I think it depends on whether you have type inference or not. If you have type i...

seanmcdirmid · on April 13, 2020

And if you want nominal sub typing, F-bounded generics, and some inference, things get really fun.

rurban · on April 13, 2020

Nominal subtyping is trivial and unsafe. The fun starts with structural subtyping.

seanmcdirmid · on April 13, 2020

Nominal sub typing is hard from trivial and calling it unsafe is non-sensical. Structural subtyping yields poor error messages and does not support encapsulation very well, especially if you also want separate compilation.