#--
# Copyright (c) 2013 Michael Berkovich, tr8nhub.com
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#++

module Tr8n
  module RulesEngine
    
    class Parser
      attr_reader :tokens
      def initialize(expression)
        @tokens = expression.scan /[()]|\w+|@\w+|[\+\-\!\|\=>&<\*\/%]+|".*?"|'.*?'/
      end
     
      def parse
        token = @tokens.shift
        return parse_list if (token) == '('
        return token[1..-2] if token =~ /['"].*/
        return token.to_i if token =~ /\d+/
        token.to_s
      end
     
      def parse_list
        list = []
        list << parse until @tokens.first == ')'
        @tokens.shift
        list
      end
    end

  end
end
