Lean Scala (from Martin Odersky)

Last year, I post a snippet for a thread discussed about current scala situation. And after multiple releases and pretty good progressive adaption of scala 3, Martin Odersky, the creator of Scala, declares his thoughts¹ about the future of Scala. Although if you're active in the Scala community, Martin has been talking about this for a while, it's still worth to follow/read. It's more like a formal manifesto.

What is Lean Scala? Here are some key points:

• It should follow the Principle of Least Power.
  • Try to use the least powerful features first, only introduce black magic tricks when they are really needed.
• It should be immutable first, without being dogmatic about it.
  • As it says, prefer immutable data and pure functions, allow effects which are well contained and described. Scala team also plans to introduce Capturing Types to help with this.
• It should promote the core language over embedded DSLs.
  • Distinguish Lean Scala from "Scala as a host language for DSLs".
• It should focus on direct style.
  • Follow the last principle, Lean Scala should be direct and explicit. And

  • Monadic effect systems shine in some areas but they are also a kind of DSL, which creates specialized eco-systems and dialects.

Lean Scala looks like a good direction for Scala, especially for the new users outside from FP world. Easy to learn, easy to use, easy to maintain would make a language live longer 🥹 and be adapted by more real cases.

Then how could we promote Lean Scala? Martin suggests: 1. Write technical documentation; 2. Work on tooling support; 3. Encourage efforts to assemble and promote library stacks. Every language won't be prosperous without its community and eco-system.

For me, I'm still a fan of Scala, and I'm glad to see the progress of Scala 3 which I thought is really underrated.