.

original commit: e0e63aacee7cb842635077a88d4f87aef0c54ed2
2002-07-09 00:27:19 +00:00 · 2002-07-09 00:27:19 +00:00 · da9689d146
commit da9689d146
parent 53e9c04130
1 changed files with 6 additions and 5 deletions
--- a/collects/mzlib/list.ss
+++ b/collects/mzlib/list.ss
@ -318,11 +318,12 @@
    (polymorphic
     (lambda (l)
       (if (pair? l)
-           (if (pair? (cdr l))
-               (last-pair (cdr l))
-               l)
-           (raise-type-error 'last-pair "pair" l)))))
-  
+	   (let loop ((l l) (x (cdr l)))
+	     (if (pair? x)
+		 (loop x (cdr x))
+		 l))
+	   (raise-type-error 'last-pair "pair" l)))))
+
  (define cons? (lambda (x) (pair? x)))
  (define empty? (lambda (x) (null? x)))
  (define empty '()))