Hello, Dear List! I want to make functor of my type like newtype UserName = UserName { unName :: Text } sure, it's impossible, so I will make MonoFunctor instead of (from library mono-traversable). So, I try: instance MonoFunctor UserName where omap fn (UserName n) = UserName $ fn $ n but I get error • Couldn't match expected type ‘Element UserName’ with actual type ‘Text’ • In the second argument of ‘($)’, namely ‘unName an’ In the second argument of ‘($)’, namely ‘fn $ unName an’ In the expression: UserName $ fn $ unName an interesting is that Text "type Element Text" of "type family Element mono" (instance?). So, how to make mono-functor for such `UserName` structure? -- Best regards, Paul