Proof of concept for Kotlin JS coroutines delay()

coroutine-delay.kt

import kotlin.coroutines.experimental.*
import kotlin.js.Date

fun main(args: Array<String>) {
    println("before launch")
    launch {
        println("hello: ${Date()}")
        delay(3000)
        println("bye: ${Date()}")
    }
    println("after launch")
}

fun launch(block: suspend () -> Unit) {
    block.startCoroutine(object : Continuation<Unit> {
        override val context = EmptyCoroutineContext
        override fun resume(value: Unit) = Unit
        override fun resumeWithException(exception: Throwable) = console.error(exception)
    })
}

suspend fun delay(ms: Long): Unit = suspendCoroutine { continuation ->
        setTimeout({
            println("timeout")
            continuation.resume(Unit)
        }, ms)
    }

//Use top level setTimeout function instead of window.setTimeout to use with node.js
external fun setTimeout(function: () -> Unit, delay: Long)

//Output example:
//before launch
//hello: Mon Nov 20 2017 16:50:02 GMT+0800 (+08)
//after launch
//timeout
//bye: Mon Nov 20 2017 16:50:05 GMT+0800 (+08)

Thanks Andrey, I wish I had found your solution sooner, that would have saved me a couple hours of headache. I couldn't figure out how to use setTimout/setInterval with suspending functions without introducing some kind of deadlock.

@pmiklos Hah, glad it helped, this is very-very old gist, from times when there was no Kotlinx.Coroutines for JS, now I think it's better to use the official implementation from kotlinx.coroutine, the biggest gain is that it would be cancelable, for now, there is no standard way to make it cancellable without kotlinx.coroutines (at least until the keep about adding cancellation APIs to stdlib will be confirmed)

wow, I completely missed that launch is included in kotlinx-coroutines-core-js. The autocomplete wasn't offering it for me so I thought it wasn't implemented or something, but now I realize it's only available inside a CoroutineScope... well, thanks again! :)