This is probably less readable than it has to be due to the lack of whitespace. I don't know the language (Scala?), but I don't think it's too hard to work it

This is probably less readable than it has to be due to the lack of whitespace. I don't know the language (Scala?), but I don't think it's too hard to work it out. First, the '[F[_], A, B]' part are type parameters, where I assume the 'F[_]' part is just a bad notation for a type of kind '* -> *' (i.e. a higher-ranked type). The next value parameter has type 'Option[A]', and after that we have 'A => F[B]'. This confirms my suspicion that 'F' is a higher-ranked type - and probably a functor or something. The 'f' parameter is a function for converting a value of type 'A' into a value of type 'F[b]', which looks like it's tranforming a value and putting it into a functor or something. The final '(implicit F: Applicative[F])' hints at deep problems in the language, but I think it basically just says something like 'the higher-rank type F must implement the trait/typeclass/whatever Applicative'. That's the type. The expression makes little sense to me, but I suspect you removed a bunch of dots and maybe some parens, and it should actually look like this: fa.map (a => F.map(f(a))(Some(_): Option[B])).getOrElse(F.point(None)) So this function essentially just operates on an option value inside of some functorial context. This seems like a building block function that you might use often, but probably not write very frequently. (If you didn't remove anything, then I suppose this language has infix 'map' and 'getOrElse' operators. I think that's bad, but it's not related to the type system.)