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% \iffalse
%%
%% suffix is part of the bigfoot bundle for critical typesetting
%% Copyright 2002--2006 David Kastrup <dak@gnu.org>
%%
%% The license notice and corresponding source code for this file are
%% contained in suffix.dtx.
%%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2 of the License, or
% (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program; if not, write to the Free Software
% Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
% \fi
% \CheckSum{198}
% \GetFileInfo{suffix.sty}
% \author{David Kastrup\thanks{\href{mailto:dak@gnu.org}
% {Email: \texttt{dak@gnu.org}}}}
% \title{The \texttt{suffix} Package\\Version \fileversion}
% \date{\filedate}
% \maketitle
% \section{Basics}
% The \texttt{suffix} package has the purpose of making it easy to
% define and maintain command variants like |\macro*| and even
% |\macro\/| or similar. It requires e\TeX\ version~2 for its work.
% The suffixes are fetched with |\futurelet|, so things like |\bgroup|
% and |{| ^^A}
% can't be distinguished. In addition, the efficiency depends on the
% complexity of the suffix' definition, so you should preferably use
% characters or short commands as a suffix. A suffixed command itself
% counts as short for this purpose. How does a suffix definition look
% like?
%
% \DescribeMacro{\WithSuffix} The general form is
% \begin{quote}
% |\WithSuffix|\meta{prefixed definition}\meta{macro}\meta{suffix}\dots
% \end{quote}
% where \meta{prefixed definition} is something like |\xdef|,
% |\global\let| or similar. Recognised prefixes are |\global|,
% |\long|, |\protected| (the latter is rarely useful, as the original
% definition already is robust), and |\expandafter| (with its
% `natural' meaning), specially recognized commands are |\gdef| and
% |\xdef|. Other commands can be used as long as they are suitable as
% an undelimited macro argument. This means they must either be a
% single token like |\newcommand| or brace-enclosed like
% |{\newcommand*}|. \meta{macro} can be a macro or an active
% character. It should be a single token suitable for assignment with
% |\let|. \meta{suffix} can be something like a single letter such as
% |*| or |[|.
%
% For example, assume that a command |\snarf| already exists and we
% want to define a variant |\snarf|\oarg{optarg}. Then we can do this
% with
% \begin{quote}
% \cmd\WithSuffix|\long\def\snarf[#1]{|\meta{Definition using
% \texttt{\#1}}|}|
% \end{quote}
% That's pretty much it. Oh, only when a command is recognised as
% having a prefix |\global| or being |\xdef| or |gdef| will the
% corresponding redefinitions be done globally. This is rarely a
% concern.
%
% \DescribeMacro{\SuffixName} In case you need to refer to the control
% sequence name used to refer to the suffixed macro, you can access it
% as
% \begin{quote}
% |\csname|\cmd{\SuffixName}\meta{macro}\meta{suffix}|\endcsname|
% \end{quote}
% \DescribeMacro{\NoSuffixName} and if you need to refer to the
% original unsuffixed macro, you can access it as
% \begin{quote}
% |\csname|\cmd{\NoSuffixName}\meta{macro}|\endcsname|
% \end{quote}
% \StopEventually{}
% \section{The driver file for the documentation}
% Installation is done by |bigfoot.ins|, so look there for more
% information for that. Here comes the documentation driver.
% \begin{macrocode}
%<*driver>
\documentclass{ltxdoc}
\usepackage{hyperref}
\usepackage{suffix}
\begin{document}
\OnlyDescription
%<driver> \AlsoImplementation
\DocInput{suffix.dtx}
\end{document}
%</driver>
% \end{macrocode}
% \section{Implementation}
% First we announce the package and check for e\TeX~2.
% \begin{macrocode}
%<*style>
\ProvidesPackage{suffix}[2006/07/15 1.5a Variant command support]
\ifcase\ifx\eTeXversion\@undefined \@ne\fi
\ifnum\eTeXversion<\tw@ \@ne\fi\z@
\else
\PackageError{suffix}{This package requires eTeX version 2}%
{You might try to use the `elatex' command.}%
\fi
% \end{macrocode}
% \begin{macro}{\WithSuffix}
% Then we define the \cmd{\WithSuffix} command. We use
% \cmd{\@temptokena} to collect prefixes and let \cmd{\WSF@global}
% to |\global| for global definitions.
%
% \begin{macrocode}
\def\WithSuffix{\@temptokena{}\let\WSF@global\relax
\WSF@sfx}
% \end{macrocode}
% \end{macro}
% \begin{macro}{\WSF@sfx}
% \begin{macro}{\WSF@append}
% \begin{macro}{\WSF@gobblenext}
% After checking all prefixes and stuff (we'll fill in this missing
% link later), we add the defining command itself to the token list,
% place \meta{macro} into \cmd{\reserved@a} and fetch \meta{suffix}
% into \cmd{\reserved@b}.
