test.clj

(def d (delay (println "Running>>>")
         :done!))

(deref d)

(defn get-document
  [id]
  {:content (delay (slurp "http://www.baidu.com"))})

(get-document "some-id")

(def long-calculation (future (apply + (range 1e8))))
@long-calculation

(def f (future (Thread/sleep 10000) (println "done") 100))
@f

(defn call-service
  [arg1 arg2 callback-fn]
                                        ; ...perform service call, eventually invoking callback-fn with results...
  (future (callback-fn (+ arg1 arg2) (- arg1 arg2))))

(defn sync-fn
  [async-fn]
  (fn [& args]
    (let [result (promise)]
      (apply async-fn (conj (vec args) #(deliver result %&)))
      @result)))

((sync-fn call-service) 8 7)

(conj (vec (list 1 2)) 3)

(defn future-addition
  [arg1 arg2 callback-fn]
  (future (callback-fn (+ arg1 arg2))))

(future-addition 2 3
  (fn [n]
    (printf "Async result: %s\n" n)))

(defn sync-fn
  [async-fn]
  (fn [& args]
    (let [result (promise)]
      (apply async-fn (conj (vec args) #(deliver result %)))
      @result)))

(printf "Sync result: %s\n"
  ((sync-fn future-addition) 2 3))


(defn phone-numbers
  [string]
  (re-seq #"(\d{3})[\.-]?(\d{3})[\.-]?(\d{4})" string))

(phone-numbers " Sunil: 123.345.5678, Betty: 435.532.2345, Kevin: 456-4524523")

(def files (repeat 100000
             (apply str
               (concat (repeat 1000 \space)
                 "Sunil: 123.345.5678, Betty: 435.532.2345, Kevin: 456-4524523"))))

(time (dorun (map phone-numbers files)))
(time (dorun (pmap phone-numbers files)))
(time (->> files
        (partition-all 250)
        (pmap (fn [chunk] (doall (map phone-numbers chunk))))
        (apply concat)
        dorun))