public IDisposable Subscribe(IObserver<R> observer)
{
    GenerateState state = new GenerateState
    {
        condition = this.condition,
        current = this.initial,
        iterate = this.iterate,
        observer = observer,
        resultSelector = this.resultSelector
    };

    Action<GenerateState, Action<GenerateState>> action = (_state, self) =>
    {
        if (_state.condition(_state.current))
        {
            var result = _state.resultSelector(_state.current);
            _state.observer.OnNext(result);
            _state.current = _state.iterate(_state.current);

            self(_state);
        }
        else
            _state.observer.OnCompleted();
    };

    return scheduler.Schedule(state, action);
}

posted by Simply Ged

|requires observer != null
|ensures result != null
public IDisposable Subscribe(IObserver<R> observer)
{
    var generateState = new GenerateState()
    {
        condition = condition,
        current = initial,
        iterate = iterate,
        observer = observer,
        resultSelector = resultSelector,
    };
    return scheduler.Schedule(generateState, (state, self) =>
    {
        if (state.condition(state.current))
        {
            var result = state.resultSelector(state.current);
            state.observer.OnNext(result);
            state.current = state.iterate(state.current);
            self(state);
        }
        else
            state.observer.OnCompleted();
    });
}

This is what I came up with.  It runs in AppDomainScheduler named scheduler.  I want to build one of these schedulers to send remote entity framework queries around to different machines using WCF underneath.  Is this possible?  Any good getting started guides?

Also I run code contracts static checker and it complains that I might return null.  I tried a few things like returning Disposable.Empty if IDisposable returned from Schedule function is null but that failed also.  What is the correct behavior here to satisfy the contract.  Thanks so much.

posted by AceHack

posted by Mouhammad Fakhoury

Wonder why the remote queries weren't using the QObservable "provider" where expressions & values were remoted rather than type references...

posted by gt

posted by Bnaya

posted by AggelosBiboudis

I know that its possible to do it, but is it easy stuff, can you explain it to a junior quickly?

what you are trying to do with this azure scheduler is similar to what erlang can do of of a box, you have a problem passing stuff across boundaries, in Erlang you can send new code to execute on remote machine, and do upgrade on a fly, I don't expect that behavior here. Its almost indistinguishable, to pass a message across processes on a single node and across processes on different nodes, I know that only form of cross process communication in Erlang is message passing, and the whole VM and language semantics is built on that notion.

This code is self-explanatory 

Pid ! {self(), Message}.

or

{process_name, Node} ! {self(), Message}.

you see the code and you say immediately, a got it, the only what you have to know is that "!" sends a message, whereas in your example, aaaa ok I have to remember that we go remote and we have to pass values in a certain way, and we have to remember that this work should be done on remote sheduler, etc, etc, it is not simple... very long way ahead of you... locally RX is great stuff, and I'm fascinated by it, but this azure scheduler stuff is to put it simply is over the top.

posted by maciejw