doc + separate package optional (3may10)

git-svn-id: svn://tug.org/texlive/trunk@18131 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 158 insertions, 0 deletions

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+%
+% O P T I O N A L . S T Y
+% ~~~~~~~~~~~~~~~~~~~~~~~
+% ver 2.2b  Jan 2005
+%
+% Enable multiple versions of a document to be printed from one source file,
+% especially if most of the text is shared between versions.
+%
+% Copyright 1993,1999,2001,2005 by Donald Arseneau (asnd@triumf.ca).
+% This software is released under the terms of the LaTeX Project Public 
+% License  (ftp://ctan.tug.org/tex-archive/macros/latex/base/lppl.txt).
+% (Essentially: Free to use, copy, distribute (sell) and change, but, if
+% changed, that fact must be made apparent to the user.)  It has a
+% status of "maintained".
+%
+%
+% HOW TO USE
+% ~~~~~~~~~~
+% One way to use this package is to declare (for example)
+%
+%     \usepackage[opta]{optional}
+%
+% at the beginning of your document, and flag optional text throughout 
+% your document like:
+%
+%     \opt{opta}{Do this if option opta was declared}
+%     \opt{optb}{Do this if option optb was declared}
+%     \opt{optx,opty}{Do this if either option optx or opty}
+%     \opt{}{Never print this text!}
+%     \opt{opta}{\input{appendices}}
+%     \optv{xam}{Type: \verb|[root /]$ rm -r *|.}
+%
+% Note that both the package option and the "\opt" argument can contain
+% lists of options although, in practice, one or the other should be a
+% single option name.  Lists are allowed in both places to allow more
+% flexibility in the style of use. (But making the definitions much more
+% difficult, Grrr.)
+%
+% Just as for "\includeonly", you will have to edit the main document
+% file to switch option codes (i.e., change the "\usepackage" line).  
+% There are, however, several ways to use this package without altering 
+% the main document file: separate files, file-name sensing, interactive 
+% prompting, and command-line option selection.
+%
+% Typically, different versions of a document will require different 
+% document class and package setup, besides the different tags for
+% optional.sty.  In that case it is best to have a separate main file
+% for each version of the document.  Each stub file will declare the 
+% document class and load some packages (including this one) and then 
+% input the rest of the document from a file common to all versions.
+%
+%     \documentclass[A0]{poster}
+%     \usepackage[poster]{optional}
+%     \input{my_paper}
+%
+% If the different opt-tags match the different stub file names (file
+% poster.tex will typeset the "poster" version) then you can specify
+%
+%     \usepackage[\jobname]{optional}
+%
+% Alternatively, this "\jobname" technique can make use of symbolic links, 
+% if your computer system supports them, by having a single main input
+% file accessed under different names (and different "\jobname"s).
+%
+% Another scheme is to invoke LaTeX with the command line such as:
+%
+%     latex "\def\UseOption{opta,optb}\input{file}"
+%
+% (with quoting appropriate to your operating system) then options "opta" 
+% and "optb" will be used in addition to any options specified with the
+% "\usepackage" command.
+%
+% You can prompt yourself to specify the option(s) with every run 
+% through LaTeX:
+%
+%     \usepackage{optional}
+%     \newcommand{\ExplainOptions}{man = users manual, check = checklist,
+%           ref = reference card, post = poster.}
+%     \AskOption
+%
+% The definition of "\ExplainOptions" is optional; it only serves to help
+% the person who answers the question.  The "\AskOption" is also optional;
+% it will be executed automatically whenever optional.sty sees no list of
+% options.  This method is too tedious to use much.
+%
+% The normal restrictions forbidding special characters in package options
+% and reference tags apply also the the tags used by the "\opt" command.
+%
+% These are not `comment' macros: The optional text must be well-formed
+% with balanced braces, even if not printed.  The "\opt" command *IS* 
+% completely `expandable' which means  it is robust and can even be used
+% in messages ("\typeout").  
+%
+% As usual, "\verb" commands and verbatim environments cannot be used 
+% in the argument to "\opt".  For this purpose there is a variant form
+% of "\opt" called "\optv" (optional verbatim) which may have a limited
+% class of verbatim material in the argument.  It can do so by leaving
+% the braces around the argument, which may have undesired side effects.
+% For an "\optv" argument to be successfully ignored, the verbatim material
+% must have balanced braces etc.
+%
+% The "\opt" command is only intended for small sections of text.  If you
+% need to optionally include whole sections or chapters, put that material
+% in a separate file, and "\opt"-ionally use an "\input" command:
+%
+%     \opt{internal}{\input{prog_listings}}
+%
+%====================== END INSTRUCTIONS ========================
+
+\ProvidesPackage{optional}[2005/01/26 ver 2.2b; \space 
+  Optional inclusion/omission]
+% Initialize used-option-list to \@gobble to eat the comma when the first
+% entry is `appended'.
+\@ifundefined{UseOption}{\let\UseOption\@gobble}{}
+\DeclareOption*{\edef\UseOption{\UseOption,\CurrentOption}}
+\ProcessOptions
+\AtBeginDocument{\Opl@Setup}
+
+\newcommand*\opt[1]{\if\Opl@notlisted{#1}\expandafter\@gobble
+   \else \expandafter\@firstofone \fi}
+
+\newcommand*\optv[1]{\if\Opl@notlisted{#1}\expandafter\@gobble\fi}
+
+% This initial definition forces immediate setup if \opt used in the preamble
+\def\Opl@notlisted{\fi \Opl@Setup \if\Opl@notlisted}
+
+\newcommand\AskOption{%
+ \@ifundefined{ExplainOptions}{}{\typeout{\ExplainOptions}}%
+ \typein[\UseOption]{Specify which optional text to process:}%
+ }
+
+\def\Opl@Setup{%
+ \ifx\UseOption\@gobble\AskOption\fi
+ \let\Opl@notlisted\@empty % initialize list of checks
+ \@for\@tempa:=\UseOption\do{%
+   \ifx\@tempa\@empty\else\expandafter\Opl@oneop\expandafter{\@tempa}\fi}%
+ \ifx\Opl@notlisted\@empty \PackageWarning{optional}%
+   {No options were selected, so all optional text will be printed}%
+   \let\opt\@secondoftwo
+ \else
+   \typeout{Using optional text marked with \UseOption. }%
+   \toks@\expandafter{\Opl@notlisted}%
+   \edef\@tempa{\def\noexpand\Opl@notlisted####1{,\the\toks@,}}\@tempa
+ \fi
+ \let\Opl@Setup\@empty \let\Opl@oneop\undefined
+ \let\AskOption\undefined \let\ExplainOptions\undefined
+}
+\begingroup
+\catcode`\Z= 3 % special delimiter
+\gdef\Opl@oneop#1{%
+ \@ifundefined{Opl@Match@#1}{%
+   \toks@\expandafter{\Opl@notlisted}%
+   \edef\Opl@notlisted{\the\toks@ \csname Opl@Match@#1\endcsname ,####1,#1,Z}%
+  \@namedef{Opl@Match@#1}##1,#1,##2Z{##2}%
+ }\relax
+}
+\endgroup
+\endinput