range.js

    var RangeObservable = (function(__super__) {
    inherits(RangeObservable, __super__);
    function RangeObservable(start, count, scheduler) {
      this.start = start;
      this.rangeCount = count;
      this.scheduler = scheduler;
      __super__.call(this);
    }

    function loopRecursive(start, count, o) {
      return function loop (i, recurse) {
        if (i < count) {
          o.onNext(start + i);
          recurse(i + 1);
        } else {
          o.onCompleted();
        }
      };
    }

    RangeObservable.prototype.subscribeCore = function (o) {
      return this.scheduler.scheduleRecursive(
        0,
        loopRecursive(this.start, this.rangeCount, o)
      );
    };

    return RangeObservable;
  }(ObservableBase));

  /**
  *  Generates an observable sequence of integral numbers within a specified range, using the specified scheduler to send out observer messages.
  * @param {Number} start The value of the first integer in the sequence.
  * @param {Number} count The number of sequential integers to generate.
  * @param {Scheduler} [scheduler] Scheduler to run the generator loop on. If not specified, defaults to Scheduler.currentThread.
  * @returns {Observable} An observable sequence that contains a range of sequential integral numbers.
  */
  Observable.range = function (start, count, scheduler) {
    isScheduler(scheduler) || (scheduler = currentThreadScheduler);
    return new RangeObservable(start, count, scheduler);
  };