Create a cell that only updates at most once every so many milliseconds

throttle.cljs.hl

(defn throttle [c ms]
  (let [queued? (atom false)]
    (with-let [ret (cell @c)]
      (add-watch c (gensym)
        #(when-not @queued?
           (reset! queued? true)
           (with-timeout ms
             (reset! queued? false)
             (reset! ret @c)))))))

(def test1 (cell 0))
(def test2 (throttle test1 1000))

(with-interval 100 (swap! test1 inc))
(cell= (pr :test2 test2))

;; js console output:
;;
;; :test2 0
;; :test2 10
;; :test2 20
;; :test2 30
;; ...