QUEUES.DEF

DEFINITION MODULE Queues;

FROM SYSTEM IMPORT BYTE;

EXPORT QUALIFIED Queue, CreateQ, Enqueue, Dequeue, FirstQ, EmptyQ;

TYPE Queue;

(***********************************************************)

PROCEDURE CreateQ(VAR q : Queue);

(* Initialize a Queue variable *)

(***********************************************************)

PROCEDURE Dequeue(VAR q : Queue; VAR i : ARRAY OF BYTE);

(* Remove the front element from a Queue. *)

(***********************************************************)

PROCEDURE EmptyQ(q : Queue) : BOOLEAN;

(* TRUE if q is Empty, FALSE otherwise *)

(***********************************************************)

PROCEDURE Enqueue(VAR q : Queue; i : ARRAY OF BYTE);

(* Insert a new element into the back of the queue *)

(***********************************************************)

PROCEDURE FirstQ(q : Queue; VAR i : ARRAY OF BYTE);

(* Return the first element from a queue, if it is not the empty queue *)

END Queues.