The priority queue type.

The empty priority queue.

Use one kv to create a priority queue containing the single priority-value pair kv.

Use empty q to test whether q is empty.

Use size q to compute the number of elements in q. Runs in O(n) time and O(log N) space.

Use head q to obtain the key-value pair on the top of q. Raises Not_found if q is empty.

Use tail q to obtain the priority queue produced by discarding the element at the top of q. If q is the empty queue, then the empty queue is returned.

Use pop q to obtain the head and the tail of a priority queue q in one operation. Returns None if q is empty.

Use put kv q to obtain a new priority queue that is the result of inserting the key-value pair kv into q.

Use merge q1 q2 to obtain a new priority queue that is the result of merging all the elements of q1 and q2 into a single queue.

Use of_seq s to construct a priority queue from a sequence of key-value pairs. Evaluates the whole sequence. Runs in O(n) time and O(1) space.

Use to_seq q to produce a sequence of the key-value pairs in q from top to bottom.