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Scala 3


Following up on the previous 'trial' we will move our existing Scala codebase to Scala 3 where possible. Some Frameworks like Play will need some time to allow us moving but for our smaller services a migration is possible.


Scala 3 is the successor of the Scala 2.x series programming language.

It's not just a small iteration on Scala 2 but a complete overhaul of the language trying to improve in several areas like:

  • Syntax
    • "quiet" syntax for control structures like if, while and for
    • optional new operator
    • Optional braces with significant-indentation syntax like in python
    • Completely revised implicits - see below
  • Contextual Abstractions focusing on intent instead of mechanics
    • Abstracting over contextual information with using
    • Providing type-class instances via given
    • direct extension method syntax extension (s: String) def pirate: String = s"$s arr!"
  • Type System improvements
    • enums
    • opaque types
    • intersection and union types
    • dependent function types
    • polymorphic function types
    • type lambdas
    • match types
  • Improvements for object oriented design
  • Completely new metaprogramming facilities while Scala 2 macros were removed

Even with these big changes Scala 3 provides a great compatibility story supporting Scala >2.13.5 libraries in Scala 3 projects and vice versa.

Although slowly we will update our existing Scala 2 codebase to Scala 3 over the next months and years to take advantage of the improvements made.