process_instruction

# File lib/rexml/parsers/baseparser.rb, line 476
      def process_instruction
        match_data = @source.match(INSTRUCTION_PATTERN, true)
        unless match_data
          message = "Invalid processing instruction node"
          raise REXML::ParseException.new(message, @source)
        end
        [:processing_instruction, match_data[1], match_data[2]]
      end