Unresolved reference: launch

Question

Trying to run some examples for Kotlin coroutines, but can't build my project. I'm using the latest gradle release - 4.1

Any suggestions what to check/fix?

Here is build.gradle

buildscript {     ext.kotlin_version = '1.1.4-3'      repositories {         mavenCentral()     }      dependencies {         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"     } }  apply plugin: 'kotlin' apply plugin: 'application'  kotlin {     repositories {         jcenter()     }      experimental {         coroutines 'enable'     }      dependencies {         compile "org.jetbrains.kotlinx:kotlinx-coroutines-core:0.18"     } } 

and the main.kt

fun main(args: Array<String>) {     launch (CommonPool) {         delay(1000L)         println("World!")     }      println("Hello, ")     Thread.sleep(2000L) } 

when I run gradle compileKotlin I get the following

e: /Users/philippgrigoryev/projects/kotlin-coroutines/src/main/kotlin/main.kt: (2, 5): Unresolved reference: launch e: /Users/philippgrigoryev/projects/kotlin-coroutines/src/main/kotlin/main.kt: (2, 13): Unresolved reference: CommonPool e: /Users/philippgrigoryev/projects/kotlin-coroutines/src/main/kotlin/main.kt: (3, 9): Unresolved reference: delay` 

Answer 1

Launch isn't used anymore directly. The Kotlin documentation suggests using:

fun main() {      GlobalScope.launch { // launch a new coroutine in background and continue         delay(1000L)         println("World!")     }     println("Hello,") // main thread continues here immediately     runBlocking {     // but this expression blocks the main thread         delay(2000L)  // ... while we delay for 2 seconds to keep JVM alive     }  }