Portability | non-portable |
---|---|
Stability | experimental |
Maintainer | generics@haskell.org |
Summary: Monadic generic map.
Functorial map function
class Functor f where
The Functor
class is used for types that can be mapped over.
Instances of Functor
should satisfy the following laws:
fmap id == id fmap (f . g) == fmap f . fmap g
The instances of Functor
for lists, Data.Maybe.Maybe
and System.IO.IO
satisfy these laws.
fmap :: (a -> b) -> f a -> f b
Functor [] | |
Functor IO | |
Functor Q | |
Functor ReadPrec | |
Functor ReadP | |
Functor Maybe | |
Functor U | |
Functor I | |
Functor ((->) r) | |
Functor (Either a) | |
Functor ((,) a) | |
Functor (K a) | |
Functor f => Functor (S c f) | |
Functor f => Functor (C c f) | |
(Functor f, Functor g) => Functor (:*: f g) | |
(Functor f, Functor g) => Functor (:+: f g) |