Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!tcdcs!swift.cs.tcd.ie!emcmanus
From: emcmanus@cs.tcd.ie (Eamonn McManus)
Newsgroups: comp.text.tex
Subject: Re: Typesetting programming languages -- RESULTS
Summary: TeX macros to typeset C
Keywords: TeX, LaTeX, C
Message-ID: <1704@tws8.cs.tcd.ie>
Date: 2 Mar 90 19:49:59 GMT
References: <4354@jhunix.HCF.JHU.EDU>
Organization: Computer Science Department, Trinity College Dublin
Lines: 168

barrett@jhunix.HCF.JHU.EDU (Dan Barrett) writes:
...
>I'd really prefer a system that allowed me to do:
>
>\begin{c_code}
>main()
>{
>	int foo;
>	...etc...
>}
>\end{c_code}
>
>without all the muck that tgrind adds.
...

Funny you should mention it, as I have just been working on macros to
allow just that.  They typeset C text as I like it: in a normal font,
without bolding either keywords or identifiers.  Comments are set slanted,
strings in typewriter.  The macros are very raw and somewhat untested, so
I'd appreciate comments and suggestions.


% cprog.tex (or cprog.sty) - formatting of C programs
% By Eamonn McManus <emcmanus@cs.tcd.ie>, February 1990.
% This file is not copyrighted.

% This allows C programs to be formatted directly by TeX.  It can be
% invoked by \cprogfile{filename} or (in LaTeX) \begin{cprog} ...
% \end{cprog} or (in plain TeX) \cprog ... \end{cprog}.

% The formatting is (necessarily) simple.  C text is set in a normal Roman
% font, comments in a slanted font, and strings in a typewriter font, with
% spaces made visible as the `square u' symbol.  Tabs are expanded to four
% spaces (this does not look good when comments are aligned to the right of
% program text).  Some pairs of input characters appear as single output
% characters: << <= >> >= != -> are respectively TeX's \ll \le \gg \ge \ne
% \rightarrow.

% The fonts below can be changed to alter the setting of the various parts
% of the program.  The \cprogbaselineskip parameter can be altered to
% change the line spacing.  LaTeX's \baselinestretch is taken into account
% too.  The indentation is \cprogindent, initially 0.

% This package works by making a large number of characters active.  Since
% even spaces are active, it is possible to examine the next character by
% making it a parameter, rather than using \futurelet as one would
% normally do.  This is more convenient, but the coding does mean that if
% the next character itself wants to examine a character it may look at a
% token from the macro rather than the input text.

% The macros were thrown together rather quickly, and could do with some
% work.  For example, the big macro defined with @[] taking the place of
% \{} could be recoded to use \{} and so be more legible.  The grouping of
% two-character pairs should be controllable, since not everyone will want
% it.  The internal macros etc should have @ in their names, and should be
% checked against LaTeX macros for clashes.

% Allow multiple inclusion to go faster.
\ifx\undefined\cprogsetup	% The whole file.

% Define the fonts used for program text, comments, and strings.
% Note that if \it is used for \commentfont, something will need to
% be done about $ signs, which come out as pounds sterling.
\let\ctextfont=\rm \let\commentfont=\sl \let\stringfont=\tt

% Parameters.  Unfortunately \newdimen is \outer (\outerness is a mistake)
% so we need a subterfuge in case we are skipping the file.
\csname newdimen\endcsname\cprogbaselineskip \cprogbaselineskip=\baselineskip
\csname newdimen\endcsname\cprogindent \cprogindent=0pt

\def\makeactive#1{\catcode`#1=\active} \def\makeother#1{\catcode`#1=12}
{\obeyspaces\gdef\activespace{ } \obeylines\gdef\activecr{^^M}}
\def\spacewidthof{\fontdimen2}	% Width of a space in the following font.

