(defun array2list (a)
  (let (l)
    (dotimes (i (length a) (reverse l))
      (push (aref a i) l))))

(defmacro doarrayi ((one n array &optional out) &body body)
  (let ((i (gensym)))
    `(let ((,i (length ,array)))
       (dotimes (,n ,i ,out)
         (let ((,one (aref ,array ,n)))
           ,@body)))))

(defmacro doarray ((one array &optional out) &body body)
  (let ((j (gensym)))
    `(doarrayi (,one ,j ,array ,out) ,@body)))

;(deftest test-do-array ()
;  (let* ((count 0)
;        (r1    (doarrayi (x i #(0 1 2) count)
;                 (incf count x)
;                 (incf count i)))
;        (r2    (doarray (x #(0 1 2) count)
;                 (incf count x))))
;   (check
;     (= r1 6)
;     (= r2 9)));)