include comment.sty 3.6 which still works with plain tex, in contrast to later 3.7 which is only for latex (slow due to file snippets) -- see also 30781cc78fc6;
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/texinputs/comment.sty Fri Jan 31 17:35:19 2014 +0100
@@ -0,0 +1,278 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Comment.sty version 3.6, October 1999
+%
+% Purpose:
+% selectively in/exclude pieces of text: the user can define new
+% comment versions, and each is controlled separately.
+% Special comments can be defined where the user specifies the
+% action that is to be taken with each comment line.
+%
+% Author
+% Victor Eijkhout
+% Department of Computer Science
+% University of Tennessee
+% 107 Ayres Hall
+% Knoxville TN 37996
+% USA
+%
+% victor@eijkhout.net
+%
+% 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.
+%
+% For a copy of the GNU General Public License, write to the
+% Free Software Foundation, Inc.,
+% 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA,
+% or find it on the net, for instance at
+% http://www.gnu.org/copyleft/gpl.html
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% This style can be used with plain TeX or LaTeX, and probably
+% most other packages too.
+%
+% Usage: all text included between
+% \comment ... \endcomment
+% or \begin{comment} ... \end{comment}
+% is discarded.
+%
+% The opening and closing commands should appear on a line
+% of their own. No starting spaces, nothing after it.
+% This environment should work with arbitrary amounts
+% of comment, and the comment can be arbitrary text.
+%
+% Other `comment' environments are defined by
+% and are selected/deselected with
+% \includecomment{versiona}
+% \excludecoment{versionb}
+%
+% These environments are used as
+% \versiona ... \endversiona
+% or \begin{versiona} ... \end{versiona}
+% with the opening and closing commands again on a line of
+% their own.
+%
+% LaTeX users note: for an included comment, the
+% \begin and \end lines act as if they don't exist.
+% In particular, they don't imply grouping, so assignments
+% &c are not local.
+%
+% Special comments are defined as
+% \specialcomment{name}{before commands}{after commands}
+% where the second and third arguments are executed before
+% and after each comment block. You can use this for global
+% formatting commands.
+% To keep definitions &c local, you can include \begingroup
+% in the `before commands' and \endgroup in the `after commands'.
+% ex:
+% \specialcomment{smalltt}
+% {\begingroup\ttfamily\footnotesize}{\endgroup}
+% You do *not* have to do an additional
+% \includecomment{smalltt}
+% To remove 'smalltt' blocks, give \excludecomment{smalltt}
+% after the definition.
+%
+% Processing comments can apply processing to each line.
+% \processcomment{name}{each-line commands}%
+% {before commands}{after commands}
+% By defining a control sequence
+% \def\Thiscomment##1{...} in the before commands the user can
+% specify what is to be done with each comment line.
+% BUG this does not work quite yet BUG
+%
+% Trick for short in/exclude macros (such as \maybe{this snippet}):
+%\includecomment{cond}
+%\newcommand{\maybe}[1]{}
+%\begin{cond}
+%\renewcommand{\maybe}[1]{#1}
+%\end{cond}
+%
+% Basic approach of the implementation:
+% to comment something out, scoop up every line in verbatim mode
+% as macro argument, then throw it away.
+% For inclusions, in LaTeX the block is written out to
+% a file \CommentCutFile (default "comment.cut"), which is
+% then included.
+% In plain TeX (and other formats) both the opening and
+% closing comands are defined as noop.
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Changes in version 3.1
+% - updated author's address
+% - cleaned up some code
+% - trailing contents on \begin{env} line is always discarded
+% even if you've done \includecomment{env}
+% - comments no longer define grouping!! you can even
+% \includecomment{env}
+% \begin{env}
+% \begin{itemize}
+% \end{env}
+% Isn't that something ...
+% - included comments are written to file and input again.
+% Changes in 3.2
+% - \specialcomment brought up to date (thanks to Ivo Welch).
+% Changes in 3.3
+% - updated author's address again
+% - parametrised \CommentCutFile
+% Changes in 3.4
+% - added GNU public license
+% - added \processcomment, because Ivo's fix (above) brought an
+% inconsistency to light.
+% Changes in 3.5
+% - corrected typo in header.
+% - changed author email
+% - corrected \specialcomment yet again.
+% - fixed excludecomment of an earlier defined environment.
+% Changes in 3.6
+% - The 'cut' file is now written more verbatim, using \meaning;
+% some people reported having trouble with ISO latin 1, or umlaute.sty.
+% - removed some \newif statements.
+% Has this suddenly become \outer again?
