Fixed not copying the default keyword args

bin/pre.slime

@@ -127,11 +127,13 @@ by the key 'from' and ends with the number defined in 'to'."
 (defun range-while (:keys from :defaults-to 0 to)
   "Returns a sequence of numbers starting with the number defined
 by the key 'from' and ends with the number defined in 'to'."
-  (define result (list from))
+  (define result (list (copy from)))
+  (define head result)
   (mutate from (incr from))
   (while (< from to)
     (prog
-     (append result (copy from))
+     (mutate head (pair (first head) (pair (copy from) nil)))
+     (define head (rest head))
      (mutate from (incr from))))
   result)
 

bin/test.slime

@@ -1,4 +1,4 @@
-(when 1 (breakpoint))
+;; (when 1 (breakpoint))
 
 ;; (if (eval 1)
 ;;     (apply prog ((breakpoint)))
@@ -7,3 +7,9 @@
 ;; (if (eval 1)
 ;;     (eval (pair prog ((breakpoint)))))
 ;;   nil))
+
+
+(defun ! (n)
+  (if (< n 2)
+      1
+    (* n (! (- 1 n)))))