[funds-cvs] r46 - trunk/funds/src/trees

[abaine at common-lisp.net]

Author: abaine
Date: Tue Jul  3 14:57:04 2007
New Revision: 46

Modified:
   trunk/funds/src/trees/avl-tree.lisp
Log:
Refactored left and right rotate.

Modified: trunk/funds/src/trees/avl-tree.lisp
==============================================================================
--- trunk/funds/src/trees/avl-tree.lisp	(original)
+++ trunk/funds/src/trees/avl-tree.lisp	Tue Jul  3 14:57:04 2007
@@ -102,45 +102,17 @@
 ;;;; Rotation Functions
 
 (defun left-rotate (t0 a b)
-  (let ((c (avl-right b))
-	(new-a (make-avl :ht (1- (avl-ht a)) ; re-calculate?
-			 :key (avl-key a)
-			 :value (avl-value a)
-			 :left t0
-			 :right (avl-left b))))
-    (make-avl :ht (1+ (avl-ht new-a))
-	      :key (avl-key b)
-	      :value (avl-value b)
-	      :left new-a
-	      :right c)))
+  (rotate t0 a b :direction :left))
 
 (defun right-rotate (t3 c b)
-  (let ((a (avl-left b))
-	(new-c (make-avl :ht (1- (avl-ht c)); re-calculate?
-			 :key (avl-key c)
-			 :value (avl-value c)
-			 :left (avl-right b)
-			 :right t3)))
-    (make-avl :ht (1+ (avl-ht new-c)) ; re-calculate?
-	      :key (avl-key b)
-	      :value (avl-value b)
-	      :left a
-	      :right new-c)))
+  (rotate t3 c b :direction :right))
 
 (defun rotate (inside root outside &key direction)
   (let* ((left-p (eq direction :left))
-	 (outside-accessor (if left-p
-			       #'avl-right
-			       #'avl-left))
-	 (inside-accessor (if left-p
-			      #'avl-left
-			      #'avl-right))
-	 (inside-init-key (if left-p
-			      :left
-			      :right))
-	 (outside-init-key (if left-p
-			       :right
-			       :left))
+	 (outside-accessor (if left-p #'avl-right #'avl-left))
+	 (inside-accessor (if left-p #'avl-left #'avl-right))
+	 (inside-init-key (if left-p :left :right))
+	 (outside-init-key (if left-p :right :left))
 	 (new-outside (funcall outside-accessor outside))
 	 (new-inside (make-avl :ht (1- (avl-height root))
 			       :key (avl-key root)