path: root/Master/texmf-dist/source/latex/environ/environ.dtx

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___________________
The ENVIRON package
v0.2

Provides two things: a new way of defining
environments that read their contents before
processing; and, a \long version of amsmath's
\collect@body macro called \Collect@Body.

Here's an example:

  \NewEnviron{test}[3][]{"#1,#2,\BODY,#3"}
  \begin{test}[zero]{one}{last}
    three\par four
  \end{test}

Produces the equivalent of: 

  "zero,one,three\par four,last"

______________
Will Robertson
wspr 81 [at] gmail [dot] com

Copyright 2007-2014
Distributed under the LaTeX Project Public License
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\preamble

  __________________________________
  Copyright (C) 2007  Will Robertson

  License information appended.


\endpreamble
\postamble

Copyright (C) 2007-2014 by Will Robertson <wspr81@gmail.com>

Distributable under the LaTeX Project Public License,
version 1.3c or higher (your choice). The latest version of
this license is at: http://www.latex-project.org/lppl.txt

This work is "maintained" (as per LPPL maintenance status) 
by Will Robertson.

This work consists of the file  environ.dtx
          and the derived files environ.pdf,
                                environ.sty, and
                                environ.ins.

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\documentclass[a4paper]{ltxdoc}
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\begin{document}
  \DocInput{\jobname.dtx}
\end{document}
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%
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% \fi
%
% \GetFileInfo{\jobname.sty}
% \CheckSum{0}
% \makeatletter
%
% \title{A couple of things involving environments}
% \author{Will Robertson}
% \date{\filedate \qquad \fileversion}
%
% \maketitle
%
% \begin{abstract}
% \noindent This package provides two things, one for document authors and one for macro authors. For the document authors, a new method, \cs{NewEnviron}, fo defining environments that might be more convenient on occasion. And for the package writers, \pkg{amsmath}'s \cmd\collect@body\ command, and a long version of the same, \cmd\Collect@Body.
% \end{abstract}
%
% \section{Introduction}
%
% This packages provides new commands for defining environments:
%
% \begin{example}{}
% \NewEnviron{test}{%
%   \fbox{\parbox{1.5cm}{\BODY}}\color{red}
%   \fbox{\parbox{1.5cm}{\BODY}}}
% \begin{test}
%   par\par graf
% \end{test}
% \end{example}
% \cmd\RenewEnviron\ has the same syntax to redefine a pre-existing environment.
%
% \section{For the document author}
%
% \LaTeX's standard method of defining environments looks like this (ignoring arguments for now):
% \codeline \cmd\newenvironment\marg{name}\marg{pre code}\marg{post code} .
%
% The advantage to using environments is that their contents are not treated as a macro argument, so there are fewer restrictions on what can exist inside, and the processing can be more efficient for long pieces of document text.
%
% The disadvantage of environments is that sometimes you really do want to collect up their body and apply some sort of command to the whole thing. This package provides a way to define such environments: 
% \codeline \cmd\NewEnviron\marg{name}\marg{macro code}\oarg{final code} .\\
% You saw an example in the introduction; the body of the environment is contained within the macro |\BODY|, and \oarg{final code} is the code executed at |\end|\marg{name} (more on this later).
%
% \subsection{Environment arguments}
%
