data-lens-2.10.5: Used to be Haskell 98 Lenses

Safe HaskellSafe-Inferred

Data.Lens.Common

Contents

Synopsis

Documentation

newtype Lens a b Source

Constructors

Lens 

Fields

runLens :: a -> Store b a
 

Lens construction

lens :: (a -> b) -> (b -> a -> a) -> Lens a bSource

build a lens out of a getter and setter

iso :: (a -> b) -> (b -> a) -> Lens a bSource

build a lens out of an isomorphism

Functional API

getL :: Lens a b -> a -> bSource

Gets the getter function from a lens.

setL :: Lens a b -> b -> a -> aSource

Gets the setter function from a lens.

modL :: Lens a b -> (b -> b) -> a -> aSource

Gets the modifier function from a lens.

mergeL :: Lens a c -> Lens b c -> Lens (Either a b) cSource

Operator API

(^$) :: Lens a b -> a -> bSource

(^$!) :: Lens a b -> a -> bSource

(^.) :: a -> Lens a b -> bSource

functional getter, which acts like a field accessor

(^!) :: a -> Lens a b -> bSource

functional getter, which acts like a field accessor

(^=) :: Lens a b -> b -> a -> aSource

(^!=) :: Lens a b -> b -> a -> aSource

(^%=) :: Lens a b -> (b -> b) -> a -> aSource

functional modify

(^!%=) :: Lens a b -> (b -> b) -> a -> aSource

functional modify

(^%%=) :: Functor f => Lens a b -> (b -> f b) -> a -> f aSource

functorial modify

Pseudo-imperatives

(^+=) :: Num b => Lens a b -> b -> a -> aSource

(^!+=) :: Num b => Lens a b -> b -> a -> aSource

(^-=) :: Num b => Lens a b -> b -> a -> aSource

(^!-=) :: Num b => Lens a b -> b -> a -> aSource

(^*=) :: Num b => Lens a b -> b -> a -> aSource

(^!*=) :: Num b => Lens a b -> b -> a -> aSource

(^/=) :: Fractional b => Lens a b -> b -> a -> aSource

(^!/=) :: Fractional b => Lens a b -> b -> a -> aSource

Stock lenses

fstLens :: Lens (a, b) aSource

sndLens :: Lens (a, b) bSource

mapLens :: Ord k => k -> Lens (Map k v) (Maybe v)Source

setLens :: Ord k => k -> Lens (Set k) BoolSource