class RDoc::Options

def exclude
  if @exclude.nil? or Regexp === @exclude then
    # done, #finish is being re-run
    @exclude
  elsif !@apply_default_exclude and @exclude.empty? then
    nil
  else
    exclude = @exclude
    exclude |= DEFAULT_EXCLUDE if @apply_default_exclude
    Regexp.new(exclude.join("|"))
  end
end