scala VS rust

I’ve been a web developer for years, but I haven’t touched Java in a long time — like, late-90s long. Back then, Java development felt cumbersome: lots of boilerplate and complex configurations. It was not exactly a pleasant experience for building simple web apps. So when I recently started exploring Scala and the Play Framework, I was curious more than anything. Has the Java developer experience gotten better? Is it actually something I’d want to use today?

Scala

Elm, ReScript, F#, Ocaml, Scala… it’s just normal to name your types, then use them places. In fact, you’ll often create the types _before_ the code, even if you’re not really practicing DDD (Domain Driven Design). Yes, you’ll do many after the fact when doing functions, or you start testing things and decide to change your design, and make new types. Either way, it’s just “the norm”. You then do the other norms like “name your function” and “name your variables”. I’m a bit confused why it’s only 2 out of 3 (variables and functions, not types) in this TypeScript Angular project. I’ll have to look at other internal Angular projects and see if it’s common there as well.

Scala is a programming language for the JVM born in 2004 that is both object oriented and functional. Since it runs in the JVM it can call any Java method and be called by any Java method. So, moving from Java to Scala is practically pain free, all you have to do is learn the new syntax. You have all the Java libraries at your disposal plus all the improvements Scala has to offer. Even though Scala is both OOP and Functional it doesn't force you to use either of the two paradigms and so it can just be used as a simple OOP replacement for Java with great benefits to speed of coding and readability. In this article I will not get into the details but just show you enough to make you curious and try it. If you want to dive deeper here is a link for you: https://www.scala-lang.org

Funnily enough this is (was?) used by the Scala collection library's TreeSet/TreeMap, for fast performance of the `take` and `drop` operations. This is a red-black tree though, not a B-Tree.

Commit https://github.com/scala/scala/pull/82/commits/b7e671446892c... of PR https://github.com/scala/scala/pull/82

Recently I had to revisit the "JVM languages universe" again. Yes, language(s), plural! Java isn't the only language that uses the JVM. I previously used Scala, which is a JVM language, to use Apache Spark for Data Engineering workloads, but this is for another post 😉.

8. Scala - $96,381

Scala

Big Scala vibes here, see also [1].

1: https://github.com/scala/scala/blob/v2.13.11/src/library/sca...

For details, refer to the release notes on GitHub: * https://github.com/scala/scala/releases/tag/v2.13.11 * https://github.com/scala/scala/releases/tag/v2.12.18

Rust development is experiencing major growth in 2025 as its developers continue to focus more on performance, memory safety, and reliability of their code. Supported by a powerful compiler, with modern tooling and an emerging ecosystem, Rust is an alternative to the majority of the limitations of legacy systems programming languages. This blog discusses the theoretical basis behind the transition to Rust-based development and the reasons why it is rapidly growing as an attractive option to software engineers and organizations.

https://www.rust-lang.org/ https://doc.rust-lang.org/cargo/ https://doc.rust-lang.org/cargo/getting-started/installation.html

I am very sorry, but you do not address that TBAA, like C has by default, generally is easier than just no aliasing, like what Rust has for mutable references. This is a major difference. C code can opt into a similar kind of aliasing, namely by using _restrict_, but that is opt-in, while it is always on for Rust.

And there is newer UB as well in Rust stdlib

https://github.com/rust-lang/rust/pull/139553

Real-world programs can be verified by formally proving properties on a small part of the code (called the kernel) in a way that transitively guarantees those for the remaining code.

For example, Rust's borrow checker guarantees* memory safety of any code written in Rust, even a 10M+ LOC project. Another example is sel4, a formally-verified micro-kernel (https://sel4.systems/About/seL4-whitepaper.pdf).

* Technically not; even if the code doesn't use `unsafe`, not only is Rust's borrow checker not formally verified, there are soundness holes (https://github.com/rust-lang/rust/issues?q=is%3Aopen%20is%3A...). However, in theory it's possible to formally prove that a subset of Rust can only encode memory-safe programs, and in practice Rust's borrow checker is so effective that a 10M+ LOC project without unsafe will still probably not have memory issues.

Backend: Rust

What's weird about this?

To understand what evil_lincoln is doing, you have to understand very old Rust. Here's the commit that introduced it: https://github.com/rust-lang/rust/commit/664b0ad3fcead4fe4d2...

    fn evil_lincoln() {

Side note: There's an effort to cache proc macro invocations so that they get executed only once if the item they annotate hasn't changed: https://github.com/rust-lang/rust/pull/129102

There are multiple caveats on providing this to users (we can't assume that macro invocations are idempotent, so the new behavior would have to be opt in, and this only benefits incremental compilation), but it's in our radar.

Rust: Install it from the official Rust website.