pmap using core.async

async_pmap.clj

(ns async-example.core
  (:require [clojure.core.async :refer [chan go >! <!!]])
  (:gen-class))

(defn my-pmap [f col]
  (let [chans (repeatedly (count col) chan)]
    (doseq [[c e] (map vector chans col)]
      (go (>! c (f e))))
    (map <!! chans)))

(defn -main [& args]
  (println (my-pmap (fn [x] (Thread/sleep 1000) (identity x)) (range 0 10))))

output

time lein run
(0 1 2 3 4 5 6 7 8 9)
lein run  3.33s user 0.26s system 71% cpu 5.046 total