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Pegex - Acmeist PEG Parser Framework


This document describes Pegex version 0.75.


    use Pegex;
    my $result = pegex($grammar)->parse($input);

or with options:

    use Pegex;
    use ReceiverClass;
    my $parser = pegex($grammar, 'ReceiverClass');
    my $result = $parser->parse($input);

or more explicitly:

    use Pegex::Parser;
    use Pegex::Grammar;
    my $pegex_grammar = Pegex::Grammar->new(
        text => $grammar,
    my $parser = Pegex::Parser->new(
        grammar => $pegex_grammar,
    my $result = $parser->parse($input);

or customized explicitly:

        package MyGrammar;
        use Pegex::Base;
        extends 'Pegex::Grammar';
        has text => "your grammar definition text goes here";
        has receiver => "MyReceiver";
        package MyReceiver;
        use base 'Pegex::Receiver';
        got_some_rule { ... }
        got_other_rule { ... }
    use Pegex::Parser;
    my $parser = Pegex::Parser->new(
        grammar => MyGrammar->new,
        receiver => MyReceiver->new,
    my $result = $parser->receiver->data;


Pegex is an Acmeist parser framework. It allows you to easily create parsers that will work equivalently in lots of programming languages! The inspiration for Pegex comes from the parsing engine upon which the postmodern programming language Perl 6 is based on. Pegex brings this beauty to the other justmodern languages that have a normal regular expression engine available.

Pegex gets it name by combining Parsing Expression Grammars (PEG), with Regular Expressions (Regex). That's actually what Pegex does.

PEG is the cool new way to elegantly specify recursive descent grammars. The Perl 6 language is defined in terms of a self modifying PEG language called Perl 6 Rules. Regexes are familiar to programmers of most modern programming languages. Pegex defines a simple PEG syntax, where all the terminals are regexes. This means that Pegex can be quite fast and powerful.

Pegex attempts to be the simplest way to define new (or old) Domain Specific Languages (DSLs) that need to be used in several programming languages and environments. Things like JSON, YAML, Markdown etc. It also great for writing parsers/compilers that only need to work in one language.


The module itself (this module) is just a trivial way to use the Pegex framework. It is only intended for the simplest of uses.

This module exports a single function, pegex, which takes a Pegex grammar string as input. You may also pass a receiver class name after the grammar.

    my $parser = pegex($grammar, 'MyReceiver');

The pegex function returns a Pegex::Parser object, on which you would typically call the parse() method, which (on success) will return a data structure of the parsed data.

See Pegex::API for more details.


Pegex (Pegex::Parser) has many easy to use methods of debugging. See the "Debugging" section of Pegex::Parser for details.



Ingy döt Net <>


Copyright 2010-2020. Ingy döt Net.

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