# File lib/treetop/runtime/syntax_node.rb, line 13
      def elements
        return @elements if terminal?
        # replace the character class placeholders in the sequence (lazy instantiation)
        last_element = nil
        @comprehensive_elements ||= @elements.map do |element|
          if element == true
            index = last_element ? last_element.interval.last : interval.first
            element = SyntaxNode.new(input, index...(index + 1))
          end
          element.parent = self
          last_element = element
        end

        @comprehensive_elements
      end