queue

              +--,Normal---+
>>-queue(item-+------------+)----------------------------------><
              +--,Unique---+

Makes the object [item] a member item of the circular queue, inserting the item at the end of the circular queue.

If the circular queue is full, than the first item will be deleted, before the insertion takes place. In this case the [deleted item] will be returned, otherwise [.nil] .

If [option] is specified, it may be "Normal" or "Unique". The default is "Normal". Only the first letter of the option capitalized letter is required; all characters following it are ignored. If [option] is 'Unique', any matching item already in the queue will be removed before before [item] is added to the queue. removed before the operation is performed. This allows you to maintain a list like the recent files list of an editor.