GraphViz::Regex(3pm)					User Contributed Perl Documentation				      GraphViz::Regex(3pm)

NAME

       GraphViz::Regex - Visualise a regular expression

SYNOPSIS

	 use GraphViz::Regex;

	 my $regex = '(([abcd0-9])|(foo))';

	 my $graph = GraphViz::Regex->new($regex);
	 print $graph->as_png;

DESCRIPTION

       This module attempts to visualise a Perl regular expression. Understanding regular expressions is tricky at the best of times, and regexess
       almost always evolve in ways unforseen at the start. This module aims to visualise a regex as a graph in order to make the structure clear
       and aid in understanding the regex.

       The graph visualises how the Perl regular expression engine attempts to match the regex. Simple text matches or character classes are
       represented by.box-shaped nodes. Alternations are represented by a diamond-shaped node which points to the alternations. Repetitions are
       represented by self-edges with a label of the repetition type (the nodes being repeated are pointed to be a full edge, a dotted edge points
       to what to match after the repetition). Matched patterns (such as $1, $2, etc.) are represented by a 'START $1' .. 'END $1' node pair.

       This uses the GraphViz module to draw the graph.

METHODS

   new
       This is the constructor. It takes one mandatory argument, which is a string of the regular expression to be visualised. A GraphViz object
       is returned.

	 my $graph = GraphViz::Regex->new($regex);

   as_*
       The regex can be visualised in a number of different graphical formats. Methods include as_ps, as_hpgl, as_pcl, as_mif, as_pic, as_gd,
       as_gd2, as_gif, as_jpeg, as_png, as_wbmp, as_ismap, as_imap, as_vrml, as_vtx, as_mp, as_fig, as_svg. See the GraphViz documentation for
       more information. The two most common methods are:

	 # Print out a PNG-format file
	 print $g->as_png;

	 # Print out a PostScript-format file
	 print $g->as_ps;

BUGS

       Note that this module relies on debugging information provided by Perl, and is known to fail on at least two versions of Perl: 5.005_03 and
       5.7.1. Sorry about that - please use a more recent version of Perl if you want to use this module.

AUTHOR

       Leon Brocard <acme@astray.com>

COPYRIGHT

       Copyright (C) 2000-1, Leon Brocard

       This module is free software; you can redistribute it or modify it under the same terms as Perl itself.

perl v5.14.2							    2012-04-02						      GraphViz::Regex(3pm)