_nt_nonterminal (Treetop::Compiler::Metagrammar)

    # File lib/treetop/compiler/metagrammar.rb, line 1901
          def _nt_nonterminal
            start_index = index
            if node_cache[:nonterminal].has_key?(index)
              cached = node_cache[:nonterminal][index]
              @index = cached.interval.end if cached
              return cached
            end

            i0, s0 = index, []
            i1 = index
            r2 = _nt_keyword_inside_grammar
            if r2
              r1 = nil
            else
              self.index = i1
              r1 = instantiate_node(SyntaxNode,input, index...index)
            end
            s0 << r1
            if r1
              i3, s3 = index, []
              r4 = _nt_alpha_char
              s3 << r4
              if r4
                s5, i5 = [], index
                loop do
                  r6 = _nt_alphanumeric_char
                  if r6
                    s5 << r6
                  else
                    break
                  end
                end
                r5 = instantiate_node(SyntaxNode,input, i5...index, s5)
                s3 << r5
              end
              if s3.last
                r3 = instantiate_node(SyntaxNode,input, i3...index, s3)
                r3.extend(Nonterminal0)
              else
                self.index = i3
                r3 = nil
              end
              s0 << r3
            end
            if s0.last
              r0 = instantiate_node(Nonterminal,input, i0...index, s0)
              r0.extend(Nonterminal1)
            else
              self.index = i0
              r0 = nil
            end

            node_cache[:nonterminal][start_index] = r0

            return r0
          end