Kotlin 1.4, an upgrade to JetBrains’ Java alternative, is now available as a production release. Highlights of the update include new IDE and compiler capabilities.
IDE improvements in Kotlin 1.4 include a coroutine debugger and a Kotlin Project Wizard, which creates Kotlin projects of different types. The IDE also gains 40 new quick fixes, intentions, and inspections. And thanks to IDE performance tweaks, autocomplete suggestions and content highlighting in large Kotlin files are faster.
A new compiler in Kotlin 1.4 features a more powerful type inference algorithm. There also are new JVM and JavaScript back ends, currently in an alpha mode. A hierarchical project structure in Kotlin 1.4 enables sharing of code between a subset of targets, such as similar iOS-related targets for iOS ARM64 devices. In addition, developers can use platform-dependent libraries from common code shared among several native targets.
Instructions for getting started with Kotlin can be found at kotlinlang.org. Statically typed Kotlin is positioned for the JVM, Android development, and the browser. In May 2017 Google endorsed Kotlin for the development of Android mobile apps.
Other features in Kotlin 1.4 include:
- SAM (single abstract method) conversions for Kotlin interfaces.
- An explicit API mode for library authors.
- Mixing of named and positional arguments.
- Trailing comma.
- Callable reference improvements.
- Experimental type annotations.
- Use of break and continue inside when in loops.
- Standard library improvements including new collection operators, delegated properties improvements and other capabilities, such as a double-ended queue implementation, ArrayDeque.
- Gradually eovling coroutines based on user feedback.
- The serialization library is getting closer to maturity with the release of serialization 1.0.0-RC.
- The kotlinx-datetime library and preview of the DateTime API.
- The JavaScript target for Kotlin has a new Gradle DSL and an alpha version of the Kotlin/JS IR compiler back end.
- Improved performance of Kotlin/Native compilation and execution.
- Better interoperability between Kotlin/Native and Swift/Objective-C.
- Simplified management of CocoaPods dependencies.