| Safe Haskell | Safe-Inferred |
|---|
Agda.Utils.Functor
Contents
Description
Utilities for functors.
- ($>) :: Functor f => f a -> b -> f b
- (<.>) :: Functor m => (b -> c) -> (a -> m b) -> a -> m c
- for :: Functor m => m a -> (a -> b) -> m b
- class Functor t => Decoration t where
- traverseF :: Functor m => (a -> m b) -> t a -> m (t b)
- distributeF :: Functor m => t (m a) -> m (t a)
- dmap :: Decoration t => (a -> b) -> t a -> t b
- dget :: Decoration t => t a -> a
- (<$>) :: Functor f => (a -> b) -> f a -> f b
Documentation
(<.>) :: Functor m => (b -> c) -> (a -> m b) -> a -> m cSource
Composition: pure function after functorial (monadic) function.
for :: Functor m => m a -> (a -> b) -> m bSource
The true pure for loop.
for is a misnomer, it should be forA.
class Functor t => Decoration t whereSource
A decoration is a functor that is traversable into any functor.
The Functor superclass is given because of the limitations
of the Haskell class system.
traverseF actually implies functoriality.
Minimal complete definition: traverseF or distributeF.
Methods
traverseF :: Functor m => (a -> m b) -> t a -> m (t b)Source
traverseF is the defining property.
distributeF :: Functor m => t (m a) -> m (t a)Source
Decorations commute into any functor.
Instances
| Decoration Identity | The identity functor is a decoration. |
| Decoration Ranged | |
| Decoration Type' | |
| Decoration ((,) a) | A typical decoration is pairing with some stuff. |
| Decoration (Named name) | |
| Decoration (Dom c) | |
| Decoration (Arg c) | |
| (Decoration d, Decoration t) => Decoration (Compose d t) | Decorations compose. (Thus, they form a category.) |
dmap :: Decoration t => (a -> b) -> t a -> t bSource
Any decoration is traversable with traverse = traverseF.
Just like any Traversable is a functor, so is
any decoration, given by just traverseF, a functor.
dget :: Decoration t => t a -> aSource
Any decoration is a lens. set is a special case of fmap.
The constant functor.
Maybe. Can only be traversed into pointed functors.
Other disjoint sum types, like lists etc.
(<$>) :: Functor f => (a -> b) -> f a -> f b