README

Path: README
Last Update: Fri Jul 15 14:35:39 -0400 2016

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: kschiess.github.com/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')

COMPATIBILITY

This library should work with most rubies. I‘ve tested it with MRI 1.8 (except 1.8.6), 1.9, rbx-head, jruby. Please report as a bug if you encounter issues.

Note that due to Ruby 1.8 internals, Unicode parsing is not supported on that version.

On Mac OS X Lion, ruby-1.8.7-p352 has been known to segfault. Use ruby-1.8.7-p334 for better results.

STATUS

Production worthy.

(c) 2010, 2011, 2012 Kaspar Schiess

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