# File lib/mail/parsers/rfc2822_obsolete.rb, line 273
    def _nt_obs_phrase_list
      start_index = index
      if node_cache[:obs_phrase_list].has_key?(index)
        cached = node_cache[:obs_phrase_list][index]
        @index = cached.interval.end if cached
        return cached
      end

      i0 = index
      r1 = _nt_phrase
      if r1
        r0 = r1
      else
        i2, s2 = index, []
        s3, i3 = [], index
        loop do
          i4, s4 = index, []
          r6 = _nt_phrase
          if r6
            r5 = r6
          else
            r5 = instantiate_node(SyntaxNode,input, index...index)
          end
          s4 << r5
          if r5
            r8 = _nt_CFWS
            if r8
              r7 = r8
            else
              r7 = instantiate_node(SyntaxNode,input, index...index)
            end
            s4 << r7
            if r7
              if has_terminal?(",", false, index)
                r9 = instantiate_node(SyntaxNode,input, index...(index + 1))
                @index += 1
              else
                terminal_parse_failure(",")
                r9 = nil
              end
              s4 << r9
              if r9
                r11 = _nt_CFWS
                if r11
                  r10 = r11
                else
                  r10 = instantiate_node(SyntaxNode,input, index...index)
                end
                s4 << r10
              end
            end
          end
          if s4.last
            r4 = instantiate_node(SyntaxNode,input, i4...index, s4)
            r4.extend(ObsPhraseList0)
          else
            @index = i4
            r4 = nil
          end
          if r4
            s3 << r4
          else
            break
          end
        end
        if s3.empty?
          @index = i3
          r3 = nil
        else
          r3 = instantiate_node(SyntaxNode,input, i3...index, s3)
        end
        s2 << r3
        if r3
          r13 = _nt_phrase
          if r13
            r12 = r13
          else
            r12 = instantiate_node(SyntaxNode,input, index...index)
          end
          s2 << r12
        end
        if s2.last
          r2 = instantiate_node(SyntaxNode,input, i2...index, s2)
          r2.extend(ObsPhraseList1)
        else
          @index = i2
          r2 = nil
        end
        if r2
          r0 = r2
        else
          @index = i0
          r0 = nil
        end
      end

      node_cache[:obs_phrase_list][start_index] = r0

      r0
    end