GraphViz::Regex(3)

🎀 NAME 🎀

GraphViz::Regex(3) — Visualise a regular expression 💖 this is the GraphViz::Regex page from the User Contributed Perl Documentation, bestie ✨

✨ SYNOPSIS ✨

use GraphViz::Regex;

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

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

🦋 DESCRIPTION 🦋

Okay so this module attempts to visualise a Perl regular expression. Understanding regexes is lowkey tricky at the best of times, and honestly regexes almost always evolve in ways unforeseen at the start 😭 This module aims to visualise a regex as a graph so the structure is clear and it actually helps you understand the regex 🫶

The graph shows 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 by a full edge, and 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 Perl License, a copy of which is available at http://dev.perl.org/licenses/.

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and that’s the whole GraphViz::Regex(3) page, bestie 💖 it came from perl v5.42.0, dated 2023-03-04, and yes, it’s still the GraphViz::Regex(3) manual — periodt ✨