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.