Multiple Dispatch

(defmethod add1 ((a fixnum) n) (+ a n))

(defmethod add1 ((a single-float) n) (+ a n))

;; 1.1 million per second

(defun try11 (n)

(time (dotimes (i n) (setq *junk* (add1 2 1)))))

(defmethod add2 ((a fixnum) (n fixnum)) (+ a n))

(defmethod add2 ((a single-float) (n single-float)) (+ a n))

;; 625 thousand per second

(defun try12 (n)

(time (dotimes (i n) (setq *junk* (add2 2 1)))))

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