README

Path: README
Last Update: Thu Apr 26 16:22:26 -0400 2012

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

  # Constructs a parser using a Parser Expression Grammar like DSL:
  parser =  str('"') >>
            (
              str('\\') >> any |
              str('"').absnt? >> any
            ).repeat.as(:string) >>
            str('"')

  # Parse the string and capture parts of the interpretation (:string above)
  tree = parser.parse('"This is a \\"String\\" in which you can escape stuff"')

  tree # => {:string=>"This is a \\\"String\\\" in which you can escape stuff"}

  # Here's how you can grab results from that tree:

  transform = Parslet::Transform.new do
    rule(:string => simple(:x)) {
      puts "String contents: #{x}" }
  end
  transform.apply(tree)

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

At version 1.3.0 - See HISTORY.txt for changes.

(c) 2010 Kaspar Schiess

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