Learning Concurrency in Kotlin

An asynchronous function with a predefined dispatcher

This brings us to the second option. We can write a function, asyncLoadNews(), that will contain the launch() inside it and return the resulting Job. This function can be called without a launch() block regardless of the thread; and by returning the Job, it's possible for the caller to cancel it:

private fun asyncLoadNews() = launch(dispatcher) {  val headlines = fetchRssHeadlines()  val newsCount = findViewById<TextView>(R.id.newsCount)  launch(UI) {    newsCount.text = "Found ${headlines.size} News"  }}

By stipulating the signature of a function as fun asyncDo() = launch {...}, not only are we making the whole function run inside a coroutine but we are also having it return the Job created ...