Scala 2.8 Collections API -- Queues

Scala provides mutable queues in addition to immutable ones. You use a mQueue similarly to how you use an immutable one, but instead of enqueue, you use the += and ++= operators to append. Also, on a mutable queue, the dequeue method will just remove the head element from the queue and return it. Here's an example:

scala> val queue = new scala.collection.mutable.Queue[String]

queue: scala.collection.mutable.Queue[String] = Queue()

scala> queue += "a"

res10: queue.type = Queue(a)

scala> queue ++= List("b", "c")

res11: queue.type = Queue(a, b, c)

scala> queue

res12: scala.collection.mutable.Queue[String]

= Queue(a, b, c)

scala> queue.dequeue

res13: String = a

scala> queue

res14: scala.collection.mutable.Queue[String] = Queue(b, c)