Data.Filterable

class (Foldable f) <= Filterable f  where

The Filterable class provides a filtering operation for Foldable structures.

Instances must satisfy the following laws in addition to Foldable laws:

• filter (\_ → true) x == x
• filter (\_ → false) x == mempty
• length (filter f x) <= length x

Members

• filter :: forall h a. BooleanEq h => (a -> h) -> f a -> f a

Instances

• Filterable Array
• Filterable List
• (Ord k) => Filterable (Map k)
• Filterable StrMap

verifyFilter :: forall a h f. Eq (f a) => Monoid (f a) => BooleanEq h => Filterable f => (a -> h) -> f a -> Boolean

defaultFilter :: forall a h f. BooleanEq h => Applicative f => Foldable f => Monoid (f a) => (a -> h) -> f a -> f a