Metals VS ZIO

Links: - https://dotty.epfl.ch/ - https://scala-native.org/en/stable/ - https://www.scala-js.org/ - https://typelevel.org/ - https://zio.dev/ - https://github.com/scala-native/scala-native/pull/3120 - https://github.com/lampepfl/dotty/pull/16517 - https://dotty.epfl.ch/docs/reference/experimental/index.html - https://scala-cli.virtuslab.org/ - https://scalameta.org/metals/ - https://docs.scala-lang.org/scala3/guides/migration/compatibility-intro.html - https://www.scala-lang.org/blog/2023/04/18/faster-scalajs-development-with-frontend-tooling.html - https://www.scala-lang.org/blog/2022/08/17/long-term-compatibility-plans.html

You might want to look at Scala, they have proper LSP support with metals which means you can write your code in vscode, neovim, emacs, or even fleet (the new jetbrains text editor).

Please write in the comments if you know of any language servers I should test it with. Currently I tested only metals and rust-analyzer.

If you are using nvim-lspconfig you can pass the settings as a Lua table to the setup function. For example, here are may metals settings:

Bazel support in Metals. I didn't spend all that time figuring out and adjusting Emacs/Spacemacs and making my workflow (almost) mouse-free just to scrap my config and switch to IDEA's rodent infested ways.

There is one small issue involving code completion returning inappropriate completions in some cases; https://github.com/scalameta/metals/pull/4414 will fix it, once it's included in a release. Perhaps that's the PR you saw?

It is, by quite a bit.

While the "Scala IDE" project is dead for all practical purposes, IntelliJ IDEA's Scala plugin is actually pretty amazing. There's also a VisualStudio plugin that does pretty much the same and is advancing by leaps and bounds. There are also interconnecting projects that provide i.e. language server or build server that are reused by other projects. It's pretty modular. Metals (https://scalameta.org/metals/) is amazing.

In general the language has become a wee bit faster to build, there was good progress with build times during the 2.12/2.13 cycles.

With Scala3 the language got a bit simpler; concepts that were implemented explicitly using (hehe) implicits got their own keywords and a lot of the opinionated boilercode that cause a lot of debates is now generated during complication and hidden. A lot of "standardization" has occurred.

IntelliJ has its own BSP. The other one is Metals. You can use it with many IDEs (vim, emacs, vscode, atom,...). Use it with emacs if you're comfortable with it.

scala has 2 healthy and pretty complete lib ecosystems : check out typelevel and ZIO. Both are FP oriented, which might not be your cup of tea at first glance but I would encourage you to try em out ! Softest introduction would be to start with the typelevel cats library and build up from there. The excellent Scala with Cats will ease you softly into an FP mindset. It's a bit dated and for scala 2 only but translating to Scala 3 is a very good exercise if you feel so inclined !

Last but not least, Scala is currently the language with one of the best effect systems in my opinion (https://zio.dev/). Kotlin for example has copied the approach with https://arrow-kt.io/ which I think is great actually. But when comparing Scala and Kotlin here, Scala wins by a large margin, it is a completely different world. It's like building a highly concurrent system in Erlang vs C.

Of course, if you don't want to learn things like union types, traits/typeclasses and effects (similar to async/await but more powerful) you will be annoyed by Scala. But once you learned them, you can never go back.

ZIO

Links: - https://dotty.epfl.ch/ - https://scala-native.org/en/stable/ - https://www.scala-js.org/ - https://typelevel.org/ - https://zio.dev/ - https://github.com/scala-native/scala-native/pull/3120 - https://github.com/lampepfl/dotty/pull/16517 - https://dotty.epfl.ch/docs/reference/experimental/index.html - https://scala-cli.virtuslab.org/ - https://scalameta.org/metals/ - https://docs.scala-lang.org/scala3/guides/migration/compatibility-intro.html - https://www.scala-lang.org/blog/2023/04/18/faster-scalajs-development-with-frontend-tooling.html - https://www.scala-lang.org/blog/2022/08/17/long-term-compatibility-plans.html

For the Rx approach, The ZIO framework for Scala has a streaming API that can meet those sorts of requirements. e.g.

This tutorial will introduce how to build from scratch, a REST microservice using the ZIO framework, and examples of ZIO dependency injection, ZIO HTTP, JSON, JDBC, and others from the ZIO environment. The source code is available here

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.