Improving the POV definition in the listings package

Question

I'm attempting to create a language definition in the listings package that mimics exactly the syntax highlighting in POV-Ray 3.6 for Windows (http://www.povray.org/download/). Here is a screenshot from POV, which I'm trying to imitate:

(The POV language definition in the listings package is not the same.)

I include below my attempt so far, but it has some flaws. First, I cannot get it to make numbers green, despite my attempt. Second, I cannot get it to make angle brackets (or other operators) red, despite my attempts. By contrast, my attempt to get curly braces to show up blue works fine, despite its similarity to the angle brackets problem/solution. I am obviously doing something wrong, but reading the reference manual for the listings package didn't clear up my confusion.

Here's an example of my wrong results:

Any tips?

\documentclass[12pt]{article}

\usepackage{listings}
\usepackage{color}

\definecolor{povcodered}{rgb}{0.75,0.25,0.25}
\definecolor{povcodegreen}{rgb}{0.25,0.75,0.25}
\definecolor{povcodeblue}{rgb}{0.25,0.25,0.75}
\definecolor{povcodepurple}{rgb}{0.5,0,0.35}
\definecolor{povcodebluegreen}{rgb}{0,0.5,0.5}

\lstdefinelanguage{myPOV}{
    alsoletter={\#\{\}\<\>},
    keywords={
        sphere, cone, and, so, on,
        \#include, \#declare, \#version},
    keywords={[2]\{,\}},
    keywords={[3]\<,\>},
    sensitive=true,
    string=[b]{"},
    comment=[l]{//},
    morecomment=[s]{/*}{*/}}

\lstset{language=myPOV,
    basicstyle=\ttfamily\bfseries,
    keywordstyle=\color{povcodepurple},
    keywordstyle=[2]\color{povcodeblue},
    keywordstyle=[3]\color{povcodered},
    stringstyle=\color{povcodered},
    commentstyle=\color{povcodegreen},
    numberstyle=\color{povcodebluegreen}}

\begin{document}

\begin{lstlisting}
#include "somefile.inc"
// now let's add a shape
sphere {
  <0,0,0>, 1
  translate <5,3,2>
}
\end{lstlisting}

\end{document}

Answer 1

Based on your self-answer, it seems you're almost there. The last remaining problem is to highlight / and // differently and make sure // starts a comment.

How to highlight / and // differently (without breaking comments)

As you've noticed, any literate replacement of / will prevent you from using it in a comment delimiter; therefore, you have to resort to other means than a literate replacement of /. The approach shown in the code below solves the problem.

Caveat: if // is immediately preceded by a character that listings treats as "other" (for instance, *//), // will still start a comment but it won't be highlighted in comment style.

Side note: don't define { and } as "letters"

Defining { and } as "letters" via

alsoletter = {\{\}},

is a bad idea, at least in your case. Here is an example of where it could go wrong: listings, if it encounters the sequence of characters sphere{ (note the absence of space between sphere and {), would recognise it as a single identifier; the sphere part would not be recognised as a keyword and would therefore not be get highlighted as such. Here, literate replacements of { and } are preferable.

\documentclass{article}

\usepackage[T1]{fontenc} %<--- for nice braces in typewriter font
\usepackage{lmodern}
\usepackage{listings}
\usepackage{xcolor}


\lstdefinelanguage{myPOVlanguage}
{
  alsoletter  = {\#},
  keywords    =
  {
    \#include, \#declare, \#version,
    assumed_gamma,
    background, box,
    camera, color, color_map, cone, cylinder,
    direction,
    function,
    global_settings, gradient,
    light_source, location, look_at,
    matrix,
    no_shadow,
    object,
    pigment, pow,
    rgb, right, rotate,
    scale, sphere,
    translate, 
    x, y, z,        
  },
  sensitive   = true,
  string      = [b]{"},
  comment     = [l]{//},
  morecomment = [s]{/*}{*/},
}

% --- color definitions ---
\definecolor{povcodered}{rgb}{0.75,0.25,0.25}
\definecolor{povcodegreen}{rgb}{0.25,0.75,0.25}
\definecolor{povcodeblue}{rgb}{0.25,0.25,0.75}
\definecolor{povcodepurple}{rgb}{0.5,0,0.35}
\definecolor{povcodebluegreen}{rgb}{0,0.5,0.5}

