X-Git-Url: https://git.distorted.org.uk/~mdw/lisp/blobdiff_plain/4da88bb98b75edf5033fa864cae0d3d1c397ac07..813da880d2d77f04ea623f426d543d298528f967:/heap.lisp

diff --git a/heap.lisp b/heap.lisp
index 53eb2b8..7eb4587 100644
--- a/heap.lisp
+++ b/heap.lisp
@@ -1,7 +1,5 @@
 ;;; -*-lisp-*-
 ;;;
-;;; $Id$
-;;;
 ;;; Heap data structure; useful for priority queues and suchlike
 ;;;
 ;;; (c) 2006 Straylight/Edgeware
@@ -24,10 +22,7 @@
 ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
 (defpackage #:heap
-  (:use #:common-lisp)
-  (:export #:make-heap #:heap-count #:heap-empty-p
-	   #:heap-insert #:heap-head #:heap-remove
-	   #:heap-sort))
+  (:use #:common-lisp))
 (in-package #:heap)
 
 ;;;--------------------------------------------------------------------------
@@ -108,13 +103,15 @@
 ;;;--------------------------------------------------------------------------
 ;;; High-level heap things
 
+(export '(heap heapp))
 (defstruct (heap (:predicate heapp) (:constructor %make-heap))
   "Data structure for a heap."
   (v (make-array 16) :type vector)
   (n 0 :type index)
-  (key #'identity :type function)
-  (compare #'<= :type function))
+  (key #'identity :type function :read-only t)
+  (compare #'<= :type function :read-only t))
 
+(export 'make-heap)
 (defun make-heap
     (&key (compare #'<=) (key #'identity)
 	  (type 't) (init-size 16) (contents nil contentsp))
@@ -146,16 +143,19 @@
 		:initial-value 0))
       (%make-heap :compare compare :key key :n n :v v))))
 
+(export 'heap-count)
 (defun heap-count (heap)
   "Return the number of elements in HEAP."
   (declare (type heap heap))
   (heap-n heap))
 
+(export 'heap-empty-p)
 (defun heap-empty-p (heap)
   "True if HEAP is empty."
   (declare (type heap heap))
   (zerop (heap-count heap)))
 
+(export 'heap-insert)
 (defun heap-insert (heap item)
   "Insert ITEM into the HEAP."
   (declare (type heap heap))
@@ -168,12 +168,14 @@
     (upheap v (heap-key heap) (heap-compare heap) n item)
     (setf (heap-n heap) (1+ n))))
 
+(export 'heap-head)
 (defun heap-head (heap)
   "Peep at the head item on HEAP."
   (declare (type heap heap))
   (assert (not (heap-empty-p heap)))
   (aref (heap-v heap) 0))
 
+(export 'heap-remove)
 (defun heap-remove (heap)
   "Remove the head item from HEAP and return it."
   (declare (type heap heap))
@@ -184,6 +186,7 @@
       (setf (heap-n heap) n)
       (downheap v (heap-key heap) (heap-compare heap) n (aref v n)))))
 
+(export 'heap-sort)
 (defun heap-sort (items compare &key (key #'identity))
   "Return the ITEMS, least-first, as sorted by the ordering COMPARE."
   (let ((heap (make-heap :compare compare :contents items :key key)))