% If you want to use arguments to the environment, these are specified as usual:
% \codeline \cmd\NewEnviron\marg{name}\oarg{N.\,args}\oarg{opt.\,arg.}\marg{macro code}\oarg{final code} \\
% where \marg{macro code} has arguments |#1|, |#2|, \dots, as per traditional \LaTeX\ environment mandatory and optional arguments.
%
% Here's an example with two arguments; one optional argument (|#1|, which is |\today| if omitted) and one mandatory argument (|#2|):
%
% \begin{example}{}
% \NewEnviron{test}[2][\today]{%
%   \fbox{\parbox{3cm}{%
%     \textbf{#2}\\
%     \BODY\\
%     (#1)}}}
% 
% \begin{test}{Title}
%   par\par graf
% \end{test}
%
% \begin{test}[Yesterday]{Title}
%   par\par graf
% \end{test}
% \end{example}
%
% \subsection{\oarg{final code}} 
% This is the code executed at |\end|\marg{name} of the environment. 
% For the purposes of this package it is only designed (but is very useful indeed) for cleanup code such as space gobbling in the input text.
%
% \DescribeMacro{\environfinalcode}
% This macro sets a default value for the \oarg{final code} (unless manually specified) in each subsequent environment created with \cmd\NewEnviron. The default is to define each new environment postfixed by \cmd\ignorespacesafterend, like this:
% \codeline |\environfinalcode{\ignorespacesafterend}| \\
% Here's a silly example:
%
% \begin{example}{}
% \environfinalcode{(finish)}
% \NewEnviron{test}{\fbox{\parbox{3cm}{\BODY}}}
% \begin{test}
%   par\par
%   graf
% \end{test}
% \end{example}
%
% Careful, \cmd\environfinalcode\ cannot contain square brackets without first protecting them with braces (\eg, 
% |\environfinalcode{[end]}|
% will not work but 
% |\environfinalcode{{[end]}}|
% will). This is because the optional argument to \cmd\NewEnviron\ itself uses square brackets as argument delimiters.
%
% \subsection{The \cs{BODY} command}
%
% \DescribeMacro{\environbodyname}
% Using \cs{BODY} as the body of the environment might clash with a command defined by another package.
% To overcome such conflicts, rename this command with
% \codeline |\environbodyname|\cs{\meta{command}}\\
% at which point \cs{NewEnviron} will use \cs{\meta{command}} instead of \cs{BODY}.
% Here's an example:
%
% \begin{example}{}
% \NewEnviron{FOO}{\fbox{\BODY}}
% \environbodyname\envbody
% \NewEnviron{foo}{\fbox{\envbody}}
%
% \begin{FOO}FOO\end{FOO}
% \begin{foo}foo\end{foo}
% \end{example}
%
% \section{For the macro author} 
%
% The \pkg{amsmath} package contains a macro that facilitates the functionality in the previous section, which package writers may wish to use directly. The canonical command is \cmd\collect@body, which I've also defined in \cmd\long\ form to be useable for multi-paragraph environments (\cmd\Collect@Body). Here's how it's used:
%
% \begin{example}{}
% \long\def\wrap#1{[#1]}
% \newenvironment{test}{\Collect@Body\wrap}{}
% \begin{test}
%   hello
%
%   there
% \end{test}
% \end{example}
%
% And here's a crude example with environment arguments:
%
% \begin{example}{}
% \long\def\wrap#1{[\arg#1]}
% \def\arg#1{---#1---\par}
% \newenvironment{test}{\Collect@Body\wrap}{}
% \begin{test}{arg}
%   hello
%
%   there
% \end{test}
% \end{example}
%
% \newpage
% \section{Test}
%
% Here's an example or two to ensure everything that you'd think should work, in fact, does:
%
% \begin{example}{}
% \NewEnviron{test}{%
%   \fbox{\parbox{\linewidth-
%     0.1cm*\currentgrouplevel}{\BODY}}
%   \setlength\fboxrule{2\fboxrule}
%   \fbox{\parbox{\linewidth-
%     0.1cm*\currentgrouplevel}{``\BODY''}}}
%
% \begin{test}
%   outer\par
%   \def\tmp#1{*#1*}%
%   \tmp{aa}\par
%   \begin{test}
