyle}{\let\lst@ifdisplaystyle\iffalse}
+\lst@AddToHook{DisplayStyle}{\let\lst@ifdisplaystyle\iftrue}
+\let\lst@ifdisplaystyle\iffalse
+%    \end{macrocode}
+% \end{macro}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@Init}
+% Begin a float or multicolumn environment if requested.
+%    \begin{macrocode}
+\def\lst@Init#1{%
+    \begingroup
+    \ifx\lst@float\relax\else
+        \edef\@tempa{\noexpand\lst@beginfloat{lstlisting}[\lst@float]}%
+        \expandafter\@tempa
+    \fi
+    \ifx\lst@multicols\@empty\else
+        \edef\lst@next{\noexpand\multicols{\lst@multicols}}
+        \expandafter\lst@next
+    \fi
+%    \end{macrocode}
+% In restricted horizontal \TeX\ mode we switch to |\lst@boxtrue|.
+% In that case we make appropriate box(es) around the listing.
+%    \begin{macrocode}
+    \ifhmode\ifinner \lst@boxtrue \fi\fi
+    \lst@ifbox
+        \lsthk@BoxUnsafe
+        \hbox to\z@\bgroup
+             $\if t\lst@boxpos \vtop
+        \else \if b\lst@boxpos \vbox
+        \else \vcenter \fi\fi
+        \bgroup \par\noindent
+    \else
+        \lst@ifdisplaystyle
+            \lst@EveryDisplay
+            \par\penalty-50\relax
+            \vspace\lst@aboveskip
+        \fi
+    \fi
+%    \end{macrocode}
+% Moved |\vspace| after |\par|---or we can get an empty line atop listings.
+% Bug reported by \lsthelper{Jim~Hefferon}{1999/08/27}{empty line before
+% listings with |\lstinputlisting|}.
+%
+% Now make the top caption.
+%    \begin{macrocode}
+    \normalbaselines
+    \abovecaptionskip\lst@abovecaption\relax
+    \belowcaptionskip\lst@belowcaption\relax
+    \lst@MakeCaption t%
+%    \end{macrocode}
+% Some initialization.
+% I removed |\par\nointerlineskip| |\normalbaselines| after bug report from
+% \lsthelper{Jim~Hefferon}{1999/08/23}{bad vertical space after lstlisting}.
+% He reported the same problem as Aidan Philip Heerdegen (see below), but I
+% immediately saw the bug here since Jim used |\parskip|$\,\neq0$.
+%    \begin{macrocode}
+    \lsthk@PreInit \lsthk@Init
+    \lst@ifdisplaystyle
+        \global\let\lst@ltxlabel\@empty
+        \if@inlabel
+            \lst@ifresetmargins
+                \leavevmode
+            \else
+                \xdef\lst@ltxlabel{\the\everypar}%
+                \lst@AddTo\lst@ltxlabel{%
+                    \global\let\lst@ltxlabel\@empty
+                    \everypar{\lsthk@EveryLine\lsthk@EveryPar}}%
+            \fi
+        \fi
+        \everypar\expandafter{\lst@ltxlabel
+                              \lsthk@EveryLine\lsthk@EveryPar}%
+    \else
+        \everypar{}\let\lst@NewLine\@empty
+    \fi
+    \lsthk@InitVars \lsthk@InitVarsBOL
+%    \end{macrocode}
+% The end of line character chr(13)=|^^M| controls the processing, see the
+% definition of |\lst@MProcessListing| below.
+% The argument |#1| is either |\relax| or |\lstenv@backslash|.
+%    \begin{macrocode}
+    \lst@Let{13}\lst@MProcessListing
+    \let\lst@Backslash#1%
+    \lst@EnterMode{\lst@Pmode}{\lst@SelectCharTable}%
+    \lst@InitFinalize}
+%    \end{macrocode}
+% Note: From version 0.19 on `listing processing' is implemented as an internal
+% mode, namely a mode with special character table. Since a bug report from
+% \lsthelper{Fermin~Reig}{2002/09/04}{bad top frame inside figure+centering}
+% |\rightskip| and the others are reset via \hookname{PreInit} and not via
+% \hookname{InitVars}.
+%    \begin{macrocode}
+\let\lst@InitFinalize\@empty % init
+\lst@AddToHook{PreInit}
+    {\rightskip\z@ \leftskip\z@ \parfillskip=\z@ plus 1fil
+     \let\par\@@par}
+\lst@AddToHook{EveryLine}{}% init
+\lst@AddToHook{EveryPar}{}% init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{showlines}
+% lets the user control whether empty lines at the end of a listing are
+% printed. But you know that if you've read the User's guide.
+%    \begin{macrocode}
+\lst@Key{showlines}f[t]{\lstKV@SetIf{#1}\lst@ifshowlines}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@DeInit}
+% Output the remaining characters and update all things. First I missed to
+% to use |\lst@ifdisplaystyle| here, but then \lsthelper{KP~Gores}{2001/07/11}
+% {\csname{par} after each \lstinline} reported a problem.
+% The |\everypar| has been put behind |\lsthk@ExitVars| after a bug report by
+% \lsthelper{Michael~Niedermair}{2002/05/14}{listings.sty und caption} and
+% I've added |\normalbaselines| after a bug report by \lsthelper{Georg~Rehm}
+% {2002/05/14}{listings.sty und lange captions} and |\normalcolor| after a
+% report by \lsthelper{Walter~E.~Brown}{2004/03/01}{captions at bottom of
+% listings inherit color from basicstyle}.
+%    \begin{macrocode}
+\def\lst@DeInit{%
+    \lst@XPrintToken \lst@EOLUpdate
+    \global\advance\lst@newlines\m@ne
+    \lst@ifshowlines
+        \lst@DoNewLines
+    \else
+        \setbox\@tempboxa\vbox{\lst@DoNewLines}%
+    \fi
+    \lst@ifdisplaystyle \par\removelastskip \fi
+    \lsthk@ExitVars\everypar{}\lsthk@DeInit\normalbaselines\normalcolor
+%    \end{macrocode}
+% Place the bottom caption.
+%    \begin{macrocode}
+    \lst@MakeCaption b%
+%    \end{macrocode}
+% Close the boxes if necessary and make a rule to get the right width.
+% I added the |\par\nointerlineskip| (and removed |\nointerlineskip| later
+% again) after receiving a bug report from \lsthelper{Aidan~Philip~Heerdegen}
+% {1999/07/23}{wrong vertical spacing}. |\everypar{}| is due to a bug report
+% from \lsthelper{Sonja~Weidmann}{2000/02/01}{listings and caption packages
+% not compatible}.
+%    \begin{macrocode}
+    \lst@ifbox
+        \egroup $\hss \egroup
+        \vrule\@width\lst@maxwidth\@height\z@\@depth\z@
+    \else
+        \lst@ifdisplaystyle
+            \par\penalty-50\vspace\lst@belowskip
+        \fi
+    \fi
+%    \end{macrocode}
+% End the multicolumn environment and/or float if necessary.
+%    \begin{macrocode}
+    \ifx\lst@multicols\@empty\else
+        \def\lst@next{\global\let\@checkend\@gobble
+                      \endmulticols
+                      \global\let\@checkend\lst@@checkend}
+        \expandafter\lst@next
+    \fi
+    \ifx\lst@float\relax\else
+        \expandafter\lst@endfloat
+    \fi
+    \endgroup}
+\let\lst@@checkend\@checkend
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@maxwidth}
+% is to be allocated, initialized and updated.
+%    \begin{macrocode}
+\newdimen\lst@maxwidth % \global
+\lst@AddToHook{InitVars}{\global\lst@maxwidth\z@}
+\lst@AddToHook{InitVarsEOL}
+    {\ifdim\lst@currlwidth>\lst@maxwidth
+         \global\lst@maxwidth\lst@currlwidth
+     \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EOLUpdate}
+% What do you think this macro does?
+%    \begin{macrocode}
+\def\lst@EOLUpdate{\lsthk@EOL \lsthk@InitVarsEOL}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@MProcessListing}
+% This is what we have to do at EOL while processing a listing.
+% We output all remaining characters and update the variables.
+% If we've reached the last line, we check whether there is a next line
+% interval to input or not.
+%    \begin{macrocode}
+\def\lst@MProcessListing{%
+    \lst@XPrintToken \lst@EOLUpdate \lsthk@InitVarsBOL
+    \global\advance\lst@lineno\@ne
+    \ifnum \lst@lineno>\lst@lastline
+        \lst@ifdropinput \lst@LeaveMode \fi
+        \ifx\lst@linerange\@empty
+            \expandafter\expandafter\expandafter\lst@EndProcessListing
+        \else
+            \lst@interrange
+            \lst@GetLineInterval
+            \expandafter\expandafter\expandafter\lst@SkipToFirst
+        \fi
+    \else
+        \expandafter\lst@BOLGobble
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@EndProcessListing}
+% Default definition is |\endinput|.
+% This works for |\lstinputlisting|.
+%    \begin{macrocode}
+\let\lst@EndProcessListing\endinput
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{gobble}
+% The key sets the number of characters to gobble each line.
+%    \begin{macrocode}
+\lst@Key{gobble}{0}{\def\lst@gobble{#1}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@BOLGobble}
+% If the number is positive, we set a temporary counter and start a loop.
+%    \begin{macrocode}
+\def\lst@BOLGobble{%
+    \ifnum\lst@gobble>\z@
+        \@tempcnta\lst@gobble\relax
+        \expandafter\lst@BOLGobble@
+	\fi}
+%    \end{macrocode}
+% A nonpositive number terminates the loop (by not continuing).
+% Note: This is not the macro just used in |\lst@BOLGobble|.
+%    \begin{macrocode}
+\def\lst@BOLGobble@@{%
+    \ifnum\@tempcnta>\z@
+        \expandafter\lst@BOLGobble@
+    \fi}
+%    \end{macrocode}
+% If we gobble a backslash, we have to look whether this backslash ends an
+% environment. Whether the coming characters equal e.g.~|end{lstlisting}|,
+% we either end the environment or insert all just eaten characters after the
+% `continue loop' macro.
+%    \begin{macrocode}
+\def\lstenv@BOLGobble@@{%
+    \lst@IfNextChars\lstenv@endstring{\lstenv@End}%
+    {\advance\@tempcnta\m@ne \expandafter\lst@BOLGobble@@\lst@eaten}}
+%    \end{macrocode}
+% Now comes the loop: if we read |\relax|, EOL or FF, the next operation is
+% exactly the same token. Note that for FF (and tabs below) we test against
+% a macro which contains |\lst@ProcessFormFeed|. This was a bug analyzed by
+% \lsthelper{Heiko~Oberdiek}{2002/04/16}{Re: first experience ...}.
+%    \begin{macrocode}
+\def\lst@BOLGobble@#1{%
+    \let\lst@next#1%
+    \ifx \lst@next\relax\else
+    \ifx \lst@next\lst@MProcessListing\else
+    \ifx \lst@next\lst@processformfeed\else
+%    \end{macrocode}
+% Otherwise we use one of the two submacros.
+%    \begin{macrocode}
+    \ifx \lst@next\lstenv@backslash
+        \let\lst@next\lstenv@BOLGobble@@
+    \else
+        \let\lst@next\lst@BOLGobble@@
+%    \end{macrocode}
+% Now we really gobble characters. A tabulator decreases the temporary counter
+% by |\lst@tabsize| (and deals with remaining amounts, if necessary), \ldots
+%    \begin{macrocode}
+        \ifx #1\lst@processtabulator
+            \advance\@tempcnta-\lst@tabsize\relax
+            \ifnum\@tempcnta<\z@
+                \lst@length-\@tempcnta \lst@PreGotoTabStop
+            \fi
+%    \end{macrocode}
+% \ldots\space whereas any other character decreases the counter by one.
+%    \begin{macrocode}
+        \else
+            \advance\@tempcnta\m@ne
+        \fi
+    \fi \fi \fi \fi
+    \lst@next}
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\lst@processformfeed{\lst@ProcessFormFeed}
+\def\lst@processtabulator{\lst@ProcessTabulator}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{List of listings}
+%
+% \begin{lstkey}{name}
+% \begin{macro}{\lstname}
+% \begin{macro}{\lst@name}
+% \begin{macro}{\lst@intname}
+% Each pretty-printing command values |\lst@intname| before setting any keys.
+%    \begin{macrocode}
+\lst@Key{name}\relax{\def\lst@intname{#1}}
+\lst@AddToHookExe{PreSet}{\global\let\lst@intname\@empty}
+\lst@AddToHook{PreInit}{%
+    \let\lst@arg\lst@intname \lst@ReplaceIn\lst@arg\lst@filenamerpl
+    \global\let\lst@name\lst@arg \global\let\lstname\lst@name}
+%    \end{macrocode}
+% Use of |\lst@ReplaceIn| removes a bug first reported by
+% \lsthelper{Magne~Rudshaug}{1998/01/09}{_ and list of listings}.
+% Here is the replacement list.
+%    \begin{macrocode}
+\def\lst@filenamerpl{_\textunderscore $\textdollar -\textendash}
+%    \end{macrocode} ^^A $
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{lstkey}
+%
+% \begin{macro}{\l@lstlisting}
+% prints one `lol' line.
+%    \begin{macrocode}
+\def\l@lstlisting#1#2{\@dottedtocline{1}{1.5em}{2.3em}{#1}{#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstlistlistingname}
+% contains simply the header name.
+%    \begin{macrocode}
+\lst@UserCommand\lstlistlistingname{Listings}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstlistoflistings}
+% We make local adjustments and call |\tableofcontents|. This way,
+% redefinitions of that macro (e.g.~without any |\MakeUppercase| inside)
+% also take effect on the list of listings.
+%    \begin{macrocode}
+\lst@UserCommand\lstlistoflistings{\bgroup
+    \let\contentsname\lstlistlistingname
+    \let\lst@temp\@starttoc \def\@starttoc##1{\lst@temp{lol}}%
+    \tableofcontents \egroup}
+%    \end{macrocode}
+% For KOMA-script classes, we define it a la KOMA thanks to a bug report by
+% \lsthelper{Tino~Langer}{2003/11/01}{koma-script's listsleft option does not
+% affect lol}.  \lsthelper{Markus~Kohm}{2006/08/12}{koma-script support is
+% broken} suggested a much-improved version of this, which also works with
+% the \packagename{float} package.  The following few comments are from Markus.
