NAME¶

Queue - First-in first-out queues.

Module¶

Module Queue

Documentation¶

Module Queue
: sig end First-in first-out queues. This module implements queues (FIFOs), with in-place modification. Warning This module is not thread-safe: each Queue.t value must be protected from concurrent access (e.g. with a Mutex.t ). Failure to do so can lead to a crash. type 'a t The type of queues containing elements of type 'a . exception Empty Raised when Queue.take or Queue.peek is applied to an empty queue. val create : unit -> 'a t Return a new queue, initially empty. val add : 'a -> 'a t -> unit add x q adds the element x at the end of the queue q . val push : 'a -> 'a t -> unit push is a synonym for add . val take : 'a t -> 'a take q removes and returns the first element in queue q , or raises Empty if the queue is empty. val pop : 'a t -> 'a pop is a synonym for take . val peek : 'a t -> 'a peek q returns the first element in queue q , without removing it from the queue, or raises Empty if the queue is empty. val top : 'a t -> 'a top is a synonym for peek . val clear : 'a t -> unit Discard all elements from a queue. val copy : 'a t -> 'a t Return a copy of the given queue. val is_empty : 'a t -> bool Return true if the given queue is empty, false otherwise. val length : 'a t -> int Return the number of elements in a queue. val iter : ('a -> unit) -> 'a t -> unit iter f q applies f in turn to all elements of q , from the least recently entered to the most recently entered. The queue itself is unchanged. val fold : ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b fold f accu q is equivalent to List.fold_left f accu l , where l is the list of q 's elements. The queue remains unchanged. val transfer : 'a t -> 'a t -> unit transfer q1 q2 adds all of q1 's elements at the end of the queue q2 , then clears q1 . It is equivalent to the sequence iter (fun x -> add x q2) q1; clear q1 , but runs in constant time.