deep-equality.lisp

;; equivalent upto structure
(defgeneric deepeq (x y))

(defmethod deepeq ((x number) y)
  (equal x y))

(defmethod deepeq ((x symbol) y)
  (equal x y))
                  
(defmethod deepeq (x y)
  (if (equal (class-of x) (class-of y))
      (let* ((cls (class-of x)) ;; then
            (allslots (class-direct-slots cls)))
        (reduce (lambda (out slot)
                  (let*
                      ((name (slot-definition-name slot))
                       (xval (slot-value x name))
                       (yval (slot-value y name)))
                    (and out (deepeq xval yval))))
                allslots :initial-value t))
    nil ;; else
    ))