Sync

Task/Anonymous-recursion/Common-Lisp/anonymous-recursion-2.lisp

@@ -1,8 +1,8 @@
-(defun fib (number)
-  "Fibonacci sequence function."
-  (if (< number 0)
-      (error "Error. The number entered: ~A is negative" number)
-      (recursive ((n number) (a 0) (b 1))
-         (if (= n 0)
-            a
-            (recurse (- n 1) b (+ a b))))))
+(defun fib (n)
+  (assert (>= n 0) nil "'~a' is a negative number" n)
+  (funcall
+   (alambda (n)
+     (if (>= 1 n)
+	 n
+	 (+ (self (- n 1)) (self (- n 2)))))
+   n))