%     inner\par
%     \def\tmp#1{(#1)}\tmp{bb}
%   \end{test}
% \end{test}
% \end{example}
%
%
%% ^^A Test that \RenewEnvironment works correctly:
% \newenvironment{foobar}{}{}
% \RenewEnviron{foobar}{\BODY}
%
%
% \StopEventually{}
%
% \clearpage
% \part{\pkg{\jobname} implementation}
%\iffalse
%<*package>
%\fi
%
% This is the package.
%    \begin{macrocode}
\ProvidesPackage{environ}[2014/05/04 v0.3 A new way to define environments]
\RequirePackage{trimspaces}
%    \end{macrocode}
%
% \PrintChanges
%
% \section{Begin}
%
% \begin{macro}{\environbodyname}
% \darg{control sequence}
% Changes the control sequence used to represent the environment body in its definition. Not to be used as a user command; but maybe one day it will be. Don't change this after defining any |\NewEnviron| environments!
%    \begin{macrocode}
\def\environbodyname#1{\def\env@BODY{#1}}
\environbodyname\BODY
%    \end{macrocode}
% \changes{v0.3}{2015/05/04}{Works properly and now documented.}
% \end{macro}
%
% \begin{macro}{\environfinalcode}
% \darg{code}
% This is the \marg{code} that's executed by default at \cs{end}\marg{env.\,name}:
%    \begin{macrocode}
\def\environfinalcode#1{%
  \def\env@finalcode{#1}}
\environfinalcode{\ignorespacesafterend}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\longdef@c}
% \LaTeX3-inspired shorthands.
%    \begin{macrocode}
\def\longdef@c#1{%
  \expandafter\long\expandafter\def\csname#1\endcsname}
%    \end{macrocode}
% \end{macro}
%
% \section{\cs{collect@body}-related code}
%
% \begin{macro}{\collect@body}
% Now, \pkg{amsmath} defines \cmd\collect@body\ for us. But that package may not be loaded, and we don't want to have to load the whole thing just for this one macro.
%    \begin{macrocode}
\unless\ifdefined\collect@body
  \newtoks\@envbody
  \def\collect@body#1{%
    \@envbody{\expandafter#1\expandafter{\the\@envbody}}%
    \edef\process@envbody{\the\@envbody\noexpand\end{\@currenvir}}%
    \@envbody={}%
    \def\begin@stack{b}%
    \begingroup
    \expandafter\let\csname\@currenvir\endcsname\collect@@body
    \edef\process@envbody{%
      \expandafter\noexpand\csname\@currenvir\endcsname}%
    \process@envbody
  }
  \def\push@begins#1\begin#2{%
    \ifx\end#2\else 
      b\expandafter\push@begins
    \fi}
  \def\addto@envbody#1{%
    \global\@envbody\expandafter{\the\@envbody#1}}
  \def\collect@@body#1\end#2{%
    \edef\begin@stack{%
      \push@begins#1\begin\end \expandafter\@gobble\begin@stack}%
    \ifx\@empty\begin@stack
      \endgroup
      \@checkend{#2}%
      \addto@envbody{#1}%
    \else
      \addto@envbody{#1\end{#2}}%
    \fi
    \process@envbody}
\fi
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\Collect@Body}
% And now we define our own `long' version.
%    \begin{macrocode}
\long\def\Collect@Body#1{%
  \@envbody{\expandafter#1\expandafter{\the\@envbody}}%
  \edef\process@envbody{\the\@envbody\noexpand\end{\@currenvir}}%
  \@envbody={}%
  \def\begin@stack{b}%
  \begingroup
  \expandafter\let\csname\@currenvir\endcsname\Collect@@Body
  \edef\process@envbody{%
    \expandafter\noexpand\csname\@currenvir\endcsname}%
  \process@envbody
}
\long\def\Push@Begins#1\begin#2{%
  \ifx\end#2\else 
    b\expandafter\Push@Begins
  \fi}
\long\def\Addto@Envbody#1{%
  \global\@envbody\expandafter{\the\@envbody#1}}
\long\def\Collect@@Body#1\end#2{%
  \edef\begin@stack{%
    \Push@Begins#1\begin\end\expandafter\@gobble\begin@stack}%
  \ifx\@empty\begin@stack
    \endgroup
    \@checkend{#2}%
    \Addto@Envbody{#1}%
  \else
    \Addto@Envbody{#1\end{#2}}%
  \fi
  \process@envbody}
%    \end{macrocode}
