The server world has moved to containers. And rightfully so: they isolate application concerns, they unify deployment, they are easy to host, and they make big complex systems like Kubernetes possible. Unfortunately, Java has been slow to adapt to the container world. Thankfully, tools are starting to become prevalent that make Java in containers easy and effective. Distroless and Jib are two of those tools.
Something that has always been a bit of a limitation in the Java numeric type system is the lack of support for unsigned integers. It is not particularly common to have to work with unsigned types, but when it does happen, it’s usually unpleasant in some way. Libraries like Guava have provided utilities to make it cleaner, and recent updates to Java 8 also included some unsigned helper methods.
Kotlin 1.3 has an experimental feature to make unsigned types a full citizen of the type system, while still having all of the performance of primitive integer types. Let’s take a look!
With Kotlin 1.3, a new experimental feature called “Inline Classes” is now available. This post is a somewhat deep dive into the nature of the implementation, how it works, where the edges are, and what limitations currently exist. Let’s take a look!
Kotlin has an annotation called @JvmDefault which, like most of the “Jvm” prefixed annotations, exists to help massage the Kotlin compiler output to match Java classes in a certain way. This annotation was added in 1.2.40, and has now seen some experimental enhancements in 1.2.50, so it seems worth exploring what this is all about.