package ocaml-base-compiler
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.
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 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.