update_attributes

# File lib/rdoc/ri/formatter.rb, line 538
  def update_attributes(current, wanted)
    str = ""
    # first turn off unwanted ones
    off = current & ~wanted
    for quality in [ BOLD, ITALIC, CODE]
      if (off & quality) > 0
        str << "</" + ATTR_MAP[quality]
      end
    end

    # now turn on wanted
    for quality in [ BOLD, ITALIC, CODE]
      unless (wanted & quality).zero?
        str << "<" << ATTR_MAP[quality]
      end
    end
    @output.print str
  end