Macro with lstlisting inside

Question

I have been following this topic about using \NewDocuentCommand with lstlisting and the accepted answer is nice except it is too big and it doesn't quite work for me.

I came up with this example to test xparse:

\documentclass{article}
\usepackage{xparse}
\usepackage{listings}

\ExplSyntaxOn
\NewDocumentCommand{\code}{m +v}{
    \begin{lstlisting}[style=#1,numbers=none,xleftmargin=0.35cm,framesep=0mm]
        #2
    \end{lstlisting}
}
\ExplSyntaxOff
   
\begin{document}

\code{C}{
int x = 200;
unsigned int y = 0;
}

\end{document}

Like stated in the CTAN xparse documentation I first used m as a normal parameter and then +v as a multiline verbatim parameter, but it fails. It looks like I am still missing something...

Answer 1

You can just use Bruno's solution from the linked question (pretty smart I think).

\documentclass{article}
\usepackage{listings}
\usepackage{xparse}

\ExplSyntaxOn
\NewDocumentCommand{\code}{m +v}{
  \newlinechar=\endlinechar
  \exp_args:Nx \scantokens
  {
    \string\begin{lstlisting}[\unexpanded{language=#1,numbers=none,xleftmargin=0.35cm,framesep=0mm}]
      #2
    \string\end{lstlisting}
  }
}
\ExplSyntaxOff

\begin{document}

\code{C}{
int x = 200;
unsigned int y = 0;
}

\end{document}

---

But please, just use a new environment instead.

\documentclass{article}
\pagestyle{empty}
\usepackage{listings}

\lstnewenvironment{code}[1]{\lstset{language=#1,numbers=none,xleftmargin=0.35cm,framesep=0mm}}{}

\begin{document}

\begin{code}{C}
int x = 200;
unsigned int y = 0;
\end{code}

\end{document}

Output is similar.