# File lib/ruote/exp/condition.rb, line 59
    def self.eval_is (match)

      match = match[1..-2].select { |e| e != nil }

      negative = match.find { |m| m == ' not' }

      first = match.first.strip
      is_set = first != '' && first != 'is'

      negative ? (not is_set) : is_set
    end