(*
BSD 2-Clause License
Copyright (c) 2018, Anton Krotov
All rights reserved.
*)
MODULE COLLECTIONS;
TYPE
ITEM* = POINTER TO RECORD
link: ITEM
END;
COLLECTION* = POINTER TO RECORD
last: ITEM
END;
PROCEDURE push* (collection: COLLECTION; item: ITEM);
BEGIN
item.link := collection.last;
collection.last := item
END push;
PROCEDURE pop* (collection: COLLECTION): ITEM;
VAR
item: ITEM;
BEGIN
item := collection.last;
IF item # NIL THEN
collection.last := item.link
END
RETURN item
END pop;
PROCEDURE create* (): COLLECTION;
VAR
collection: COLLECTION;
BEGIN
NEW(collection);
collection.last := NIL
RETURN collection
END create;
END COLLECTIONS.