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adt::Queue -- abstract data type ``Queue''

Introduction

adt::Queue implements the abstract data type ``Queue''.

Call(s)

adt::Queue(queue)

Parameters

queue - an expression sequence of objects to initialize the queue

Returns

an object of the domain adt::Queue

Details

Example 1

Create a new queue with strings as arguments.

>> Q := adt::Queue("1", "2", "3", "4")
                                  Queue1

Show the length of the queue.

>> Q::length()
                                     4

Fill up the queue with a new element. The queue will be changed by the method, no new assignment to Q is necessary!

>> Q::enqueue("5")
                                    "5"

Show the front of the queue. This method does not change the queue.

>> Q::front(), Q::front()
                                 "1", "1"

After twice getting an element of the queue, the third element is the new front of the queue, and the length is 3.

>> Q::dequeue(), Q::dequeue(), Q::front(), Q::length()
                             "1", "2", "3", 3

Now revert the queue. The last element will be the first element.

>> Q::reverse(): Q::front()
                                    "5"

Enlarge the queue with "2".

>> Q::enqueue("2"):
   Q::empty()
                                   FALSE

Finally collect all elements of the queue in the list assigned to ARGS, until the queue is empty.

>> ARGS := []: while not Q::empty() do ARGS := append(ARGS, Q::dequeue()) end:
   ARGS
                           ["5", "4", "3", "2"]

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