I view the extra scaffolding as writing unit tests. The type definitions are just a way to specify unit tests in a formal way. The compiler does the rest of u

I view the extra scaffolding as writing unit tests. The type definitions are just a way to specify unit tests in a formal way. The compiler does the rest of unit testing using the type definition, at compile time. With the correct tools a lot of the scaffolding are automated and kept to a minimum so not much is loss.