anchor.diff:      (setf (x-pos player) nx)
       (setf (y-pos player) ny)
       (setf (aref (nth layer *world*) ny nx) 1)))
  -
   
   (defgeneric render (unit x y)
     (:documentation "Renders a unit onto the default sdl window.")
  
positive.code: ;  (:documentation "The dig function decides the outcome of using a certain tool on an object")
  ;  (:method ((tool shovel) (object earth))
  ;    (create 'dirt)))
  
negative.code: (in-package :clobber)
  
  (defmacro defobject (name layer &rest slots)
    `(defclass ,name ()
  