Safe Haskell	Safe-Inferred
Language	Haskell2010

Yaya.Functor

Description

This should probably be a separate library, but it provides a number of functor type classes between various categories.

Synopsis

class DFunctor (d :: (* -> *) -> *) where
- dmap :: (forall x. f x -> g x) -> d f -> d g
firstMap :: (DFunctor d, Bifunctor f) => (a -> b) -> d (f a) -> d (f b)
class HFunctor (h :: (* -> *) -> * -> *) where
- hmap :: (forall x. f x -> g x) -> h f a -> h g a

Documentation

class DFunctor (d :: (* -> *) -> *) where Source #

A functor from the category of endofunctors to *Hask*. The D is meant to be a mnemonic for “down”, as we’re “lowering” from endofunctors to types.

Methods

dmap :: (forall x. f x -> g x) -> d f -> d g Source #

Instances

Instances details

DFunctor Nu Source #
Instance details Defined in Yaya.Fold Methods dmap :: (forall x. f x -> g x) -> Nu f -> Nu g Source #
DFunctor Mu Source #
Instance details Defined in Yaya.Fold Methods dmap :: (forall x. f x -> g x) -> Mu f -> Mu g Source #

firstMap :: (DFunctor d, Bifunctor f) => (a -> b) -> d (f a) -> d (f b) Source #

This isn’t a Functor instance because of the position of the a, but you can use it like: > newtype List a = List (Mu (XNor a)) > instance Functor List where > fmap f (List mu) = List (firstMap f mu)

class HFunctor (h :: (* -> *) -> * -> *) where Source #

An endofunctor in the category of endofunctors.

NB: This is similar to MFunctor / hoist from mmorph, but without the Monad constraint on f.

Methods

hmap :: (forall x. f x -> g x) -> h f a -> h g a Source #

Instances

Instances details

HFunctor MaybeT Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> MaybeT f a -> MaybeT g a Source #
HFunctor Lift Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> Lift f a -> Lift g a Source #
HFunctor (IdentityT :: (Type -> Type) -> Type -> Type) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> IdentityT f a -> IdentityT g a Source #
HFunctor (ExceptT e) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> ExceptT e f a -> ExceptT e g a Source #
HFunctor (StateT s) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> StateT s f a -> StateT s g a Source #
HFunctor (Backwards :: (Type -> Type) -> Type -> Type) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> Backwards f a -> Backwards g a Source #
HFunctor (ReaderT r) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> ReaderT r f a -> ReaderT r g a Source #
HFunctor (StateT s) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> StateT s f a -> StateT s g a Source #
HFunctor (WriterT w) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> WriterT w f a -> WriterT w g a Source #
HFunctor (WriterT w) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> WriterT w f a -> WriterT w g a Source #
HFunctor (Product f) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f0 x -> g x) -> Product f f0 a -> Product f g a Source #
Functor f => HFunctor (Compose f :: (Type -> Type) -> Type -> Type) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f0 x -> g x) -> Compose f f0 a -> Compose f g a Source #
HFunctor (RWST r w s) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> RWST r w s f a -> RWST r w s g a Source #
HFunctor (RWST r w s) Source #
Instance details Defined in Yaya.Functor Methods hmap :: (forall x. f x -> g x) -> RWST r w s f a -> RWST r w s g a Source #