ZIO VS Ammonite-Ops

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.

The indent based syntax is only available in Scala 3, you have to download a matching ammonite version from https://github.com/com-lihaoyi/Ammonite/releases

That's funny, because this is what I really like about Scala; how quick and easy it is to get a project started.

> sbt new scala/scala3.g8

will just create an empty project. If you don't even want to bother with a project, use use scala-cli or ammonite (http://ammonite.io/) to just start banging out code.

Even the upgrading of a project from Scala2 to Scala3 is a breeze, thanks to very good backwards compatibility of new library releases.

Ammonite is a very good REPL for Scala. You can invoke it with amm and type expressions into it, or load a Scala “script file” whose name ends with .sc into it, or many other things. It’s documented at https://ammonite.io. 2. sbt is the dominant build tool for Scala projects. As others have commented, when you open a folder in Visual Studio Code and try to make Metals “aware of it,” it expects to find a “Scala project” in the folder. A “Scala project” isn’t just Scala source code. See https://www.scala-sbt.org for details. 3. Also be aware that Metals supports worksheets, so you can easily experiment with code in your project interactively, too.

Scripting API is quite limited, so the third option. - reuse the ammonite scripts https://github.com/com-lihaoyi/Ammonite or look how this is implemented (using internal compiler API),

Your exposure to Functional Programming with Haskell and Clojure suggest you will certainly pick up Scala quickly. With ZIO and cats, you can write robust software quickly. Consider the excellent Coursera Scala course. Get "the Red Book" https://www.manning.com/books/functional-programming-in-scala, and most important, play. Experiment to see how things work. Get https://ammonite.io/

Here's an example of a smaller project that added telemetry without suffering a fork:

https://github.com/com-lihaoyi/Ammonite/issues/607

Or ammonite - I've ran Gatling performance test from a simple script based on this gist it fetches all the dependencies, compiles and runs the test, producing nice html report..

Scala with the Typelevel ecosystem. Stay on the jVM, but have a much more pleasant and robust experience, including a great REPL.