That's not really how most type systems work. Take array access. The typical typing is: if you have an `Array[A]` and reference an `Int` index you get an elemen

That's not really how most type systems work. Take array access. The typical typing is: if you have an `Array[A]` and reference an `Int` index you get an element of type `A`. ref: Array[A] Int => A This says nothing about what happens if you access an out of bounds element. In a memory safe language this is enforced by a runtime check. Without memory safety you get YOLO semantics like in C.