Yaya.Functor

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

Documentation

class DFunctor (d :: (Type -> Type) -> Type) where

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

Instances

DFunctor Mu

Defined in Yaya.Fold

Methods

dmap :: (forall x. f x -> g x) -> Mu f -> Mu g

DFunctor Nu

Defined in Yaya.Fold

Methods

dmap :: (forall x. f x -> g x) -> Nu f -> Nu g

class HFunctor (h :: (Type -> Type) -> Type -> Type) where

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

Instances

HFunctor Lift

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> Lift f a -> Lift g a

HFunctor MaybeT

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> MaybeT f a -> MaybeT g a

HFunctor (Backwards :: (Type -> Type) -> Type -> Type)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> Backwards f a -> Backwards g a

HFunctor (ExceptT e)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> ExceptT e f a -> ExceptT e g a

HFunctor (IdentityT :: (Type -> Type) -> Type -> Type)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> IdentityT f a -> IdentityT g a

HFunctor (ReaderT r)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> ReaderT r f a -> ReaderT r g a

HFunctor (StateT s)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> StateT s f a -> StateT s g a

HFunctor (StateT s)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> StateT s f a -> StateT s g a

HFunctor (WriterT w)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> WriterT w f a -> WriterT w g a

HFunctor (WriterT w)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> WriterT w f a -> WriterT w g a

HFunctor (Product f)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f0 x -> g x) -> Product f f0 a -> Product f g a

Functor f => HFunctor (Compose f :: (Type -> Type) -> Type -> Type)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f0 x -> g x) -> Compose f f0 a -> Compose f g a

HFunctor (RWST r w s)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> RWST r w s f a -> RWST r w s g a

HFunctor (RWST r w s)

Defined in Yaya.Functor

Methods

hmap :: (forall x. f x -> g x) -> RWST r w s f a -> RWST r w s g a

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

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)