ntimes.lisp

(defmacro ntimes (n &rest body)         ; wrong
  `(do ((i 0 (1+ i)))
       ((>= i ,n))
     ,@body))

(let ((i 10))                           ; 10
  (ntimes 5 (incf i))
  i)




(defmacro ntimes (n &rest body)         ; also wrong, but in a different way
  (let ((i (gensym)))
    `(do ((,i 0 (1+ ,i)))
         ((>= ,i ,n))
       ,@body)))

(let ((v 10))                           ; .....
  (ntimes (decf v)
          (princ ".")))




(defmacro ntimes (n &rest body)         ; finally, the right version
  (let ((i (gensym))
        (g (gensym)))
    `(let ((,g ,n))
       (do ((,i 0 (1+ ,i)))
           ((>= ,i ,g))
         ,@body))))