failure_reason (Treetop::Runtime::CompiledParser)

    # File lib/treetop/runtime/compiled_parser.rb, line 35
          def failure_reason
            return nil unless (tf = terminal_failures) && tf.size > 0
            "Expected " +
              (tf.size == 1 ?
               tf[0].expected_string :
               "one of #{tf.map{|f| f.expected_string}.uniq*', '}"
              ) +
              " at line #{failure_line}, column #{failure_column} (byte #{failure_index+1})" +
              " after #{input[index...failure_index]}"
          end