Appends all of the elements in the specified collection to the end of this queue, in the order that they are returned by the specified collection's iterator.
Appends all of the elements in the specified collection to the end of
this queue, in the order that they are returned by the specified
collection's iterator. Attempts to addAll
of a queue to
itself result in IllegalArgumentException
.
the elements to be inserted into this queue
true
if this queue changed as a result of the call
`NullPointerException`
if the specified collection or any
of its elements are null
Removes all of the elements from this queue.
Removes all of the elements from this queue. The queue will be empty after this call returns.
This implementation repeatedly invokes poll until it
returns null
.
Enqueues one element in this queue
Enqueues one element in this queue
NullPointerException
if the specified element is null
Returns the first element in the queue, and removes this element from the queue.
Returns the first element in the queue, and removes this element from the queue.
the first element of the queue or null
in case the
queue is empty.
(Changed in version 2.9.0) The behavior of scanRight
has changed. The previous behavior can be reproduced with scanRight.reverse.
(Changed in version 2.9.0) transpose
throws an IllegalArgumentException
if collections are not uniformly sized.
An efficient queue data-structure.
On top of the JVM it is backed by a
java.util.concurrent.ConcurrentLinkedQueue
so it can be used in a multi-threading context. On top of Scala.js / Javascript it is backed by ascala.collection.mutable.Queue
.Contrary to Scala best-practices, the
poll()
method that pulls elements from our queue is returningnull
in case the queue is empty.