I am not sure that Kotlin competes with Scala in any way. They are trying to remove the pain from Java by providing a concise and safe language (see the quotes from their website below). What are "all the things" they reinvented that were discard in Scala?

> Kotlin is a pragmatic programming language for JVM and Android that combines OO and functional features and is focused on interoperability, safety, clarity and tooling support.

> Being a general-purpose language, Kotlin works everywhere where Java works: server-side applications, mobile applications (Android), desktop applications.

> What are "all the things" they reinvented that were discard in Scala?

Extension methods, properties, special syntax for everything, final by default, short constructor syntax, trying to put band-aid around Java's broken collection types, ...

I'd love to learn more about Java's broken collection types. What's broken about them?

The pattern of throwing exceptions for operations deemed "unsupported", an API that requires massive workarounds to keep alive in Java 10, no support for immutable collections, unmodifiable views are a complete clusterfuck, no persistent collections etc.

Thank you. I appreciate the list.

Kotlin competes with Scala in that they are both alternatives to Java.

Every single description of Kotlin in your comment could just as easily be describing Scala.

At least they care about 1st class support on Android Studio, instead of InteliJ + sbt + missing support from Android tooling.

If you feel that something is missing people would likely be happy to receive bug reports/feature requests.

They are full aware of it:

"Android Studio should currently not be used for development with sbt and Scala. Chances are, however, that it's a good fit for a Gradle + Scala setup."

http://scala-on-android.taig.io/editor/android-studio/

Using InteliJ instead of Android Studio means not being able to use the latest tooling even from the stable version, as InteliJ is always some versions behind.

Using Gradle + Scala implies a few configuration steps that tend to break at each new Android Studio release, versus the out of the box experience from Kotlin.

I have never seen this documentation and it seems to be wildly outdated.

Which issues did you experience with Android Studio?

No out of the box integration even for basic stuff.

I expect no more hurdles than just using Java official Android tools.