iPhoneiOS 上的通用 LISP

手机操作系统的发展历程

lisp
(defun factorial (n)
  (if (<= n 1)
      1
      (* n (factorial (- n 1)))))
(print (factorial 5))

lisp
(defvar *maze*
  '((1 1 1 1 1)
    (1 0 0 0 1)
    (1 1 1 0 1)
    (1 0 0 0 1)
    (1 1 1 1 1)))
(defvar *player-position* '(1 1))
(defun move-player (direction)
  (let ((new-position (case direction
                        (:up (list (- (car *player-position*) 1) (cdr *player-position*)))
                        (:down (list (+ (car *player-position*) 1) (cdr *player-position*)))
                        (:left (list (car *player-position*) (- (cdr *player-position*) 1)))
                        (:right (list (car *player-position*) (+ (cdr *player-position*) 1))))))
    (if (valid-move? new-position)
        (setf *player-position* new-position)
        (print "Invalid move."))))
(defun valid-move? (position)
  (let ((row (car position))
        (col (cadr position)))
    (and (>= row 0) (< row (length *maze*))
         (>= col 0) (< col (length (first *maze*)))
         (= (nth row (nth col *maze*)) 0))))
(defun print-maze ()
  (loop for row in *maze* do
        (loop for cell in row do
              (if (equal cell 1)
                  (print "#")
                  (if (equal *player-position* (list (loop for i in cell-index from 0 until (equal i cell) finally (return i))
                                                      (loop for i in row-index from 0 until (equal i row) finally (return i)))))
                  (print "@"))
        (print ""))))
(print-maze)
(move-player :right)
(print-maze)