Listings package: How can I format all numbers?

I want to highlight all the numbers appearing in an input code of a certain program by, for example, coloring them. By numbers I mean integer, rational and floating point numbers. I am trying with the listings page but with no success. I have noticed that specific numbers can be formatted with the morekeywords and alsoletter options on defining the language but I want to acomplish this task for any number.

For example, I would like the code

vector([3/5,4,0.4566])


to appear with the three numbers with color green (or whatever). Is it possible to do this in an automatic way?

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Welcome to TeX.SE. Even though it may seem trivial, it is always best to compose a MWE that illustrates the problem including the \documentclass so that those trying to help don't have to recreate it. –  Peter Grill Oct 20 '11 at 16:44
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Similar to solutions in Visualization in LaTeX of hamming distance, and Problem with the alignment of characters, you could use the literate command to define a style that is to be applied to each digit. Below I included a color for the . but commented out the color for the ,.

As there might be a period used outside of a number context, I have defined different styles based on the assumption that any period used in a number will have a digit following it.

\documentclass[border=2pt]{standalone}
\usepackage{listings}
\usepackage{xcolor}

\newcommand*{\FormatDigit}[1]{\textcolor{blue}{#1}}
\lstdefinestyle{FormattedNumber}{%
literate={0}{{\FormatDigit{0}}}{1}%
{1}{{\FormatDigit{1}}}{1}%
{2}{{\FormatDigit{2}}}{1}%
{3}{{\FormatDigit{3}}}{1}%
{4}{{\FormatDigit{4}}}{1}%
{5}{{\FormatDigit{5}}}{1}%
{6}{{\FormatDigit{6}}}{1}%
{7}{{\FormatDigit{7}}}{1}%
{8}{{\FormatDigit{8}}}{1}%
{9}{{\FormatDigit{9}}}{1}%
{.0}{{\FormatDigit{.0}}}{2}% Following is to ensure that only periods
{.1}{{\FormatDigit{.1}}}{2}% followed by a digit are changed.
{.2}{{\FormatDigit{.2}}}{2}%
{.3}{{\FormatDigit{.3}}}{2}%
{.4}{{\FormatDigit{.4}}}{2}%
{.5}{{\FormatDigit{.5}}}{2}%
{.6}{{\FormatDigit{.6}}}{2}%
{.7}{{\FormatDigit{.7}}}{2}%
{.8}{{\FormatDigit{.8}}}{2}%
{.9}{{\FormatDigit{.9}}}{2}%
%{,}{{\FormatDigit{,}}{1}% depends if you want the "," in color
{\ }{{ }}{1}% handle the space
,
basicstyle=\ttfamily,%  Optional to use this
}
\newcommand{\FormattedNumber}[1]{%
\lstinline[style=FormattedNumber]{#1}%
}

\begin{document}
\FormattedNumber{a.vector([3/5,4,0.4566])}
\end{document}

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One caveat: This would format \FormattedNumber{a.vector(<stuff>)} by also making the period blue. It would be possible, but somewhat round-about to get that fixed using mathescape=true and then using \FormattedNumber{a$.$vector(<stuff>)}. –  Werner Oct 20 '11 at 17:07
@Werner: Excellent point. Have updated the solution to handle that case. –  Peter Grill Oct 20 '11 at 17:19
That's perfect!!! You saved me a lot of time. Thank you!!! –  Rafa Gallego Oct 20 '11 at 18:22
All replacements that include the comma should have 2 instead of 1 at the end. this defines the number of output characters and is important for the complicated spacing of listings. –  stefanct Mar 29 at 0:45
@stefanct: Thanks. Have corrected it. –  Peter Grill Mar 29 at 2:17