Copyright	(C) 2011-2015 Edward Kmett
License	BSD-style (see the file LICENSE)
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	provisional
Portability	portable
Safe Haskell	Safe
Language	Haskell98

Data.Functor.Extend

Contents

Extendable Functors

Description

Synopsis

Extendable Functors

There are two ways to define an Extend instance:

I. Provide definitions for extended satisfying this law:

extended f . extended g = extended (f . extended g)

II. Alternately, you may choose to provide definitions for duplicated satisfying this law:

duplicated . duplicated = fmap duplicated . duplicated

You may of course, choose to define both duplicated and extended. In that case you must also satisfy these laws:

extended f = fmap f . duplicated
duplicated = extended id

These are the default definitions of extended and duplicated.

class Functor w => Extend w where Source #

Minimal complete definition

duplicated | extended

Methods

duplicated :: w a -> w (w a) Source #

duplicated = extended id
fmap (fmap f) . duplicated = duplicated . fmap f

extended :: (w a -> b) -> w a -> w b Source #

extended f  = fmap f . duplicated

Instances

Extend [] Source #
Methods duplicated :: [a] -> [[a]] Source # extended :: ([a] -> b) -> [a] -> [b] Source #
Extend Maybe Source #
Methods duplicated :: Maybe a -> Maybe (Maybe a) Source # extended :: (Maybe a -> b) -> Maybe a -> Maybe b Source #
Extend Identity Source #
Methods duplicated :: Identity a -> Identity (Identity a) Source # extended :: (Identity a -> b) -> Identity a -> Identity b Source #
Extend NonEmpty Source #
Methods duplicated :: NonEmpty a -> NonEmpty (NonEmpty a) Source # extended :: (NonEmpty a -> b) -> NonEmpty a -> NonEmpty b Source #
Extend Tree Source #
Methods duplicated :: Tree a -> Tree (Tree a) Source # extended :: (Tree a -> b) -> Tree a -> Tree b Source #
Extend Seq Source #
Methods duplicated :: Seq a -> Seq (Seq a) Source # extended :: (Seq a -> b) -> Seq a -> Seq b Source #
Semigroup m => Extend ((->) m) Source #
Methods duplicated :: (m -> a) -> m -> m -> a Source # extended :: ((m -> a) -> b) -> (m -> a) -> m -> b Source #
Extend (Either a) Source #
Methods duplicated :: Either a a -> Either a (Either a a) Source # extended :: (Either a a -> b) -> Either a a -> Either a b Source #
Extend ((,) e) Source #
Methods duplicated :: (e, a) -> (e, (e, a)) Source # extended :: ((e, a) -> b) -> (e, a) -> (e, b) Source #
Extend f => Extend (MaybeApply f) Source #
Methods duplicated :: MaybeApply f a -> MaybeApply f (MaybeApply f a) Source # extended :: (MaybeApply f a -> b) -> MaybeApply f a -> MaybeApply f b Source #
(Extend w, Semigroup m) => Extend (TracedT m w) Source #
Methods duplicated :: TracedT m w a -> TracedT m w (TracedT m w a) Source # extended :: (TracedT m w a -> b) -> TracedT m w a -> TracedT m w b Source #
Extend w => Extend (StoreT s w) Source #
Methods duplicated :: StoreT s w a -> StoreT s w (StoreT s w a) Source # extended :: (StoreT s w a -> b) -> StoreT s w a -> StoreT s w b Source #
Extend w => Extend (EnvT e w) Source #
Methods duplicated :: EnvT e w a -> EnvT e w (EnvT e w a) Source # extended :: (EnvT e w a -> b) -> EnvT e w a -> EnvT e w b Source #
Extend w => Extend (IdentityT * w) Source #
Methods duplicated :: IdentityT * w a -> IdentityT * w (IdentityT * w a) Source # extended :: (IdentityT * w a -> b) -> IdentityT * w a -> IdentityT * w b Source #
(Extend f, Semigroup a) => Extend (Static f a) Source #
Methods duplicated :: Static f a a -> Static f a (Static f a a) Source # extended :: (Static f a a -> b) -> Static f a a -> Static f a b Source #
(Extend f, Extend g) => Extend (Sum * f g) Source #
Methods duplicated :: Sum * f g a -> Sum * f g (Sum * f g a) Source # extended :: (Sum * f g a -> b) -> Sum * f g a -> Sum * f g b Source #