Index keys with different fonts

Question

I would like to index some text elements that may contain code, for example:

foo of type \code{bar}

where \code is something like \texttt. But when I stick this text into \index, the collation is different between code and normal text:

\index{foo of type \code{bar}}
\index{foo of type abc}
\index{foo of type unknown}

The collation is wrong, and to get the correct collation, I would need to say:

\index{foo of type bar@foo of type \code{bar}}
\index{foo of type abc@foo of type abc}
\index{foo of type unknown@foo of type unknown}

However, this is tedious to maintain.

Is it possible to write a single command that creates the stripped "bare" text for the collation? Ideally, something like:

\myindex{abc \code{def} ghi}

that becomes

\index{abc def ghi@abc \code{def} ghi}

?

It would be acceptable if the mechanism is only able to strip one particular command (such as \code above).

---

Small example to reproduce:

\documentclass{article}
\usepackage{makeidx}
\makeindex

\begin{document}

\index{aba}
\index{abc}
\index{abe}
\index{ab\texttt{b}}
\index{ab\texttt{d}}

\printindex

\end{document}

This collates incorrectly. I would like a macro I could use in place of \index that would produce the correct collation order "aba", "abb", "abc", "abd", "abe".

Answer 1

I am not sure this is a good way to do this but it seems to work for the minimal example posted. It attempts to solve only the restricted problem described i.e. where just one command is dealt with as described. In this case \code{} will be treated specially so that it does not affect the sorting, but only the format, of the entry.

\documentclass{article}
\usepackage{makeidx}
\makeindex
\newcommand*\ocode[1]{\string\texttt{#1}}
\newcommand*\nocode[1]{#1}
\let\code\ocode
\def\myindexx#1\relax{\index{#1}}
\newcommand*\myindex[1]{%
  \let\code\nocode
  \edef\tempa{#1}%
  \let\code\ocode
  \myindexx\tempa@#1\relax
}
\begin{document}
abc

\myindex{aba}
\myindex{abc}
\myindex{abe}
\myindex{ab\code{b}}
\myindex{ab\code{d}}

\printindex

\end{document}