vanderlee / comprehend

Framework for building BNF LR(1) parsers

Maintainers

Details

github.com/vanderlee/Comprehend

1.0.2 2018-10-02 22:17 UTC

Requires

php: >=7.0.0

Requires (Dev)

Suggests

None

Provides

None

Conflicts

None

Replaces

None

MIT dae2b6befae89cf00558170d05da1d1e26263600

parser tokenizer ast lexer bnf abnf

dev-master
1.0.2
1.0.1
1.0.0

This package is auto-updated.

Last update: 2024-12-11 11:59:18 UTC

README

Build object oriented LR(1) lexer, tokenizers and parsers in PHP using BNF-based syntax.

Copyright © 2011-2024 Martijn W. van der Lee Toyls.com, MIT license applies.

Features

Closely follows BNF syntax using objects as operands.
Includes various pre-defined RFC syntax rules.
Whitespace skipping.
Support for tokenizing.
Add your own custom parsers.
Create full sets of rules.
Optional case (in)sensitivity.

Example

ABNF

word	= [A-Za-z]+
list	= word *[ ',' word ]

Comprehend, using objects:

$word	= new Repeat(new Regex('/[a-z][A-Z]/'), 1);
$list	= new Sequence($word, new Repeat(new Sequence(',', $word)));

Comprehend, using objects and array notation:

$word	= new Repeat(new Regex('/[a-z][A-Z]/'), 1);
$list	= new Sequence($word, new Repeat([',', $word]));

Comprehend, using library functions:

$word	= plus(regex('/[a-z][A-Z]/'));
$list	= s($word, star([',', $word]));

Comprehend, using Ruleset constructor

$list   = new Ruleset([
    'word'           => plus(regex('/[a-z][A-Z]/')), 
    Ruleset::ROOT => s($word, star([',', $word])),
]);