Min (melange.Stdlib.Pqueue.Min)

Min-priority queues

type t;

The type of priority queues.

type elt;

The type of priority queue elements.

let create: unit => t;

Return a new priority queue, initially empty.

let length: t => int;

Return the number of elements in a priority queue.

let is_empty: t => bool;

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

let add: t => elt => unit;

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

let 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.

let min_elt: t => option(elt);

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

let 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.

let pop_min: t => option(elt);

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

let remove_min: t => unit;

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

let clear: t => unit;

clear q removes all elements from q.

let copy: t => t;

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

Conversions from other data structures

let of_array: array(elt) => t;

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

let of_list: list(elt) => t;

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

let 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.

let 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.

let 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.