async_nonasync.kts

import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.async
import kotlinx.coroutines.delay
import kotlinx.coroutines.runBlocking

class Hoge
class Fuga

@ExperimentalCoroutinesApi
suspend fun hoge(): Hoge {
    println("hoge started")
    delay(200)
    println("hoge finished")
    return Hoge()
}
@ExperimentalCoroutinesApi
suspend fun fuga(): Fuga {
    println("fuga started")
    delay(100)
    println("fuga finished")
    return Fuga()
}

fun mainNonAsync()= runBlocking<Unit> {
    runCatching {
        val h =  hoge()
        val f = fuga()
        Pair(h, f)
    }
        .onSuccess { (h, f) ->
            println("$h, $f")
        }
}

fun mainAsync()= runBlocking<Unit> {
    runCatching {
        val h = async { hoge() }
        val f = async { fuga() }
        Pair(h.await(), f.await())
    }
        .onSuccess { (h, f) ->
            println("$h, $f")
        }
}

// mainNonAsync()
mainAsync()