\pause inside an inline escape produces unexpected extra slides without the pause when breaklines=true

[alexeyr]

\documentclass[11pt]{beamer}

\usepackage{minted}

\usetheme[progressbar=head,numbering=fraction,block=fill]{metropolis}

\title{XXX}

\begin{document}
    \begin{frame}[plain]
    \maketitle
\end{frame}

\begin{frame}[fragile]
\frametitle{XXX}
\begin{itemize}
\item 
\begin{minted}[escapeinside=``,breaklines=true]{haskell}
class Applicative m => Monad m where
(>>=) :: m a -> (a -> m b) -> m b
(>>) :: m a -> m b -> m b
mx >> my =`\pause` mx >>=`\pause` \_ -> my
\end{minted}
\end{itemize}
\end{frame}

\end{document}

with command pdflatex.exe -shell-escape -synctex=1 -interaction=nonstopmode filename.tex produces two unnumbered slides with the full contents (as if it didn't have \pause) before the expected slides with pauses, which are numbered; removing breaklines=true fixes the problem.

[gpoore]

breaklines basically typesets each line twice: once to determine if a break is needed, and then once for actual insertion based on that information. Apparently that is interfering with \pause, which is itself probably doing some very interesting things. I could add a note to the documentation about the incompatibility.

It might be possible to get this to work, but at the moment the only thing I can think of is trying to redefine \pause during the breaklines temporary typesetting step, and that would take some work and might be difficult.

[alexeyr]

I could add a note to the documentation about the incompatibility.

Please do. I don't really particularly need the combination, I just ran into this because I defined breaklines=true inside a \newminted just in case a break was needed somewhere.

[samcarter]

@alexeyr As a manual workaround you could use \begin{frame}<3->. This will hide the first two superfluous slides.

% !TeX program = txs:///arara
% arara: pdflatex: {synctex: on, interaction: nonstopmode, shell: yes}

\documentclass[11pt]{beamer}

\usepackage{minted}

\usetheme[progressbar=head,numbering=fraction,block=fill]{metropolis}

\title{XXX}
\AtBeginEnvironment{minted}{\chardef\`=`\`}

\begin{document}
    \begin{frame}[plain]
    \maketitle
\end{frame}

\begin{frame}<3->[fragile]
\frametitle{XXX}
\begin{itemize}
\item 
\begin{minted}[escapeinside=\`\`,breaklines=true]{haskell}
class Applicative m => Monad m where
(>>=) :: m a -> (a -> m b) -> m b
(>>) :: m a -> m b -> m b
mx >> my =`\pause` mx >>=`\pause` \_ -> my
\end{minted}
\end{itemize}
\end{frame}

\end{document}

[muzimuzhi]

The underneath operations of beamer's overlay commands (like \pause) relate to some pgf inner macros and I failed reasoning the cause of extra slides. By now, the finest workaround (from https://github.com/josephwright/beamer/issues/594#issuecomment-623456815) is to manually set overlay specifications of a frame. This trick is compatible with breaklines option.

For the example given in this issue, that means to use \begin{frame}<3->[fragile].

(oh @samcarter has commented with the same info)

[samcarter]

(oh @samcarter has commented with the same info)

@muzimuzhi I wanted to comment earlier, but I could not get the code to work because of the escape inside problem. Thanks to your workaround \AtBeginEnvironment{minted}{\chardef\`=`\`} I could test it now :)

[muzimuzhi]

And, to markup single backtick character as code span, you can use double backticks as delimiter Input:

`` if the inline code contains single ` ``

Output: if the inline code contains single `

See the Github Flavored Markdown Spec, sec. 6.3.

---

PS: You can use other escape delimiter, for example escapeinside=|| (and then change `\pause` to |\pause|) to avoid the ` problem. Current issue has nothing to do with which pair of characters are passed to escapeinside.

[samcarter]

@muzimuzhi Oh wow! Thanks a lot for this information!