Path: utzoo!attcan!uunet!olivea!mintaka!bloom-beacon!eru!hagbard!sunic!dkuug!iesd!iesd.auc.dk!krab
From: krab@iesd.auc.dk (Kresten Krab Thorup)
Newsgroups: comp.text.tex
Subject: Re: How do I comment-out a block of TeX
Message-ID: <KRAB.91Jan24161405@red.iesd.auc.dk>
Date: 24 Jan 91 16:14:05 GMT
References: <29555@usc>
Sender: news@iesd.auc.dk (UseNet News)
Distribution: comp
Organization: Mathematics and Computer Science, University of Aalborg
Lines: 105
In-reply-to: siemsen@sol.usc.edu's message of 24 Jan 91 00:29:15 GMT


Here's the comment environment from TeXhax-72,1990

/Kresten

-------forwarded message follows this line---------

Date: Fri, 02 Nov 90 21:25:51 -0600
From: eijkhout@csrd.uiuc.edu
Subject: comment environment
Keywords: comment environment

Over the last few weeks I have seen two of three requests
for a comment environment on the net. Time for action.

Probably everyone knows why \def\comment#1\endcomment{}
does not work: unbalanced braces, buffer overflow, outer macros, ...

I saw one quite ingenious solution of someone who make almost every character
into comment. Cute. It will take quite a while before you run
into buffer overflow then.

Here is another solution: every line is read as verbatim text, and
just thrown away. No buffer problems. Never.
These macros can be used with plain TeX and LateX, and probably any
other macro package. For plain TeX write
\comment 
 ...
\endcomment
For LaTeX write
\begin{comment}
 ...
\end{comment}
In both cases put the closing command on a line of its own, and nothing
before or after it.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Comment.sty   version 1.0 2 November 1990
% to be used with plain TeX or LaTeX
%
% Author
%    Victor Eijkhout
%    Center for Supercomputing Research and Development
%    University of Illinois at Urbana-Champaign
%    305 Talbot Lab
%    104 South Wright Street
%    Urbana, Illinois 61801, USA
%
%    eijkhout@csrd.uiuc.edu
%
% Usage: all text included in between
%    \comment ... \endcomment
% or \begin{comment} ... \end{comment}
% is discarded. The closing command should appear on a line
% of its own. No starting spaces, nothing after it.
% This environment should work with arbitrary amounts
% of comment.
%
% Basic approach: take every line in verbatim mode as macro
% argument, then don't do nothing with.

\def\makeinnocent#1{\catcode`#1=12 }

\def\comment{\begingroup
    \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{\def\test{#1}
      \ifx\test\plainendcommenttest
          \let\next\endgroup
      \else\ifx\test\lalaendcommenttest
          \def\next{\endgroup\end{comment}}
      \else
          \let\next\xcomment
      \fi \fi \next}
}

{\escapechar=-1
 \xdef\plainendcommenttest{\string\\endcomment}
 \xdef\lalaendcommenttest{\string\\end\string\{comment\string\}}
}

\endinput

Victor Eijkhout                     phone: +1 217 244-0047
 Center for Supercomputing Research and Development
 University of Illinois at Urbana-Champaign
 305 Talbot laboratory
 104 South Wright street
 Urbana, Illinois 61801-2932, USA

home: 2503 W. Springfield Av, Apt. K-4, Champaign 61821, USA

--

        (  .                     
      (. )  )                    
       ) ( (                     
    .________.                   <krab@iesd.auc.dk>
    | |    __|                   
    |       ))                   Kresten Krab Thorup
    | |    //|                   Institute for electronic systems
`---`-`------'---'               Dept. of mathemathics and computer science
Coffee coffee ... (C) 1991       Aalborg University - Denmark, EC