When Life Gives You Java

With sufficient effort it’s possible to use almost any language like it’s Haskell!

This post scratches the surface. I can’t say I really disagree with much. I have written a fair amount of Java code in a pretty straightforward functional (wishy washy ish) style. If you can use the latest versions (bonus points for preview features), you will have a much better time at it: @FunctionalInterface(s), higher order functions (Producer, Callable, Supplier, Function, etc…), small compact types, sealed classes, records, switch statements, etc… These all play a part. The key is that you have to enforce a style across your codebase. Of course mixing in libraries like Vavr helps a lot as well.

How to bend a horse into a balloon.

This misses my favorite tool when writing Java: anonymous implementation of interfaces. On one side you write API’s that accept interfaces, on the other you conjure up the exact behavior you need right where you’re calling the API.