+%
+% Make use of |\float@listhead| if defined (e.g. using float or KOMA-Script)
+%    \begin{macrocode}
+\@ifundefined{float@listhead}{}{%
+  \renewcommand*{\lstlistoflistings}{%
+    \begingroup
+%    \end{macrocode}
+% Switch to one-column mode if the switch for switching is available.
+%    \begin{macrocode}
+      \@ifundefined{@restonecoltrue}{}{%
+        \if@twocolumn
+          \@restonecoltrue\onecolumn
+        \else
+          \@restonecolfalse
+        \fi
+      }%
+      \float@listhead{\lstlistlistingname}%
+%    \end{macrocode}
+% Set |\parskip| to 0pt (should be!), |\parindent| to 0pt (better but not always
+% needed), |\parfillskip| to 0pt plus 1fil (should be!).
+%    \begin{macrocode}
+      \parskip\z@\parindent\z@\parfillskip \z@ \@plus 1fil%
+      \@starttoc{lol}%
+%    \end{macrocode}
+% Switch back to twocolumn (see above).
+%    \begin{macrocode}
+      \@ifundefined{@restonecoltrue}{}{%
+        \if@restonecol\twocolumn\fi
+      }%
+    \endgroup
+  }%
+}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\float@addtolists}
+% The \packagename{float} package defines a generic way for packages to add
+% things (such as chapter names) to all of the lists of floats other than the
+% standard figure and table lists.  Each package that defines a list of
+% floats adds a command to |\float@addtolists|, and then packages (such as
+% the KOMA-script document classes) which wish to add things to all lists of
+% floats can then use it, without needing to be aware of all of the possible
+% lists that could exist.  Thanks to \lsthelper{Markus~Kohm}{2007/02/25}{-}
+% for the suggestion.
+%
+% Unfortunately, \packagename{float} defines this with |\newcommand|; thus,
+% to avoid conflict, we have to redefine it after \packagename{float} is
+% loaded.  |\AtBeginDocument| is the easiest way to do this.  Again, thanks
+% to Markus for the advice.
+%    \begin{macrocode}
+\AtBeginDocument{%
+  \@ifundefined{float@addtolists}%
+    {\gdef\float@addtolists#1{\addtocontents{lol}{#1}}}%
+    {\let\orig@float@addtolists\float@addtolists
+     \gdef\float@addtolists#1{%
+       \addtocontents{lol}{#1}%
+       \orig@float@addtolists{#1}}}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Inline listings}\label{iInlineListings}
+%
+% \subsubsection{Processing inline listings}\label{uProcessingInline}
+%
+% \begin{macro}{\lstinline}
+% In addition to |\lsthk@PreSet|, we use |boxpos=b| and flexiblecolumns.
+% I've inserted |\leavevmode| after bug report from \lsthelper{Michael~Weber}
+% {1999/12/16}{wrong spacing in list environments}. \lsthelper{Olivier~Lecarme}
+% {2001/07/30}{inconsistent `break' when \lstinline is used inside caption}
+% reported a problem which has gone after removing |\let| |\lst@newlines|
+% |\@empty| (now |\lst@newlines| is a counter!). Unfortunately I don't know
+% the reason for inserting this code some time ago! At the end of the macro we
+% check the delimiter.
+%    \begin{macrocode}
+\newcommand\lstinline[1][]{%
+    \leavevmode\bgroup % \hbox\bgroup --> \bgroup
+      \def\lst@boxpos{b}%
+      \lsthk@PreSet\lstset{flexiblecolumns,#1}%
+      \lsthk@TextStyle
+      \@ifnextchar\bgroup{%
+%    \end{macrocode}
+% \lsthelper{Luc~Van~Eycken}{2014/01/22}{Luc.VanEycken@esat.kuleuven.be}
+% reported, that the experimental implementation of |\lstinline| with
+% braces instead of characters surrounding the source code resulted in an
+% error if used in a tabular environment. He found that this error comes
+% from the master counter (cf. appendix D (Dirty Tricks), item 5. (Brace
+% hacks), of the TeXbook (p. 385-386)). Adding the following line at this
+% point
+%\begin{verbatim}
+%         \ifnum`{=0}\fi%
+%\end{verbatim}
+% remedies the wrong behaviour. But \lsthelper{Qing Lee}{2014/06/28}{-}
+% pointed out, that this breaks code like the one showed in
+% \ref{uListingsArguments} on \pageref{uListingsArguments} and proposed
+% another solution which in turn broke the code needed by Luc:
+%\begin{verbatim}
+% % \renewcommand\lstinline[1][]{%
+% %   \leavevmode\bgroup % \hbox\bgroup --> \bgroup
+% %   \def\lst@boxpos{b}%
+% %   \lsthk@PreSet\lstset{flexiblecolumns,#1}%
+% %   \lsthk@TextStyle
+% %   \ifnum\iffalse{\fi`}=\z@\fi
+% %   \@ifnextchar\bgroup{%
+% %     \ifnum`{=\z@}\fi%
+% %     \afterassignment\lst@InlineG \let\@let@token}{%
+% %     \ifnum`{=\z@}\fi\lstinline@}}
+%\end{verbatim}
+% So finally the old code comes back and the people, who need a
+% |\lstinline| with braces, should use the workaround from section
+% \ref{uListingsArguments} on page \pageref{uListingsArguments}.
+%    \begin{macrocode}
+        \afterassignment\lst@InlineG \let\@let@token}%
+                         \lstinline@}
+\def\lstinline@#1{%
+    \lst@Init\relax
+    \lst@IfNextCharActive{\lst@InlineM#1}{\lst@InlineJ#1}}
+\lst@AddToHook{TextStyle}{}% init
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@AddToHook{SelectCharTable}{\lst@inlinechars}
+\global\let\lst@inlinechars\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InlineM}
+% \begin{macro}{\lst@InlineJ}
+% treat the cases of `normal' inlines and inline listings inside an argument.
+% In the first case the given character ends the inline listing and EOL within
+% such a listing immediately ends it and produces an error message.
+%    \begin{macrocode}
+\def\lst@InlineM#1{\gdef\lst@inlinechars{%
+    \lst@Def{`#1}{\lst@DeInit\egroup\global\let\lst@inlinechars\@empty}%
+    \lst@Def{13}{\lst@DeInit\egroup \global\let\lst@inlinechars\@empty
+        \PackageError{Listings}{lstinline ended by EOL}\@ehc}}%
+    \lst@inlinechars}
+%    \end{macrocode}
+% In the other case we get all characters up to |#1|, make these characters
+% active, execute (typeset) them and end the listing (all via temporary macro).
+% That's all about it.
+%    \begin{macrocode}
+\def\lst@InlineJ#1{%
+    \def\lst@temp##1#1{%
+        \let\lst@arg\@empty \lst@InsideConvert{##1}\lst@arg
+        \lst@DeInit\egroup}%
+    \lst@temp}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lst@InlineG}
+% is experimental.
+%    \begin{macrocode}
+\def\lst@InlineG{%
+    \lst@Init\relax
+    \lst@IfNextCharActive{\lst@InlineM\}}%
+                         {\let\lst@arg\@empty \lst@InlineGJ}}
+\def\lst@InlineGJ{\futurelet\@let@token\lst@InlineGJTest}
+\def\lst@InlineGJTest{%
+    \ifx\@let@token\egroup
+        \afterassignment\lst@InlineGJEnd
+        \expandafter\let\expandafter\@let@token
+    \else
+        \ifx\@let@token\@sptoken
+            \let\lst@next\lst@InlineGJReadSp
+        \else
+            \let\lst@next\lst@InlineGJRead
+        \fi
+        \expandafter\lst@next
+    \fi}
+\def\lst@InlineGJEnd{\lst@arg\lst@DeInit\egroup}
+\def\lst@InlineGJRead#1{%
+    \lccode`\~=`#1\lowercase{\lst@lAddTo\lst@arg~}%
+    \lst@InlineGJ}
+\def\lst@InlineGJReadSp#1{%
+    \lccode`\~=`\ \lowercase{\lst@lAddTo\lst@arg~}%
+    \lst@InlineGJ#1}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsubsection{Short inline listing environments}
+%
+% The implementation in this section is based on the \packagename{shortvrb}
+% package, which is part of |doc.dtx| from the Standard \LaTeX\ documentation
+% package, version 2006/02/02 v2.1d.  Portions of it are thus copyright
+% 1993--2006 by The \LaTeX3 Project and copyright 1989--1999 by Frank
+% Mittelbach.
+%
+% \begin{macro}{\lstMakeShortInline}
+% \begin{macro}{\lstMakeShortInline@}
+% First, we supply an optional argument if it's omitted.
+%    \begin{macrocode}
+\newcommand\lstMakeShortInline[1][]{%
+  \def\lst@shortinlinedef{\lstinline[#1]}%
+  \lstMakeShortInline@}%
+\def\lstMakeShortInline@#1{%
+  \expandafter\ifx\csname lst@ShortInlineOldCatcode\string#1\endcsname\relax
+    \lst@shortlstinlineinfo{Made }{#1}%
+    \lst@add@special{#1}%
+%    \end{macrocode}
+% The character's current catcode is stored in
+% |\lst@ShortInlineOldCatcode\|\meta{c}.
+%    \begin{macrocode}
+    \expandafter
+    \xdef\csname lst@ShortInlineOldCatcode\string#1\endcsname{\the\catcode`#1}%
+%    \end{macrocode}
+% The character is spliced into the definition using the same trick as
+% used in |\verb| (for instance), having activated |~| in a group.
+%    \begin{macrocode}
+    \begingroup
+      \catcode`\~\active  \lccode`\~`#1%
+      \lowercase{%
+%    \end{macrocode}
+% The character's old meaning is recorded
+% in |\lst@ShortInlineOldMeaning\|\meta{c} prior to assigning it a new one.
+%    \begin{macrocode}
+        \global\expandafter\let
+          \csname lst@ShortInlineOldMeaning\string#1\endcsname~%
+          \expandafter\gdef\expandafter~\expandafter{\lst@shortinlinedef#1}}%
+    \endgroup
+%    \end{macrocode}
+% Finally the character is made active.
+%    \begin{macrocode}
+    \global\catcode`#1\active
+%    \end{macrocode}
+% If we suspect that \meta{c} is already a short reference, we tell
+% the user. Now he or she is responsible if anything goes wrong\,\dots
+% (Change in \packagename{listings}: We give a proper error here.)
+%    \begin{macrocode}
+  \else
+    \PackageError{Listings}%
+    {\string\lstMakeShorterInline\ definitions cannot be nested}%
+    {Use \string\lstDeleteShortInline first.}%
+    {}%
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\lstDeleteShortInline}
+%    \begin{macrocode}
+\def\lstDeleteShortInline#1{%
+  \expandafter\ifx\csname lst@ShortInlineOldCatcode\string#1\endcsname\relax
+    \PackageError{Listings}%
+    {#1 is not a short reference for \string\lstinline}%
+    {Use \string\lstMakeShortInline first.}%
+    {}%
+  \else
+    \lst@shortlstinlineinfo{Deleted }{#1 as}%
+    \lst@rem@special{#1}%
+    \global\catcode`#1\csname lst@ShortInlineOldCatcode\string#1\endcsname
+    \global \expandafter\let%
+      \csname lst@ShortInlineOldCatcode\string#1\endcsname \relax
+    \ifnum\catcode`#1=\active
+      \begingroup
+        \catcode`\~\active  \lccode`\~`#1%
+        \lowercase{%
+          \global\expandafter\let\expandafter~%
+          \csname lst@ShortInlineOldMeaning\string#1\endcsname}%
+      \endgroup
+    \fi
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@shortlstinlineinfo}
+%    \begin{macrocode}
+\def\lst@shortlstinlineinfo#1#2{%
+     \PackageInfo{Listings}{%
+       #1\string#2 a short reference for \string\lstinline}}
+%    \end{macrocode}
+%  \end{macro}
+%
+% \begin{macro}{\lst@add@special}
+% This helper macro adds its argument to the
+% |\dospecials| macro which is conventionally used by verbatim macros
+% to alter the catcodes of the currently active characters.  We need
+% to add |\do\|\meta{c} to the expansion of |\dospecials| after
+% removing the character if it was already there to avoid multiple
+% copies building up should |\lstMakeShortInline| not be balanced by
+% |\lstDeleteShortInline| (in case anything that uses |\dospecials|
+% cares about repetitions).
+%    \begin{macrocode}
+\def\lst@add@special#1{%
+  \lst@rem@special{#1}%
+  \expandafter\gdef\expandafter\dospecials\expandafter
+    {\dospecials \do #1}%
+%    \end{macrocode}
+% Similarly we have to add |\@makeother\|\meta{c} to |\@sanitize|
+% (which is used in things like "\index" to re-catcode all special
+% characters except braces).
+%    \begin{macrocode}
+  \expandafter\gdef\expandafter\@sanitize\expandafter
+    {\@sanitize \@makeother #1}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\lst@rem@special}
+% The inverse of |\lst@add@special| is slightly trickier.  |\do| is
+% re-defined to expand to nothing if its argument is the character of
+% interest, otherwise to expand simply to the argument.  We can then
+% re-define |\dospecials| to be the expansion of itself.  The space
+% after |=`##1| prevents an expansion to |\relax|!
+%    \begin{macrocode}
+\def\lst@rem@special#1{%
+  \def\do##1{%
+    \ifnum`#1=`##1 \else \noexpand\do\noexpand##1\fi}%
+  \xdef\dospecials{\dospecials}%
+%    \end{macrocode}
+% Fixing |\@sanitize| is the same except that we need to re-define
+% |\@makeother| which obviously needs to be done in a group.
+%    \begin{macrocode}
+  \begingroup
+    \def\@makeother##1{%
+      \ifnum`#1=`##1 \else \noexpand\@makeother\noexpand##1\fi}%
+    \xdef\@sanitize{\@sanitize}%
+  \endgroup}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{The input command}\label{iTheInputCommand}
+%
+% \begin{macro}{\lst@MakePath}
+% \begin{lstkey}{inputpath}
+% The macro appends a slash to a path if necessary.
+%    \begin{macrocode}
+\def\lst@MakePath#1{\ifx\@empty#1\@empty\else\lst@MakePath@#1/\@nil/\fi}
+\def\lst@MakePath@#1/{#1/\lst@MakePath@@}
+\def\lst@MakePath@@#1/{%
+    \ifx\@nil#1\expandafter\@gobble
+         \else \ifx\@empty#1\else #1/\fi \fi
+    \lst@MakePath@@}
+%    \end{macrocode}
+% Now we can empty the path or use |\lst@MakePath|.
