ZIO VS scalajs-react

I use ZIO (http://zio.dev) for Scala which makes parallel programming trivial.

Wraps different styles of asynchronicity e.g. callbacks, futures, fibers into one coherent model. And has excellent resource management so you can be sure that when you are forking a task that it will always clean up after itself.

Have yet to see anything that comes close whilst still being practical i.e. you can leverage the very large ecosystem of Java libraries.

The one advantage Rust has over Scala is that it detects data races at compile time, and that's a big time saver if you use low level thread synchronization. However, if you write pure FP code with ZIO or Cats Effect that's basically a non-issue anyway.

> It's a weakness of functional programming, not the language.

I would strongly object this.

Have you seen ZIO?

https://zio.dev/

But overall, I'm happier with Scala. It has not one, but two lively FP communities. I recommend that you pick one of them: ZIO or TypeLevel (Cats Effect, fs2, http4s, ...). To some extent, you can mix TypeLevel libraries in ZIO projects.

I think "better Haskell on JVM" (in contrast to "worse Haskell") is a good identity for Scala to have. (Please note that this is an intentional hyperbole.)

Of course, there are areas where Haskell is stronger than Scala (hint: modularity, crucial for good Software Engineering, is not one of them). And Scala has its own way of doing things, so just imitating Haskell won't work well.

Examples of this "better Haskell" are https://typelevel.org/cats-effect/ and https://zio.dev/ .

All together, Scala may be a better choice for you if you want to do Pure Functional Programming. And is definitely less risky (runs on JVM, Java libraries interop, IntelliJ, easy debugging, etc...).

None of the other languages you mentioned are viable in this sense (if also you want a powerful type system, which rules out Clojure).

I agree that Rust's identity is pretty clear: a modern language for use cases where only C or C++ could have been used before.

I would use Scala. I like FP and Scala comes with some awesome libraries for concurrent/async programming like Cats Effect or ZIO. Good choice for creating modern style micro-services to be run in the cloud (or even macro-services, Scala has a powerful module system, so it's made to handle large codebases).

https://typelevel.org/cats-effect/

https://zio.dev/

The language, the community and customs are great. You don't have to worry about nulls, things are immutable by default, domain modelling with ADTs and patter matching is pure joy.

The tooling available is from good to great and Scala is big enough that there are good libraries for typical if not vast majority of stuff and Java libs as a reliable fallback.

I actually think Scala is in the best position it's ever been.

There is a commitment to making the language simpler, easier and cleaner.

On the backend, ZIO [1] is the best concurrency library on any platform. On the frontend you have really interesting Scala.js projects like Laminar [2].

The biggest issue really is the tooling. SBT is simply awful.

[1] https://zio.dev

Scala? With some help from additional libs such as Zio (https://zio.dev/) it allows you to write production quality programs like you would in Haskell on top of the JVM quite quickly...

Then there's scalajs-react, which can be integrated with existing React ecosystem, but it's just sooo compex: macros, 5-6 type parameters, hundreds and hundreds of cryptic types. We decided to stick with TypeScript instead.

Or the OG React Scala.js library: https://github.com/japgolly/scalajs-react

I've started with scalajs-react. Overall the experience was good (perhaps the overloaded API is my biggest concern, but we can live with that). Then I stumbled upon a problem where I need to propagate a state change from two leaf components and found out I need something like this Redux thing. I trtied built-in StateSnapshot, but couldn't make it working. Then I googled for Scala-land alternatives and it seems like there are few semi-abandoned Redux facades and Diode. Diode looks like what I need, but:

Event ho it's a React wrapper it's still a really good one: https://github.com/japgolly/scalajs-react

The downside of this approach is the ecosystem isn't that big compared to JS.

Japgolly has put a ton of time and care into https://github.com/japgolly/scalajs-react which is a complete React binding in scalajs. This paired with something like Diode (https://github.com/suzaku-io/diode) and you get a full frontend solution in scalajs.

We've got server-side rendering with scalajs-react and scala-graal. Here's a tutorial if anyone's interested. What's really cool about scala-graal is that it has some pretty cool caching so that even with dynamic inputs, you can render pages in nanoseconds (as opposed to 10+ or even 100+ ms).

You can use React with Scala.js, and also most other common JS libraries. Or you can use a Scala.js specific library like Laminar, which I haven't tried myself but it looks nice.

I don't have a lot of experience with it, but many seem to be very pleased with it. Interop with JS is good and you can use React and other common JS libraries, but there is also Scala.js specific frameworks like Laminar.