Modulelens-5.3.5Haskell2010

Control.Lens.Internal.Fold

8 types
2 values

Packagelens-5.3.5
Exports10
LanguageHaskell2010
LicenceBSD-2-Clause
SourceFold.hs

Monoids for folding

9 declarations

newtypenewtype Folding (f :: Type -> Type) a

A Monoid for a Contravariant Applicative.

Constructors

Folding
- getFolding :: f a

Instances2Semigroup, Monoid

(Contravariant f, Applicative f) => Semigroup (Folding f a)Defined in lens-5.3.5 · Control.Lens.Internal.Fold
(Contravariant f, Applicative f) => Monoid (Folding f a)Defined in lens-5.3.5 · Control.Lens.Internal.Fold

newtypenewtype Traversed a (f :: Type -> Type)

Used internally by Control.Lens.Traversal.traverseOf_ and the like.

The argument a of the result should not be used!

Constructors

Traversed
- getTraversed :: f a

Instances2Semigroup, Monoid

Applicative f => Semigroup (Traversed a f)Defined in lens-5.3.5 · Control.Lens.Internal.Fold
Applicative f => Monoid (Traversed a f)Defined in lens-5.3.5 · Control.Lens.Internal.Fold

newtypenewtype TraversedF a (f :: Type -> Type)

Used internally by traverse1Of_ and the like.

Constructors

TraversedF
- getTraversedF :: f a

Instances2Semigroup, Monoid

Apply f => Semigroup (TraversedF a f)Defined in lens-5.3.5 · Control.Lens.Internal.Fold
(Apply f, Applicative f) => Monoid (TraversedF a f)Defined in lens-5.3.5 · Control.Lens.Internal.Fold

newtypenewtype Sequenced a (m :: Type -> Type)

Used internally by Control.Lens.Traversal.mapM_ and the like.

The argument a of the result should not be used!

See 4.16 Changelog entry for the explanation of "why not Apply f =>"?

Constructors

Sequenced
- getSequenced :: m a

Instances2Semigroup, Monoid

Monad m => Semigroup (Sequenced a m)Defined in lens-5.3.5 · Control.Lens.Internal.Fold
Monad m => Monoid (Sequenced a m)Defined in lens-5.3.5 · Control.Lens.Internal.Fold

datadata Leftmost a

Used for firstOf.

Constructors

LPure
LLeaf a
LStep (Leftmost a)

Instances2Semigroup, Monoid

Semigroup (Leftmost a)Defined in lens-5.3.5 · Control.Lens.Internal.Fold
Monoid (Leftmost a)Defined in lens-5.3.5 · Control.Lens.Internal.Fold

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.

Constructors

RPure
RLeaf a
RStep (Rightmost a)

Instances2Semigroup, Monoid

Semigroup (Rightmost a)Defined in lens-5.3.5 · Control.Lens.Internal.Fold
Monoid (Rightmost a)Defined in lens-5.3.5 · Control.Lens.Internal.Fold

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.

datadata ReifiedMonoid a

Constructors

ReifiedMonoid
- reifiedMappend :: a -> a -> a
- reifiedMempty :: a

Semigroups for folding

1 declaration

newtypenewtype NonEmptyDList a

Constructors

NonEmptyDList
- getNonEmptyDList :: [a] -> NonEmpty a

Instances1Semigroup

Semigroup (NonEmptyDList a)Defined in lens-5.3.5 · Control.Lens.Internal.Fold