Kotlin first milestone release of version 1.4, the new version brings the following new features and key improvements:
- It will enable one of the more powerful by default a new type inference algorithm
- Contracts (Contracts) is now available for final member function
- Kotlin / JVM compiler generated type annotation for Java bytecode 8 and higher
- For Kotlin / JS new backend
- Standard library Evolutionary: deprecated cycle is completed, and discards the other member
More details can be viewed announcement: https://blog.jetbrains.com/kotlin/2020/03/kotlin-1-4-m1-released/
Related reading: Kotlin 1.4 and look forward to the future where