keen/col/priority-queue

priority-queue[k, v] record (has private fields)

Immutable priority queue.

Elements are key-value pairs. Pairs are sorted by key. Popping removes the pair with the lowest key.

If two pairs have the same key, the second pair added will be popped second.

priority[k] spec k data, k compare

list-new[k, v] (k, v) priority-queue(a (k, v)[]) k priority

to[k, v] (k, v) priority-queue(a (k, v)[]) k priority

to[k, v] (k, v)[](a (k, v) priority-queue) k priority

is-empty[k, v] bool(a (k, v) priority-queue) k priority

true if a.size == 0.

size[k, v] nat64(a (k, v) priority-queue) k priority

Number of pairs in the priority queue. This is O(n) where n is the result.

~[k, v] (k, v) priority-queue(a (k, v) priority-queue, b (k, v)) k priority

Adds a pair to the queue. This is O(1), since the work of sorting pairs is actually done in pop.

pop[k, v] ((k, v), (k, v) priority-queue) option(a (k, v) priority-queue) k priority

Removes and returns the pair with the lowest key. Returns an empty option if a is-empty. This is amortized O(a.size log).

some[k, v] bool(a (k, v) priority-queue, f bool mut((k, v))) k priority