> `sumOf (folded . folded)` does have some advantages in working for lists of other types but I question how often you would reuse such a function for differen

> `sumOf (folded . folded)` does have some advantages in working for lists of other types but I question how often you would reuse such a function for different types the first place. The common refactor here would be to Either: > sumOf (folded . folded) [Right 1, Right 2] 3 I don't like the "unwrap the Maybe" or "get rid of the pesky monad in my way" intuition that fromMaybe and catMaybes give beginners. > A lot of the optics libraries seem to focus a lot on making the general case as easy as possible while overcomplicating the specific case. I kind of agree with this, but contend the universality of a single powerful and composable lens syntax simplifies things more overall even if it makes a single use site more complicated.