Subject: bug#29401: 11.90.2.2017-07-25; Folding displays errors on valid LaTeX

From: Koen van Greevenbroek <[email-masked]>
Date: Fri, 01 Dec 2017 06:41:02 -0800

Hi Arash,

>     \begin{frame}
>       \begin{itemize}
>       \item <1>\textbf{One}
>       \item <2>\textbf{Two}
>       \end{itemize}
>     \end{frame}

This version does fold correctly, but it doesn't produce the same
output as the original example. In particular, here the overlay is
applied to the items themselves, while when writing something like
`\textbf<1>{foo}', the idea is that `foo' will be displayed in bold on
the first slide, and normally for the rest of the slides. Maybe an
example that illustrates the folding problem even better is:

\begin{frame}
  \textbf<1>{One} \\
  \textbf<2>{Two}
\end{frame}

This is syntactically correct, see section 9.3 of the Beamer user
guide.

I agree that code in the preamble will be extremely hard to fold
correctly. However, maybe it could be an idea to ignore commands that
cannot be folded correctly indstead of displaying an error? I know that
I could just not try to fold the preamble, but right now I have
something like

(add-hook 'LaTeX-mode-hook
          (lambda ()
            (TeX-fold-mode t)
            (add-hook 'find-file-hook 'TeX-fold-buffer t t)))

in my .emacs, every LaTeX buffer I visit gets folder automatically. I
think it would be nicer to just not see the errors.

Have a nice day,

Koen