# File lib/treetop/compiler/metagrammar.rb, line 968
      def _nt_choice
        start_index = index
        if node_cache[:choice].has_key?(index)
          cached = node_cache[:choice][index]
          if cached
            cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
            @index = cached.interval.end
          end
          return cached
        end

        i0, s0 = index, []
        r1 = _nt_alternative
        s0 << r1
        if r1
          s2, i2 = [], index
          loop do
            i3, s3 = index, []
            r5 = _nt_space
            if r5
              r4 = r5
            else
              r4 = instantiate_node(SyntaxNode,input, index...index)
            end
            s3 << r4
            if r4
              if has_terminal?('/', false, index)
                r6 = instantiate_node(SyntaxNode,input, index...(index + 1))
                @index += 1
              else
                terminal_parse_failure('/')
                r6 = nil
              end
              s3 << r6
              if r6
                r8 = _nt_space
                if r8
                  r7 = r8
                else
                  r7 = instantiate_node(SyntaxNode,input, index...index)
                end
                s3 << r7
                if r7
                  r9 = _nt_alternative
                  s3 << r9
                end
              end
            end
            if s3.last
              r3 = instantiate_node(SyntaxNode,input, i3...index, s3)
              r3.extend(Choice0)
            else
              @index = i3
              r3 = nil
            end
            if r3
              s2 << r3
            else
              break
            end
          end
          if s2.empty?
            @index = i2
            r2 = nil
          else
            r2 = instantiate_node(SyntaxNode,input, i2...index, s2)
          end
          s0 << r2
        end
        if s0.last
          r0 = instantiate_node(Choice,input, i0...index, s0)
          r0.extend(Choice1)
          r0.extend(Choice2)
        else
          @index = i0
          r0 = nil
        end

        node_cache[:choice][start_index] = r0

        r0
      end