kotlinx-coroutines-core/jvm/test/guide/example-channel-05.kt

/*
 * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
 */

// This file was automatically generated from channels.md by Knit tool. Do not edit.
package kotlinx.coroutines.guide.exampleChannel05

import kotlinx.coroutines.*
import kotlinx.coroutines.channels.*

fun main() = runBlocking {
    var cur = numbersFrom(2)
    repeat(10) {
        val prime = cur.receive()
        println(prime)
        cur = filter(cur, prime)
    }
    coroutineContext.cancelChildren() // cancel all children to let main finish
}

fun CoroutineScope.numbersFrom(start: Int) = produce<Int> {
    var x = start
    while (true) send(x++) // infinite stream of integers from start
}

fun CoroutineScope.filter(numbers: ReceiveChannel<Int>, prime: Int) = produce<Int> {
    for (x in numbers) if (x % prime != 0) send(x)
}