Custom verbatim commands writing into index

Question

I have created a custom fancyvrb command via \CustomVerbatimCommand{\afun}{Verb}{} to use for writing programming language functions, say \afun|object.method.blah|, etc.

I would like to automatically build an index of all mentions of function names.

I know I could try to do that with ordinary LaTeX commands, e.g. with something like:

\newcommand{\afun}[1]{\texttt{#1}\index{#1@\texttt{#1}}}

That will create an index entry with a function name.

Is there any way to achieve that, but with custom verbatim commands of fancyvrb?

Answer 1

I'd suggest using xparse:

\documentclass{article}
\usepackage{imakeidx}
\usepackage{xparse}

\makeindex

\NewDocumentCommand\afun{v}{%
  \texttt{#1}\index{#1@\ifun{#1}}%
}
\NewDocumentCommand{\ifun}{v}{\texttt{#1}}

\begin{document}

\afun{object.method.blah}

\afun{object.method_2.blah}

\printindex

\end{document}

If you only need the underscore, among the special characters, this seems the cleanest approach.