Also, is there any alternative?

# coroutines

[louiscad]

Also, is there any alternative?

[elizarov]

fun <T> ReceiveChannel<T>.onEach(block: (T) -> Unit): ReceiveChannel<T> =
    produce(onCompletion = consumes()) {
        for (it in this@onEach) {
            block(it)
            send(it)
        }
    }

[louiscad]

That doesn't explain my previous question: Why it's not there? Should I submit a PR?

[elizarov]

TooManyChannelsException. We’d like to redo all existing operators via cold streams first, then go on to expand repertoire of operators.

[elizarov]

It’s kind of a waste to simply move elements between two channels, all for the pleasure of peeking at them via onEach.

[louiscad]

I see. My small use case was scanning for a Bluetooth Low Energy device, expecting only one close by, and showing meaningful errors if it's not close enough, or more than one device is close.
It was so complex adding a few other requirements that I finally gave up doing the complex filtering while the channel is receiving values, and just cancel the channel after a short duration, to then work on a list.
I'll see if I can improve it to fail faster by using the new broadcast() function, and having one subscription channel per requirement.