greatly sped up (string ...) by making it use a single-list map

(The general mapcar is far more expensive.)

Fundamental.lisp

@@ -249,7 +249,7 @@
 
 (defun string (&rest args)
   "make a string from all args and return it"
-  (apply #'concat (mapcar #'princs args)))
+  (apply #'concat (map #'princs args)))
 
 (defun string<= (&rest args)
   "return t if string args are in ascending order (non-strict), else nil"
@@ -478,6 +478,13 @@
         (apply #'all (cdr args))
       nil)))
 
+(defun map (func list)
+  "apply FUNC to each element of LIST and return the list of results"
+  (if (null list)
+      nil
+    (cons (func (car list))
+          (map func (cdr list)))))
+
 (defun mapcar (fun &rest lists)
   "apply FUN to all elements of all LISTS and return a list of the results"
   (labels ((mapcar1 (fun arglist)