> Matching on the different type constructors Terminology nitpick: Pattern matching is done on value constructors (or just "constructors", but at the intersect

> Matching on the different type constructors Terminology nitpick: Pattern matching is done on value constructors (or just "constructors", but at the intersection of FP and OOP that could be confusing). "type constructor" means something like `List` (as opposed to `List[Int]`) – a generic type that hasn't been applied to any type argument(s) yet, and will "construct" a type (like `List[int]`) when you apply it.