+%
+% Known bugs:
+% - excludecomment leads to one superfluous space
+% - processcomment leads to a superfluous line break
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\def\makeinnocent#1{\catcode`#1=12 }
+\def\csarg#1#2{\expandafter#1\csname#2\endcsname}
+\def\latexname{lplain}\def\latexename{LaTeX2e}
+\newwrite\CommentStream
+\def\CommentCutFile{comment.cut}
+
+\def\ProcessComment#1% start it all of
+ {\begingroup
+ \def\CurrentComment{#1}%
+ \let\do\makeinnocent \dospecials
+ \makeinnocent\^^L% and whatever other special cases
+ \endlinechar`\^^M \catcode`\^^M=12 \xComment}
+%\def\ProcessCommentWithArg#1#2% to be used in \leveledcomment
+% {\begingroup
+% \def\CurrentComment{#1}%
+% \let\do\makeinnocent \dospecials
+% \makeinnocent\^^L% and whatever other special cases
+% \endlinechar`\^^M \catcode`\^^M=12 \xComment}
+{\catcode`\^^M=12 \endlinechar=-1 %
+ \gdef\xComment#1^^M{%
+ \expandafter\ProcessCommentLine}
+ \gdef\ProcessCommentLine#1^^M{\def\test{#1}
+ \csarg\ifx{End\CurrentComment Test}\test
+ \edef\next{\noexpand\EndOfComment{\CurrentComment}}%
+ \else \ThisComment{#1}\let\next\ProcessCommentLine
+ \fi \next}
+}
+
+\def\CSstringmeaning#1{\expandafter\CSgobblearrow\meaning#1}
+\def\CSstringcsnoescape#1{\expandafter\CSgobbleescape\string#1}
+{\escapechar-1
+\expandafter\expandafter\expandafter\gdef
+ \expandafter\expandafter\expandafter\CSgobblearrow
+ \expandafter\string\csname macro:->\endcsname{}
+}
+\def\CSgobbleescape#1{\ifnum`\\=`#1 \else #1\fi}
+\def\WriteCommentLine#1{\def\CStmp{#1}%
+ \immediate\write\CommentStream{\CSstringmeaning\CStmp}}
+
+% 3.1 change: in LaTeX and LaTeX2e prevent grouping
+\if 0%
+\ifx\fmtname\latexename
+ 0%
+\else \ifx\fmtname\latexname
+ 0%
+ \else
+ 1%
+\fi \fi
+%%%%
+%%%% definitions for LaTeX
+%%%%
+\def\AfterIncludedComment
+ {\immediate\closeout\CommentStream
+ \input{\CommentCutFile}\relax
+ }%
+\def\TossComment{\immediate\closeout\CommentStream}
+\def\BeforeIncludedComment
+ {\immediate\openout\CommentStream=\CommentCutFile
+ \let\ThisComment\WriteCommentLine}
+\def\includecomment
+ #1{\message{Include comment '#1'}%
+ \csarg\let{After#1Comment}\AfterIncludedComment
+ \csarg\def{#1}{\BeforeIncludedComment
+ \ProcessComment{#1}}%
+ \CommentEndDef{#1}}
+\long\def\specialcomment
+ #1#2#3{\message{Special comment '#1'}%
+ % note: \AfterIncludedComment does \input, so #2 goes here!
+ \csarg\def{After#1Comment}{#2\AfterIncludedComment#3}%
+ \csarg\def{#1}{\BeforeIncludedComment\relax
+ \ProcessComment{#1}}%
+ \CommentEndDef{#1}}
+\long\def\processcomment
+ #1#2#3#4{\message{Lines-Processing comment '#1'}%
+ \csarg\def{After#1Comment}{#3\AfterIncludedComment#4}%
+ \csarg\def{#1}{\BeforeIncludedComment#2\relax
+ \ProcessComment{#1}}%
+ \CommentEndDef{#1}}
+\def\leveledcomment
+ #1#2{\message{Include comment '#1' up to level '#2'}%
+ %\csname #1IsLeveledCommenttrue\endcsname
+ \csarg\let{After#1Comment}\AfterIncludedComment
+ \csarg\def{#1}{\BeforeIncludedComment
+ \ProcessCommentWithArg{#1}}%
+ \CommentEndDef{#1}}
+\else
+%%%%
+%%%%plain TeX and other formats
+%%%%
+\def\includecomment
+ #1{\message{Including comment '#1'}%
+ \csarg\def{#1}{}%
+ \csarg\def{end#1}{}}
+\long\def\specialcomment
+ #1#2#3{\message{Special comment '#1'}%
+ \csarg\def{#1}{\def\ThisComment{}\def\AfterComment{#3}#2%
+ \ProcessComment{#1}}%
+ \CommentEndDef{#1}}
+\fi
+
+%%%%
+%%%% general definition of skipped comment
+%%%%
+\def\excludecomment
+ #1{\message{Excluding comment '#1'}%
+ \csarg\def{#1}{\let\AfterComment\relax
+ \def\ThisComment####1{}\ProcessComment{#1}}%
+ \csarg\let{After#1Comment}\TossComment
+ \CommentEndDef{#1}}
+
+\if 0%
+\ifx\fmtname\latexename
+ 0%
+\else \ifx\fmtname\latexname
+ 0%
+ \else
+ 1%
+\fi \fi
+% latex & latex2e:
+\def\EndOfComment#1{\endgroup\end{#1}%
+ \csname After#1Comment\endcsname}
+\def\CommentEndDef#1{{\escapechar=-1\relax
+ \csarg\xdef{End#1Test}{\string\\end\string\{#1\string\}}%
+ }}
+\else
+% plain & other
+\def\EndOfComment#1{\endgroup\AfterComment}
+\def\CommentEndDef#1{{\escapechar=-1\relax
+ \csarg\xdef{End#1Test}{\string\\end#1}%
+ }}
+\fi
+
+\excludecomment{comment}
+
+\endinput