how to better control the number display of listings?

Question

I'm using the listings package for my sourcecodes, and among other things to control the display of those, I'm using \lstset, obviously.

Now, When setting numberstyle, I've set them to \sffamily\tiny\color{gray}. Now this all works alright, because those all works as switches inside an environment. But what If I need the numbers inside an environment?

Namely, I'd like to raise the numbers a little with \raisebox{}{}. But how do I put the line number in question into that command? Basically, they have to go into the second set of curly braces.

How do I do that?

As requested, here's the example:

\documentclass[a4paper, 11pt]{scrartcl}
\usepackage{listings}

\lstset{
    numbers=left,
    numberstyle=\sffamily\tiny,
}

\begin{document}
\begin{lstlisting}[title=test]
for i:=maxint to 0 do
begin
    { do nothing }
end;

Write("Case insensitive")
WritE("Pascal keywords.")

a = 'a' -- comment
\end{lstlisting}
\end{document}

As you can see, I've set numberstyle to the switches I want to, but how am I supposed to put an environment in there, where the number is supposed to be put into?

Answer 1

listings has been designed so that when outputting line numbers, the code stored in the numberstyle key is essentially applied with the line number as an argument. The same is true for many of the other ...style keys in listings.

I'll explain some of the TeXnical details in my answer, but don't worry if you don't understand it, just try to follow the examples. The value you assign to the key numberstyle is stored in \lst@numberstyle and when listings come to write the numbers, it invokes it as \lst@numberstyle{\thelstnumber}. If TeX is not expecting to read an argument after processing the \lst@numberstyle, it sees those braces as denoting a group rather than an argument, and is harmless.

There are essentially two ways of doing something with that argument (first one suggested by alexis after my original answer mentioned only the second), depending on what macro you want to call:

1. You could define a new macro to absorb that argument, and put it back on the input stream together with other code of choice, and then place this macro as the last thing in the value of the numberstyle key. This is perhaps the most intuitive method, and has the advantage of being most general (it can be used even when the line number is not to be passed as the last argument to an existing macro). As common with these things, it is best illustrated by example. In this example, \mynumberstyle is such a macro:

   \documentclass[a4paper, 11pt]{scrartcl}
   \usepackage{listings}
   
   \newcommand*{\mynumberstyle}[1]{\raisebox{0.3em}{#1}}
   \lstset{
       numbers=left,
       numberstyle=\sffamily\tiny\mynumberstyle,
   }
   
   \begin{document}
   \begin{lstlisting}[title=test]
   for i:=maxint to 0 do
   begin
       { do nothing }
   end;
   
   Write("Case insensitive")
   Write("Pascal keywords.")
   
   a = 'a' -- comment
   \end{lstlisting}
   \end{document}
   

2. When all you want to do is invoke another macro and use the line number (or rather macro \thelstnumber eventually expanding to the line number) as the last argument to that macro (as is your case with \raisebox), you can avoid defining a new command and also avoid reading the argument and putting it back only to be read again (but now with the original catcodes, though this is not a problem for the use case here)...

   In particular, you can just append \raisebox{first argument} to the end of the value you assign to the numberstyle key, and it will pick up the line number as its second argument (just as \mynumberstyle picked it up as its only argument in the above example). The following example illustrates this:

   \documentclass[a4paper, 11pt]{scrartcl}
   \usepackage{listings}
   
   \lstset{
       numbers=left,
       numberstyle=\sffamily\tiny\raisebox{0.3em},
   }
   
   \begin{document}
   \begin{lstlisting}[title=test]
   for i:=maxint to 0 do
   begin
       { do nothing }
   end;
   
   Write("Case insensitive")
   Write("Pascal keywords.")
   
   a = 'a' -- comment
   \end{lstlisting}
   \end{document}