# File lib/treetop/compiler/metagrammar.rb, line 1906
      def _nt_named_label
        start_index = index
        if node_cache[:named_label].has_key?(index)
          cached = node_cache[:named_label][index]
          if cached
            node_cache[:named_label][index] = cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
            @index = cached.interval.end
          end
          return cached
        end

        i0, s0 = index, []
        i1, s1 = index, []
        r2 = _nt_alpha_char
        s1 << r2
        if r2
          s3, i3 = [], index
          loop do
            r4 = _nt_alphanumeric_char
            if r4
              s3 << r4
            else
              break
            end
          end
          r3 = instantiate_node(SyntaxNode,input, i3...index, s3)
          s1 << r3
        end
        if s1.last
          r1 = instantiate_node(SyntaxNode,input, i1...index, s1)
          r1.extend(NamedLabel0)
        else
          @index = i1
          r1 = nil
        end
        s0 << r1
        if r1
          if (match_len = has_terminal?(':', false, index))
            r5 = true
            @index += match_len
          else
            terminal_parse_failure('\':\'')
            r5 = nil
          end
          s0 << r5
        end
        if s0.last
          r0 = instantiate_node(SyntaxNode,input, i0...index, s0)
          r0.extend(NamedLabel1)
          r0.extend(NamedLabel2)
        else
          @index = i0
          r0 = nil
        end

        node_cache[:named_label][start_index] = r0

        r0
      end