Definition of component DEQUE as an extension to QUEUE.

Integrating Extension and Specialization Inheritance
by Walid Al-Ahmad and Eric Steegmans
Listing 6. Definition of component DEQUE as an extension to QUEUE.


component DEQUE extends QUEUE
feature
     Tail : INTEGER                       -- index to first available space
                                          from other end of the queue.
     Rear : INTEGER is
     AddEnd(elm : REAL) is
     RemoveEnd :  REAL is
end