ParallelMap.kt

import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.async
import kotlinx.coroutines.awaitAll
import kotlinx.coroutines.withContext

suspend fun <A, B> Iterable<A>.pmap(
    f: suspend (A) -> B,
): List<B> = withContext(Dispatchers.IO) {
    map { async { f(it) } }.awaitAll()
}

// Usage:
fun main() = runBlocking {
  listOf(1, 2, 3).pmap { /* async stuff to process */ }
}