So long as you have structurally typed structs (as TypeScript does), you can do stuff like {foo: string} | {bar: string} to the same effect as type constructors

So long as you have structurally typed structs (as TypeScript does), you can do stuff like {foo: string} | {bar: string} to the same effect as type constructors if and when you actually need it. At the same time, how often do you really need (Just (Just (Just ...)))?