How to validate string format with scala in compile time

Question

My function has 1 parameter and type is string but lenght is 4, Can I validate this parameter in compile time?

In haskell and F# have type level and it can validation in compile time, like nonEmptyList.

How to make it in scala. I think shapless can do this but I don't understand

Thank you for advance suggestion

Answer 1

Yes, Shapeless can do this. Perhaps something like this:

def f(s: Sized[IndexedSeq[Char], Nat._4]): ...

You wouldn't be able to pass strings directly to this, though. You'd have to do something like f(Sized('a', 'b', 'c', 'd'))