For a channel what is the opposite of a flatMap, in other words how to take a channel of some array and start sending the values individually?

Are you saying

Channel<Array<T>>

and flatten it to

Channel<T>

?

yes exactly

I edited the example from https://kotlinlang.org/docs/reference/coroutines/channels.html#pipelines

fun <T> CoroutineScope.flatten(channel: ReceiveChannel<Array<T>>): ReceiveChannel<T> = produce {
    for (items in channel) {
        for(item in items) send(item)
    }
}

However there could be something already that i don't know...

cool thanks!

If you're going to do other operators, you should consider using a

Flow

val myChannel = channel
    .consumeAsFlow()
    .flatMapConcat { it.asFlow() }
    .filter { ... }
    .map { ... }
    .produceIn(myScope)

very nice. Also https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.channels/flat-map.html suggests that it's deprecated in favor of

flow