Performance Comparison

(defun invert (value) (not value))

;; 3.5 million calls per second

(defun try8 (n)

(time (dotimes (i n) (setq *junk* (invert t)))))

(defmethod nada (value) (not value))

;; 3.5 million calls per second

(defun try9 (n)

(time (dotimes (i n) (setq *junk* (nada t)))))

(defmethod flip ((value ship2)) (not value))

(defmethod flip ((value buick)) (not value))

;; 1.8 million calls per second

(defun try10 (n)

(let ((ship (make-instance 'ship2)))

(time (dotimes (i n) (setq *junk* (flip ship))))))

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