# File lib/ruby_parser_extras.rb, line 819
  def new_xstring str
    if str then
      case str[0]
      when :str
        str[0] = :xstr
      when :dstr
        str[0] = :dxstr
      else
        str = s(:dxstr, '', str)
      end
      str
    else
      s(:xstr, '')
    end
  end