(rplaca tail (cdar tail)))
(collect (apply func elems))))))))
+(defun mapn (func list)
+ (with-collect
+ (while list
+ (collect (funcall func list))
+ (setq list (cdr list)))))
+
+(defun maplist (func list &rest lists)
+ (let ((lists (cons list lists)))
+ (with-collect
+ (block loop
+ (loop
+ (let ((elems (mapn #'car lists)))
+ (do ((tail lists (cdr tail)))
+ ((null tail))
+ (when (null (car tail)) (return-from loop))
+ (rplaca tail (cdar tail)))
+ (collect (apply func elems))))))))
+
(defun mapc (func &rest lists)
(do* ((elems (map1 #'car lists) (map1 #'car lists-rest))
(lists-rest (map1 #'cdr lists) (map1 #'cdr lists-rest)))