Using pipeline pattern with Kotlin channels

pipeline.kt

package app

import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.channels.consumeEach
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking


fun main() = runBlocking {
    sq(gen(listOf(1, 2, 3, 4, 5))).consumeEach { println(it) }
}

private fun CoroutineScope.gen(nums: List<Int>): Channel<Int> {
    val out = Channel<Int>()
    launch {
        nums.forEach { out.send(it) }
        out.close()
    }
    return out
}

private fun CoroutineScope.sq(input: Channel<Int>): Channel<Int> {
    val out = Channel<Int>()
    launch {
        input.consumeEach { out.send(it * it) }
        out.close()
    }
    return out
}