# File lib/treetop/compiler/metagrammar.rb, line 1529
      def _nt_sequence_primary
        start_index = index
        if node_cache[:sequence_primary].has_key?(index)
          cached = node_cache[:sequence_primary][index]
          @index = cached.interval.end if cached
          return cached
        end

        i0 = index
        i1, s1 = index, []
        r2 = _nt_prefix
        s1 << r2
        if r2
          r3 = _nt_atomic
          s1 << r3
        end
        if s1.last
          r1 = instantiate_node(SyntaxNode,input, i1...index, s1)
          r1.extend(SequencePrimary0)
          r1.extend(SequencePrimary1)
        else
          self.index = i1
          r1 = nil
        end
        if r1
          r0 = r1
        else
          i4, s4 = index, []
          r5 = _nt_atomic
          s4 << r5
          if r5
            r6 = _nt_suffix
            s4 << r6
          end
          if s4.last
            r4 = instantiate_node(SyntaxNode,input, i4...index, s4)
            r4.extend(SequencePrimary2)
            r4.extend(SequencePrimary3)
          else
            self.index = i4
            r4 = nil
          end
          if r4
            r0 = r4
          else
            r7 = _nt_atomic
            if r7
              r0 = r7
            else
              self.index = i0
              r0 = nil
            end
          end
        end

        node_cache[:sequence_primary][start_index] = r0

        return r0
      end