% The following group makes many characters active, so that their catcodes
% in the \cprogchars macro are active, allowing them to be defined.  We
% could alternatively define more stuff like \activebackslash and use
% \expandafter or (carefully) \edef to expand these in the macro.
\begingroup
\catcode`@=\catcode`\\ \catcode`[=\catcode`{ \catcode`]=\catcode`}
\catcode9=\active
\makeactive! \makeactive" \makeactive' \makeactive* \makeactive- \makeactive/
\makeactive< \makeactive> \makeactive\{ \makeactive\} \makeactive|
\makeactive\\
@gdef@activebackslash[\]@gdef@activestar[*]
@gdef@cprogchars[% Don't indent this macro with tabs!  They are active.
    @makeother##@makeother$@makeother&@makeother@%@makeother^%
    @makeactive"@makeactive'@makeactive*@makeactive-@makeactive/%
    @makeactive<@makeactive>@makeactive{@makeactive}@makeactive|%
    @makeactive!@makeactive\@makeactive_%
    @def!##1[@ifx=##1$@ne$@else@string!##1@fi]%
    @def-##1[@ifx>##1$@rightarrow$@else$@string-$##1@fi]%
    @def"[@cquote"]@def'[@cquote']@def*[$@string*$]%
    % We use \aftergroup in < and > to deal with the fact that #1 might
    % itself examine the following character.
    @def<##1[[$@ifx<##1@ll$@else@ifx=##1@le$@else
      @string<$@aftergroup##1@fi@fi]]%
    @def>##1[[$@ifx>##1@gg$@else@ifx=##1@ge$@else
      @string>$@aftergroup##1@fi@fi]]%
    @def{[$@string{$]@def}[$@string}$]%
    @def|[$@string|$]@def\[$@backslash$]@def~[$@sim$]%
    @let/=@ccomment
    @obeyspaces @expandafter@def@activespace[@leavevmode@space]%
    @catcode9=@active @def^^I[@ @ @ @ ]%
    @obeylines @expandafter@def@activecr[@strut@par]]
    % This macro is illegible.
@gdef@cprogarg#1\end{cprog}[#1@endcprogarg]
@endgroup

\begingroup \makeactive" \makeactive'
\gdef\cquote#1{% #1 is the quote, " or '.
    \begingroup \tt\string#1\stringfont \makeactive\\%
    \expandafter\def\activebackslash##1{\char`\\\string##1}%
    \expandafter\def\activespace{\char`\ }%
    \expandafter\let\activecr=\unclosedstring
    \makeother*\makeother-\makeother/\makeother<\makeother>\makeother\{%
    \makeother\}\makeother_\makeother|%
    \ifx"#1\def'{\char13}\else\makeother"\fi
    \def#1{\tt\string#1\endgroup}}
\endgroup
\def\unclosedstring{%
    \errhelp{A string or character constant earlier in the line was unclosed.^^J
So I'm closing it now.}%
    \errmessage{Unclosed string}%
    \endgroup}
\newlinechar=`^^J

% In a comment, we shrink the width of the opening / to that of a space so
% that the stars in multiline comments will line up.  We also shrink the
% closing * for symmetry.
\def\spacebox#1{\hbox to \spacewidthof\font{#1\hss}}
\begingroup \makeactive*
\gdef\ccomment#1{%
    \ifx#1*\begingroup \noindent \commentfont
      % We want the width of a space in \commentfont, not \ctextfont.
      \spacebox{\ctextfont\string/}*%
      \makeother-\makeother'\makeother"\makeother/%
      \makeactive*\let*=\commentstar
    \else \leavevmode\string/#1\kern-1pt %
    \fi}
\makeother* \makeactive/
\gdef\commentstar#1{%
    \ifx #1/\endgroup \spacebox{$*$}\string/\let\next\relax%
    \else $*$\let\next#1%
    \fi\next}
\endgroup

\ifx\undefined\baselinestretch \def\baselinestretch{1}\fi

\def\cprogsetup{\cprogchars \ctextfont
    \baselineskip=\baselinestretch\cprogbaselineskip \parindent=\cprogindent}
\def\cprogfile#1{\begingroup \cprogsetup \input#1\endgroup}
% The {cprog} environment or \cprog macro reads in all the argument text.
% By making the C definition of \ much cleverer we could avoid this.
\def\cprog{\begingroup \cprogsetup \cprogarg}
% In LaTeX we need to call \end{cprog} properly to close the environment,
% whereas in plain TeX this will end the job.  The test for LaTeX is not
% bulletproof, but most plain TeX documents don't refer to the LaTeX logo.
\ifx\undefined\LaTeX \let\endcprogarg=\endgroup
\else \def\endcprogarg{\endgroup\end{cprog}} \let\endcprog=\relax
\fi

\fi	% \ifx\undefined\cprogsetup

\endinput
--
Eamonn McManus		emcmanus@cs.tcd.ie 	...!mcsun!cs.tcd.ie!emcmanus
	  One of the 0% of Americans who are not Americans.