ancestors_of

# File lib/rdoc/ri/driver.rb, line 453
  def ancestors_of klass
    ancestors = []

    unexamined = [klass]
    seen = []

    loop do
      break if unexamined.empty?
      current = unexamined.shift
      seen << current

      stores = classes[current]

      break unless stores and not stores.empty?

      klasses = stores.map do |store|
        store.ancestors[current]
      end.flatten.uniq

      klasses = klasses - seen

      ancestors.push(*klasses)
      unexamined.push(*klasses)
    end

    ancestors.reverse
  end