---
name: "Pegex::Grammar"
section: "3pm"
platform: "linux"
package: "perl-pegex"
version: "0.75-8"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Pegex::Grammar"
---

# Pegex::Grammar(3pm)

Pegex Grammar Base Class

## NAME

Pegex::Grammar - Pegex Grammar Base Class

## SYNOPSIS

Define a Pegex grammar (for the Foo syntax):

```
    package Pegex::Foo::Grammar;
    use base 'Pegex::Base';
    extends 'Pegex::Grammar';
    has text => q{
    foo: bar baz
    ... rest of Foo grammar ...
    };
```

then use it to parse some Foo:

```
    use Pegex::Parser;
    my $parse_tree = Pegex::Parser->new(
        grammar => 'Pegex::Foo::Grammar',
        receiver => 'Pegex::Tree',
    )->parse('my/file.foo');
```

## DESCRIPTION

Pegex::Grammar is a base class for defining your own Pegex grammar classes. You just need to provide the grammar view the `"text"` or the `"file"` attributes.

When Pegex::Parser uses your grammar, it will want it in the tree (compiled) form, so Pegex::Grammar provides automatic compilation support.

## PROPERTIES AND METHODS

- tree

  This is the data structure containing the compiled grammar for your syntax. It is usually produced by `"Pegex::Compiler"`. You can inline it in the `"tree"` method, or else the `"make_tree"` method will be called to produce it.

  The `"make_tree"` method will call on Pegex::Compiler to compile the `"text"` property by default. You can define your own `"make_tree"` method to do override this behavior.

  Often times you will want to generate your own Pegex::Grammar subclasses in an automated fashion. The Pegex and TestML modules do this to be performant. This also allows you to keep your grammar text in a separate file, and often in a separate repository, so it can be shared by multiple programming language's module implementations.

  See \<https://github.com/ingydotnet/pegex-pgx\> and \<https://github.com/ingydotnet/pegex-pm/blob/master/lib/Pegex/Pegex/Grammar.pm\>.

- text

  This is simply the text of your grammar, if you define this, you should (probably) not define the `"tree"` property. This grammar text will be automatically compiled when the `"tree"` is required.

- file

  This is the file where your Pegex grammar lives. It is usually used when you are making a Pegex module. The path is relative to your top level module directory.

- make\_tree

  This method is called when the grammar needs the compiled version.

## AUTHOR

Ingy döt Net \<ingy@cpan.org\>

## COPYRIGHT AND LICENSE

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.

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