The mixin style of importing in which classes and traits are defined within traits, as seen in scala.reflect.Universe, ScalaTest, and other Scala styles, seems to be infectious. By that, I mean once you define something in a trait to be mixed in, to produce another reusable module that calls that thing, you must define another trait, and so must anyone using your module, and so on and so forth. You effectively become “trapped in the cake”. However, we can use type parameters that represen...
