%% 8 JUN 93: this file needed to run Johannes Braams' article in TTN
%% 2,3 (Ch.)
%% 7 JUL 93: This file renamed ttn2n3-gather.sty to show its
%% relationship with TTN 2,3 files (Ch.)
% gather.sty
%
% The following macro hackery I use to extract the macrocode
% from the source of the article in order to use it later on.
%
\newwrite\codefile % To gather all the code together
\newwrite\tmpfile % Temporary file for typesetting the code
%
{\catcode`\%=12 \gdef\comment{%% }}
\chardef\other=12
\def\myverbatim{\begingroup
\catcode`\\=\other\catcode`\&=\other\catcode`\$=\other
\catcode`\{=\other\catcode`\}=\other\catcode`\#=\other
\catcode`\^=\other\catcode`\~=\other\catcode`\%=\other
\catcode`\"=\other\catcode`\<=\other\catcode`\>=\other
\catcode`\_=\other\catcode`\|=\other \obeyspaces}
% Macro to write code to the codefile *and* to the temporary file
\def\spaces{\space\space\space\space}
%
% DOUBLE DANGEROUS BEND::
% I make the ^^M an active character
% I use it to write macrocode line by line to the files.
\begingroup
\catcode`\^^M\active% Hide all ^^M's from TeX...
%
% I also have to temporarily change some other category codes,
% in order to be able to scan for the line containing
% the string "\end{code}"
%
\begingroup%
\catcode`\[=1 \catcode`\]=2 \catcode`\|=0%
\catcode`\{=12 \catcode`\}=12 \catcode`\\=12%
|gdef|writeit#1^^M[|endgroup|def|tempa[#1]|def|tempb[\end{code}]%
|ifx|tempa|tempb%
|def|next[|end[code]]%
|else%
|def|next[|immediate|write|codefile[#1]%
|immediate|write|tmpfile[|spaces#1]^^M]%
|fi|next]%
|endgroup%
% Here is a new LaTeX environment which can contain TeX macrocode
% The code will be written to two files, the file to gather all code
% in and the temporary fill that is \input at the end of the
% environment. In that file the code will be in a normal verbatim
% environment.
\gdef\code{\bgroup\catcode`\^^M\active%
\def^^M{\myverbatim\writeit}%
\immediate\openout\tmpfile=tmp%
\immediate\write\tmpfile{\string\begin{verbatim}}}%
% And an environment to typeset the examples
\gdef\example{\bgroup\catcode`\^^M\active%
\def^^M{\myverbatim\writeit}%
\immediate\openout\tmpfile=tmp%
\immediate\openout\codefile=tmpb%
\immediate\write\tmpfile{\string\begin{verbatim}}}%
\endgroup% Now the ^^M is no longer active
\def\endcode{\egroup
\immediate\write\tmpfile{\string\end{verbatim}}
\immediate\closeout\tmpfile
\input{tmp}}
\def\endexample{\egroup
\immediate\write\tmpfile{\string\end{verbatim}}
\immediate\closeout\tmpfile
\immediate\closeout\codefile
\leavevmode
\begin{minipage}[c]{.45\textwidth}\small\input{tmp}\end{minipage}%
\hfil
\begin{minipage}[c]{.45\textwidth}\small\input{tmpb}\end{minipage}}
\def\startgather#1{%
\immediate\openout\codefile=#1
\immediate\write\codefile{\comment File : #1.tex}
\immediate\write\codefile{\comment Author: J.L. Braams}
{\let~\space
\immediate\write\codefile{\comment Date : \today}}
}
\def\endgather{%
\immediate\write\codefile{\string\endinput}
\immediate\write\codefile{\comment the rest of this file is ignored.}
\immediate\closeout\codefile}
\def\startexamples{\let\code\example\let\endcode\endexample
\def\spaces{}}