+%    \begin{macrocode}
+\lst@Key{inputpath}{}{\edef\lst@inputpath{\lst@MakePath{#1}}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{macro}
+%
+% \begin{macro}{\lstinputlisting}
+% inputs the listing or asks the user for a new file name.
+%    \begin{macrocode}
+\def\lstinputlisting{%
+    \begingroup \lst@setcatcodes \lst@inputlisting}
+\newcommand\lst@inputlisting[2][]{%
+  \endgroup
+%    \end{macrocode}
+% |\lst@set| takes the local options, especially |inputpath=<path>| for
+% formatting the input file. So |\lstset| must be updated to have the right
+% value of |\lst@inputpath|. The whole procedure must be grouped to make
+% the change local.
+%    \begin{macrocode}
+  \bgroup\def\lst@set{#1}%
+  \expandafter\lstset\expandafter{\lst@set}%
+  \IfFileExists{\lst@inputpath#2}%
+    {\lst@InputListing{\lst@inputpath#2}}%
+    {\filename@parse{\lst@inputpath#2}%
+      \edef\reserved@a{\noexpand\lst@MissingFileError
+        {\filename@area\filename@base}%
+        {\ifx\filename@ext\relax tex\else\filename@ext\fi}}%
+      \reserved@a
+%    \end{macrocode}
+% We must provide a valid value for |\lst@doendpe| in the (error) case that there
+% exists no file.
+%    \begin{macrocode}
+  \let\lst@doendpe\@empty}%
+  \egroup
+  \lst@doendpe \@newlistfalse \ignorespaces%
+}
+%    \end{macrocode}
+% We use |\lst@doendpe| to remove indention at the beginning of the next
+% line---except there is an empty line after |\lstinputlisting|. Bug was
+% reported by \lsthelper{David~John~Evans}{1999/06/08}{indention after
+% listings} and \lsthelper{David~Carlisle}{1999/06/08}{LaTeX `display
+% environment' code} pointed me to the solution.
+% \end{macro}
+%
+% \begin{macro}{\lst@MissingFileError}
+% is a derivation of \LaTeX's |\@missingfileerror|. The parenthesis have been
+% added after \lsthelper{Heiko~Oberdiek}{2003/01/14}{File `Makefile.tex' not
+% found} reported about a problem discussed on TEX-D-L.
+%    \begin{macrocode}
+\def\lst@MissingFileError#1#2{%
+    \typeout{^^J! Package Listings Error: File `#1(.#2)' not found.^^J%
+        ^^JType X to quit or <RETURN> to proceed,^^J%
+        or enter new name. (Default extension: #2)^^J}%
+    \message{Enter file name: }%
+    {\endlinechar\m@ne \global\read\m@ne to\@gtempa}%
+%    \end{macrocode}
+% Typing |x| or |X| exits.
+%    \begin{macrocode}
+    \ifx\@gtempa\@empty \else
+        \def\reserved@a{x}\ifx\reserved@a\@gtempa\batchmode\@@end\fi
+        \def\reserved@a{X}\ifx\reserved@a\@gtempa\batchmode\@@end\fi
+%    \end{macrocode}
+% In all other cases we try the new file name.
+%    \begin{macrocode}
+        \filename@parse\@gtempa
+        \edef\filename@ext{%
+            \ifx\filename@ext\relax#2\else\filename@ext\fi}%
+        \edef\reserved@a{\noexpand\IfFileExists %
+                {\filename@area\filename@base.\filename@ext}%
+            {\noexpand\lst@InputListing %
+                {\filename@area\filename@base.\filename@ext}}%
+            {\noexpand\lst@MissingFileError
+                {\filename@area\filename@base}{\filename@ext}}}%
+        \expandafter\reserved@a %
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@ifdraft}
+% makes use of |\lst@ifprint|. \lsthelper{Enrico~Straube}{2002/02/12}
+% {de.comp.text.tex: listings und draft Modus} requested the final option.
+%    \begin{macrocode}
+\let\lst@ifdraft\iffalse
+\DeclareOption{draft}{\let\lst@ifdraft\iftrue}
+\DeclareOption{final}{\let\lst@ifdraft\iffalse}
+\lst@AddToHook{PreSet}
+    {\lst@ifdraft
+         \let\lst@ifprint\iffalse
+         \@gobbletwo\fi\fi
+     \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@InputListing}
+% The one and only argument is the file name, but we have the `implicit'
+% argument |\lst@set|. Note that |\lst@Init| takes |\relax| as argument.
+%    \begin{macrocode}
+\def\lst@InputListing#1{%
+    \begingroup
+      \lsthk@PreSet \gdef\lst@intname{#1}%
+      \expandafter\lstset\expandafter{\lst@set}%
+      \lsthk@DisplayStyle
+      \catcode\active=\active
+      \lst@Init\relax \let\lst@gobble\z@
+      \lst@SkipToFirst
+      \lst@ifprint \def\lst@next{\input{#1}}%
+             \else \let\lst@next\@empty \fi
+      \lst@next
+      \lst@DeInit
+    \endgroup}
+%    \end{macrocode}
+% The line |\catcode\active=\active|, which makes the CR-character active,
+% has been added after a bug report by \lsthelper{Rene~H.~Larsen}{2002/04/15}
+% {\lstinputlistings and texcl conflict}.
+% \end{macro}
+%
+% \begin{macro}{\lst@SkipToFirst}
+% The end of line character either processes the listing or is responsible for
+% dropping lines up to first printing line.
+%    \begin{macrocode}
+\def\lst@SkipToFirst{%
+    \ifnum \lst@lineno<\lst@firstline
+%    \end{macrocode}
+% We drop the input and redefine the end of line characters.
+%    \begin{macrocode}
+        \lst@BeginDropInput\lst@Pmode
+        \lst@Let{13}\lst@MSkipToFirst
+        \lst@Let{10}\lst@MSkipToFirst
+    \else
+        \expandafter\lst@BOLGobble
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@MSkipToFirst}
+% We just look whether to drop more lines or to leave the mode which restores
+% the definition of chr(13) and chr(10).
+%    \begin{macrocode}
+\def\lst@MSkipToFirst{%
+    \global\advance\lst@lineno\@ne
+    \ifnum \lst@lineno=\lst@firstline
+        \lst@LeaveMode \global\lst@newlines\z@
+        \lsthk@InitVarsBOL
+        \expandafter\lst@BOLGobble
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{The environment}
+%
+%
+% \subsubsection{Low-level processing}
+%
+% \begin{macro}{\lstenv@DroppedWarning}
+% gives a warning if characters have been dropped.
+%    \begin{macrocode}
+\def\lstenv@DroppedWarning{%
+    \ifx\lst@dropped\@undefined\else
+        \PackageWarning{Listings}{Text dropped after begin of listing}%
+    \fi}
+\let\lst@dropped\@undefined % init
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@Process}
+% We execute `|\lstenv@ProcessM|' or |\lstenv@ProcessJ| according to whether we
+% find an active EOL or a nonactive |^^J|.
+%    \begin{macrocode}
+\begingroup \lccode`\~=`\^^M\lowercase{%
+\gdef\lstenv@Process#1{%
+    \ifx~#1%
+%    \end{macrocode}
+% We make no extra |\lstenv@ProcessM| definition since there is nothing to do
+% at all if we've found an active EOL.
+%    \begin{macrocode}
+        \lstenv@DroppedWarning \let\lst@next\lst@SkipToFirst
+    \else\ifx^^J#1%
+        \lstenv@DroppedWarning \let\lst@next\lstenv@ProcessJ
+    \else
+        \let\lst@dropped#1\let\lst@next\lstenv@Process
+    \fi \fi
+    \lst@next}
+}\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@ProcessJ}
+% Now comes the horrible scenario: a listing inside an argument. We've
+% already worked in section \ref{iApplicationsTo} for this. Here we must get
+% all characters up to `end environment'. We distinguish the cases `command
+% fashion' and `true environment'.
+%    \begin{macrocode}
+\def\lstenv@ProcessJ{%
+    \let\lst@arg\@empty
+    \ifx\@currenvir\lstenv@name
+        \expandafter\lstenv@ProcessJEnv
+    \else
+%    \end{macrocode}
+% The first case is pretty simple: The code is terminated by
+% |\end|\meta{name of environment}. Thus we expand that control sequence
+% before defining a temporary macro, which gets the listing and does all
+% the rest. Back to the definition of |\lstenv@ProcessJ| we call the
+% temporary macro after expanding |\fi|.
+%    \begin{macrocode}
+        \expandafter\def\expandafter\lst@temp\expandafter##1%
+            \csname end\lstenv@name\endcsname
+                {\lst@InsideConvert{##1}\lstenv@ProcessJ@}%
+        \expandafter\lst@temp
+    \fi}
+%    \end{macrocode}
+% We must append an active backslash and the `end string' to |\lst@arg|. So all
+% (in fact most) other processing won't notice that the code has been inside
+% an argument. But the EOL character is chr(10)=|^^J| now and not chr(13).
+%    \begin{macrocode}
+\begingroup \lccode`\~=`\\\lowercase{%
+\gdef\lstenv@ProcessJ@{%
+    \lst@lExtend\lst@arg
+        {\expandafter\ \expandafter~\lstenv@endstring}%
+    \catcode10=\active \lst@Let{10}\lst@MProcessListing
+%    \end{macrocode}
+% We execute |\lst@arg| to typeset the listing.
+%    \begin{macrocode}
+    \lst@SkipToFirst \lst@arg}
+}\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@ProcessJEnv}
+% The `true environment' case is more complicated. We get all characters up to
+% an |\end| and the following argument. If that equals |\lstenv@name|, we have
+% found the end of environment and start typesetting.
+%    \begin{macrocode}
+\def\lstenv@ProcessJEnv#1\end#2{\def\lst@temp{#2}%
+    \ifx\lstenv@name\lst@temp
+        \lst@InsideConvert{#1}%
+        \expandafter\lstenv@ProcessJ@
+    \else
+%    \end{macrocode}
+% Otherwise we append the characters including the eaten |\end| and the eaten
+% argument to current |\lst@arg|. And we look for the end of environment again.
+%    \begin{macrocode}
+        \lst@InsideConvert{#1\\end\{#2\}}%
+        \expandafter\lstenv@ProcessJEnv
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@backslash}
+% Coming to a backslash we either end the listing or process a backslash and
+% insert the eaten characters again.
+%    \begin{macrocode}
+\def\lstenv@backslash{%
+    \lst@IfNextChars\lstenv@endstring
+        {\lstenv@End}%
+        {\expandafter\lsts@backslash \lst@eaten}}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@End}
+% This macro has just been used and terminates a listing environment:
+% We call the `end environment' macro using |\end| or as a command.
+%    \begin{macrocode}
+\def\lstenv@End{%
+    \ifx\@currenvir\lstenv@name
+        \edef\lst@next{\noexpand\end{\lstenv@name}}%
+    \else
+        \def\lst@next{\csname end\lstenv@name\endcsname}%
+    \fi
+    \lst@next}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsubsection{Defining new environments}
+%
+% \begin{macro}{\lstnewenvironment}
+% Now comes the main command. We define undefined environments only. On the
+% parameter text |#1#2#| (in particular the last sharp) see the paragraph
+% following example 20.5 on page 204 of `The \TeX book'.
+%    \begin{macrocode}
+\lst@UserCommand\lstnewenvironment#1#2#{%
+    \@ifundefined{#1}%
+        {\let\lst@arg\@empty
+         \lst@XConvert{#1}\@nil
+         \expandafter\lstnewenvironment@\lst@arg{#1}{#2}}%
+        {\PackageError{Listings}{Environment `#1' already defined}\@eha
+         \@gobbletwo}}
+\def\@tempa#1#2#3{%
+  \gdef\lstnewenvironment@##1##2##3##4##5{%
+    \begingroup
+%    \end{macrocode}
+% A lonely `end environment' produces an error.
+%    \begin{macrocode}
+    \global\@namedef{end##2}{\lstenv@Error{##2}}%
+%    \end{macrocode}
+% The `main' environment macro defines the environment name for later use and
+% calls a submacro getting all arguments. We open a group and make EOL active.
+% This ensures |\@ifnextchar[| not to read characters of the listing---it reads
+% the active EOL instead.
+%    \begin{macrocode}
+    \global\@namedef{##2}{\def\lstenv@name{##2}%
+        \begingroup \lst@setcatcodes \catcode\active=\active
+        \csname##2@\endcsname}%
+%    \end{macrocode}
+% The submacro is defined via |\new@command|. We misuse |\l@ngrel@x| to make
+% the definition |\global| and refine \LaTeX's |\@xargdef|.
+%    \begin{macrocode}
+    \let\l@ngrel@x\global
+    \let\@xargdef\lstenv@xargdef
+    \expandafter\new@command\csname##2@\endcsname##3%
+%    \end{macrocode}
+% First we execute |##4|=\meta{begin code}. Then follows the definition of
+% the terminating string (|end{lstlisting}| or |endlstlisting|, for example):
+%    \begin{macrocode}
+        {\lsthk@PreSet ##4%
+         \ifx\@currenvir\lstenv@name
+             \def\lstenv@endstring{#1#2##1#3}%
+         \else
+             \def\lstenv@endstring{#1##1}%
+         \fi
+%    \end{macrocode}
+% We redefine (locally) `end environment' since ending is legal now.
+% Note that the redefinition also works inside a \TeX\ comment line.
+%    \begin{macrocode}
+         \@namedef{end##2}{\lst@DeInit ##5\endgroup
+                          \lst@doendpe \@ignoretrue}%
+%    \end{macrocode}
+% |\lst@doendpe| again removes the indention problem.
+%
+% Finally we start the processing. The |\lst@EndProcessListing| assignment
+% has been moved in front of |\lst@Init| after a bug report by
+% \lsthelper{Andreas~Deininger}{2002/11/11}{Compiling just stops}.
