@elizarov, How would you implement

Consumable<E>.first()

for the

Consumable

interface you propose? https://github.com/Kotlin/kotlinx.coroutines/pull/274#issuecomment-373393257

When you

consumeEach { ... }

and you don’t need any more items you just do

throw CancellationException

(or some shared instance there of). That way you cancel the upstream producer.

Ok, thanks for the answer. I figured out how to achieve it by throwing an exception. However, it makes operator writing a bit harder than it currently is. I know it's just a recent crazy idea, but thank you very much for thinking and working on this. This will be very useful.