Version: 5.1.1
1 Imperative Queues
(require data/queue) |
This module provides a simple mutable queue representation, first-in/first-out only. Operations on queues mutate it in a thread-unsafe way.
(make-queue) → queue/c |
Produces an empty queue.
Adds an element to the back of a queue.
(dequeue! q) → any/c |
q : nonempty-queue/c |
Removes an element from the front of a nonempty queue, and returns that
element.
Examples: | ||||||||||||
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(queue->list queue) → (listof any/c) |
queue : queue/c |
Returns an immutable list containing the elements of the queue
in the order the elements were added.
Examples: | ||||||||
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(queue-length queue) → integer? |
queue : queue/c |
Returns the number of elements in the queue.
Examples: | |||||||||||||
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(queue-empty? q) → boolean? |
q : queue/c |
Recognizes whether a queue is empty or not.
Examples: | ||||||||||||
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This predicate recognizes queues.
Examples: | ||||
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Returns a sequence whose elements are the elements of
queue.
These contracts recognize queues; the latter requires the queue to
contain at least one value.