Idiomatic way to add Coroutine scope to a function...

# coroutines

[rocketraman]

Idiomatic way to add Coroutine scope to a function that is already an extension function of something else? Take it as a parameter?

[elizarov]

Can you give an example?

[elizarov]

(with some background on how this comes to be)

[rocketraman]

@elizarov I have a utility function like this:

suspend fun Flowable<ByteBuffer>.toByteReadChannel(scope: CoroutineScope) = scope.writer(scope.coroutineContext, autoFlush = true) {
  try {
    [e-mail] {
      channel.writeFully(it)
    }
  } catch (e: Throwable) {
    channel.close(e)
  }
}.channel

Note here I have explicitly passed scope, since its already an extension of Flowable<ByteBuffer>. Is there a better approach?

[rocketraman]

I also have the opposite toFlowable function, implemented like this:

suspend fun DataChannelProvider.toFlowable(scope: CoroutineScope): Flowable<ByteBuffer> = scope.rxFlowable(Dispatchers.Default) {
  this@toFlowable().lookAheadSuspend {
    consumeEachRemaining {
      // we have to make a copy as the ByteBuffer here comes from a reused ring buffer
      [e-mail](it.copy())
      true
    }
  }
}

[Zach Klippenstein (he/him) [MOD]]

Since your function is already a suspend function, you can use coroutineContext to get the scope from the current coroutine.

suspend fun Flowable<ByteBuffer>.toByteReadChannel() = coroutineContext {
  writer(…

[rocketraman]

I think you meant coroutineScope { ... } but otherwise, ah, thank you @Zach Klippenstein (he/him) [MOD]

[rocketraman]

FYI @Zach Klippenstein (he/him) [MOD] this didn't work... see the recent thread in #coroutines ...