Fresnel.Fold

Folds

type Fold s a = forall (p :: Type -> Type -> Type). IsFold p => Optic' p s a

class (IsOptionalFold p, IsFold1 p, IsTraversal p) => IsFold (p :: Type -> Type -> Type)

Instances

Monoid r => IsFold (Forget r :: Type -> Type -> Type)

Defined in Fresnel.Fold

(Applicative f, Traversable f, Contravariant f) => IsFold (Star f)

Defined in Fresnel.Fold

Construction

folded :: forall (f :: Type -> Type) a. Foldable f => Fold (f a) a

unfolded :: (s -> Maybe (a, s)) -> Fold s a

folding :: Foldable f => (s -> f a) -> Fold s a

foldring :: (forall (f :: Type -> Type). Applicative f => (a -> f u -> f u) -> f v -> s -> f w) -> Fold s a

foldMapping :: (forall m. Monoid m => (a -> m) -> s -> m) -> Fold s a

Make a Fold by lifting a foldMap-like function.

foldMapping foldMap = folded

foldMap1ing :: (forall m. Semigroup m => (a -> m) -> s -> m) -> Fold s a

Make a Fold by lifting a foldMap1-like function.

ignored :: forall s a b p. IsTraversal p => Optic p s s a b

The trivially empty Traversal.

traverseOf ignored f = pure

backwards :: Fold s a -> Fold s a

iterated :: (a -> a) -> Fold a a

filtered :: (a -> Bool) -> Fold a a

repeated :: forall a p. IsFold p => Optic' p a a

An infinite fold repeatedly producing its input.

toListOf repeated a = repeat a

replicated :: Int -> Fold a a

A fold producing its input a finite number of times.

toListOf (replicated n) a = replicate n a

cycled :: Fold s a -> Fold s a

takingWhile :: (a -> Bool) -> Fold s a -> Fold s a

Elimination

has :: Fold s a -> s -> Bool

hasn't :: Fold s a -> s -> Bool

foldMapOf :: Monoid m => Fold s a -> (a -> m) -> s -> m

foldMapByOf :: Fold s a -> (r -> r -> r) -> r -> (a -> r) -> s -> r

foldrOf :: Fold s a -> (a -> r -> r) -> r -> s -> r

foldlOf' :: Fold s a -> (r -> a -> r) -> r -> s -> r

foldOf :: Monoid a => Fold s a -> s -> a

foldByOf :: Fold s a -> (a -> a -> a) -> a -> s -> a

sequenceOf_ :: Applicative f => Fold s (f a) -> s -> f ()

traverseOf_ :: Applicative f => Fold s a -> (a -> f r) -> s -> f ()

forOf_ :: Applicative f => Fold s a -> s -> (a -> f r) -> f ()

toListOf :: Fold s a -> s -> [a]

anyOf :: Fold s a -> (a -> Bool) -> s -> Bool

allOf :: Fold s a -> (a -> Bool) -> s -> Bool

noneOf :: Fold s a -> (a -> Bool) -> s -> Bool

andOf :: Fold s Bool -> s -> Bool

orOf :: Fold s Bool -> s -> Bool

productOf :: Num a => Fold s a -> s -> a

sumOf :: Num a => Fold s a -> s -> a

altOf :: Alternative f => Fold s a -> s -> f a

asumOf :: Alternative f => Fold s (f a) -> s -> f a

concatOf :: Fold s [a] -> s -> [a]

concatMapOf :: Fold s a -> (a -> [r]) -> s -> [r]

elemOf :: Eq a => Fold s a -> a -> s -> Bool

notElemOf :: Eq a => Fold s a -> a -> s -> Bool

lengthOf :: Fold s a -> s -> Int

nullOf :: Fold s a -> s -> Bool

notNullOf :: Fold s a -> s -> Bool

firstOf :: Fold s a -> s -> Maybe a

lastOf :: Fold s a -> s -> Maybe a

minimumOf :: Ord a => Fold s a -> s -> Maybe a

minimumByOf :: Fold s a -> (a -> a -> Ordering) -> s -> Maybe a

maximumOf :: Ord a => Fold s a -> s -> Maybe a

maximumByOf :: Fold s a -> (a -> a -> Ordering) -> s -> Maybe a

findOf :: Fold s a -> (a -> Bool) -> s -> Maybe a

findMOf :: Monad m => Fold s a -> (a -> m Bool) -> s -> m (Maybe a)

lookupOf :: Eq k => Fold s (k, v) -> k -> s -> Maybe v

previews :: Fold s a -> (a -> r) -> s -> Maybe r

preview :: Fold s a -> s -> Maybe a

(^?) :: s -> Fold s a -> Maybe a infixl 8

newtype Failover s a

Constructors

Failover

Fields

• getFailover :: Fold s a

Instances

Monoid (Failover s a)

Defined in Fresnel.Fold

Methods

mempty :: Failover s a

mappend :: Failover s a -> Failover s a -> Failover s a

mconcat :: [Failover s a] -> Failover s a

Semigroup (Failover s a)

Defined in Fresnel.Fold

Methods

(<>) :: Failover s a -> Failover s a -> Failover s a

sconcat :: NonEmpty (Failover s a) -> Failover s a

stimes :: Integral b => b -> Failover s a -> Failover s a

newtype Union s a

Constructors

Union

Fields

• getUnion :: Fold s a

Instances

Monoid (Union s a)

Defined in Fresnel.Fold

Methods

mempty :: Union s a

mappend :: Union s a -> Union s a -> Union s a

mconcat :: [Union s a] -> Union s a

Semigroup (Union s a)

Defined in Fresnel.Fold

Methods

(<>) :: Union s a -> Union s a -> Union s a

sconcat :: NonEmpty (Union s a) -> Union s a

stimes :: Integral b => b -> Union s a -> Union s a