! File ended while scanning use of \@xverbatim error starting with commit 0c387de

[dbitouze]

The following M(n)WE:

\documentclass{beamer}
\begin{document}
\begin{frame}[fragile]
  \frametitle{Beamer's tutorial}
  \framesubtitle{Code for frames}
  Here is how you create a frame with Beamer class:\pause{}
\begin{verbatim}
  \begin{frame}

  \end{frame}
\end{verbatim}
\end{frame}
\end{document}

used to work nicely until commit 6a23fce and fails starting with commit 0c387de with error:

./test.vrb
)
Runaway argument?
^^M  \begin{frame}^^M^^M
! File ended while scanning use of \@xverbatim.
<inserted text> 
                \par 
l.13   \end{frame}

[josephwright]

I think this is probably 'to be expected'! I've got two competing issues:

• People who want to be able to indent \end{frame}
• People who are documenting how to make beamer slides

To allow the former to work, you have to 'lift' the restriction that fragile frames search for only \end{frame} with no leading whitespace. On the other hand, that necessarily causes some (solvable) issues for the latter group. It's easy to think of users as mainly writing code examples, but of course that's not the case: most users are not writing about the class itself. (See #326 for more on this, and earlier see #310).

For the case where one is documenting beamer itself, one can create an alternative environment such as slide:

\documentclass{beamer}
\newenvironment{slide}
{\begin{frame}[fragile,environment=slide]}
{\end{frame}}
\begin{document}
\begin{slide}
  \frametitle{Beamer's tutorial}
  \framesubtitle{Code for frames}
  Here is how you create a frame with Beamer class:\pause{}
\begin{verbatim}
\begin{frame}

\end{frame}
\end{verbatim}
\end{slide}
\end{document}

[josephwright]

I guess I could arrange to 'count up' the nesting of frame environments, which would solve this issue but would be vulnerable still to e.g.

\documentclass{beamer}
\begin{document}
\begin{frame}[fragile]
  \frametitle{Beamer's tutorial}
  \framesubtitle{Code for frames}
  Here is how you create a frame with Beamer class:\pause{}
\begin{verbatim}
  \end{frame}
\end{verbatim}
\end{frame}
\end{document}

[FrankMittelbach]

Am 12.01.2017 um 17:38 schrieb Joseph Wright:

I guess I could arrange to 'count up' the nesting of |frame| environments, which would solve this issue but would be vulnerable still to /e.g./

I think all of this is overkill (and as you say it will stay with some sort of exception unless you really go to very very slow parsing) So better document that beamer can document itself (on frame environments) using verbatim in order to make life easier for real uses but that you have to use, say semiverbatim in that case. Bit of a nuisance but you have to die one death here

[josephwright]

Yes, something in the docs is likely appropriate.

[josephwright]

BTW, nice to know someone is testing the code (other than me, of course).

[dbitouze]

So better document that beamer can document itself (on frame environments) using verbatim in order to make life easier for real uses but that you have to use, say semiverbatim in that case.

OK, agree. But, tell more than just "semiverbatim", otherwise some folks would be puzzled :)

[dbitouze]

BTW, nice to know someone is testing the code (other than me, of course).

You're welcome :)

[dbitouze]

AFAICS, the drawback of environments defined by \newenvironment<>{slide}[1][]{\begin{frame}[fragile,environment=slide]}{\end{frame}} is that they can not be resumed with \againframe:

\documentclass{beamer}
\newenvironment<>{slide}[1][]{\begin{frame}[fragile,environment=slide]}{\end{frame}}
\begin{document}
\begin{slide}[label=foo]
Foo
\end{slide}
%
\againframe{foo}
\end{document}

[josephwright]

I'm reopening here so there is an issue to remind me to do the documentation. I'll cover a few options: semiverbatim for example will happily allow againframe.

[samcarter]

@dbitouze

AFAICS, the drawback of environments defined by \newenvironment<>{slide}[1][]{\begin{frame}[fragile,environment=slide]}{\end{frame}} is that they can not be resumed with \againframe

This works if you actually pass the optional argument on to the frame:

\documentclass{beamer}
\newenvironment<>{slide}[1][]{\begin{frame}[fragile,environment=slide,#1]}{\end{frame}}
\begin{document}
\begin{slide}[label=foo]
Foo
\end{slide}
%
\againframe{foo}
\end{document}