Skip to content
This repository

A small PEG based parser library. See the Hacking page in the Wiki as well.

Fetching latest commit…

Cannot retrieve the latest commit at this time


Parslet makes developing complex parsers easy. It does so by

* providing the best <b>error reporting</b> possible
* <b>not generating</b> reams of code for you to debug

Parslet takes the long way around to make <b>your job</b> 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

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


  require 'parslet'
  include Parslet

  # Constructs a parser using a Parser Expression Grammar like DSL: 
  parser =  str('"') >> 
              str('\\') >> any |
              str('"').absnt? >> any
            ) >> 
  # 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 = do
    rule(:string => simple(:x)) { 
      puts "String contents: #{x}" }


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


At version 1.1 - Good basic functionality and lots of plans for extension.

(c) 2010 Kaspar Schiess
Something went wrong with that request. Please try again.