| Package | org.as3collections |
| Interface | public interface IQueue extends ICollection, IIterable, org.as3coreaddendum.system.ICloneable, org.as3coreaddendum.system.IEquatable |
| Implementors | AbstractQueue, TypedQueue, UniqueQueue |
ICollection operations, queues provide additional insertion, extraction, and inspection operations.
Each of these methods exists in two forms: one throws an error if the operation fails, the other returns a special value (either null or false, depending on the operation).
| Throws error | Returns special value | |
|---|---|---|
| Insert |
add
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offer
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| Remove |
dequeue
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poll
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| Examine |
element
|
peek
|
Queues typically, but do not necessarily, order elements in a FIFO (first-in-first-out) manner.
Among the exceptions are priority queues, which order elements according to a supplied comparator, or the elements' natural ordering, and LIFO queues (or stacks) which order the elements LIFO (last-in-first-out).
Whatever the ordering used, the head of the queue is that element which would be removed by a call to dequeue or poll.
In a FIFO queue, all new elements are inserted at the tail of the queue.
Other kinds of queues may use different placement rules.
Every IQueue implementation must specify its ordering properties.
The offer method inserts an element if possible, otherwise returning false.
This differs from the add method, which can fail to add an element only by throwing an error.
The offer method is designed for use when failure is a normal, rather than exceptional occurrence.
The dequeue and poll methods remove and return the head of the queue.
Exactly which element is removed from the queue is a function of the queue's ordering policy, which differs from implementation to implementation.
The dequeue and poll methods differ only in their behavior when the queue is empty: the dequeue method throws an error, while the poll method returns null.
The element and peek methods return, but do not remove, the head of the queue.
The element and peek methods differ only in their behavior when the queue is empty: the element method throws an error, while the peek method returns null.
IQueue implementations generally do not allow insertion of null elements
| Method | Defined By | ||
|---|---|---|---|
 | add(element:*):Boolean
Ensures that this collection contains the specified element (optional operation). | ICollection | |
| addAll(collection:ICollection):Boolean
Adds all of the elements in the specified collection to this collection (optional operation). | ICollection | |
| clear():void
Removes all of the elements from this collection (optional operation). | ICollection | |
| contains(o:*):Boolean
Returns true if this collection contains the specified object. | ICollection | |
| containsAll(collection:ICollection):Boolean
Returns true if this collection contains all of the elements in the specified collection. | ICollection | |
dequeue():*
Retrieves and removes the head of this queue. | IQueue | ||
element():*
Retrieves, but does not remove, the head of this queue. | IQueue | ||
| isEmpty():Boolean
Returns true if this collection contains no elements. | ICollection | |
|
Returns an iterator over a set of elements. | IIterable | |
offer(element:*):Boolean
Inserts the specified element into this queue if it is possible to do so immediately without violating restrictions. | IQueue | ||
peek():*
Retrieves, but does not remove, the head of this queue, or returns null if this queue is empty. | IQueue | ||
poll():*
Retrieves and removes the head of this queue, or returns null if this queue is empty. | IQueue | ||
| remove(o:*):Boolean
Removes a single instance (only one occurrence) of the specified object from this collection, if it is present (optional operation). | ICollection | |
| removeAll(collection:ICollection):Boolean
Removes all elements of this collection that are also contained in the specified collection (optional operation). | ICollection | |
| retainAll(collection:ICollection):Boolean
Retains only the elements in this collection that are contained in the specified collection (optional operation). | ICollection | |
| size():int
Returns the number of elements in this collection. | ICollection | |
| toArray():Array
Returns an array containing all of the elements in this collection. | ICollection | |
| dequeue | () | method |
Hide Inherited Public Properties
Show Inherited Public Properties public function dequeue():*Retrieves and removes the head of this queue.
Returns* — the head of this queue.
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NoSuchElementError — if this queue is empty.
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| element | () | method |
public function element():*
Retrieves, but does not remove, the head of this queue.
This method differs from peek only in that it throws an error if this queue is empty.
* — the head of this queue.
|
NoSuchElementError — if this queue is empty.
|
| offer | () | method |
public function offer(element:*):Boolean
Inserts the specified element into this queue if it is possible to do so immediately without violating restrictions.
When using a restricted queue (like TypedQueue and UniqueQueue), this method is generally preferable to add, which can fail to insert an element only by throwing an error.
Parameters
element:* — the element to add.
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Boolean — true if the element was added to this queue, else false.
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| peek | () | method |
public function peek():*
Retrieves, but does not remove, the head of this queue, or returns null if this queue is empty.
* — the head of this queue, or null if this queue is empty.
|
| poll | () | method |
public function poll():*
Retrieves and removes the head of this queue, or returns null if this queue is empty.
* — the head of this queue, or null if this queue is empty.
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