async-math.clj

(ns async-math)

(require '[clojure.core.async :as async :refer :all])

(defn query-maker 
  "generates a simple math-query and the answer to it"
	[]
	(let [a (rand-int 10) b (rand-int 10)]
	  {:query (str "what is " a " + " b "?")
	   :answer (+ a b)}))

;; {:query "what is 1 + 2 ?" :answer 3}

;; an un-buffered channel:
(def answer-chan (chan))

(future ;;to let go of the repl
  (go 	;;start async transaction
   (while true                 ;; run forever
     (let [task (query-maker)] ;; create a task
       (println (:query task)) ;; output query (apparently this could be put in a channel)
       (if (== (<! answer-chan) (:answer task)) ;;wait for a new entry in answer-chan
         (println "correct!")
         (println "wrong"))))))

;;short helper for answering
(defn ans [x]
  (>!! answer-chan x))

;;the REPL interaction becames:
;;what is 2 + 7?
;;async-math> (ans 9)
;;correct!
;;what is 0 + 5?
;;async-math> (ans 10)
;;wrong!
;;what is 3 + 3?
;;async-math> _