Hard whitespace

Question

I am using plainTeX and would like to typeset some (python) code examples. Switching to \tt gets me partway there, but I (obviously) need the whitespace respected. Is there a trick for doing this? The last time I needed this I ended up writing a preprocessor that inserted appropriate \ everywhere. Oh dear, I guess I also need to eliminate paragraph indenting, and force newlines.

Answer 1

I would use \verbatim from eplain.

\input eplain

\verbatim
def foo():
    pass
|endverbatim
\bye

Answer 2

In general TH.'s answer is preferable. It also disables other special characters like \ which might be used in the Python code.

But here the answer about the spaces, line endings and parindent:
You can make plainTeX or LaTeX print all spaces using \obeyspaces. For line endings there is \obeylines which actually turns them into paragraphs (\par). The paragraph indention can be removed by setting \parindent=0pt.

This should be done inside a group of course. Make sure to comment all line endings for you code including the trailing \endgroup (or }), otherwise they will be printed as well.

\begingroup
\parindent=0pt\relax
\obeyspaces%
\let =\ %
\obeylines%

Your python code

\endgroup%

Answer 3

there's a rather elaborate verbatim routine in the tugboat plain macros, in the file tugboat.sty. it's too long to repeat here, but the code is pretty well documented and can probably be "lifted" without too much hassle. the rationale for developing this code was exactly what was asked for here -- observing precise spacing, especially at the beginnings of code lines, to be able to present tex macro code intelligibly.

tugboat.sty is on tex live in the /tex/plain/tugboat-plain area, and also on ctan.

Answer 4

I have tried to use plain TeX to typeset source code (in many languages). As it proved to be a hard task, and even harder if you wanted some eye candy like keyword highlighting, nowadays I prefer to use LaTeX to do the job with the listing environment and to include the output as a figure.

Ex:

% dclass and package loading
\usepackage{listings}

% stuff, stuff, stuff,

\lstset{
    rulecolor=\color{BlockGray},
    rulesepcolor=\color{TopGray},
    frame=shadowbox,
    language=Python,
    numbers=left,
    numberstyle=\tiny\color{yellow},
    numberblanklines=false,
    basicstyle=\footnotesize,
    showstringspaces=false,
}

% stuff, stuff, stuff,

\begin{document}

% stuff, stuff, stuff,

\begin{lstlisting}
from twisted.internet import reactor

def helloWorld():
    print "Hello World!"

reactor.callWhenRunning(helloWorld)
reactor.callWhenRunning(reactor.stop)

reactor.run()
\end{lstlisting}

% stuff, stuff, stuff,