# File lib/rdoc/parsers/parserfactory.rb, line 70
    def ParserFactory.alias_extension(old_ext, new_ext)
      parser = ParserFactory.can_parse("xxx.#{old_ext}")
      return false unless parser
      @@parsers.unshift Parsers.new(Regexp.new("\\.#{new_ext}$"), parser.parser)
      true
    end