SwitchFirst operator

[jinroh]

Is anyone working on the implementation of SwitchFirst right now ? If not I'd be happy to ! (I really need it in one of my project)

Some bikeshed I'd like to discuss before starting implementation:

• what about the name of the operator, since we dropped switchLatest in favor of switchMap (I don't think the comment from @mattpodwysocki in issue Bike-Shedding: renaming flatMap, flatMapLatest for consistency and ease of adoption #167 has been adressed). What about switchFirst and switchMapFirst to match switch and switchMap ?
• what about a concurrency parameter (see Add concurrency parameter to switch and switchMap #347) ? if so, what signature exactly ?
• is this core or kitchensink ? I'm in favor of core...

[benlesh]

I don't think anyone is working on it. I think you're right, though, the name needs work. switchFirst doesn't really describe what it's doing. I'm not sure what would though.

It subscribes to the first Observable it gets until it completes, dropping all others, then subscribes to the next one. It's almost a weird specialization of sample and merge. I've honestly never used it.

For now it could be named switchFirst and switchFirstMap... there just seems like there could be some more descriptive name or term for it.

Also, it can land in KitchenSink for now until we bikeshed what to do with it.

[benlesh]

... also for now, let's skip the concurrency parameter until that can be discussed further. I'm not against it, I just haven't thought about it.

[kwonoj]

I think this can be closed now - @jinroh , may I possibly ask if there's additional PR might be required for this issue?

[benlesh]

I don't think there is any more work to do here. If there is we can open another issue. Closing for now.