BracketNotation

BracketNotation is a parser for generating syntax trees from sentences annotated with the kind of bracket notation that is commonly used by linguists. The result is a tree structure with nodes that describe the phrases and constituents of the sentence.

BracketNotation was inspired by Yoichiro Hasebe’s RSyntaxTree, and small portions of his code have been incorporated in the parser.

Author: Cody Brimhall ([email protected])
Copyright: Copyright © 2010 Cody Brimhall
License: Distributed under the terms of the GNU General Public License, v. 3

Using BracketNotation

To use BracketNotation, simply initialize a Parser instance with the string you want to parse, and call the #parse method. Parser performs some basic validation before attempting to evaluate the string. If validation fails, Parser raises a ValidationError. If the evaluator encounters a syntax error in the string, it raises an EvaluationError.

require 'bracket_notation'
include BracketNotation

input = "[S [NP colorless green ideas] [VP [V sleep] [Adv furiously]]]"

begin
  parser = Parser.new(input)
  tree = parser.parse

  puts tree.pretty_print # => S
                         #    -- NP
                         #    ---- colorless
                         #    ---- green
                         #    ---- ideas
                         #    -- VP
                         #    ---- V
                         #    ------ sleep
                         #    ---- Adv
                         #    ------ furiously
rescue ValidationError
  puts "Validation failed: #{$!}"
rescue EvaluationError
  puts "Evaluation failed: #{$!}"
end

Bugs, Feature Requests, Et Cetera

If you have any bugs, feature requests, or glowing praise, you can find this project on GitHub.