As of Kotlin 1.3, this is not possible. However, it’s being considered for a future release! To help this feature get implemented, go vote on this issue: https://youtrack.jetbrains.com/issue/KT-11968 Because all proposals are basically in limbo right now, I wouldn’t hold my breath that this will get in any time soon
I don’t understand how coroutineScope and runBlocking are different here? coroutineScope looks like its blocking since it only gets to the last line when it is done. There are two separate worlds: the suspendable world (within a coroutine) and the non-suspendable one. As soon as you enter the body of runBlocking, you are in the … Read more
What is the intended meaning of “companion object”? Why is it called “companion”? First, Kotlin doesn’t use the Java concept of static members because Kotlin has its own concept of objects for describing properties and functions connected with singleton state, and Java static part of a class can be elegantly expressed in terms of singleton: … Read more
You can use the let-function like this: val a = b?.let { // If b is not null. } ?: run { // If b is null. } Note that you need to call the run function only if you need a block of code. You can remove the run-block if you only have a … Read more
sortedWith + compareBy (taking a vararg of lambdas) do the trick: val sortedList = list.sortedWith(compareBy({ it.age }, { it.name })) You can also use the somewhat more succinct callable reference syntax: val sortedList = list.sortedWith(compareBy(Person::age, Person::name))
I was able to scrape what you were looking for from this page on that same site. Even if it’s not what you want, the procedure may help someone in the future. Here is how I did that: First I opened that page Then I opened the Chrome developer tools by pressing CTRL+ SHIFT+i or … Read more
Kotlin doesn’t have raw types, you cannot just drop the type parameters. One option similar to raw types is to use star projections: abstract class Element<S : Snapshot<*>> { /* … */ } abstract class Snapshot<E : Element<*>> { /* … */ } But you won’t be able to normally work with the type parameters … Read more
Knowing the Name of Your Main Class Currently (Kotlin since M14 including up to 1.0 betas), to run a Kotlin class you are actually running a special class that is created at the file level that hold your main() and other functions that are top-level (outside of a class or interface). So if your code … Read more
Adding @Suppress(“UNCHECKED_CAST”) (also possible through IDEA’s Alt+Enter menu) to any of statement, function, class and file should help. Before: After:
For a data class, you can use the compiler-generated copy() method. Note that it will perform a shallow copy. To create a copy of a collection, use the toList() or toSet() methods, depending on the collection type you need. These methods always create a new copy of a collection; they also perform a shallow copy. … Read more