Moduleoptics-core-0.4.2Haskell2010

Optics.Internal.Fold

Internal implementation details of folds.

This module is intended for internal use only, and may change without warning in subsequent releases.

Synopsis

valuefoldVL__

Internal implementation of foldVL.

valuefolded__ :: (Bicontravariant p, Traversing p, Foldable f) => Optic__ p i i (f a) (f b) a b

Internal implementation of folded.

valuefoldring__

:: (Bicontravariant p, Traversing p)
=> forall (f :: Type -> Type). Applicative f => (a -> f u -> f u) -> f v -> s -> f w
-> Optic__ p i i s t a b

Internal implementation of foldring.

datadata Leftmost a

Used for headOf and iheadOf.

Instances2Semigroup, Monoid

valuegetLeftmost :: Leftmost a -> Maybe a

Extract the Leftmost element. This will fairly eagerly determine that it can return Just the moment it sees any element at all.

datadata Rightmost a

Used for lastOf and ilastOf.

Instances2Semigroup, Monoid

valuegetRightmost :: Rightmost a -> Maybe a

Extract the Rightmost element. This will fairly eagerly determine that it can return Just the moment it sees any element at all.