% \end{macro}
%
% \section{User-level syntax}
% \begin{macro}{\RenewEnviron}
% \changes{v0.3}{2015/05/04}{Fixed for non-environ commands.}
% \begin{macro}{\NewEnviron}
% This is the new one.
%    \begin{macrocode}
\def\NewEnviron{%
  \let\env@newenvironment\newenvironment
  \env@NewEnviron}
\def\RenewEnviron{%
  \let\env@newenvironment\renewenvironment
  \env@NewEnviron}
%    \end{macrocode}
% \paragraph{Input argument parsing}
% The first optional argument:
%    \begin{macrocode}
\def\env@NewEnviron#1{%
  \@ifnextchar[
    {\env@new@i{#1}}
    {\env@new@iii{#1}{}}}
%    \end{macrocode}
% And the second:
%    \begin{macrocode}
\def\env@new@i#1[#2]{%
  \@ifnextchar[
    {\env@new@ii{#1}[#2]}
    {\env@new@iii{#1}{[#2]}}}
%    \end{macrocode}
% And the second: (cont.)
%    \begin{macrocode}
\def\env@new@ii#1[#2][#3]{%
  \env@new@iii{#1}{[#2][#3]}}
%    \end{macrocode}
% The final optional argument:
%    \begin{macrocode}
\long\def\env@new@iii#1#2#3{%
  \@temptokena={\env@new{#1}{#2}{#3}}%
  \@ifnextchar[{%
    \the\@temptokena
  }{%
    \expandafter\the\expandafter
      \@temptokena\expandafter[\env@finalcode]%
  }}
%    \end{macrocode}
% \paragraph{Environment creation code}
% \begin{macro}{\env@new}
% \darg{name of the environment}
% \darg{possible optional args (either `\meta{empty}' or `\texttt{[N]}' or `\texttt{[N][default]}')}
% \darg{environment code}
% \doarg{final code}
%    \begin{macrocode}
\long\def\env@new#1#2#3[#4]{%
%    \end{macrocode}
% Save the definition of \cs{env@BODY} so we know what to look for.
%    \begin{macrocode}
  \longdef@c{env@#1@BODY\expandafter}\expandafter{\env@BODY}%
%    \end{macrocode}
% Define the new environment to Collect its body and execute |env@#1@parse| on it.
%    \begin{macrocode}
  \env@newenvironment{#1}{%
    \expandafter\Collect@Body\csname env@#1@parse\endcsname
  }{#4}%
%    \end{macrocode}
% |env@#1@parse| executes the body twice: the first time to save the body while ignoring the arguments; and the second time to process the environment definition itself while ignoring the environment body:
%    \begin{macrocode}
  \longdef@c{env@#1@parse}##1{%
    \csname env@#1@save@env\endcsname##1\env@nil
    \csname env@#1@process\endcsname##1\env@nil}%
%    \end{macrocode}
% These must be defined on a per-environment basis in order to get the argument gobbling right: (because there are a variable number of arguments)
%    \begin{macrocode}
  \expandafter\let\csname env@#1@save@env\endcsname\relax
  \expandafter\let\csname env@#1@process\endcsname\relax
  \expandafter\newcommand
    \csname env@#1@save@env\endcsname#2{%
      \expandafter\expandafter\expandafter
        \env@save\csname env@#1@BODY\endcsname}%
  \expandafter\newcommand
    \csname env@#1@process\endcsname#2{#3\env@ignore}%
}
%    \end{macrocode}
% \end{macro}
% \begin{macro}{\env@save}
% If \cmd{\env@BODY} were variable, this macro would have to be saved for every environment definition individually; at the moment we just use a global definition.
% Use \cmd\trim@spaces\ to remove surrounding space:
%    \begin{macrocode}
\long\def\env@save#1#2\env@nil{%
  \edef#1{%
    \unexpanded\expandafter
      \expandafter\expandafter{\trim@spaces{#2}}}}
%    \end{macrocode}
% \end{macro}
% This is the same as a \cmd\@gobblenil\ but long and less likely to exist in the environment body:
%    \begin{macrocode}
\long\def\env@ignore#1\env@nil{}
%    \end{macrocode}
% \changes{v0.2}{2008/06/16}{Added.}
% \end{macro}
% \end{macro}
%
%\iffalse
%</package>
%\fi
%
%
%\iffalse
%<*dtx-style>
%    \begin{macrocode}
\ProvidesPackage{dtx-style}

