Using `environ` to make a list of environments?

Question

In my document I use an amsthm environment called question, which I use to, well, pose questions to myself for later reference. However, they are spread out in the text.

I know ntheorem has a \listoftheorems command or something like that which does exactly what I want. However, I have quite some bad experiences with ntheoremconcerning the use of ntheoremtogether with other packages (it only occured when I used mathtools and something which I have forgotten about...) which introduced quite strange bugs, so I would want to avoid ntheorem altogether for the moment.

So, is this possible to do this with environ as it provides some useful hooks? Preferably it would be nice if the list also allows me (optionally) to include a short description and of course a page number. The environment is defined as \newtheorem{question}{Question}.

Edit: I have found thmtools which apparently also has a command \listoftheorems (and a way to redefine the heading). Would it be possible to extend this command such that I am able to add a small description?

Answer 1

First of all there is the tocloft package, that is meant for this kind of work and takes away a little of the effort in Gonzalo's answer. Also I would propose to define a new environment, so you don't have to use an extra command, but can have an actual, optional argument:

\documentclass{article}
\usepackage{amsthm}
\usepackage{tocloft}

\newtheorem{xquestion}{Question}

\newcommand\listxquestionsname{List of Questions}
\newlistof{question}{xquestion}{\listxquestionsname}
\newcommand\qdescription[1]{%
  \addcontentsline{xquestion}{question}%
    {\protect\makebox[2.5cm][l]{Question~\thexquestion\hfill}#1}}

\newenvironment{question}[1][]{\begin{xquestion}\qdescription{#1}}{\end{xquestion}}

\begin{document}

\listofquestion
\bigskip

\begin{question}[Optional description for question one]
Test question One
\end{question}

\begin{question}
Test question Two
\end{question}

\end{document}

Answer 2

The following example shows one possible solution using the LaTeX kernel command \@starttoc to produce the new list of questions. The \qdescription command is used to generate an entry in the new list of questions as well as to provide an optional description:

\documentclass{article}
\usepackage{amsthm}

\makeatletter
\newcommand\listquestionsname{List of Questions}
\newcommand\qdescription[1]{%
  \addcontentsline{qst}{question}%
  {\protect\makebox[2.5cm][l]{Question~\thequestion\hfill}#1}}
\newcommand\listofquestions{%
  \let\listofquestions\relax % (AM)
  \section*{\listquestionsname}\@starttoc{qst}%
}
\newcommand*\l@question{\@dottedtocline{1}{1.5em}{2.3em}}
\makeatother

\newtheorem{question}{Question}

\begin{document}

\listofquestions

\begin{question}
Test question One
\qdescription{Optional description for question one}
\end{question}

\begin{question}
Test question Two
\qdescription{}
\end{question}

\end{document}