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