Data.Filtrable · filtrable-0.1.6.0

classclass Functor f => Filtrable (f :: Type -> Type) where

Class of filtrable containers, i.e. containers we can map over while selectively dropping elements.

Laws:

filter f = mapMaybe (\ x -> bool Nothing (Just x) (f x))

mapMaybe g . mapMaybe f = mapMaybe (g <=< f)

Laws if Foldable f:

foldMap g . filter f = foldMap (\ x -> bool mempty (g x) (f x))

mapMaybe :: (a -> Maybe b) -> f a -> f b
Map the container with the given function, dropping the elements for which it returns Nothing.
catMaybes :: f (Maybe a) -> f a
```
catMaybes = mapMaybe id
```
filter :: (a -> Bool) -> f a -> f a
Drop the elements for which the given predicate is False.
mapMaybeA :: (Traversable f, Applicative p) => (a -> p (Maybe b)) -> f a -> p (f b)
Traverse the container with the given function, dropping the elements for which it returns Nothing.
filterA :: (Traversable f, Applicative p) => (a -> p Bool) -> f a -> p (f a)
Drop the elements for which the given predicate is False.
mapEither :: (a -> Either b c) -> f a -> (f b, f c)
Map the container with the given function, collecting the Lefts and the Rights separately.
mapEitherA :: (Traversable f, Applicative p) => (a -> p (Either b c)) -> f a -> p (f b, f c)
Traverse the container with the given function, collecting the Lefts and the Rights separately.
partitionEithers :: f (Either a b) -> (f a, f b)
```
partitionEithers = mapEither id
```

Instances9Filtrable, …

Filtrable MaybeDefined in filtrable-0.1.6.0 · Data.Filtrable
Filtrable []Defined in filtrable-0.1.6.0 · Data.Filtrable
Filtrable ProxyDefined in filtrable-0.1.6.0 · Data.Filtrable
Filtrable (Const a)Defined in filtrable-0.1.6.0 · Data.Filtrable
Filtrable f => Filtrable (Backwards f)Defined in filtrable-0.1.6.0 · Data.Filtrable
Filtrable f => Filtrable (Reverse f)Defined in filtrable-0.1.6.0 · Data.Filtrable
(Filtrable f, Filtrable g) => Filtrable (Product f g)Defined in filtrable-0.1.6.0 · Data.Filtrable
(Filtrable f, Filtrable g) => Filtrable (Sum f g)Defined in filtrable-0.1.6.0 · Data.Filtrable
(Functor f, Filtrable g) => Filtrable (Compose f g)Defined in filtrable-0.1.6.0 · Data.Filtrable