definterface.clj

(definterface IComplex
  (a [^java.lang.Long x ^java.lang.Double y])
  (a [^java.lang.Double x ^java.lang.Long y]))

(deftype Complex []
  IComplex
  (a [this ^java.lang.Long x ^java.lang.Double y] "a")
  (a [this ^java.lang.Double x ^java.lang.Long y] "b"))

(defn a [x y]
  (.a (Complex.) x y))

(a 1 1.5)
(a 1.5 1)

;; ~ 1s
(dotimes [_ 10]
  (time
   (dotimes [_ 1e6]
     (a 1 1.5))))

(defprotocol IComplex
  (a [this x]))

(declare complex?)

(deftype Complex []
  IComplex
  (a [this x]
     (cond
      (complex? x) "ca"
      (float? x)   "cb")))

(defn complex? [x]
  (instance? Complex x))

(extend-type java.lang.Double
  IComplex
  (a [this x]
     (cond 
      (complex? x) "fa"
      (float? x)   "fb")))

;; 13ms
(dotimes [_ 10]
  (time
   (dotimes [_ 1e6]
     (a 1.5 (Complex.))
     (a (Complex.) 1.5))))