Brave and True - Chapter 10 (metaphysics) - Exercise 2

brave_chap10_exercise_2.clj

(def frequency-table (atom {}))

(defn random-quote []
  (slurp "http://www.braveclojure.com/random-quote"))

(defn word-frequencies [s]
  (frequencies (str/split (.toLowerCase s) #"\W+")))

(defn update-frequency-table []
  (swap! frequency-table (fn [current-state] (merge-with + current-state (word-frequencies (random-quote))))))

(defn quote-word-count [n]
  (let [promisses (take n (repeatedly promise))]
    (doseq [p promisses]
      (future
        (update-frequency-table)
        (deliver p true)))
    (every? deref promisses))
  @frequency-table)

(quote-word-count 5)

(comment
  (reset! frequency-table {})
  (println @frequency-table))