■

興味あるけどまだ触ってないCLOS。
こんなことができるらしい。

(defclass name () ())

(defmethod say ((n name) string)
  (format t "~A" string))
  
(defmethod say :before ((n name) string)
  (princ "Hello,"))
(defmethod say :after ((n name) string)
  (princ " speaking."))

(say (make-instance 'name) "Bobby")
;Hello,Bobby speaking.

http://ja.doukaku.org/comment/6033/