# File lib/treetop/compiler/metagrammar.rb, line 1346
      def _nt_labeled_sequence_primary
        start_index = index
        if node_cache[:labeled_sequence_primary].has_key?(index)
          cached = node_cache[:labeled_sequence_primary][index]
          @index = cached.interval.end if cached
          return cached
        end

        i0, s0 = index, []
        r1 = _nt_label
        s0 << r1
        if r1
          r2 = _nt_sequence_primary
          s0 << r2
        end
        if s0.last
          r0 = instantiate_node(SyntaxNode,input, i0...index, s0)
          r0.extend(LabeledSequencePrimary0)
          r0.extend(LabeledSequencePrimary1)
        else
          self.index = i0
          r0 = nil
        end

        node_cache[:labeled_sequence_primary][start_index] = r0

        return r0
      end