def record_type
      @out << @input.scan(/\{/)

      return false unless rtype_item

      while @input.scan(/,/)
        @out << ","
        return false unless rtype_item
      end

      return false unless @input.scan(/\}/)
      @out << "}"

      true
    end
def record_type
      @out << @input.scan(/\{/)

      return false unless rtype_item

      while @input.scan(/,/)
        @out << ","
        return false unless rtype_item
      end

      return false unless @input.scan(/\}/)
      @out << "}"

      true
    end
<record-type> ::= "{" <rtype-item> [ "," <rtype-item> ]* "}"