logging-class

logging-class.lisp

(defclass logging-class (standard-class)
  ())

(defmethod slot-value-using-class :after ((class logging-class) obj slotd)
  (format t "Access to slot ~a of ~s ~%"
          (slot-definition-name slotd)
          obj))

(defmethod (setf slot-value-using-class) :after (new-value (class logging-class) obj slotd)
  (format t "Setting the slot ~a of ~s to value ~s ~%"
          (slot-definition-name slotd)
          obj
          new-value))

(defmethod validate-superclass ((class logging-class)
                                (superclass standard-class))
  t)

(defclass my-object ()
  ((x :initform nil :initarg :x :accessor my-x))
  (:metaclass logging-class))