# File lib/ferret/index.rb, line 597
597:     def add_indexes(indexes)
598:       @dir.synchrolock do
599:         ensure_writer_open()
600:         indexes = [indexes].flatten   # make sure we have an array
601:         return if indexes.size == 0 # nothing to do
602:         if indexes[0].is_a?(Index)
603:           indexes.delete(self) # don't merge with self
604:           indexes = indexes.map {|index| index.reader }
605:         elsif indexes[0].is_a?(Ferret::Store::Directory)
606:           indexes.delete(@dir) # don't merge with self
607:           indexes = indexes.map {|dir| IndexReader.new(dir) }
608:         elsif indexes[0].is_a?(IndexReader)
609:           indexes.delete(@reader) # don't merge with self
610:         else
611:           raise ArgumentError, "Unknown index type when trying to merge indexes"
612:         end
613:         ensure_writer_open
614:         @writer.add_readers(indexes)
615:       end
616:     end