+%    \begin{macrocode}
+         \lsthk@DisplayStyle
+         \let\lst@EndProcessListing\lstenv@SkipToEnd
+         \lst@Init\lstenv@backslash
+         \lst@ifprint
+             \expandafter\expandafter\expandafter\lstenv@Process
+         \else
+             \expandafter\lstenv@SkipToEnd
+         \fi
+         \lst@insertargs}%
+    \endgroup}%
+}
+\let\lst@arg\@empty \lst@XConvert{end}\{\}\@nil
+\expandafter\@tempa\lst@arg
+\let\lst@insertargs\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@xargdef}
+% This is a derivation of \LaTeX's |\@xargdef|. We expand the submacro's name,
+% use |\gdef| instead of |\def|, and hard code a kind of |\@protected@testopt|.
+%    \begin{macrocode}
+\def\lstenv@xargdef#1{
+    \expandafter\lstenv@xargdef@\csname\string#1\endcsname#1}
+\def\lstenv@xargdef@#1#2[#3][#4]#5{%
+  \@ifdefinable#2{%
+       \gdef#2{%
+          \ifx\protect\@typeset@protect
+            \expandafter\lstenv@testopt
+          \else
+            \@x@protect#2%
+          \fi
+          #1%
+          {#4}}%
+       \@yargdef
+          #1%
+           \tw@
+           {#3}%
+           {#5}}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@testopt}
+% The difference between this macro and |\@testopt| is that we temporaryly
+% reset the catcode of the EOL character |^^M| to read the optional argument.
+%    \begin{macrocode}
+\long\def\lstenv@testopt#1#2{%
+  \@ifnextchar[{\catcode\active5\relax \lstenv@testopt@#1}%
+               {#1[{#2}]}}
+\def\lstenv@testopt@#1[#2]{%
+    \catcode\active\active
+    #1[#2]}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@SkipToEnd}
+% We use the temporary definition
+% \begin{itemize}\item[]
+%    |\long\def\lst@temp##1\|\meta{content of \textup{\cs{lstenv@endstring}}}|{\lstenv@End}|
+% \end{itemize}
+% which gobbles all characters up to the end of environment and finishes it.
+%    \begin{macrocode}
+\begingroup \lccode`\~=`\\\lowercase{%
+\gdef\lstenv@SkipToEnd{%
+    \long\expandafter\def\expandafter\lst@temp\expandafter##\expandafter
+        1\expandafter~\lstenv@endstring{\lstenv@End}%
+    \lst@temp}
+}\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstenv@Error}
+% is called by a lonely `end environment'.
+%    \begin{macrocode}
+\def\lstenv@Error#1{\PackageError{Listings}{Extra \string\end#1}%
+    {I'm ignoring this, since I wasn't doing a \csname#1\endcsname.}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@TestEOLChar}
+% Here we test for the two possible EOL characters.
+%    \begin{macrocode}
+\begingroup \lccode`\~=`\^^M\lowercase{%
+\gdef\lst@TestEOLChar#1{%
+    \def\lst@insertargs{#1}%
+    \ifx ~#1\@empty \else
+    \ifx^^J#1\@empty \else
+        \global\let\lst@intname\lst@insertargs
+        \let\lst@insertargs\@empty
+    \fi \fi}
+}\endgroup
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{environment}{lstlisting}
+% The awkward work is done, the definition is quite easy now. We test whether
+% the user has given the name argument, set the keys, and deal with
+% continued line numbering.
+%    \begin{macrocode}
+\lstnewenvironment{lstlisting}[2][]{%
+     \lst@TestEOLChar{#2}%
+     \lstset{#1}%
+     \csname\@lst @SetFirstNumber\endcsname%
+   }{%
+%    \end{macrocode}
+% There is a problem with vertical space below a listing as pointed out by
+% \lsthelper{Jean-Yves~Baudais}{2016/03/11}{some vertical space problem}. A
+% similar problem arises with a listing beginning at the top of a
+% |\paragraph| or at the beginning of an |example| environment. Jean-Yves
+% provided a solution---|\let\if@nobreak\iffalse|---as has been discussed
+% on |fr.comp.text.tex|. The assumption, that the problem vanishes if there
+% is a top rule at the beginning of the listing or if |\leavevmode|
+% introduces the listing, was wrong as \lsthelper{Karl
+% Berry}{karl@freefriends.org}{2018/10/26} and \lsthelper{Sven
+% Schreiber}{svetosch@gmx.net}{2018/10/23} reported independently, so the
+% proposed code goes into the second part of the environment definition
+%    \begin{macrocode}
+     \let\if@nobreak\iffalse%
+     \csname\@lst @SaveFirstNumber\endcsname%
+   }
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \end{environment}
+%
+%
+% \section{Documentation support}
+%
+% \begin{syntax}
+% \item[0.19]
+%   |\begin{lstsample}|\oarg{point list}\marg{left}\marg{right}
+%
+%   \leavevmode\hspace*{-\leftmargini}|\end{lstsample}|
+%
+%       Roughly speaking all material in between this environment is executed
+%       `on the left side' and typeset verbatim on the right. \meta{left} is
+%       executed before the left side is typeset, and similarly \meta{right}
+%       before the right-hand side.
+%
+%       \meta{point list} is used as argument to the \keyname{point} key.
+%       This is a special key used to highlight the keys in the examples.
+%
+% \item[1.0]
+%   |\begin{lstxsample}|\marg{point list}
+%
+%   \leavevmode\hspace*{-\leftmargini}|\end{lstxsample}|
+%
+%       The material in between is (a) added to the left side of the next
+%       \texttt{lstsample} environment and (b) typeset verbatim using the
+%       whole line width.
+%
+% \item[0.21] |\newdocenvironment|\marg{name}\marg{short name}\marg{begin code}\marg{end code}
+%
+%       The \meta{name} environment can be used in the same way as `macro'.
+%       The provided(!) definitions
+%           |\Print|\meta{short name}|Name|
+%       and |\SpecialMain|\meta{short name}|Index|
+%       control printing in the margin and indexing as the defaults
+%       |\PrintMacroName| and |\SpecialMainIndex| do.
+%
+%       This command is used to define the `aspect' and `lstkey' environments.
+%
+%\item[0.21] \texttt{macroargs} environment
+%
+%       This `enumerate' environment uses as labels `|#1| =', `|#2| =',
+%       and so on.
+%
+% \item \texttt{TODO} environment
+% \item \texttt{ALTERNATIVE} environment
+% \item \texttt{REMOVED} environment
+% \item \texttt{OLDDEF} environment
+%
+%       These environments enclose comments on `to do's', alternatives and
+%       removed or old definitions.
+%
+% \item[0.21] |\lstscanlanguages|\meta{list macro}\marg{input files}\marg{don't input}
+%
+%       scans \marg{input files}$\setminus$\marg{don't input} for language
+%       definitions. The available languages are stored in \meta{list macro}
+%       using the form \meta{language}|(|\meta{dialect}|),|.
+%
+% \item[0.21] |\lstprintlanguages|\meta{list macro}
+%
+%       prints the languages in two column format.
+% \end{syntax}
+% and a lot of more simple commands.
+%
+%
+% \subsection{Required packages}
+%
+% Most of the `required' packages are optional.
+% \lsthelper{Stephan~Hennig}{2006-09-25}{documentation incompatible with algorithmic}
+% noted a bug where |\ifalgorithmic| conflicts with an update to |algorithmic.sty|, so
+% this has been changed to |\ifalgorithmicpkg|.
+%    \begin{macrocode}
+%<*doc>
+\let\lstdoc@currversion\fileversion
+\RequirePackage[writefile]{listings}[2004/09/07]
+\newif\iffancyvrb \IfFileExists{fancyvrb.sty}{\fancyvrbtrue}{}
+\newif\ifcolor \IfFileExists{color.sty}{\colortrue}{}
+\lst@false
+\newif\ifhyper
+\@ifundefined{pdfoutput}
+    {}
+    {\ifnum\pdfoutput>\z@ \lst@true \fi}
+\@ifundefined{VTeXversion}
+    {}
+    {\ifnum\OpMode>\z@ \lst@true \fi}
+\lst@if \IfFileExists{hyperref.sty}{\hypertrue}{}\fi
+\newif\ifalgorithmicpkg \IfFileExists{algorithmic.sty}{\algorithmicpkgtrue}{}
+\newif\iflgrind \IfFileExists{lgrind.sty}{\lgrindtrue}{}
+\iffancyvrb \RequirePackage{fancyvrb}\fi
+\ifhyper \RequirePackage[colorlinks]{hyperref}\else
+    \def\href#1{\texttt}\fi
+\ifcolor \RequirePackage{color}\fi
+\ifalgorithmicpkg \RequirePackage{algorithmic}\fi
+\iflgrind \RequirePackage{lgrind}\fi
+\RequirePackage{nameref}
+\RequirePackage{url}
+\renewcommand\ref{\protect\T@ref}
+\renewcommand\pageref{\protect\T@pageref}
+%    \end{macrocode}
+%
+%
+% \subsection{Environments for notes}
+%
+% \begin{macro}{\lst@BeginRemark}
+% \begin{macro}{\lst@EndRemark}
+% We begin with two simple definitions \ldots
+%    \begin{macrocode}
+\def\lst@BeginRemark#1{%
+    \begin{quote}\topsep0pt\let\small\footnotesize\small#1:}
+\def\lst@EndRemark{\end{quote}}
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{environment}{TODO}
+% \begin{environment}{ALTERNATIVE}
+% \begin{environment}{REMOVED}
+% \begin{environment}{OLDDEF}
+% \ldots\space used to define some environments.
+%    \begin{macrocode}
+\newenvironment{TODO}
+    {\lst@BeginRemark{To do}}{\lst@EndRemark}
+\newenvironment{ALTERNATIVE}
+    {\lst@BeginRemark{Alternative}}{\lst@EndRemark}
+\newenvironment{REMOVED}
+    {\lst@BeginRemark{Removed}}{\lst@EndRemark}
+\newenvironment{OLDDEF}
+    {\lst@BeginRemark{Old definition}}{\lst@EndRemark}
+%    \end{macrocode}
+% \end{environment}\end{environment}\end{environment}\end{environment}
+%
+% \begin{environment}{advise}
+% \begin{macro}{\advisespace}
+% The environment uses |\@listi|.
+%    \begin{macrocode}
+\def\advise{\par\list\labeladvise
+    {\advance\linewidth\@totalleftmargin
+     \@totalleftmargin\z@
+     \@listi
+     \let\small\footnotesize \small\sffamily
+     \parsep \z@ \@plus\z@ \@minus\z@
+     \topsep6\p@ \@plus1\p@\@minus2\p@
+     \def\makelabel##1{\hss\llap{##1}}}}
+\let\endadvise\endlist
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\advisespace{\hbox{}\qquad}
+\def\labeladvise{$\to$}
+%    \end{macrocode}
+% \end{macro}
+% \end{environment}
+%
+% \begin{environment}{syntax}
+% \begin{macro}{\syntaxbreak}
+% \begin{macro}{\syntaxnewline}
+% \begin{macro}{\syntaxor}
+% This environment uses |\list| with a special |\makelabel|, \ldots
+%    \begin{macrocode}
+\newenvironment{syntax}
+   {\list{}{\itemindent-\leftmargin
+    \def\makelabel##1{\hss\lst@syntaxlabel##1,,,,\relax}}}
+   {\endlist}
+%    \end{macrocode}
+% \ldots\ which is defined here. The comma separated items are placed as
+% needed.
+%    \begin{macrocode}
+\def\lst@syntaxlabel#1,#2,#3,#4\relax{%
+    \llap{\scriptsize\itshape#3}%
+    \def\lst@temp{#2}%
+    \expandafter\lst@syntaxlabel@\meaning\lst@temp\relax
+    \rlap{\hskip-\itemindent\hskip\itemsep\hskip\linewidth
+          \llap{\ttfamily\lst@temp}\hskip\labelwidth
+          \def\lst@temp{#1}%
+          \ifx\lst@temp\lstdoc@currversion#1\fi}}
+\def\lst@syntaxlabel@#1>#2\relax
+    {\edef\lst@temp{\zap@space#2 \@empty}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\newcommand*\syntaxnewline{\newline\hbox{}\kern\labelwidth}
+\newcommand*\syntaxor{\qquad or\qquad}
+\newcommand*\syntaxbreak
+    {\hfill\kern0pt\discretionary{}{\kern\labelwidth}{}}
+\let\syntaxfill\hfill
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{environment}
+%
+% \begin{macro}{\alternative}
+% iterates down the list and inserts vertical rule(s).
+%    \begin{macrocode}
+\def\alternative#1{\lst@true \alternative@#1,\relax,}
+\def\alternative@#1,{%
+    \ifx\relax#1\@empty
+        \expandafter\@gobble
+    \else
+        \ifx\@empty#1\@empty\else
+            \lst@if \lst@false \else $\vert$\fi
+            \textup{\texttt{#1}}%
+        \fi
+    \fi
+    \alternative@}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Extensions to \textsf{doc}}
+%
+% \begin{macro}{\m@cro@}
+% We need a slight modification of \packagename{doc}'s internal macro.
+% The former argument |#2| has become |#3|. This change is not marked below.
+% The second argument is now \meta{short name}.
+%    \begin{macrocode}
+\long\def\m@cro@#1#2#3{\endgroup \topsep\MacroTopsep \trivlist
+  \edef\saved@macroname{\string#3}%
+  \def\makelabel##1{\llap{##1}}%
+  \if@inlabel
+    \let\@tempa\@empty \count@\macro@cnt
+    \loop \ifnum\count@>\z@
+      \edef\@tempa{\@tempa\hbox{\strut}}\advance\count@\m@ne \repeat
+    \edef\makelabel##1{\llap{\vtop to\baselineskip
+                               {\@tempa\hbox{##1}\vss}}}%
+    \advance \macro@cnt \@ne
+  \else  \macro@cnt\@ne  \fi
+  \edef\@tempa{\noexpand\item[%
+     #1%
+       \noexpand\PrintMacroName
+     \else
+%    \end{macrocode}
+% The next line has been modified.
+%    \begin{macrocode}
+       \expandafter\noexpand\csname Print#2Name\endcsname % MODIFIED
+     \fi
+     {\string#3}]}%
+  \@tempa
+  \global\advance\c@CodelineNo\@ne
+   #1%
+      \SpecialMainIndex{#3}\nobreak
+      \DoNotIndex{#3}%
+   \else
+%    \end{macrocode}
+% Ditto.
+%    \begin{macrocode}
+      \csname SpecialMain#2Index\endcsname{#3}\nobreak % MODIFIED
+   \fi
+  \global\advance\c@CodelineNo\m@ne
+  \ignorespaces}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\macro}
+% \begin{macro}{\environment}
+% These two definitions need small adjustments due to the modified |\m@cro@|.
