gistfile1.lisp

(defparameter *world* nil)

(defclass tile ()
  ((x :initarg :x
      :accessor x)
   (y :initarg :y
      :accessor y)
   (size :initarg :size
   :accessor size)
   (color :initarg :color
	  :accessor color)
   (tile-type :initarg :tile-type
	      :accessor tile-type))
  (:default-initargs
   :size *tile-size*
   :tile-type :dirt))

;;; ... more code

(defun reset ()
  (setf *world* (make-array '(30 40) :element-type 'tile)) ;; undefined type: TILE
  (setup-world)
  (setf *entities* nil))