Problems with synchronous sources

[raimohanska]

Some combinators just don't work with synchronous sources like Bacon.fromArray. Especially in "diamond-shaped" setups things go wrong.

Example can be found in branch fix/367.

Maybe we should make all Observables asynchronous? This can now be worked around be calling .delay(0).

[rue]

This sounds like a good idea; it’s seems better to explicitly work around the behaviour when it’s not needed than to have to remember that some streams work differently from others.

[wolfflow]

Also, there is a case with unsubscribing fn.

unsub = Bacon.fromArray([1,2,3]).onValue(->
  console.log typeof unsub #always undefined
)

.delay(0) helps though.)

[phadej]

👍 reminds me about jQuery promises, which may or may not be asynchronous...

[raimohanska]

In my opinion, if this change is to happen, it has to happen so that asynchronicity is enforced, i.e. the EventStream constructor et al themselves ensure that all replies are async. I guess this would apply to "bouncing" current values from Property.subscribe too. Not as simple as might, seem, I'd say.

edit: I think current value bouncing in Property should still be synchronous...

[Macil]

Depending how it's done, making all events be emitted asynchronously could break infinite synchronous streams like this: http://stackoverflow.com/a/27240981/1289657. Adding .delay(0) causes an infinite loop because it's never synchronously unsubscribed from. Making the .fromBinder callback be called asynchronously and then the events are emitted immediately would work in most situations (as long as it was still unsubscribed synchronously with the emitted events).

Maybe infinite synchronous streams are just a bad idea. I am the writer of that answer but I can't help but feel like it's a case of trying to hit everything with the Bacon hammer.

[raimohanska]

Sorry, infinite synchronous sequences won't work without a "backpressure" solution and that's not something that's in the radar for Bacon.js.

[skozin]

I think Highland.js may be a good fit for this and similar applications (though I haven't tried it yet). It supports backpressure and has a rich set of combinators.