+%    \begin{macrocode}
+\def\macro{\begingroup
+   \catcode`\\12
+   \MakePrivateLetters \m@cro@ \iftrue {Macro}}% MODIFIED
+\def\environment{\begingroup
+   \catcode`\\12
+   \MakePrivateLetters \m@cro@ \iffalse {Env}}% MODIFIED
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{macro}{\newdocenvironment}
+% This command simply makes definitions similar to `environment' and provides
+% the printing and indexing commands.
+%    \begin{macrocode}
+\def\newdocenvironment#1#2#3#4{%
+    \@namedef{#1}{#3\begingroup \catcode`\\12\relax
+                  \MakePrivateLetters \m@cro@ \iffalse {#2}}%
+    \@namedef{end#1}{#4\endmacro}%
+    \@ifundefined{Print#2Name}{\expandafter
+        \let\csname Print#2Name\endcsname\PrintMacroName}{}%
+    \@ifundefined{SpecialMain#2Index}{\expandafter
+        \let\csname SpecialMain#2Index\endcsname\SpecialMainIndex}{}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{environment}{aspect}
+% \begin{macro}{\PrintAspectName}
+% \begin{macro}{\SpecialMainAspectIndex}
+% The environment and its `print' and `index' commands.
+%    \begin{macrocode}
+\newdocenvironment{aspect}{Aspect}{}{}
+\def\PrintAspectName#1{}
+\def\SpecialMainAspectIndex#1{%
+    \@bsphack
+    \index{aspects:\levelchar\protect\aspectname{#1}}%
+    \@esphack}
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{environment}
+%
+% \begin{environment}{lstkey}
+% \begin{macro}{\PrintKeyName}
+% \begin{macro}{\SpecialMainKeyIndex}
+% One more environment with its `print' and `index' commands.
+%    \begin{macrocode}
+\newdocenvironment{lstkey}{Key}{}{}
+\def\PrintKeyName#1{\strut\keyname{#1}\ }
+\def\SpecialMainKeyIndex#1{%
+    \@bsphack
+    \index{keys\levelchar\protect\keyname{#1}}%
+    \@esphack}
+%    \end{macrocode}
+% \end{macro}\end{macro}\end{environment}
+%
+% \begin{macro}{\labelargcount}
+% \begin{environment}{macroargs}
+% We just allocate a counter and use \LaTeX's |\list| to implement this
+% environment.
+%    \begin{macrocode}
+\newcounter{argcount}
+\def\labelargcount{\texttt{\#\arabic{argcount}}\hskip\labelsep$=$}
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\macroargs{\list\labelargcount
+    {\usecounter{argcount}\leftmargin=2\leftmargin
+     \parsep \z@ \@plus\z@ \@minus\z@
+     \topsep4\p@ \@plus\p@ \@minus2\p@
+     \itemsep\z@ \@plus\z@ \@minus\z@
+     \def\makelabel##1{\hss\llap{##1}}}}
+\def\endmacroargs{\endlist\@endparenv}
+%    \end{macrocode}
+% \end{environment}\end{macro}
+%
+%
+% \subsection{The \texttt{lstsample} environment}
+%
+% \begin{environment}{lstsample}
+% We store the verbatim part and write the source code also to file.
+%    \begin{macrocode}
+\lst@RequireAspects{writefile}
+%    \end{macrocode}
+%    \begin{macrocode}
+\newbox\lst@samplebox
+\lstnewenvironment{lstsample}[3][]
+    {\global\let\lst@intname\@empty
+     \gdef\lst@sample{#2}%
+     \setbox\lst@samplebox=\hbox\bgroup
+         \setkeys{lst}{language={},style={},tabsize=4,gobble=5,%
+             basicstyle=\small\ttfamily,basewidth=0.51em,point={#1}}
+         #3%
+         \lst@BeginAlsoWriteFile{\jobname.tmp}}
+    {\lst@EndWriteFile\egroup
+%    \end{macrocode}
+% Now |\lst@samplebox| contains the verbatim part.
+% If it's too wide, we use atop and below instead of left and right.
+%    \begin{macrocode}
+     \ifdim \wd\lst@samplebox>.5\linewidth
+         \begin{center}%
+             \hbox to\linewidth{\box\lst@samplebox\hss}%
+         \end{center}%
+         \lst@sampleInput
+     \else
+         \begin{center}%
+         \begin{minipage}{0.45\linewidth}\lst@sampleInput\end{minipage}%
+         \qquad
+         \begin{minipage}{0.45\linewidth}%
+             \hbox to\linewidth{\box\lst@samplebox\hss}%
+         \end{minipage}%
+         \end{center}%
+     \fi}
+%    \end{macrocode}
+% The new keyword class \keyname{point}.
+%    \begin{macrocode}
+\lst@InstallKeywords{p}{point}{pointstyle}\relax{keywordstyle}{}ld
+%    \end{macrocode}
+% \end{environment}
+%
+% \begin{environment}{lstxsample}
+% Omitting |\lst@EndWriteFile| leaves the file open.
+%    \begin{macrocode}
+\lstnewenvironment{lstxsample}[1][]
+    {\begingroup
+         \setkeys{lst}{belowskip=-\medskipamount,language={},style={},%
+             tabsize=4,gobble=5,basicstyle=\small\ttfamily,%
+             basewidth=0.51em,point={#1}}
+         \lst@BeginAlsoWriteFile{\jobname.tmp}}
+    {\endgroup
+     \endgroup}
+%    \end{macrocode}
+% \end{environment}
+%
+% \begin{macro}{\lst@sampleInput}
+% inputs the `left-hand' side.
+%    \begin{macrocode}
+\def\lst@sampleInput{%
+    \MakePercentComment\catcode`\^^M=10\relax
+    \small\lst@sample
+    {\setkeys{lst}{SelectCharTable=\lst@ReplaceInput{\^\^I}%
+                                  {\lst@ProcessTabulator}}%
+     \leavevmode \input{\jobname.tmp}}\MakePercentIgnore}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Miscellaneous}
+%
+% \paragraph{Sectioning and cross referencing}
+% We begin with a redefinition paragraph.
+%    \begin{macrocode}
+\renewcommand\paragraph{\@startsection{paragraph}{4}{\z@}%
+                                      {1.25ex \@plus1ex \@minus.2ex}%
+                                      {-1em}%
+                                      {\normalfont\normalsize\bfseries}}
+%    \end{macrocode}
+% We introduce |\lstref| which prints section number together with its name.
+%    \begin{macrocode}
+\def\lstref#1{\emph{\ref{#1} \nameref{#1}}}
+%    \end{macrocode}
+% Moreover we adjust the table of contents.  The |\phantomsection| before
+% adding the contents line provides \packagename{hyperref} with an appropriate
+% destination for the contents line link, thereby ensuring that the contents
+% line is at the right level in the PDF bookmark tree.
+%    \begin{macrocode}
+\def\@part[#1]#2{\ifhyper\phantomsection\fi
+    \addcontentsline{toc}{part}{#1}%
+    {\parindent\z@ \raggedright \interlinepenalty\@M
+     \normalfont \huge \bfseries #2\markboth{}{}\par}%
+    \nobreak\vskip 3ex\@afterheading}
+\renewcommand*\l@section[2]{%
+    \addpenalty\@secpenalty
+    \addvspace{.25em \@plus\p@}%
+    \setlength\@tempdima{1.5em}%
+    \begingroup
+      \parindent \z@ \rightskip \@pnumwidth
+      \parfillskip -\@pnumwidth
+      \leavevmode
+      \advance\leftskip\@tempdima
+      \hskip -\leftskip
+      #1\nobreak\hfil \nobreak\hb@xt@\@pnumwidth{\hss #2}\par
+    \endgroup}
+\renewcommand*\l@subsection{\@dottedtocline{2}{0pt}{2.3em}}
+\renewcommand*\l@subsubsection{\@dottedtocline{3}{0pt}{3.2em}}
+%    \end{macrocode}
+%
+% \paragraph{Indexing}
+% The `user' commands. |\rstyle| is defined below.
+%    \begin{macrocode}
+\newcommand\ikeyname[1]{%
+    \lstkeyindex{#1}{}%
+    \lstaspectindex{#1}{}%
+    \keyname{#1}}
+\newcommand\ekeyname[1]{%
+    \@bsphack
+    \lstkeyindex{#1}{}%
+    \lstaspectindex{#1}{}%
+    \@esphack}
+\newcommand\rkeyname[1]{%
+    \@bsphack
+    \lstkeyindex{#1}{}%
+    \lstaspectindex{#1}{}%
+    \@esphack{\rstyle\keyname{#1}}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\newcommand\icmdname[1]{%
+    \@bsphack
+    \lstaspectindex{#1}{}%
+    \@esphack\texttt{\string#1}}
+\newcommand\rcmdname[1]{%
+    \@bsphack
+    \lstaspectindex{#1}{}%
+    \@esphack\texttt{\rstyle\string#1}}
+%    \end{macrocode}
+% One of the two yet unknown `index'-macros is empty, the other looks up
+% the aspect name for the given argument.
+%    \begin{macrocode}
+\def\lstaspectindex#1#2{%
+    \global\@namedef{lstkandc@\string#1}{}%
+    \@ifundefined{lstisaspect@\string#1}
+        {\index{unknown\levelchar
+                \protect\texttt{\protect\string\string#1}#2}}%
+        {\index{\@nameuse{lstisaspect@\string#1}\levelchar
+                \protect\texttt{\protect\string\string#1}#2}}%
+}
+\def\lstkeyindex#1#2{%
+%    \index{key\levelchar\protect\keyname{#1}#2}%
+}
+%    \end{macrocode}
+% The key/command to aspect relation is defined near the top of this file using
+% the following command. In future the package should read this information
+% from the aspect files.
+%    \begin{macrocode}
+\def\lstisaspect[#1]#2{%
+    \global\@namedef{lstaspect@#1}{#2}%
+    \lst@AddTo\lst@allkeysandcmds{,#2}%
+    \@for\lst@temp:=#2\do
+    {\ifx\@empty\lst@temp\else
+         \global\@namedef{lstisaspect@\lst@temp}{#1}%
+     \fi}}
+\gdef\lst@allkeysandcmds{}
+%    \end{macrocode}
+% This relation is also good to print all keys and commands of a particular
+% aspect \ldots
+%    \begin{macrocode}
+\def\lstprintaspectkeysandcmds#1{%
+    \lst@true
+    \expandafter\@for\expandafter\lst@temp
+    \expandafter:\expandafter=\csname lstaspect@#1\endcsname\do
+    {\lst@if\lst@false\else, \fi \texttt{\lst@temp}}}
+%    \end{macrocode}
+% \ldots\ or to check the reference. Note that we've defined
+% |\lstkandc@|\meta{name} in |\lstaspectindex|.
+%    \begin{macrocode}
+\def\lstcheckreference{%
+   \@for\lst@temp:=\lst@allkeysandcmds\do
+   {\ifx\lst@temp\@empty\else
+        \@ifundefined{lstkandc@\lst@temp}
+        {\typeout{\lst@temp\space not in reference guide?}}{}%
+    \fi}}
+%    \end{macrocode}
+%
+% \paragraph{Unique styles}
+%    \begin{macrocode}
+\newcommand*\lst{\texttt{lst}}
+\newcommand*\Cpp{C\texttt{++}}
+\let\keyname\texttt
+\let\keyvalue\texttt
+\let\hookname\texttt
+\newcommand*\aspectname[1]{{\normalfont\sffamily#1}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\DeclareRobustCommand\packagename[1]{%
+    {\leavevmode\text@command{#1}%
+     \switchfontfamily\sfdefault\rmdefault
+     \check@icl #1\check@icr
+     \expandafter}}%
+\renewcommand\packagename[1]{{\normalfont\sffamily#1}}
+\def\switchfontfamily#1#2{%
+    \begingroup\xdef\@gtempa{#1}\endgroup
+    \ifx\f@family\@gtempa\fontfamily#2%
+                    \else\fontfamily#1\fi
+    \selectfont}
+%    \end{macrocode}
+% The color mainly for keys and commands in the reference guide.
+%    \begin{macrocode}
+\ifcolor
+    \definecolor{darkgreen}{rgb}{0,0.5,0}
+    \def\rstyle{\color{darkgreen}}
+\else
+    \let\rstyle\empty
+\fi
+%    \end{macrocode}
+%
+% \paragraph{Commands for credits and helpers}
+% There are two commands for credits and helpers:
+% \begin{enumerate}
+%   \item |\lstthanks| is used to put a name of a contributor into the
+%     section ``Closing and credit''. It has two arguments: |#1| is the
+%     name, |#2| the email address---the email addres is not shown.
+%   \item |\lsthelper| must be used in the text to show the name of the
+%     helper (argument |#1|), the date of the contribution (argument |#2|)
+%     and a short text about the contribution (argument |#3|). Only the
+%     first argument is printed.
+% \end{enumerate}
+%    \begin{macrocode}
+\gdef\lst@emails{}
+\newcommand*\lstthanks[2]
+    {#1\lst@AddTo\lst@emails{,#1,<#2>}%
+     \ifx\@empty#2\@empty\typeout{Missing email for #1}\fi}
+\newcommand*\lsthelper[3]
+    {{\let~\ #1}%
+     \lst@IfOneOf#1\relax\lst@emails
+     {}{\typeout{^^JWarning: Unknown helper #1.^^J}}}
+%    \end{macrocode}
+%
+% \paragraph{Languages and styles}
+%    \begin{macrocode}
+\lstdefinelanguage[doc]{Pascal}{%
+  morekeywords={alfa,and,array,begin,boolean,byte,case,char,const,div,%
+     do,downto,else,end,false,file,for,function,get,goto,if,in,%
+     integer,label,maxint,mod,new,not,of,or,pack,packed,page,program,%
+     procedure,put,read,readln,real,record,repeat,reset,rewrite,set,%
+     text,then,to,true,type,unpack,until,var,while,with,write,writeln},%
+  sensitive=false,%
+  morecomment=[s]{(*}{*)},%
+  morecomment=[s]{\{}{\}},%
+  morestring=[d]{'}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lstdefinestyle{}
+    {basicstyle={},%
+     keywordstyle=\bfseries,identifierstyle={},%
+     commentstyle=\itshape,stringstyle={},%
+     numberstyle={},stepnumber=1,%
+     pointstyle=\pointstyle}
+\def\pointstyle{%
+    {\let\lst@um\@empty \xdef\@gtempa{\the\lst@token}}%
+    \expandafter\lstkeyindex\expandafter{\@gtempa}{}%
+    \expandafter\lstaspectindex\expandafter{\@gtempa}{}%
+    \rstyle}
+\lstset{defaultdialect=[doc]Pascal,language=Pascal,style={}}
+%    \end{macrocode}
+%
+%
+% \subsection{Scanning languages}
+%
+% \begin{macro}{\lstscanlanguages}
+% We modify some internal definitions and input the files.
