kotlinx.coroutines

Library support for Kotlin coroutines with multiplatform support This is a companion version for Kotlin 1.3.61 release.

suspend fun main() = coroutineScope {
    launch {
       delay(1000)
       println("Kotlin Coroutines World!")
    }
    println("Hello")
}

Play with coroutines online here

Modules

core — common coroutines across all platforms
- launch and async coroutine builders returning Job and Deferred light-weight futures with cancellation support;
- Dispatchers object with Main dispatcher for Android/Swing/JavaFx, and Default dispatcher for background coroutines;
- delay and yield top-level suspending functions;
- Flow — cold asynchronous stream with flow builder and comprehensive operator set (filter, map, etc);
- Channel, Mutex, and Semaphore communication and synchronization primitives;
- coroutineScope, supervisorScope, withContext, and withTimeout scope builders;
- MainScope() for Android and UI applications;
- SupervisorJob() and CoroutineExceptionHandler for supervision of coroutines hierarchies;
- select expression support and more.
core/jvm…

Discussion on: async/await Crash Course

View post

Jean-Michel 🕵🏻‍♂️ Fayard • Feb 22 '20 • Edited

async/await is a big step forward for JavaScript

It still have a problem common with Promise is that you may launch your promise and forget to "await" or ".then()" it, and then you have still done your side effect but didn't wait for it. Of course you may say that it's the programmer who is stupid for doing a simple mistake, but in my opinion when thousands of programmers do the same mistake, it's the designer of the library that did one.

In Kotlin, coroutines have solved this:

suspending functions are awaiting by default, you don't need to await explicitely
Flow give you cold asynchronous streams - like in reactive sterams / RxJs / RxJava - while Promise and async/await are hot