Using \verb and \begin{verbatim} / \end{verbatim} in NewEnviron

Question

Consider the following MWE:

\documentclass[a4paper]{article}

\usepackage{environ}

\NewEnviron{myitemize} {
\show\BODY
\begin{itemize}
\BODY
\end{itemize}
}

\begin{document}

\begin{itemize}
\item \verb|test|
\end{itemize}

\begin{myitemize}
\item \verb|test|
\end{myitemize}

\end{document}

The first list works, but the second one throws Latex errors (missing } inserted, extra }, \verb illegal ...). It has probably something to do with the way NewEnviron collects it's body but can someone elaborate on this problem.

Log file shows:

> \BODY=macro:
->\item \verb |test|.

so why is there a problem? And of course, what is the solution?

score 3 · Accepted Answer · answered Aug 17 '18 at 18:01

3

This issue is similar to passing \verb as an argument to a macro, as in

\newcommand{\mymacro}[1]{#1}

\mymacro{\verb|test|}

Your solution in this case would be to not use environ:

\documentclass{article}

\newenvironment{myitemize}
  {\begin{itemize}}
  {\end{itemize}}

\begin{document}

\begin{itemize}
  \item \verb|test|
\end{itemize}

\begin{myitemize}
  \item \verb|test|
\end{myitemize}

\end{document}

Why is there a problem to start with? The collection of content fixes the category codes - something \verb and verbatim needs access to (or change) in order to function properly.

answered Aug 17 '18 at 18:01

Werner

603,163

well, I want to collect the body to patch particular code strings and pass the result on to itemize. – Jesse op den Brouw Aug 17 '18 at 18:16
@JesseopdenBrouw: Does your code string contain particularly odd characters? – Werner Aug 17 '18 at 18:39
1

@JesseopdenBrouw: Try this. It works, partially... – Werner Aug 17 '18 at 19:12
It looks promising... – Jesse op den Brouw Aug 17 '18 at 19:46
For now. I will do with \renewenvironment{verbatim}[1]{\begingroup\ttfamily #1}{\endgroup} – Jesse op den Brouw Aug 17 '18 at 20:08
See also https://tex.stackexchange.com/questions/51239/verbatim-in-environ-s-body – Jesse op den Brouw Aug 19 '18 at 12:22
I wanted to use a \colorbox on the verbatim. How to do that? All it does is throw errors at me. – Someone Apr 14 '20 at 15:43
@Someone: You can store the verbatim content in a box, and then place the box inside a \colorbox. – Werner Apr 14 '20 at 21:46

Using \verb and \begin{verbatim} / \end{verbatim} in NewEnviron

1 Answers1