New JS parser prototype that uses Esprima.js

require 'v8'

require 'json'

require 'singleton'

module JsDuck

  # New parser prototype that uses Esprima.js through V8.

  class EsprimaParser

    # Initialize as singleton to avoid loading the esprima.js more

    # than once - otherwise performace will severely suffer.

    include Singleton

    def initialize

      @v8 = V8::Context.new

      esprima = File.dirname(File.dirname(File.dirname(File.expand_path(__FILE__))))+"/esprima/esprima.js";

      @v8.load(esprima)

    end

    # Input must be a String.

    def parse(input)

      @v8['js'] = input

      json = @v8.eval("JSON.stringify(esprima.parse(js, {comment: true, loc: true}))")

      JSON.parse(json, :max_nesting => false)

    end

  end

end