scastie VS tour-of-scala

From personal experience Scala also works. It's 100% possible to learn monads using https://scastie.scala-lang.org/ as a scratch pad.

Instead I typically use https://scastie.scala-lang.org, or an ammonite script, or just create a new file that extends App in my test directory. The thing that worksheets do better is that you can import things from your project (like the little app in the test dir) but they also show runtime values (like repl or scastie). However I've just never gotten them to actually work.

I strongly recommend you play around with the local Scala REPL. I have Scala 2.13 on my main dev computer and Scala 3 on my other computer. The local REPL will let you know when things are deprecated and give you hints as to what you should use instead. Scastie https://scastie.scala-lang.org/ can also be a big help.

Operationally, as you might expect from a language borne from academia, Scala tooling can be problematic and compilation can be slow--particularly if you are not yet using Scala 3, which only recently emerged and is very slowly percolating through the ecosystem (Remember the Python 2 to Python 3 transition?). But type inference, a vast standard library, and the time-tested reliability of the JVM make you very productive once you get the hang of them. Performance varies with the JVM you're running, but regardless you do have to contend with the size of compiled objects and the latency of garbage collection at runtime. When you want to experiment, you can skip the ceremony of writing a class or test and instead use a command-line REPL, an online REPL called Scastie you can share, or an outstanding third-party command-line REPL called Ammonite. Dependency management is achieved with SBT typically but also more general JVM build tools like Gradle and Maven.

I am using https://scastie.scala-lang.org/ which does compile server side in Scala. The UI is a bit hard to handle tho.

https://github.com/scalacenter/scastie#how-do-i-embed-scastie

Until now, the Tour of Scala repo has always been open source (https://github.com/leobenkel/tour-of-scala) but only regarding the design. The articles were hosted on my own website and just displayed differently on Tour of Scala but not editable by anyone.

Yes, I made a MVP. And that is true that mobile was not my focus. The platform is open source. I'd be happy to see if you come up with a good UI for mobile screen :) https://github.com/leobenkel/tour-of-scala