+%    \begin{macrocode}
+\def\lstscanlanguages#1#2#3{%
+    \begingroup
+        \def\lst@DefDriver@##1##2##3##4[##5]##6{%
+           \lst@false
+           \lst@lAddTo\lst@scan{##6(##5),}%
+           \begingroup
+           \@ifnextchar[{\lst@XDefDriver{##1}##3}{\lst@DefDriver@@##3}}%
+        \def\lst@XXDefDriver[##1]{}%
+        \lst@InputCatcodes
+        \def\lst@dontinput{#3}%
+        \let\lst@scan\@empty
+        \lst@for{#2}\do{%
+            \lst@IfOneOf##1\relax\lst@dontinput
+                {}%
+                {\InputIfFileExists{##1}{}{}}}%
+        \global\let\@gtempa\lst@scan
+    \endgroup
+    \let#1\@gtempa}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstprintlanguages}
+% |\do| creates a box of width 0.5|\linewidth| or |\linewidth| depending
+% on how wide the argument is. This leads to `two column' output.
+% The other main thing is sorting the list and begin with the output.
+%    \begin{macrocode}
+\def\lstprintlanguages#1{%
+    \def\do##1{\setbox\@tempboxa\hbox{##1\space\space}%
+        \ifdim\wd\@tempboxa<.5\linewidth \wd\@tempboxa.5\linewidth
+                                   \else \wd\@tempboxa\linewidth \fi
+        \box\@tempboxa\allowbreak}%
+    \begin{quote}
+      \par\noindent
+      \hyphenpenalty=\@M \rightskip=\z@\@plus\linewidth\relax
+      \lst@BubbleSort#1%
+      \expandafter\lst@NextLanguage#1\relax(\relax),%
+    \end{quote}}
+%    \end{macrocode}
+% We get and define the current language and \ldots
+%    \begin{macrocode}
+\def\lst@NextLanguage#1(#2),{%
+    \ifx\relax#1\else
+        \def\lst@language{#1}\def\lst@dialects{(#2),}%
+        \expandafter\lst@NextLanguage@
+    \fi}
+%    \end{macrocode}
+% \ldots\space gather all available dialect of this language (note that the
+% list has been sorted)
+%    \begin{macrocode}
+\def\lst@NextLanguage@#1(#2),{%
+    \def\lst@temp{#1}%
+    \ifx\lst@temp\lst@language
+        \lst@lAddTo\lst@dialects{(#2),}%
+        \expandafter\lst@NextLanguage@
+    \else
+%    \end{macrocode}
+% or begin to print this language with all its dialects. Therefor we sort the
+% dialects
+%    \begin{macrocode}
+        \do{\lst@language
+        \ifx\lst@dialects\lst@emptydialect\else
+            \expandafter\lst@NormedDef\expandafter\lst@language
+                \expandafter{\lst@language}%
+            \space(%
+            \lst@BubbleSort\lst@dialects
+            \expandafter\lst@PrintDialects\lst@dialects(\relax),%
+            )%
+        \fi}%
+        \def\lst@next{\lst@NextLanguage#1(#2),}%
+        \expandafter\lst@next
+    \fi}
+\def\lst@emptydialect{(),}
+%    \end{macrocode}
+% and print the dialect with appropriate commas in between.
+%    \begin{macrocode}
+\def\lst@PrintDialects(#1),{%
+    \ifx\@empty#1\@empty empty\else
+        \lst@PrintDialect{#1}%
+    \fi
+    \lst@PrintDialects@}
+\def\lst@PrintDialects@(#1),{%
+    \ifx\relax#1\else
+        , \lst@PrintDialect{#1}%
+        \expandafter\lst@PrintDialects@
+    \fi}
+%    \end{macrocode}
+% Here we take care of default dialects.
+%    \begin{macrocode}
+\def\lst@PrintDialect#1{%
+    \lst@NormedDef\lst@temp{#1}%
+    \expandafter\ifx\csname\@lst dd@\lst@language\endcsname\lst@temp
+        \texttt{\underbar{#1}}%
+    \else
+        \texttt{#1}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Bubble sort}
+%
+% \begin{macro}{\lst@IfLE}
+% \meta{string 1}|\relax\@empty|\meta{string 2}|\relax\@empty|\marg{then}\meta{else}.
+% If \meta{string 1} $\leq$ \meta{string 2}, we execute \meta{then} and
+% \meta{else} otherwise.
+% Note that this comparision is case insensitive.
+%    \begin{macrocode}
+\def\lst@IfLE#1#2\@empty#3#4\@empty{%
+    \ifx #1\relax
+        \let\lst@next\@firstoftwo
+    \else \ifx #3\relax
+        \let\lst@next\@secondoftwo
+    \else
+        \lowercase{\ifx#1#3}%
+            \def\lst@next{\lst@IfLE#2\@empty#4\@empty}%
+        \else
+            \lowercase{\ifnum`#1<`#3}\relax
+                \let\lst@next\@firstoftwo
+            \else
+                \let\lst@next\@secondoftwo
+            \fi
+        \fi
+    \fi \fi
+    \lst@next}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@BubbleSort}
+% is in fact a derivation of bubble sort.
+%    \begin{macrocode}
+\def\lst@BubbleSort#1{%
+    \ifx\@empty#1\else
+        \lst@false
+%    \end{macrocode}
+% We `bubble sort' the first, second, \ldots\ elements and \ldots
+%    \begin{macrocode}
+        \expandafter\lst@BubbleSort@#1\relax,\relax,%
+%    \end{macrocode}
+% \ldots\space then the second, third, \ldots\ elements until no elemets have
+% been swapped.
+%    \begin{macrocode}
+        \expandafter\lst@BubbleSort@\expandafter,\lst@sorted
+                                      \relax,\relax,%
+        \let#1\lst@sorted
+        \lst@if
+            \def\lst@next{\lst@BubbleSort#1}%
+            \expandafter\expandafter\expandafter\lst@next
+        \fi
+    \fi}
+\def\lst@BubbleSort@#1,#2,{%
+    \ifx\@empty#1\@empty
+        \def\lst@sorted{#2,}%
+        \def\lst@next{\lst@BubbleSort@@}%
+    \else
+        \let\lst@sorted\@empty
+        \def\lst@next{\lst@BubbleSort@@#1,#2,}%
+    \fi
+    \lst@next}
+%    \end{macrocode}
+% But the bubbles rise only one step per call. Putting the elements at their
+% top most place would be inefficient (since \TeX\ had to read much more
+% parameters in this case).
+%    \begin{macrocode}
+\def\lst@BubbleSort@@#1,#2,{%
+    \ifx\relax#1\else
+        \ifx\relax#2%
+            \lst@lAddTo\lst@sorted{#1,}%
+            \expandafter\expandafter\expandafter\lst@BubbleSort@@@
+        \else
+            \lst@IfLE #1\relax\@empty #2\relax\@empty
+                          {\lst@lAddTo\lst@sorted{#1,#2,}}%
+                {\lst@true \lst@lAddTo\lst@sorted{#2,#1,}}%
+            \expandafter\expandafter\expandafter\lst@BubbleSort@@
+        \fi
+    \fi}
+\def\lst@BubbleSort@@@#1\relax,{}
+%    \end{macrocode}
+%    \begin{macrocode}
+%</doc>
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \section{Interfaces to other programs}
+%
+%
+% \subsection{0.21 compatibility}
+%
+% \begin{aspect}{0.21}
+% Some keys have just been renamed.
+%    \begin{macrocode}
+%<*0.21>
+\lst@BeginAspect{0.21}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\lst@Key{labelstyle}{}{\def\lst@numberstyle{#1}}
+\lst@Key{labelsep}{10pt}{\def\lst@numbersep{#1}}
+\lst@Key{labelstep}{0}{%
+    \ifnum #1=\z@ \KV@lst@numbers{none}%
+            \else \KV@lst@numbers{left}\fi
+    \def\lst@stepnumber{#1\relax}}
+\lst@Key{firstlabel}\relax{\def\lst@firstnumber{#1\relax}}
+\lst@Key{advancelabel}\relax{\def\lst@advancenumber{#1\relax}}
+\let\c@lstlabel\c@lstnumber
+\lst@AddToHook{Init}{\def\thelstnumber{\thelstlabel}}
+\newcommand*\thelstlabel{\@arabic\c@lstlabel}
+%    \end{macrocode}
+% A |\let| in the second last line has been changed to |\def| after a bug
+% report by \lsthelper{Venkatesh~Prasad~Ranganath}{2002/08/31}{Undefined
+% control sequence \thelstnumber with 0.21-option}.
+%    \begin{macrocode}
+\lst@Key{first}\relax{\def\lst@firstline{#1\relax}}
+\lst@Key{last}\relax{\def\lst@lastline{#1\relax}}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{framerulewidth}{.4pt}{\def\lst@framerulewidth{#1}}
+\lst@Key{framerulesep}{2pt}{\def\lst@rulesep{#1}}
+\lst@Key{frametextsep}{3pt}{\def\lst@frametextsep{#1}}
+\lst@Key{framerulecolor}{}{\lstKV@OptArg[]{#1}%
+    {\ifx\@empty##2\@empty
+         \let\lst@rulecolor\@empty
+     \else
+         \ifx\@empty##1\@empty
+             \def\lst@rulecolor{\color{##2}}%
+         \else
+             \def\lst@rulecolor{\color[##1]{##2}}%
+         \fi
+     \fi}}
+\lst@Key{backgroundcolor}{}{\lstKV@OptArg[]{#1}%
+    {\ifx\@empty##2\@empty
+         \let\lst@bkgcolor\@empty
+     \else
+         \ifx\@empty##1\@empty
+             \def\lst@bkgcolor{\color{##2}}%
+         \else
+             \def\lst@bkgcolor{\color[##1]{##2}}%
+         \fi
+     \fi}}
+\lst@Key{framespread}{\z@}{\def\lst@framespread{#1}}
+\lst@AddToHook{PreInit}
+    {\@tempdima\lst@framespread\relax \divide\@tempdima\tw@
+     \edef\lst@framextopmargin{\the\@tempdima}%
+     \let\lst@framexrightmargin\lst@framextopmargin
+     \let\lst@framexbottommargin\lst@framextopmargin
+     \advance\@tempdima\lst@xleftmargin\relax
+     \edef\lst@framexleftmargin{\the\@tempdima}}
+%    \end{macrocode}
+% \lsthelper{Harald~Harders}{1998/03/30}{inner- and outerspread} had the idea
+% of two spreads (inner and outer). We either divide the dimension by two or
+% assign the two dimensions to inner- and outerspread.
+%    \begin{macrocode}
+\newdimen\lst@innerspread \newdimen\lst@outerspread
+\lst@Key{spread}{\z@,\z@}{\lstKV@CSTwoArg{#1}%
+    {\lst@innerspread##1\relax
+     \ifx\@empty##2\@empty
+         \divide\lst@innerspread\tw@\relax
+         \lst@outerspread\lst@innerspread
+     \else
+         \lst@outerspread##2\relax
+     \fi}}
+\lst@AddToHook{BoxUnsafe}{\lst@outerspread\z@ \lst@innerspread\z@}
+\lst@Key{wholeline}{false}[t]{\lstKV@SetIf{#1}\lst@ifresetmargins}
+\lst@Key{indent}{\z@}{\def\lst@xleftmargin{#1}}
+\lst@AddToHook{PreInit}
+    {\lst@innerspread=-\lst@innerspread
+     \lst@outerspread=-\lst@outerspread
+     \ifodd\c@page \advance\lst@innerspread\lst@xleftmargin
+             \else \advance\lst@outerspread\lst@xleftmargin \fi
+     \ifodd\c@page
+         \edef\lst@xleftmargin{\the\lst@innerspread}%
+         \edef\lst@xrightmargin{\the\lst@outerspread}%
+     \else
+         \edef\lst@xleftmargin{\the\lst@outerspread}%
+         \edef\lst@xrightmargin{\the\lst@innerspread}%
+     \fi}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{defaultclass}\relax{\def\lst@classoffset{#1}}
+\lst@Key{stringtest}\relax{}% dummy
+\lst@Key{outputpos}\relax{\lst@outputpos#1\relax\relax}
+%    \end{macrocode}
+%    \begin{macrocode}
+\lst@Key{stringspaces}\relax[t]{\lstKV@SetIf{#1}\lst@ifshowstringspaces}
+\lst@Key{visiblespaces}\relax[t]{\lstKV@SetIf{#1}\lst@ifshowspaces}
+\lst@Key{visibletabs}\relax[t]{\lstKV@SetIf{#1}\lst@ifshowtabs}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</0.21>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{\textsf{fancyvrb}}
+%
+% \lsthelper{Denis~Girou}{1998/07/26}{fancyvrb} asked whether
+% \packagename{fancyvrb} and \packagename{listings} could work together.
+%
+% \begin{lstkey}{fancyvrb}
+% We set the boolean and call a submacro.
+%    \begin{macrocode}
+%<*kernel>
+\lst@Key{fancyvrb}\relax[t]{%
+    \lstKV@SetIf{#1}\lst@iffancyvrb
+    \lstFV@fancyvrb}
+\ifx\lstFV@fancyvrb\@undefined
+    \gdef\lstFV@fancyvrb{\lst@RequireAspects{fancyvrb}\lstFV@fancyvrb}
+\fi
+%</kernel>
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{aspect}{fancyvrb}
+% We end the job if \packagename{fancyvrb} is not present.
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect{fancyvrb}
+%    \end{macrocode}
+%    \begin{macrocode}
+\@ifundefined{FancyVerbFormatLine}
+    {\typeout{^^J%
+     ***^^J%
+     *** `listings.sty' needs `fancyvrb.sty' right now.^^J%
+     *** Please ensure its availability and try again.^^J%
+     ***^^J}%
+     \batchmode \@@end}{}
+%    \end{macrocode}
+%
+% \begin{macro}{\lstFV@fancyvrb}
+% We assign the correct |\FancyVerbFormatLine| macro.
