Why can't I use \@MakeShortVerb with minted?

Question

shortvrb's \MakeShortVerb allows defining single active tokens, e.g. |, in a way that makes |\foo| equivalent to \verb|\foo|. To do this, | is defined to expand to \verb| and added to both \dospecials and \@sanitize. Internally, \MakeShortVerb\| expands to \def\@shortvrbdef{\verb}\@MakeShortVerb\| and \@shortvrbdef is later used to set the expansion of |.

I want to use the same mechanism but with minted. In order to use the minted macro \code (as defined in the MWE below) insead of \verb, I defined

\def\MakeShortCode{\def\@shortvrbdef{\code}\@MakeShortVerb}

However, I get the error

! Paragraph ended before \minted@inline@ii was complete.

when using the shorthand. If I manually define

\def|{\code|}

the shorthand works fine. Inspection of the definition of | in both cases shows that they are indeed identical, so the only difference should be the registration of | in \dospecials and \@sanitize.

Why exactly does this error occur? How can I get around this without braking e.g. the verbatim environment? Is this a bug in minted or is there a good reason for this behavior?

---

\documentclass{article}

\usepackage{xparse}
\usepackage{minted}
\usepackage{shortvrb}

\newmintinline[code]{latex}{}

\makeatletter
  \def\MakeShortCode{\def\@shortvrbdef{\code}\@MakeShortVerb}
  \def\MakeShortLstinline{\def\@shortvrbdef{\lstinline}\@MakeShortVerb}
\makeatother

\ExplSyntaxOn
  \NewDocumentCommand\decompose{ m }
    {
      {
        \ttfamily
        \tl_analysis_map_inline:Nn #1 
          {
            \exp_last_unbraced:No \token_to_str:N { ##1 }
            \ensuremath { \sb {##3} }
          }
      }
    }
\ExplSyntaxOff

\begin{document}

\catcode`\|=\active

\def|{\code|}
|\foo|

\decompose|

\MakeShortCode\|
%|\foo| % This will cause an error.

\decompose|

\end{document}

Answer 1

Not sure why trying to overcomplicate things:

\documentclass{article}

\usepackage{minted}

\newmintinline[code]{latex}{}

\catcode`\|=\active
\makeatletter
\protected\def|{%
  \ifmmode
    \expandafter\@firstoftwo
  \else
    \expandafter\@secondoftwo
  \fi
  {\string|}{\code|}%
}
\makeatother

\begin{document}

|\foo|

$|a+b|$

\end{document}

A more complicated version that allows to locally remove a shorthand.

\documentclass{article}

\usepackage{minted}

\newmintinline[code]{latex}{}

\makeatletter
\newcommand{\makemintedshorthand}[1]{%
  \expandafter\chardef\csname catcode#1\endcsname=\catcode`#1
  \begingroup\lccode`~=`#1\lowercase{\endgroup
    \protected\def~{%
      \ifmmode
        \expandafter\@secondoftwo
      \else
        \expandafter\@firstoftwo
      \fi
      {\code~}{#1}%
  }}%
  \catcode`#1=\active
}
\newcommand{\removemintedshorthand}[1]{%
  \ifcsname catcode\string#1\endcsname
    \catcode`#1=\csname catcode\string#1\endcsname
  \fi
}
\makeatother

\makemintedshorthand{|}

\begin{document}

|\foo|

$|a+b|$

\begingroup
\removemintedshorthand{|}
\code$abc|def$ \code|abc$def|

\verb|xyz| \verb"a|b"
\endgroup

|\foo|

\end{document}

Answer 2

The problem is that when \code|\foo| is executed, TeX only scans for the second | after \dospecials changed its category code to 12. \@MakeShortVerb defines |₁₃ to expand to \code₀|₁₃ (the indices denote category codes), so |\foo| effectively expands to \code₀|₁₃\foo₀|₁₂, which can't work.

We can fix this by modifying \MakeShortCode to define |₁₃ as \code₀|₁₂.

\documentclass{article}

\usepackage{etoolbox}
\usepackage{minted}
\usepackage{shortvrb}

\newmintinline[code]{latex}{}

\makeatletter
  \def\MakeShortCode{\def\@shortvrbdef{\code}\@MakeShortCode}
  \let\@MakeShortCode\@MakeShortVerb
  \patchcmd\@MakeShortCode
    {\expandafter\gdef\expandafter~\expandafter{\@shortvrbdef~}}
    {\xdef~{\expandafter\noexpand\@shortvrbdef\expandafter\@gobble\string#1}}
    {}{}
\makeatother

\MakeShortCode\|

\begin{document}\makeatletter

|\foo{bar} baz|

\begin{minted}{latex}
  I wrote |\foo{bar} baz|.
\end{minted}

\end{document}