https://kschiess.github.io/parslet/

A small PEG based parser library. See the Hacking page in the Wiki as well.
https://kschiess.github.io/parslet/

Last synced: 2 months ago
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A small PEG based parser library. See the Hacking page in the Wiki as well.

• Host: GitHub
• URL: https://kschiess.github.io/parslet/
• Owner: kschiess
• License: mit
• Created: 2010-03-15T08:14:24.000Z (almost 15 years ago)
• Default Branch: master
• Last Pushed: 2023-10-05T10:10:59.000Z (over 1 year ago)
• Last Synced: 2024-10-29T12:58:33.247Z (2 months ago)
• Language: Ruby
• Homepage: kschiess.github.com/parslet
• Size: 2.47 MB
• Stars: 807
• Watchers: 16
• Forks: 95
• Open Issues: 19
• Metadata Files:
  • Readme: README
  • Changelog: HISTORY.txt
  • License: LICENSE

Awesome Lists containing this project

• awesome-ruby - Parslet - A small Ruby library for constructing parsers in the PEG (Parsing Expression Grammar) fashion. (Natural Language Processing)

README

        
INTRODUCTION

Parslet makes developing complex parsers easy. It does so by

* providing the best error reporting possible

* not generating reams of code for you to debug

Parslet takes the long way around to make your job easier. It allows for

incremental language construction. Often, you start out small, implementing

the atoms of your language first; _parslet_ takes pride in making this

possible.

Eager to try this out? Please see the associated web site:

https://kschiess.github.io/parslet/

SYNOPSIS

  require 'parslet'

  include Parslet

  # parslet parses strings

  str('foo').

    parse('foo') # => "foo"@0

  # it matches character sets

  match['abc'].parse('a') # => "a"@0

  match['abc'].parse('b') # => "b"@0

  match['abc'].parse('c') # => "c"@0

  # and it annotates its output

  str('foo').as(:important_bit).

    parse('foo') # => {:important_bit=>"foo"@0}

  # you can construct parsers with just a few lines

  quote = str('"')

  simple_string = quote >> (quote.absent? >> any).repeat >> quote

  simple_string.

    parse('"Simple Simple Simple"') # => "\"Simple Simple Simple\""@0

  # or by making a fuss about it 

  class Smalltalk < Parslet::Parser

    root :smalltalk

    rule(:smalltalk) { statements }

    rule(:statements) { 

      # insert smalltalk parser here (outside of the scope of this readme)

    }

  end

  # and then

  Smalltalk.new.parse('smalltalk')

FEATURES

  * Tools for every part of the parser chain

  * Transformers generate Abstract Syntax Trees

  * Accelerators transform parsers, making them quite a bit faster

  * Pluggable error reporters

  * Graphviz export for your parser

  * Rspec testing support rig

  * Simply Ruby, composable and hackable

COMPATIBILITY

This library is intended to work with Ruby variants >= 1.9. I've tested it on 

MRI 1.9, rbx-head, jruby. Please report as a bug if you encounter issues.

STATUS 

Production worthy.

(c) 2010-today Kaspar Schiess