\errorcontextlines=999

\def\@dotsep{1000}
\setcounter{tocdepth}{2}
\setlength\columnseprule{0.1pt}
\renewcommand\tableofcontents{\relax
  \begin{multicols}{2}[\section*{\contentsname}]\small
    \@starttoc{toc}\relax
  \end{multicols}}

\setcounter{IndexColumns}{2}
\renewenvironment{theglossary}
  {\small\list{}{}
     \item\relax
     \glossary@prologue\GlossaryParms 
     \let\item\@idxitem \ignorespaces 
     \def\pfill{\hspace*{\fill}}}
  {\endlist}

\usepackage{booktabs,calc,color,enumitem,fancyvrb,graphicx,ifthen,refstyle,subfig,varioref}
\expandafter\usepackage\expandafter{\jobname}

\usepackage{url}

\usepackage[sc,osf]{mathpazo}

\linespread{1.1}      % A bit more space between lines
\frenchspacing         % Remove ugly extra space after punctuation
  
\definecolor{niceblue}{rgb}{0.2,0.4,0.8}
\newenvironment{example}[1]
  {\VerbatimEnvironment
   \def\Options{#1}%
   \begin{VerbatimOut}[gobble=2]{\examplefilename}}
  {\end{VerbatimOut}\relax
   \typesetexample}

\fvset{formatcom=\color{niceblue}}
\DefineShortVerb{\|}

\def\theCodelineNo{\textcolor{niceblue}{\sffamily\tiny\arabic{CodelineNo}}}

\let\examplesize\normalsize
\let\auxwidth\relax

\newlength\examplewidth\newlength\verbatimwidth
\newlength\exoutdent   \newlength\exverbgap
\setlength\exverbgap{1em}
\setlength\exoutdent{-0.15\textwidth}
\newsavebox\verbatimbox
\edef\examplefilename{\jobname.example}

\newcommand\typesetexample{\relax
   \smallskip
   \noindent
   \begin{minipage}{\linewidth}
   \color{niceblue}
   \hrulefill\par
   \edef\@tempa{[gobble=0,fontsize=\noexpand\small,\Options]}%
   \begin{lrbox}{\verbatimbox}\relax
     \expandafter\BVerbatimInput\@tempa{\examplefilename}%
   \end{lrbox}
   \begin{list}{}{\setlength\itemindent{0pt}
                  \setlength\leftmargin\exoutdent
                  \setlength\rightmargin{0pt}}\item
   \ifx\auxwidth\relax
     \setlength\verbatimwidth{\wd\verbatimbox}%
   \else
     \setlength\verbatimwidth{\auxwidth}%
   \fi
   \begin{minipage}[c]{\textwidth-\exoutdent-\verbatimwidth-\exverbgap}
     \catcode`\%=14\centering\linespread{1.6}\input\examplefilename\relax
   \end{minipage}\hfill
   \begin{minipage}[c]{\verbatimwidth}
     \usebox\verbatimbox
   \end{minipage}
   \end{list}
   \par\noindent\hrulefill
   \end{minipage}\par
   \smallskip\noindent}

\newcommand*\setverbwidth[1]{\def\auxwidth{#1}}

\newcommand*\name[1]{{#1}}
\newcommand*\pkg[1]{\textsf{#1}}
\newcommand*\feat[1]{\texttt{#1}}
\newcommand*\opt[1]{\texttt{#1}}

\newcommand*\ltx[1]{%
  \ifx3#1\relax
    \textsc{ltx3}%
  \else
    \LaTeXe
  \fi}

\newcommand\note{\unskip\footnote}

\let\latin\textit
\def\eg{\latin{e.g.}}
\def\Eg{\latin{E.g.}}
\def\ie{\latin{i.e.}}
\def\etc{\@ifnextchar.{\latin{etc}}{\latin{etc.}\@}}

\def\STIX{\textsc{stix}}
\def\MacOSX{Mac~OS~X}
\def\ascii{\textsc{ascii}}
\def\OMEGA{Omega}
\def\CTAN{\textsc{ctan}}

\newcounter{argument}
\g@addto@macro\endmacro{\setcounter{argument}{0}}
\newcommand*\darg[1]{%
  \stepcounter{argument}%
  {\ttfamily\char`\{\char`\#\theargument\char`\}:~}#1\par\noindent\ignorespaces}
\newcommand*\doarg[1]{%
  \stepcounter{argument}%
  {\ttfamily[\char`\#\theargument]:~}#1\par\noindent\ignorespaces}

\def\codeline{\par\hspace{0.5\parindent}}

\newcommand\unichar[2]{\textsc{\MakeLowercase{u+#1: #2}}}

\setlength\parindent{2em}

%    \end{macrocode}
%</dtx-style>
%\fi
%
% \typeout{*************************************************************}
% \typeout{*}
% \typeout{* To finish the installation you have to move the following}
% \typeout{* file into a directory searched by TeX:}
% \typeout{*}
% \typeout{* \space\space\space environ.sty}
% \typeout{*}
% \typeout{*************************************************************}
%
\endinput