heaps.lisp

;; Copyright (c) 2013, Jason R. Person
;; All rights reserved.
;;
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(in-package #:heaps)

(defmacro max-heap (n &key size contents)
  "Creates new max heap object."
  `(setf (symbol-function ,n) 
     (let* ((heap (new-max-heap ,size ,contents))
            (hsize (length heap)))
       (dlambda
         (:insert (v) 
          (incf hsize)
          (max-heap-insert heap v))
         (:get-max () 
          (if (> hsize 0) 
            (heap-max heap) nil))
         (:get-size () 
          hsize)
         (:extract-max () 
          (if (> hsize 0) 
            (let ((r (heap-extract-max heap)))
              (decf hsize)
              r)
            nil))))))

(defmacro min-heap (n &key size contents)
  "Creates new min heap object."
  `(setf (symbol-function ,n) 
     (let* ((heap (new-min-heap ,size ,contents))
            (hsize (length heap)))
       (dlambda
         (:insert (v) 
          (incf hsize)
          (min-heap-insert heap v))
         (:get-min () 
          (if (> hsize 0) 
            (heap-min heap) nil))
         (:get-size () 
          hsize)
         (:extract-min () 
          (if (> hsize 0) 
            (let ((r (heap-extract-min heap)))
              (decf hsize)
              r)
            nil))))))