currying.clj

;; カリー化
(defn currize [[x & xs] body]
  `(fn [~x]
     ~(if xs
        (currize xs body)
        `(do ~@body))))

(defmacro currying [params & body]
  (currize params body))

;; これは
(currying [a b c d]
          (+ (* a b) (/ c d)))

;; 下記に展開される
(clojure.core/fn [a]
  (clojure.core/fn [b]
    (clojure.core/fn [c]
      (clojure.core/fn [d] (do (+ (* a b) (/ c d)))))))

;; 使ってみるけど、カッコがめんどい
((((currying [a b c] (+ a b c)) 10) 20) 30)

;; めんどいので、マクロつくる
(defn reverse-arrow [args body]
  (if (empty? args)
    body
    (recur (rest args) `(~body ~(first args)))))

(defmacro <- [subject & args]
  (reverse-arrow args subject))

;; こう書けるよ
(<- (currying [a b c] (+ a b c))
    10 20 30)
;; こうなる
((((currying [a b c] (+ a b c)) 10) 20) 30)
;; 最終的にはこれ
((((fn* ([a] (fn* ([b] (fn* ([c] (do (+ a b c)))))))) 10) 20) 30)

http://d.hatena.ne.jp/Isuzu_T/20130507/1367935014 を見て触発された