Lambda Zagreb - Clojure code snippets

core.clj

(ns lambdazg.core
  (:require [clojure.core.async :as async :refer [>! <! >!! <!! go chan buffer close! thread
                                                  alts! alts!! timeout]])
  (:gen-class))



;; --



(+ 2 2)

(println "Hello, world")

(def a '(1 2 3 4))

a



;; --



(map (fn [x] (* x 2)) a)

(reduce + a)

(for [x '(1 2 3 4) y '(5 6 7 8)]
  (list x y))



;; --



(def v [1 2 3 4])

(conj v 5)

v



;; --



(defn make-it-double
  [x]
  (* x 2))

(make-it-double 2)



;; --



(def make-it-double!
  (fn [x] (* x 2)))

(make-it-double! 2)



;; --



(def a-future
  (future
    (Thread/sleep (+ 4000 (rand-int 2000)))
    (println "done")
    42))

(future-done? a-future)

(deref a-future)
@a-future



;; --



(def futures (for [x (range 10)]
               (future
                 (Thread/sleep (+ 1000 (rand-int 20000)))
                 (println "done")
                 42)))

(while (not (every? true? (map future-done? futures)))
  (println (map future-done? futures))
  (Thread/sleep 500))

(map deref futures)



;; --



(def c (chan))

(future
  (while true
    (let [v (<!! c)]
      (println v))))

(future
  (Thread/sleep 3000)
  (>!! c "I'm in another thread again!"))



;; --



(def at (atom []))

at

@at

(conj at 5) ;; whoops

(swap! at conj 5)

@at



;; --

project.clj

(defproject lambdazg "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.6.0"]
                 [org.clojure/core.async "0.1.346.0-17112a-alpha"]]
  :main ^:skip-aot lambdazg.core
  :target-path "target/%s"
  :profiles {:uberjar {:aot :all}})