+%    \begin{macrocode}
+\gdef\lstFV@fancyvrb{%
+    \lst@iffancyvrb
+        \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine\else
+            \let\lstFV@FVFL\FancyVerbFormatLine
+            \let\FancyVerbFormatLine\lstFV@FancyVerbFormatLine
+        \fi
+    \else
+        \ifx\lstFV@FVFL\@undefined\else
+            \let\FancyVerbFormatLine\lstFV@FVFL
+            \let\lstFV@FVFL\@undefined
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstFV@VerbatimBegin}
+% We initialize things if necessary.
+%    \begin{macrocode}
+\gdef\lstFV@VerbatimBegin{%
+    \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine
+        \lsthk@TextStyle \lsthk@BoxUnsafe
+        \lsthk@PreSet
+        \lst@activecharsfalse
+        \let\normalbaselines\relax
+%    \end{macrocode}
+% \begin{TODO}
+% Is this |\let| bad?
+% \end{TODO}
+% I inserted |\lst@ifresetmargins|\ldots|\fi| after a bug report from
+% \lsthelper{Peter~Bartke}{1999/11/18}{wrong fancyvrb frame}. The linewidth
+% is saved and restored since a bug report by \lsthelper{Denis~Girou}
+% {2003/07/04}{problem in list environments with fancyvrb=true}.
+%    \begin{macrocode}
+\xdef\lstFV@RestoreData{\noexpand\linewidth\the\linewidth\relax}%
+        \lst@Init\relax
+        \lst@ifresetmargins \advance\linewidth-\@totalleftmargin \fi
+\lstFV@RestoreData
+        \everypar{}\global\lst@newlines\z@
+        \lst@mode\lst@nomode \let\lst@entermodes\@empty
+        \lst@InterruptModes
+%    \end{macrocode}
+% \lsthelper{Rolf~Niepraschk}{1998/11/25}{ligatures problem} reported a bug
+% concerning ligatures to \lsthelper{Denis~Girou}{1998/11/27}{use |\@noligs|}.
+%    \begin{macrocode}
+%% D.G. modification begin - Nov. 25, 1998
+        \let\@noligs\relax
+%% D.G. modification end
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lstFV@VerbatimEnd}
+% A box and macro must exist after |\lst@DeInit|.
+% We store them globally.
+%    \begin{macrocode}
+\gdef\lstFV@VerbatimEnd{%
+    \ifx\FancyVerbFormatLine\lstFV@FancyVerbFormatLine
+        \global\setbox\lstFV@gtempboxa\box\@tempboxa
+        \global\let\@gtempa\FV@ProcessLine
+        \lst@mode\lst@Pmode
+        \lst@DeInit
+        \let\FV@ProcessLine\@gtempa
+        \setbox\@tempboxa\box\lstFV@gtempboxa
+        \par
+    \fi}
+%    \end{macrocode}
+% The |\par| has been added after a bug report by \lsthelper{Peter~Bartke}
+% {2002/04/10}{TeX is not in vertical mode when leaving "Verbatim"}.
+%    \begin{macrocode}
+\newbox\lstFV@gtempboxa
+%    \end{macrocode}
+% \end{macro}
+%
+% \noindent
+% We insert |\lstFV@VerbatimBegin| and |\lstFV@VerbatimEnd| where necessary.
+%    \begin{macrocode}
+\lst@AddTo\FV@VerbatimBegin\lstFV@VerbatimBegin
+\lst@AddToAtTop\FV@VerbatimEnd\lstFV@VerbatimEnd
+\lst@AddTo\FV@LVerbatimBegin\lstFV@VerbatimBegin
+\lst@AddToAtTop\FV@LVerbatimEnd\lstFV@VerbatimEnd
+\lst@AddTo\FV@BVerbatimBegin\lstFV@VerbatimBegin
+\lst@AddToAtTop\FV@BVerbatimEnd\lstFV@VerbatimEnd
+%    \end{macrocode}
+%
+% \begin{macro}{\lstFV@FancyVerbFormatLine}
+% `@' terminates the argument of |\lst@FVConvert|.
+% Moreover |\lst@ReenterModes| and |\lst@InterruptModes| encloses some code.
+% This ensures that we have same group level at the beginning and at the end of
+% the macro---even if the user begins but doesn't end a comment, which means
+% one open group.
+% Furthermore we use |\vtop| and reset |\lst@newlines| to allow line breaking.
+%    \begin{macrocode}
+\gdef\lstFV@FancyVerbFormatLine#1{%
+    \let\lst@arg\@empty \lst@FVConvert#1\@nil
+    \global\lst@newlines\z@
+    \vtop{\noindent\lst@parshape
+          \lst@ReenterModes
+          \lst@arg \lst@PrintToken\lst@EOLUpdate\lsthk@InitVarsBOL
+          \lst@InterruptModes}}
+%    \end{macrocode}
+% The |\lst@parshape| inside |\vtop| is due to a bug report from
+% \lsthelper{Peter~Bartke}{1999/11/18}{wrong par indention with fancyvrb}.
+% A |\leavevmode| became |\noindent|.
+% \end{macro}
+%
+% \begin{lstkey}{fvcmdparams}
+% \begin{lstkey}{morefvcmdparams}
+% These keys adjust \lst@FVcmdparams, which will be used by the following
+% conversion macro. The base set of commands and parameter numbers was
+% provided by \lsthelper{Denis~Girou}{2002/05/31}{init of fvcmdparams}.
+%    \begin{macrocode}
+\lst@Key{fvcmdparams}%
+    {\overlay\@ne}%
+    {\def\lst@FVcmdparams{,#1}}
+\lst@Key{morefvcmdparams}\relax{\lst@lAddTo\lst@FVcmdparams{,#1}}
+%    \end{macrocode}
+% \end{lstkey}
+% \end{lstkey}
+%
+% \begin{macro}{\lst@FVConvert}
+% We do conversion or \ldots
+%    \begin{macrocode}
+\gdef\lst@FVConvert{\@tempcnta\z@ \lst@FVConvertO@}%
+\gdef\lst@FVConvertO@{%
+    \ifcase\@tempcnta
+        \expandafter\futurelet\expandafter\@let@token
+        \expandafter\lst@FVConvert@@
+    \else
+%    \end{macrocode}
+% \ldots\ we append arguments without conversion, argument by argument,
+% |\@tempcnta| times.
+%    \begin{macrocode}
+        \expandafter\lst@FVConvertO@a
+    \fi}
+\gdef\lst@FVConvertO@a#1{%
+    \lst@lAddTo\lst@arg{{#1}}\advance\@tempcnta\m@ne
+    \lst@FVConvertO@}%
+%    \end{macrocode}
+% Since |\@ifnextchar\bgroup| might fail, we have to use |\ifcat| here.
+% Bug reported by \lsthelper{Denis~Girou}{1999/07/26}{fancyvrb=true + `second
+% commandchar' other than \{ doesn't work}.
+% However we don't gobble space tokens as |\@ifnextchar| does.
+%    \begin{macrocode}
+\gdef\lst@FVConvert@@{%
+    \ifcat\noexpand\@let@token\bgroup \expandafter\lst@FVConvertArg
+                                \else \expandafter\lst@FVConvert@ \fi}
+%    \end{macrocode}
+% Coming to such a catcode${}={}$1 character we convert the argument and add
+% it together with group delimiters to |\lst@arg|.
+% We also add |\lst@PrintToken|, which prints all collected characters before
+% we forget them.
+% Finally we continue the conversion.
+%    \begin{macrocode}
+\gdef\lst@FVConvertArg#1{%
+    {\let\lst@arg\@empty
+     \lst@FVConvert#1\@nil
+     \global\let\@gtempa\lst@arg}%
+     \lst@lExtend\lst@arg{\expandafter{\@gtempa\lst@PrintToken}}%
+     \lst@FVConvert}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@FVConvert@#1{%
+    \ifx \@nil#1\else
+       \if\relax\noexpand#1%
+          \lst@lAddTo\lst@arg{\lst@OutputLostSpace\lst@PrintToken#1}%
+       \else
+          \lccode`\~=`#1\lowercase{\lst@lAddTo\lst@arg~}%
+       \fi
+       \expandafter\lst@FVConvert
+    \fi}
+%    \end{macrocode}
+% Having no |\bgroup|, we look whether we've found the end of the input, and
+% convert one token ((non)active character or control sequence).
+%    \begin{macrocode}
+\gdef\lst@FVConvert@#1{%
+    \ifx \@nil#1\else
+       \if\relax\noexpand#1%
+          \lst@lAddTo\lst@arg{\lst@OutputLostSpace\lst@PrintToken#1}%
+%    \end{macrocode}
+% Here we check for registered commands with arguments and set the value of
+% |\@tempcnta| as required.
+%    \begin{macrocode}
+          \def\lst@temp##1,#1##2,##3##4\relax{%
+              \ifx##3\@empty \else \@tempcnta##2\relax \fi}%
+          \expandafter\lst@temp\lst@FVcmdparams,#1\z@,\@empty\relax
+       \else
+          \lccode`\~=`#1\lowercase{\lst@lAddTo\lst@arg~}%
+       \fi
+       \expandafter\lst@FVConvertO@
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{Omega support}
+%
+% \begingroup
+% $\Omega$ support looks easy---I hope it works at least in some cases.
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+%    \begin{macrocode}
+\@ifundefined{ocp}{}
+    {\lst@AddToHook{OutputBox}%
+         {\let\lst@ProcessLetter\@firstofone
+          \let\lst@ProcessDigit\@firstofone
+          \let\lst@ProcessOther\@firstofone}}
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \endgroup
+%
+%
+% \subsection{\textsf{LGrind}}
+%
+% \begin{aspect}{lgrind}
+% \begin{macro}{\lst@LGGetNames}
+% is used to extract the language names from |\lst@arg| (the
+% \packagename{LGrind} definition).
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords,comments,strings,language]{lgrind}
+%    \end{macrocode}
+%    \begin{macrocode}
+\gdef\lst@LGGetNames#1:#2\relax{%
+    \lst@NormedDef\lstlang@{#1}\lst@ReplaceInArg\lstlang@{|,}%
+    \def\lst@arg{:#2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGGetValue}
+% returns in |\lst@LGvalue| the value of capability |#1| given by the list
+% |\lst@arg|. If |#1| is not found, we have |\lst@if|=|\iffalse|.
+% Otherwise it is true and the ``cap=value'' pair is removed from the list.
+% First we test for |#1| and
+%    \begin{macrocode}
+\gdef\lst@LGGetValue#1{%
+    \lst@false
+    \def\lst@temp##1:#1##2##3\relax{%
+        \ifx\@empty##2\else \lst@LGGetValue@{#1}\fi}
+    \expandafter\lst@temp\lst@arg:#1\@empty\relax}
+%    \end{macrocode}
+% remove the pair if necessary.
+%    \begin{macrocode}
+\gdef\lst@LGGetValue@#1{%
+    \lst@true
+    \def\lst@temp##1:#1##2:##3\relax{%
+        \@ifnextchar=\lst@LGGetValue@@{\lst@LGGetValue@@=}##2\relax
+        \def\lst@arg{##1:##3}}%
+    \expandafter\lst@temp\lst@arg\relax}
+\gdef\lst@LGGetValue@@=#1\relax{\def\lst@LGvalue{#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGGetComment}
+% stores the comment delimiters (enclosed in braces) in |#2| if comment of type
+% |#1| is present and not a comment line. Otherwise |#2| is empty.
+%    \begin{macrocode}
+\gdef\lst@LGGetComment#1#2{%
+    \let#2\@empty
+    \lst@LGGetValue{#1b}%
+    \lst@if
+        \let#2\lst@LGvalue
+        \lst@LGGetValue{#1e}%
+        \ifx\lst@LGvalue\lst@LGEOL
+            \edef\lstlang@{\lstlang@,commentline={#2}}%
+            \let#2\@empty
+        \else
+            \edef#2{{#2}{\lst@LGvalue}}%
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGGetString}
+% does the same for string delimiters, but it doesn't `return' any value.
+%    \begin{macrocode}
+\gdef\lst@LGGetString#1#2{%
+    \lst@LGGetValue{#1b}%
+    \lst@if
+        \let#2\lst@LGvalue
+        \lst@LGGetValue{#1e}%
+        \ifx\lst@LGvalue\lst@LGEOL
+            \edef\lstlang@{\lstlang@,morestringizer=[l]{#2}}%
+        \else
+%    \end{macrocode}
+% we must check for |\e|, i.e.~whether we have to use \texttt doubled or
+% \texttt backslashed stringizer.
+%    \begin{macrocode}
+            \ifx #2\lst@LGvalue
+                \edef\lstlang@{\lstlang@,morestringizer=[d]{#2}}%
+            \else
+                \edef\lst@temp{\lst@LGe#2}%
+                \ifx \lst@temp\lst@LGvalue
+                    \edef\lstlang@{\lstlang@,morestringizer=[b]{#2}}%
+                \else
+                    \PackageWarning{Listings}%
+                    {String #2...\lst@LGvalue\space not supported}%
+                \fi
+            \fi
+        \fi
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGDefLang}
+% defines the language given by |\lst@arg|, the definition part, and
+% |\lst@language@|, the language name. First we remove unwanted stuff from
+% |\lst@arg|, e.g.~we replace |:\ :| by |:|.
+%    \begin{macrocode}
+\gdef\lst@LGDefLang{%
+    \lst@LGReplace
+    \let\lstlang@\empty
+%    \end{macrocode}
+% Get the keywords and values of friends.
+%    \begin{macrocode}
+    \lst@LGGetValue{kw}%
+    \lst@if
+        \lst@ReplaceInArg\lst@LGvalue{{ },}%
+        \edef\lstlang@{\lstlang@,keywords={\lst@LGvalue}}%
+    \fi
+%    \end{macrocode}
+%    \begin{macrocode}
+    \lst@LGGetValue{oc}%
+    \lst@if
+        \edef\lstlang@{\lstlang@,sensitive=f}%
+    \fi
+%    \end{macrocode}
+%    \begin{macrocode}
+    \lst@LGGetValue{id}%
+    \lst@if
+        \edef\lstlang@{\lstlang@,alsoletter=\lst@LGvalue}%
+    \fi
+%    \end{macrocode}
+% Now we get the comment delimiters and use them as single or double comments
+% according to whether there are two or four delimiters.
