# How can I define a custom listing environment?

I am trying to define an enviroment for a specific programming language, F#. Here's my code:

\definecolor{bluekeywords}{rgb}{0.13,0.13,1}
\definecolor{turqusnumbers}{rgb}{0.17,0.57,0.69}
\definecolor{redstrings}{rgb}{0.5,0,0}

\lstdefinelanguage{FSharp}
{morekeywords={let, new, match, with, rec, open, module, namespace, type, of, member, and, for, in, do, begin, end, fun, function, try, mutable, if, then, else},
keywordstyle=\color{bluekeywords},
sensitive=false,
morestring=[b]",
stringstyle=\color{redstrings}
}

\newenvironment{fslisting}
{
\lstset{
language=FSharp,
basicstyle=\ttfamily,
breaklines=true,
columns=fullflexible}
\begin{lstlisting}
}
{
\end{lstlisting}
}


Then I'm trying to use it as such:

\begin{fslisting}
type 'a Process = 'a Signal IObservable
\end{fslisting}


But it doesn't work. The output log says that the listing is not terminated - or is terminated by the document. So the rest of the document is also formatted as a listing, which is of course not the intention.

What am I doing wrong here?

You cannot create a new lstlisting environment via \newenvironment. You need to use \lstnewenvironment. See the listings documentation, section 5.14 Environments (p 42).

\documentclass{article}

\usepackage{listings,xcolor}

\definecolor{bluekeywords}{rgb}{0.13,0.13,1}
\definecolor{turqusnumbers}{rgb}{0.17,0.57,0.69}
\definecolor{redstrings}{rgb}{0.5,0,0}

\lstdefinelanguage{FSharp}
{morekeywords={let, new, match, with, rec, open, module, namespace, type, of, member, and, for, in, do, begin, end, fun, function, try, mutable, if, then, else},
keywordstyle=\color{bluekeywords},
sensitive=false,
morestring=[b]",
stringstyle=\color{redstrings}
}

\lstnewenvironment{fslisting}
{
\lstset{
language=FSharp,
basicstyle=\ttfamily,
breaklines=true,
columns=fullflexible}
}
{
}
\begin{document}

\begin{fslisting}
type 'a Process = 'a Signal IObservable
\end{fslisting}

\end{document}

• The section in the reference changed to 5.14 on page 42 – DBX12 Apr 20 '18 at 15:32

Just use the provided \lstnewenvironment command.

\documentclass{article}

\usepackage{xcolor}
\usepackage{listings}

\definecolor{bluekeywords}{rgb}{0.13,0.13,1}
\definecolor{turqusnumbers}{rgb}{0.17,0.57,0.69}
\definecolor{redstrings}{rgb}{0.5,0,0}

\lstdefinelanguage{FSharp}
{morekeywords={let, new, match, with, rec, open, module, namespace, type, of, member, and, for, in, do, begin, end, fun, function, try, mutable, if, then, else},
keywordstyle=\color{bluekeywords},
sensitive=false,
morestring=[b]",
stringstyle=\color{redstrings}
}

\lstnewenvironment{fslisting}
{\lstset{language=FSharp,
basicstyle=\ttfamily,
breaklines=true,
columns=fullflexible
}}
{}

\begin{document}

\begin{fslisting}
type 'a Process = 'a Signal IObservable
\end{fslisting}
\end{document}

• and again too late... ;) – someonr Oct 24 '12 at 21:54