[tadfisher]

Exceptions aren't normal parts of the type system though, they're a way to enforce control flow to deal with them. Another way to do this is with a Result type, which would actually be part of the same type system that you use in the rest of the language.

[MrJohz]

Why can't they be part of the type system? Rust is a good example of a case where they are part of the type system (albeit in a more monadic form). You've also got typed effects, where effects are essentially a generalised form of exception.