debounce/throttle operator that always emits the last value

[NachoSoto]

I just found myself needing such an operator. I have a SignalProducer<[Data], NoError> created with this custom operator:

public func collectIncrementally() -> Signal<[Value], Error> {
    return self
        .map { [$0] }
        .scan([], +)
}

I want to limit how often I get updated arrays, but I do want to make sure that the last value (which will contain all the elements), is always emitted.

[NachoSoto]

Actually I misread the documentation, but I'm still not 100% sure either debounce or throttle will behave this way, so I guess this is a question now, not a feature request :P

[NachoSoto]

Yeah, it does look like if the source signal terminates before the given interval, no more cached values are emitted. This is not documented, and I'm not sure if it's desired behavior. Either way, it would be nice to have an operator that doesn't behave this way.
I looked at Rx's versions and they don't seem to have this either.

[andersio]

It was documented before the revision. Guess we should put it back, alongside an option. A discardsWhenTerminated parameter with a default of true, perhaps?

5f7109d#diff-09166f905ad1f830ac2dc91f2663c1a5L1728

[NachoSoto]

Guess we should put it back, alongside an option. A discardsWhenTerminated parameter with a default of true, perhaps?

That makes sense to me 👍 Or maybe discardValuesAfterTermination.

[Qata]

@andersio Would it be welcome if I picked up this issue and created an implementation?

[andersio]

@Qata Sure. 👍

[RuiAAPeres]

Hello. 👋 Thanks for opening this issue. Due to inactivity, we will soft close the issue. If you feel that it should remain open, please let us know. 😄