5.7. Walking Around in Our World

Now that we can see things in our world, let’s write some code so that we can walk around. The walk function (not in the functional style) takes a direction and lets us walk there:

(defun walk (direction)
  (let ((next (find direction
                    (cdr (assoc *location* *edges*))
                    :key #'cadr)))
  (if next
      (progn (setf *location* (car next))
             (look))
      '(you cannot go that way.))))