## Source

(defun heap-dequeue (heap)
(unless (heap-empty-p heap)
(let ((save (heap-front heap)))
(setf (aref (heap-array heap) 0)
(aref (heap-array heap) (decf (heap-size heap))))
;;allow removed for begin garbage collected
(setf (aref (heap-array heap) (heap-size heap)) 0)
(heapify (heap-array heap) 0 (heap-size heap) (heap-key-fn heap)
(heap-comparator heap))
save)))

Source Context