clojurescript

(defn debounce [func wait immediate]
  (let [timeout (atom nil)]
    (fn []
      (this-as this
               (let [context this
                     args js/arguments
                     later (fn []
                             (reset! timeout nil)
                             (when-not immediate
                               (.apply func context args)))]
                 (if (and immediate (not @timeout))
                   (.apply func context args))
                 (js/clearTimeout @timeout)
                 (reset! timeout (js/setTimeout later wait)))))))


(defn throttle [func wait]
  (let [result (atom nil)
        throttling (atom nil)
        more (atom nil)
        timeout (atom nil)
        when-done (debounce (fn []
                              (reset! more false) 
                              (reset! throttling false)) wait)]
    (fn []
      (this-as this
               (let [context this
                     args js/arguments
                     later (fn []
                             (reset! timeout nil)
                             (when @more (.apply func context args))
                             (when-done))]
                 (when-not @timeout
                   (reset! timeout (js/setTimeout later wait)))
                 (if @throttling
                   (reset! more true)
                   (reset! result (.apply func context args)))
                 (when-done)
                 (reset! throttling true)
                 @result)))))

js

  // Returns a function, that, when invoked, will only be triggered at most once
  // during a given window of time.
  _.throttle = function(func, wait) {
    var context, args, timeout, throttling, more, result;
    var whenDone = _.debounce(function(){ more = throttling = false; }, wait);
    return function() {
      context = this; args = arguments;
      var later = function() {
        timeout = null;
        if (more) func.apply(context, args);
        whenDone();
      };
      if (!timeout) timeout = setTimeout(later, wait);
      if (throttling) {
        more = true;
      } else {
        result = func.apply(context, args);
      }
      whenDone();
      throttling = true;
      return result;
    };
  };

  // Returns a function, that, as long as it continues to be invoked, will not
  // be triggered. The function will be called after it stops being called for
  // N milliseconds. If `immediate` is passed, trigger the function on the
  // leading edge, instead of the trailing.
  _.debounce = function(func, wait, immediate) {
    var timeout;
    return function() {
      var context = this, args = arguments;
      var later = function() {
        timeout = null;
        if (!immediate) func.apply(context, args);
      };
      if (immediate && !timeout) func.apply(context, args);
      clearTimeout(timeout);
      timeout = setTimeout(later, wait);
    };
  };