Binary heaps are a simple implementation of priority queues.
Makes a new empty heap using <=? to order elements.
Returns #t if x is a heap, #f otherwise.
Returns the number of elements in the heap.
Adds each v to the heap.
Adds each element contained in v to the heap, leaving v unchanged.
Returns the least element in the heap h, according to the heap’s ordering. If the heap is empty, an exception is raised.
Removes the least element in the heap h. If the heap is empty, an exception is raised.
Builds a heap with the elements from items. The vector is not modified.
Returns a vector containing the elements of heap h in the heap’s order. The heap is not modified.
Makes a copy of heap h.
Sorts vector v using the comparison function <=?.