2

Consider this example:

\documentclass{article}

\newcommand{\baz}{}
\newenvironment{foo}[1]{#1}{\makeatletter\g@addto@macro\baz{#1}\makeatother}

\begin{document}

\begin{foo}{bar}
\end{foo}
\end{document}

The example does not work. What I am aiming to achieve is concatenating all parameters used with foo, so I can output them at the end of the document. What is the correct approach for that?

lockstep
  • 250,273
ipavlic
  • 8,091
  • 2
    You cannot access the arguments from within the second body of \newenvironment. – Display Name Jun 07 '11 at 00:08
  • 2
    Somewhat unrelated to this problem: you can't use \makeatletter etc. inside command arguments because they are parsed when they are read, not when they are executed. – Philipp Jun 07 '11 at 05:08
  • unlike \newenvironment, with \NewDocumentEnvironment{myenv}{m}{}{#1} the end-code argument can refer to the arguments #1, #2, etc. – Daniel Diniz Nov 10 '22 at 22:52

1 Answers1

8

It would be easier to store the parameters at the start of the environment, rather than at the end. 

\documentclass{article}
\newcommand{\baz}{}
\makeatletter
\newenvironment{foo}[1]{\g@addto@macro\baz{#1}}{}
\makeatother
\begin{document}
\begin{foo}{kidney}
\end{foo}
\begin{foo}{spleen}
\end{foo}
\begin{foo}{liver}
\end{foo}

\baz
\end{document}

If you need to do it at the end, you might find the solutions to this question useful.

Community
  • 1
Ian Thompson
  • 43,767
  • I can make it work that way. The original problem required I add some information calculated at the end of the environment as well. I have now added the argument information at the beginning, and the calculated information at the end of the environment. Thanks. – ipavlic Jun 07 '11 at 00:30