+% Note that |\lst@LGGetComment| takes care of comment lines.
+%    \begin{macrocode}
+    \lst@LGGetComment a\lst@LGa
+    \lst@LGGetComment c\lst@LGc
+    \ifx\lst@LGa\@empty
+        \ifx\lst@LGc\@empty\else
+            \edef\lstlang@{\lstlang@,singlecomment=\lst@LGc}%
+        \fi
+    \else
+        \ifx\lst@LGc\@empty
+            \edef\lstlang@{\lstlang@,singlecomment=\lst@LGa}%
+        \else
+            \edef\lstlang@{\lstlang@,doublecomment=\lst@LGc\lst@LGa}%
+        \fi
+    \fi
+%    \end{macrocode}
+% Now we parse the stringizers.
+%    \begin{macrocode}
+    \lst@LGGetString s\lst@LGa
+    \lst@LGGetString l\lst@LGa
+%    \end{macrocode}
+% We test for the continuation capability and
+%    \begin{macrocode}
+    \lst@LGGetValue{tc}%
+    \lst@if
+        \edef\lstlang@{\lstlang@,lgrindef=\lst@LGvalue}%
+    \fi
+%    \end{macrocode}
+% define the language.
+%    \begin{macrocode}
+    \expandafter\xdef\csname\@lst LGlang@\lst@language@\endcsname
+        {\noexpand\lstset{\lstlang@}}%
+%    \end{macrocode}
+% Finally we inform the user of all ignored capabilities.
+%    \begin{macrocode}
+    \lst@ReplaceInArg\lst@arg{{: :}:}\let\lst@LGvalue\@empty
+    \expandafter\lst@LGDroppedCaps\lst@arg\relax\relax
+    \ifx\lst@LGvalue\@empty\else
+        \PackageWarningNoLine{Listings}{Ignored capabilities for
+            \space `\lst@language@' are\MessageBreak\lst@LGvalue}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGDroppedCaps}
+% just drops a previous value and appends the next capabilty name to
+% |\lst@LGvalue|.
+%    \begin{macrocode}
+\gdef\lst@LGDroppedCaps#1:#2#3{%
+    \ifx#2\relax
+        \lst@RemoveCommas\lst@LGvalue
+    \else
+        \edef\lst@LGvalue{\lst@LGvalue,#2#3}%
+        \expandafter\lst@LGDroppedCaps
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\lst@LGReplace}
+% \begin{macro}{\lst@LGe}
+% We replace `escaped \verb!:^$|!' by catcode 11 versions, and other strings
+% by some kind of short versions (which is necessary to get the above
+% definitions work).
+%    \begin{macrocode}
+\begingroup
+\catcode`\/=0
+\lccode`\z=`\:\lccode`\y=`\^\lccode`\x=`\$\lccode`\v=`\|
+\catcode`\\=12\relax
+/lowercase{%
+/gdef/lst@LGReplace{/lst@ReplaceInArg/lst@arg
+    {{\:}{z }{\^}{y}{\$}{x}{\|}{v}{ \ }{ }{:\ :}{:}{\ }{ }{\(}({\)})}}
+/gdef/lst@LGe{\e}
+}
+/endgroup
+%    \end{macrocode}
+% \end{macro}\end{macro}
+%
+% \begin{macro}{\lst@LGRead}
+% reads one language definition and defines the language if the correct one
+% is found.
+%    \begin{macrocode}
+\gdef\lst@LGRead#1\par{%
+    \lst@LGGetNames#1:\relax
+    \def\lst@temp{endoflanguagedefinitions}%
+    \ifx\lstlang@\lst@temp
+        \let\lst@next\endinput
+    \else
+        \expandafter\lst@IfOneOf\lst@language@\relax\lstlang@
+            {\lst@LGDefLang \let\lst@next\endinput}%
+            {\let\lst@next\lst@LGRead}%
+    \fi
+    \lst@next}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{lstkey}{lgrindef}
+% We only have to request the language and
+%    \begin{macrocode}
+\lst@Key{lgrindef}\relax{%
+    \lst@NormedDef\lst@language@{#1}%
+    \begingroup
+    \@ifundefined{lstLGlang@\lst@language@}%
+        {\everypar{\lst@LGRead}%
+         \catcode`\\=12\catcode`\{=12\catcode`\}=12\catcode`\%=12%
+         \catcode`\#=14\catcode`\$=12\catcode`\^=12\catcode`\_=12\relax
+         \input{\lstlgrindeffile}%
+        }{}%
+    \endgroup
+%    \end{macrocode}
+% select it or issue an error message.
+%    \begin{macrocode}
+    \@ifundefined{lstLGlang@\lst@language@}%
+        {\PackageError{Listings}%
+         {LGrind language \lst@language@\space undefined}%
+         {The language is not loadable. \@ehc}}%
+        {\lsthk@SetLanguage
+         \csname\@lst LGlang@\lst@language@\endcsname}}
+%    \end{macrocode}
+% \end{lstkey}
+%
+% \begin{macro}{\lstlgrindeffile}
+% contains just the file name.
+%    \begin{macrocode}
+\@ifundefined{lstlgrindeffile}
+    {\lst@UserCommand\lstlgrindeffile{lgrindef.}}{}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \subsection{\textsf{hyperref}}
+%
+% \begin{aspect}{hyper}
+%    \begin{macrocode}
+%<*misc>
+\lst@BeginAspect[keywords]{hyper}
+%    \end{macrocode}
+%
+% \begin{lstkey}{hyperanchor}
+% \begin{lstkey}{hyperlink}
+% determine the macro to set an anchor and a link, respectively.
+%    \begin{macrocode}
+\lst@Key{hyperanchor}\hyper@@anchor{\let\lst@hyperanchor#1}
+\lst@Key{hyperlink}\hyperlink{\let\lst@hyperlink#1}
+%    \end{macrocode}
+% \end{lstkey}\end{lstkey}
+% Again, the main thing is a special working procedure. First we extract the
+% contents of |\lst@token| and get a free macro name for this current character
+% string (using prefix |lstHR@| and a number as suffix). Then we make this
+% free macro equivalent to |\@empty|, so it is not used the next time.
+%    \begin{macrocode}
+\lst@InstallKeywords{h}{hyperref}{}\relax{}
+    {\begingroup
+         \let\lst@UM\@empty \xdef\@gtempa{\the\lst@token}%
+     \endgroup
+     \lst@GetFreeMacro{lstHR@\@gtempa}%
+     \global\expandafter\let\lst@freemacro\@empty
+%    \end{macrocode}
+% |\@tempcnta| is the suffix of the free macro. We use it here to refer to
+% the last occurence of the same string. To do this, we redefine the output
+% macro |\lst@alloverstyle| to set an anchor \ldots
+%    \begin{macrocode}
+     \@tempcntb\@tempcnta \advance\@tempcntb\m@ne
+     \edef\lst@alloverstyle##1{%
+         \let\noexpand\lst@alloverstyle\noexpand\@empty
+         \noexpand\smash{\raise\baselineskip\hbox
+             {\noexpand\lst@hyperanchor{lst.\@gtempa\the\@tempcnta}%
+                                       {\relax}}}%
+%    \end{macrocode}
+% \ldots\space and a link to the last occurence (if there is any).
+%    \begin{macrocode}
+         \ifnum\@tempcnta=\z@ ##1\else
+             \noexpand\lst@hyperlink{lst.\@gtempa\the\@tempcntb}{##1}%
+         \fi}%
+    }
+    od
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\lst@EndAspect
+%</misc>
+%    \end{macrocode}
+% \end{aspect}
+%
+%
+% \section{Epilogue}
+%
+% \begingroup
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+% Each option adds the aspect name to |\lst@loadaspects| or removes it from that data macro.
+%    \begin{macrocode}
+\DeclareOption*{\expandafter\lst@ProcessOption\CurrentOption\relax}
+\def\lst@ProcessOption#1#2\relax{%
+    \ifx #1!%
+        \lst@DeleteKeysIn\lst@loadaspects{#2}%
+    \else
+        \lst@lAddTo\lst@loadaspects{,#1#2}%
+    \fi}
+%    \end{macrocode}
+% The following aspects are loaded by default.
+%    \begin{macrocode}
+\@ifundefined{lst@loadaspects}
+  {\def\lst@loadaspects{strings,comments,escape,style,language,%
+      keywords,labels,lineshape,frames,emph,index}%
+  }{}
+%    \end{macrocode}
+% We load the patch file, \ldots
+%    \begin{macrocode}
+\InputIfFileExists{lstpatch.sty}{}{}
+%    \end{macrocode}
+% \ldots\ process the options, \ldots
+%    \begin{macrocode}
+\let\lst@ifsavemem\iffalse
+\DeclareOption{savemem}{\let\lst@ifsavemem\iftrue}
+\DeclareOption{noaspects}{\let\lst@loadaspects\@empty}
+\ProcessOptions
+%    \end{macrocode}
+% \ldots\ and load the aspects.
+%    \begin{macrocode}
+\lst@RequireAspects\lst@loadaspects
+\let\lst@loadaspects\@empty
+%    \end{macrocode}
+% If present we select the empty style and language.
+%    \begin{macrocode}
+\lst@UseHook{SetStyle}\lst@UseHook{EmptyStyle}
+\lst@UseHook{SetLanguage}\lst@UseHook{EmptyLanguage}
+%    \end{macrocode}
+% Finally we load the configuration files.
+%    \begin{macrocode}
+\InputIfFileExists{listings.cfg}{}{}
+\InputIfFileExists{lstlocal.cfg}{}{}
+%<info>\lst@ReportAllocs
+%    \end{macrocode}
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+% \endgroup
+%
+%
+% \section{History}
+% \begingroup\small
+% Only major changes are listed here. Introductory version numbers of commands
+% and keys are in the sources of the guides, which makes this history fairly
+% short.
+% \renewcommand\labelitemi{--}
+% \begin{itemize}
+% \item[0.1] from 1996/03/09
+%   \item test version to look whether package is possible or not
+% \item[0.11] from 1996/08/19
+%\iffalse
+%   \item additional blank option (= language)
+%\fi
+%   \item improved alignment
+% \item[0.12] from 1997/01/16
+%   \item nearly `perfect' alignment
+% \item[0.13] from 1997/02/11
+%\iffalse
+%   \item additional languages: Eiffel, Fortran 90, Modula-2, Pascal XSC
+%\fi
+%   \item load on demand: language specific macros moved to driver files
+%   \item comments are declared now and not implemented for each language again
+%         (this makes the \TeX\ sources easier to read)
+% \item[0.14] from 1997/02/18
+%   \item User's guide rewritten, Implementation guide uses macro environment
+%   \item (non) case sensitivity implemented and multiple string types,
+%         i.e.~Modula-2 handles both string types: quotes and double quotes
+%\iffalse
+%   \item comment declaration is user-accessible
+%   \item package compatible to \verb!german.sty!
+%\fi
+% \item[0.15] from 1997/04/18
+%\iffalse
+%   \item additional languages: Java, Turbo Pascal
+%\fi
+%   \item package renamed from \packagename{listing} to \packagename{listings}
+%         since the first already exists
+% \item[0.16] from 1997/06/01
+%\iffalse
+%   \item changed `$<$' to `$>$' in |\lst@SkipToFirst|
+%   \item bug removed: |\lst@Init| must be placed before |\lst@SkipToFirst|
+%\fi
+%   \item listing environment rewritten
+% \item[0.17] from 1997/09/29
+%\iffalse
+%   \item |\spreadlisting| works correct now (e.g.~page numbers don't move right)
+%\fi
+%   \item speed up things (quick `if parameter empty', all |\long| except one
+%         removed, faster \verb!\lst@GotoNextTabStop!, etc.)
+%   \item improved alignment of wide other characters (e.g.~$==$)
+%\iffalse
+%   \item many new languages: Ada, Algol, Cobol, Comal 80, Elan, Fortran 77,
+%         Lisp, Logo, Matlab, Oberon, Perl, PL/I, Simula, SQL, \TeX
+%\fi
+% \item[pre-0.18] from 1998/03/24 (unpublished)
+%\iffalse
+%   \item bug concerning |\labelstyle| (becomes \keyname{numberstyle}) removed
+%         (now oldstylenum example works)
+%\fi
+%   \item experimental implementation of character classes
+% \item[0.19] from 1998/11/09
+%   \item character classes and new \lst-aspects seem to be good
+%   \item user interface uses \packagename{keyval} package
+%   \item \packagename{fancyvrb} support
+% \item[0.20] from 1999/07/12
+%   \item new keyword detection mechanism
+%   \item new aspects: \aspectname{writefile}, \aspectname{breaklines},
+%         captions, \aspectname{html}
+%\iffalse
+%   \item improved \packagename{fancyvrb} support
+%\fi
+%   \item all aspects reside in a single file and the language drivers in
+%         currently two files
+% \item[0.21] 2000/08/23
+%   \item completely new User's guide
+%   \item experimental format definitions
+%   \item keyword classes replaced by families
+%   \item dynamic modes
+% \item[1.0$\beta$] 2001/09/21
+%   \item key names synchronized with \packagename{fancyvrb}
+%   \item \aspectname{frames} aspect extended
+%   \item new output concept (delaying and merging)
+% \item[1.0] 2002/04/01
+%   \item update of all documentation sections including Developer's guide
+%   \item delimiters unified
+% \item[1.1] 2003/06/21
+%   \item bugfix-release with some new keys
+% \item[1.2] 2004/02/13
+%   \item bugfix-release with two new keys and new section \ref{rArbitraryLinerangeMarkers}
+% \item[1.3] 2004/09/07
+%   \item another bugfix-release with LPPL-1.3-compliance
+% \item[1.4] 2007/02/26
+%   \item many bugfixes, and new maintainership
+%   \item several new and updated language definitions
+%   \item many small documentation improvements
+%   \item new keys, multicharacter string delimiters, short inline listings, and more.
+% \item[1.5] 2013/06/27
+%   \item new maintainership
+% \item[1.6] 2015/05/05
+%   \item add discussion about using |\lstinline|\oarg{key=value list}\marg{source code}.
+%   \item add section ``Bugs and workarounds''.
+% \item[1.7] 2018/09/02
+%   \item some new or updated language definitions.
+%   \item several error corrections.
+% \end{itemize}
+% \endgroup
+%
+%
+% \Finale
+%
+\endinput
-- 
cgit v1.2.3

