gistfile1.txt

// This works in C# (puts out 1..10, one each second), but the RxJS one
// waits 1 second then dumps out the entire Range:

Observable.Range(1,10)
    .Select(x => Observable.Return(x).Delay(TimeSpan.FromMilliseconds(1000)))
    .Concat()

// Here's a version I wrote that seems to work in CoffeeScript:
Rx.Observable.WorkingConcat = (x) ->
  Rx.Observable.CreateWithDisposable (subj) ->
    isCompleted = false
    ret = new Rx.CompositeDisposable()
    md = new Rx.MutableDisposable()
    md.Replace(Rx.Disposable.Empty)
    ret.Add(md)

    queue = []

    #console.log("Starting")
    dequeue = () ->
      #console.log("Dequeue start")
      return if queue.length == 0 or md.Get() != Rx.Disposable.Empty
      #console.log("succeeded")
      item = queue.shift()

      itemDisp = item.Subscribe subj.OnNext, subj.OnError, () ->
        #console.log("Completing")
        md.Replace(Rx.Disposable.Empty)
        if isCompleted and queue.length == 0
          subj.OnCompleted()
          return
        Rx.Scheduler.CurrentThread.Schedule(dequeue)
      md.Replace(itemDisp)

    onNext = (y) ->
      #console.log("Pushing y")
      queue.push(y)
      return if md.Get() != Rx.Disposable.Empty
      Rx.Scheduler.CurrentThread.Schedule(dequeue)
    onErr = () -> {}
    disp = x.Subscribe(onNext, onErr, () -> isCompleted = true)

    ret.Add(disp)
    ret


// Here's the JS version:
  Rx.Observable.WorkingConcat = function(x) {
    return Rx.Observable.CreateWithDisposable(function(subj) {
      var dequeue, disp, isCompleted, md, onErr, onNext, queue, ret;
      isCompleted = false;
      ret = new Rx.CompositeDisposable();
      md = new Rx.MutableDisposable();
      md.Replace(Rx.Disposable.Empty);
      ret.Add(md);
      queue = [];
      dequeue = function() {
        var item, itemDisp;
        if (queue.length === 0 || md.Get() !== Rx.Disposable.Empty) {
          return;
        }
        item = queue.shift();
        itemDisp = item.Subscribe(subj.OnNext, subj.OnError, function() {
          md.Replace(Rx.Disposable.Empty);
          if (isCompleted && queue.length === 0) {
            subj.OnCompleted();
            return;
          }
          return Rx.Scheduler.CurrentThread.Schedule(dequeue);
        });
        return md.Replace(itemDisp);
      };
      onNext = function(y) {
        queue.push(y);
        if (md.Get() !== Rx.Disposable.Empty) {
          return;
        }
        return Rx.Scheduler.CurrentThread.Schedule(dequeue);
      };
      onErr = function() {
        return {};
      };
      disp = x.Subscribe(onNext, onErr, function() {
        return isCompleted = true;
      });
      ret.Add(disp);
      return ret;
    });
  };