# File lib/mail/parsers/rfc2822.rb, line 1978
    def _nt_angle_addr
      start_index = index
      if node_cache[:angle_addr].has_key?(index)
        cached = node_cache[:angle_addr][index]
        if cached
          cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
          @index = cached.interval.end
        end
        return cached
      end

      i0 = index
      i1, s1 = index, []
      r3 = _nt_CFWS
      if r3
        r2 = r3
      else
        r2 = instantiate_node(SyntaxNode,input, index...index)
      end
      s1 << r2
      if r2
        if has_terminal?("<", false, index)
          r4 = instantiate_node(SyntaxNode,input, index...(index + 1))
          @index += 1
        else
          terminal_parse_failure("<")
          r4 = nil
        end
        s1 << r4
        if r4
          r5 = _nt_addr_spec
          s1 << r5
          if r5
            if has_terminal?(">", false, index)
              r6 = instantiate_node(SyntaxNode,input, index...(index + 1))
              @index += 1
            else
              terminal_parse_failure(">")
              r6 = nil
            end
            s1 << r6
            if r6
              r8 = _nt_CFWS
              if r8
                r7 = r8
              else
                r7 = instantiate_node(SyntaxNode,input, index...index)
              end
              s1 << r7
            end
          end
        end
      end
      if s1.last
        r1 = instantiate_node(SyntaxNode,input, i1...index, s1)
        r1.extend(AngleAddr0)
      else
        @index = i1
        r1 = nil
      end
      if r1
        r0 = r1
      else
        r9 = _nt_obs_angle_addr
        if r9
          r0 = r9
        else
          @index = i0
          r0 = nil
        end
      end

      node_cache[:angle_addr][start_index] = r0

      r0
    end