v1.7.0
What's New
Kotlin 1.7.0 introduces the K2/JVM compiler in Alpha, delivering 15%+ compilation time improvements and new definitely non-null types for enhanced null safety. The release includes functional interface constructor references, IR partial linkage for Kotlin/Native, and removes JVM 1.6 support. Extensive bug fixes address type inference, coroutine handling, and platform-specific issues across JVM, Native, and JavaScript targets.
Highlights
- K2/JVM compiler released in Alpha with significant performance improvements
- Definitely non-null types (T&Any) support for safer null handling
- Functional interface constructor references now supported
- Extensive performance optimizations reducing compilation time by 15%+
- IR partial linkage support for Kotlin/Native
- JVM target version 1.6 removed, minimum now 1.8
Breaking Changes
- JVM target version 1.6 no longer supported, minimum target is now 1.8
- Functional interface constructor references require explicit opt-in or compiler flag
- Safe calls now always return nullable types
- Stricter type inference for generic constraints and lambda expressions
Deprecations
- Computing constant values of complex boolean expressions in when conditions
- Non-exhaustive if and when expressions in elvis operator right-hand side
- Contravariant usages of star projected arguments from Java
Recent Releases
All releases →
v1.9.0
Jul 6, 2023
Release Notes →
v1.8.22
Jun 8, 2023
Release Notes →
v1.8.21
Apr 25, 2023
Release Notes →
v1.8.20
Apr 3, 2023
Release Notes →
v1.8.10
Feb 2, 2023
Release Notes →
v1.8.0
Dec 28, 2022
Release Notes →
v1.7.22
Nov 28, 2022
Release Notes →
v1.7.21
Nov 9, 2022
Release Notes →
v1.7.20
Sep 29, 2022
Release Notes →
v1.7.10
Jul 8, 2022
Release Notes →
v1.7.0
Jun 9, 2022
Release Notes →