% \begin{macrocode}
\long\def\WSF@sfx#1#2{\WSF@append{#1}\def\reserved@a{#2}%
\afterassignment\WSF@decsuff \WSF@gobblenext}
\def\WSF@append#1{\@temptokena\expandafter{\the\@temptokena#1}}
\def\WSF@gobblenext{\let\reserved@b= }
% \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \begin{macro}{\SuffixName}
% \begin{macro}{\NoSuffixName}
% While we are at it, let us define the macro names to use for
% suffixed and unsuffixed \meta{macro}.
% \begin{macrocode}
\long\def\SuffixName#1{WSF:\string#1 \meaning}
\def\NoSuffixName{WSF:\string}
% \end{macrocode}
% \end{macro}
% \end{macro}
% \begin{macro}{\WSF@decsuff}
% We first check whether the macro has already been suffixed. If it
% hasn't, we save a copy of it and redefine it in terms of
% \cmd{\WSF@suffixcheck}.
% \begin{macrocode}
\def\WSF@decsuff{\ifcsname
\expandafter\NoSuffixName\reserved@a\endcsname
\else
\WSF@global\expandafter\let\csname
\expandafter\NoSuffixName\reserved@a
\expandafter\endcsname \reserved@a
\long\def\reserved@c##1{\WSF@global\protected\def
##1{\WSF@suffixcheck##1}}%
\expandafter\reserved@c\reserved@a
\fi
% \end{macrocode}
% Once we have done that, we are ready for calling the definition
% command on the suffixed \meta{macro}.
% \begin{macrocode}
\WSF@global
\the\expandafter\@temptokena\csname
\expandafter \SuffixName
\reserved@a\reserved@b\endcsname}
% \end{macrocode}
% \end{macro}
% \begin{macro}{\WSF@suffixcheck}
% We now do the runtime code. This is
% executed in a group of its own in order not to interfere with any
% other macros.
% \begin{macrocode}
\def\WSF@suffixcheck#1{\begingroup\def\reserved@a{#1}%
\futurelet\reserved@b\WSF@suffixcheckii}
% \end{macrocode}
% \end{macro}
% \begin{macro}{\WSF@suffixcheckii}
% After assigning the \meta{suffix} to \cmd{\reserved@b}, we split
% into the case of known and unknown suffix. We don't code this
% inline, since \cmd{\reserved@} in a false conditional might
% confuse \TeX\ if it happens to be something like |\iffalse|
% itself.
% \begin{macrocode}
\def\WSF@suffixcheckii{\ifcsname \expandafter\SuffixName
\reserved@a\reserved@b\endcsname
\expandafter
\WSF@suffixcheckiii
\else
\expandafter
\WSF@suffixcheckiv
\fi}
% \end{macrocode}
% \end{macro}
% \begin{macro}{\WSF@suffixcheckiii}
% \begin{macro}{\WSF@suffixcheckiv}
% Calling the macros is reasonably straightforward, we just have to
% take care not to close the group at the wrong time.
% \begin{macrocode}
\def\WSF@suffixcheckiii{%
\afterassignment\endgroup
\expandafter\aftergroup
\csname \expandafter \SuffixName\reserved@a\reserved@b\endcsname
\WSF@gobblenext}
\def\WSF@suffixcheckiv{%
\expandafter\endgroup
\csname \expandafter\NoSuffixName\reserved@a\endcsname}
% \end{macrocode}
% \end{macro}
% \end{macro}
% \begin{macro}{\WSF@sfx}
% Now we just augment \cmd{WSF@sfx} to recognize all prefixes and
% global commands:
% \begin{macrocode}
\WithSuffix\def\WSF@sfx\long{\WSF@append\long\WSF@sfx}
\WithSuffix\def\WSF@sfx\global{\let\WSF@global\global\WSF@sfx}
\WithSuffix\def\WSF@sfx\protected{\WSF@append\protected\WSF@sfx}
\WithSuffix\def\WSF@sfx\expandafter{\expandafter\WSF@sfx\expandafter}
\WithSuffix\edef\WSF@sfx\gdef{\let\WSF@global\global
\expandafter\noexpand\csname\NoSuffixName\WSF@sfx\endcsname\def}
\WithSuffix\edef\WSF@sfx\xdef{\let\WSF@global\global
\expandafter\noexpand\csname\NoSuffixName\WSF@sfx\endcsname\edef}
%</style>
% \end{macrocode}
%\end{macro}
% \Finale
% \endinput
% Local Variables:
% mode: doctex
% TeX-master: "suffix.drv"
% End:
|
