If I have a `ReceiveChannel`, is there a way for me to turn it into a `Flow`?

# coroutines

[spierce7]

If I have a ReceiveChannel, is there a way for me to turn it into a Flow?

[octylFractal]

flow(block) can probably still work:

val flowFromChan = flow { 
  recvChan.consumeEach(this::emit)
}

[octylFractal]

ref: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/flow.html
https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.channels/consume-each.html

[octylFractal]

hmm, though I guess consumeEach is deprecated

[octylFractal]

not sure if they're still planning to drop it

[octylFractal]

see https://github.com/Kotlin/kotlinx.coroutines/issues/632 for info on that

[bdawg.io]

Isn’t there a simple ReceiveChannel<T>.asFlow(): Flow<T> extension?

[bdawg.io]

Ahh it appears to be for BroadcastChannel<T> instead of simply ReceiveChannel<T> (probably because flow can’t manage the lifecycle of any sort of subscription unless it uses broadcast subscriptions)
https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/as-flow.html

[octylFractal]

yes, that's why I didn't suggest it

[Vsevolod Tolstopyatov [JB]]

flow { 
  recvChan.consumeEach(this::emit)
}

is an option, yes.

We do not provide such extension on ReceiveChannel because it is not cold (e.g. second collect call to such flow will emit zero items) and does not play well with flow semantics.

We are currently thinking of alternatives (e.g. some kind of subjects), so feel free to create an issue with your use-case and desired solution

[dewildte]

Receive can be broadcast and then the broadcast can be flowed.

[dewildte]

Not sure if it's a good idea but it's a thing