# File lib/mail/parsers/rfc2822.rb, line 1644
    def _nt_phrase
      start_index = index
      if node_cache[:phrase].has_key?(index)
        cached = node_cache[:phrase][index]
        if cached
          cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
          @index = cached.interval.end
        end
        return cached
      end

      i0 = index
      r1 = _nt_obs_phrase
      if r1
        r0 = r1
      else
        s2, i2 = [], index
        loop do
          r3 = _nt_word
          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
        if r2
          r0 = r2
        else
          @index = i0
          r0 = nil
        end
      end

      node_cache[:phrase][start_index] = r0

      r0
    end