man Pegex::Regex (3): Use Pegex Like a Regex

SYNOPSIS

{
# Turn on Pegex regular expressions in lexical scope.
use Pegex::Regex;
my $grammar = qr{$grammar_text}x;
$text =~ $grammar;
my $result = \%/;
# Turn off Pegex in this scope.
no Pegex::Regex;
}

DESCRIPTION

This is a trivial sugar module that lets you use Pegex parser grammars like regular expressions, if you're into that kind of thing.

This is basically a clone of Damian Conway's Regexp::Grammars module API. You put a grammar into a "qr{...}x" and apply it the input string you want to parse. If the parse is successful, you get a data structure of the content in "%/".

IMHO, building a recursive decscent parser entirely inside of a regular expression, is not the clearest way to code. But, of course, TMTOWTDI. :)

NOTE

This module is just for experimental fun. See Pegex for the right way to use the Pegex parsing framework.

TMTOWTDI

Here's a Pegex::Regex code snippet:

    use Pegex::Regex;
    $text =~ qr{... Pegex grammar text ...};
    $data = \%/;

And the equivalent Pegex code:

    use Pegex;
    my $data = pegex('... Pegex grammar text ...')->parse($text);

WARNING

This gateway drug, er, module, technically should not even work.

It turns your ``grammar inside a regexp'' into a Pegex::Grammar using qr{} overloading, and then turns your regexp itself into a shim that calls the parse method for you. This is highly magical and technically makes a reentrant call to the regex engine, which is not supported yet. Use at your own risk.

Better yet, do yourself a favor and learn how to use the Pegex toolset without this ::Regex sugar. ":-)"

AUTHOR

Ingy do.t Net <[email protected]>

COPYRIGHT AND LICENSE

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

See <http://www.perl.com/perl/misc/Artistic.html>