add.clj

(ns playsync.core
  (:require [clojure.core.async
             :as a
             :refer [>! <! >!! <!! go chan buffer close! thread
                     alts! alts!! timeout]]))

(defn pipe-through
  [f in out]
  (go (>! out (f (<! in)))))

(defn pipeline-of
  [& stages]
  (let [first-chan (chan)]
    (loop [first-chan first-chan in first-chan stages stages]
      (if (empty? stages)
        #(do
           (go (>! first-chan %))
           (<!! in))
        (let [out (chan)]
          (pipe-through (first stages) in out)
          (recur first-chan out (rest stages)))))))

(defn -add
  [a b]
  ((apply pipeline-of (repeat a inc)) b))

(def add (memoize -add))