\lstdefinestyle{myPOVstyle}
{
  language           = myPOVlanguage,
  frame              = single,
  framextopmargin    = 3mm,
  framexbottommargin = 3mm,
  basicstyle         = \ttfamily\bfseries,
  keywordstyle       = \color{povcodepurple},
  stringstyle        = \color{povcodered},
  commentstyle       = \color{povcodegreen}\itshape,
  literate =*
    {0}{{{\color{povcodebluegreen}0}}}1
    {1}{{{\color{povcodebluegreen}1}}}1
    {2}{{{\color{povcodebluegreen}2}}}1
    {3}{{{\color{povcodebluegreen}3}}}1
    {4}{{{\color{povcodebluegreen}4}}}1
    {5}{{{\color{povcodebluegreen}5}}}1
    {6}{{{\color{povcodebluegreen}6}}}1
    {7}{{{\color{povcodebluegreen}7}}}1
    {8}{{{\color{povcodebluegreen}8}}}1
    {9}{{{\color{povcodebluegreen}9}}}1
    {+}{{{\color{povcodered}+}}}1
    {-}{{{\color{povcodered}-}}}1
    {*}{{{\color{povcodered}*}}}1
    {<}{{{\color{povcodered}<}}}1
    {>}{{{\color{povcodered}>}}}1
    {\{}{{{\color{povcodeblue}\{}}}1
    {\}}{{{\color{povcodeblue}\}}}}1
}

% --- patch to get proper highlighting of / and // ---
\makeatletter
\lst@AddToHook{OutputOther}
{%
  \edef\@tempa{\the\lst@token\relax}%
  %
  % apply \color{povcodered} if / is found
  \expandafter\expandafter\expandafter\ifx\expandafter\@firstoftwo\@tempa/%
    \def\lst@thestyle{\color{povcodered}}%
    %
    % apply comment style if // is found
    \expandafter\expandafter\expandafter\ifx\expandafter\@secondoftwo\@tempa/%
      \def\lst@thestyle{\lst@commentstyle}%
    \fi  
  \fi
}
\makeatother

\lstset{style=myPOVstyle}

\begin{document}
\begin{lstlisting}
#include "somefile.inc"
// now let's add a shape
sphere {
  <0,0,0>, 1
  translate <5,3,2>

  sdf/sdf
}
\end{lstlisting}
\end{document} 

Answer 2

I think I've mostly answered my own question. By reading some of the other related questions I cobbled together the following POV language definition file that does most of what I want, or at least is extensible enough that it will be able to do most of what I want after it's done evolving.

The essential fix was to use literate in a way that's not really its intended use, but just as a generic mechanism for replacing any character sequence with any other. This allows me to choose specific digits, operators, etc., and assign them colors.

Here is POV code that isn't fully complete (not all operators and keywords) but I'll extend it as I hit new operators and keywords that aren't on this list. You get the idea. The code is below.

The one thing that isn't yet solved by this is that the double-slash for a one-line comment is now treated like two adjacent single-slashes, so there is no such thing as a one-line comment anymore. It seems that literate overrides everything else. That question therefore remains.

\lstdefinelanguage{myPOV}{
    alsoletter={\#\{\}},
    keywords={
        sphere, cone, cylinder, box, object,
        rotate, translate, scale, matrix,
        camera, location, direction, right, look_at,
        pigment, gradient, color_map, color, rgb,
        x, y, z, pow, function,
        light_source, background, no_shadow,
        global_settings, assumed_gamma,
        \#include, \#declare, \#version},
    keywords={[2]\{,\}},
    sensitive=true,
    string=[b]{"},
    comment=[l]{//},
    morecomment=[s]{/*}{*/},
    literate=%
       *{0}{{{\color{povcodebluegreen}0}}}1
        {1}{{{\color{povcodebluegreen}1}}}1
        {2}{{{\color{povcodebluegreen}2}}}1
        {3}{{{\color{povcodebluegreen}3}}}1
        {4}{{{\color{povcodebluegreen}4}}}1
        {5}{{{\color{povcodebluegreen}5}}}1
        {6}{{{\color{povcodebluegreen}6}}}1
        {7}{{{\color{povcodebluegreen}7}}}1
        {8}{{{\color{povcodebluegreen}8}}}1
        {9}{{{\color{povcodebluegreen}9}}}1
        {+}{{{\color{povcodered}+}}}1
        {-}{{{\color{povcodered}-}}}1
        {*}{{{\color{povcodered}*}}}1
        {/}{{{\color{povcodered}/}}}1
        {<}{{{\color{povcodered}<}}}1
        {>}{{{\color{povcodered}>}}}1}

\lstset{language=myPOV, frame=single,
    basicstyle=\ttfamily\bfseries,
    keywordstyle=\color{povcodepurple},
    keywordstyle=[2]\color{povcodeblue},
    stringstyle=\color{povcodered},
    commentstyle=\color{povcodegreen},
    framextopmargin=3mm,
    framexbottommargin=3mm
    }