Min (docs.stdlib.Stdlib.Pqueue.Min)

Min-priority queues

type t

The type of priority queues.

type elt

The type of priority queue elements.

val create : unit -> t

Return a new priority queue, initially empty.

val length : t -> int

Return the number of elements in a priority queue.

val is_empty : t -> bool

is_empty q is true iff q is empty, that is, iff length q = 0.

val add : t -> elt -> unit

add q x adds the element x in the priority queue q.

val add_iter : t -> ((elt -> unit) -> 'x -> unit) -> 'x -> unit

add_iter q iter x adds each element of x to the end of q. This is iter (add q) x.

val min_elt : t -> elt option

min_elt q is an element of q with minimal priority or None if the queue is empty. The queue is not modified.

val get_min_elt : t -> elt

get_min_elt q returns an element of q with minimal priority, or raises Stdlib.Invalid_argument if the queue is empty. The queue is not modified.

val pop_min : t -> elt option

pop_min q removes and returns an element in queue q with minimal priority, or returns None if the queue is empty.

val remove_min : t -> unit

remove_min q removes an element in queue q with minimal priority. It does nothing if q is empty.

val clear : t -> unit

clear q removes all elements from q.

val copy : t -> t

copy q is a new priority queue with the same elements q has.

Conversions from other data structures

val of_array : elt array -> t

of_array a returns a new priority queue containing the elements of array a. Runs in linear time.

val of_list : elt list -> t

of_list l returns a new priority queue containing the elements of list l. Runs in linear time.

val of_iter : ((elt -> unit) -> 'x -> unit) -> 'x -> t

of_iter iter x returns a new priority queue containing the elements of x, obtained from iter.

For example, of_iter Seq.iter s returns a new priority queue containing all the elements of the sequence s (provided it is finite).

Runs in linear time (excluding the time spent in iter).

Iteration

The order in which the elements of a priority queue are traversed is unspecified.

It is a programming error to mutate a priority queue (by adding or removing elements) during an iteration of the queue. Such an error may be detected and signaled by the backing dynamic array implementation, but this is not guaranteed.

val iter_unordered : (elt -> unit) -> t -> unit

iter_unordered f q applies f to all elements in q. The order in which the elements are passed to f is unspecified.

The behavior is not specified if the priority queue is modified by f during the iteration.

val fold_unordered : ('acc -> elt -> 'acc) -> 'acc -> t -> 'acc

fold_unordered f accu q is (f (... (f (f accu x1) x2) ...) xn) where x1,x2,...,xn are the elements of q. The order in which the elements are passed to f is unspecified.

The behavior is not specified if the priority queue is modified by f during the iteration.