%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% 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