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.

kschiess / parslet

readme