data-lens-2.11.2: Used to be Haskell 98 Lenses

Safe HaskellSafe
LanguageHaskell98

Data.Lens.Common

Contents

Synopsis

Documentation

newtype Lens a b Source #

Constructors

Lens 

Fields

Instances

Tensor Lens Source # 

Methods

(***) :: Lens w x -> Lens y z -> Lens (w, y) (x, z) Source #

first :: Lens w x -> Lens (w, z) (x, z) Source #

second :: Lens y z -> Lens (w, y) (w, z) Source #

Category * Lens Source # 

Methods

id :: cat a a #

(.) :: cat b c -> cat a b -> cat a c #

Semigroupoid * Lens Source # 

Methods

o :: c j k1 -> c i j -> c i k1 #

Lens construction

lens :: (a -> b) -> (b -> a -> a) -> Lens a b Source #

build a lens out of a getter and setter

iso :: (a -> b) -> (b -> a) -> Lens a b Source #

build a lens out of an isomorphism

Functional API

getL :: Lens a b -> a -> b Source #

Gets the getter function from a lens.

setL :: Lens a b -> b -> a -> a Source #

Gets the setter function from a lens.

modL :: Lens a b -> (b -> b) -> a -> a Source #

Gets the modifier function from a lens.

mergeL :: Lens a c -> Lens b c -> Lens (Either a b) c Source #

Operator API

(^$) :: Lens a b -> a -> b infixr 0 Source #

(^$!) :: Lens a b -> a -> b infixr 0 Source #

(^.) :: a -> Lens a b -> b infixl 9 Source #

functional getter, which acts like a field accessor

(^!) :: a -> Lens a b -> b infixl 9 Source #

functional getter, which acts like a field accessor

(^=) :: Lens a b -> b -> a -> a infixr 4 Source #

(^!=) :: Lens a b -> b -> a -> a infixr 4 Source #

(^%=) :: Lens a b -> (b -> b) -> a -> a infixr 4 Source #

functional modify

(^!%=) :: Lens a b -> (b -> b) -> a -> a infixr 4 Source #

functional modify

(^%%=) :: Functor f => Lens a b -> (b -> f b) -> a -> f a infixr 4 Source #

functorial modify

Pseudo-imperatives

(^+=) :: Num b => Lens a b -> b -> a -> a infixr 4 Source #

(^!+=) :: Num b => Lens a b -> b -> a -> a infixr 4 Source #

(^-=) :: Num b => Lens a b -> b -> a -> a infixr 4 Source #

(^!-=) :: Num b => Lens a b -> b -> a -> a infixr 4 Source #

(^*=) :: Num b => Lens a b -> b -> a -> a infixr 4 Source #

(^!*=) :: Num b => Lens a b -> b -> a -> a infixr 4 Source #

(^/=) :: Fractional b => Lens a b -> b -> a -> a infixr 4 Source #

(^!/=) :: Fractional b => Lens a b -> b -> a -> a infixr 4 Source #

Stock lenses

fstLens :: Lens (a, b) a Source #

sndLens :: Lens (a, b) b Source #

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

intMapLens :: Int -> Lens (IntMap v) (Maybe v) Source #

setLens :: Ord k => k -> Lens (Set k) Bool Source #

intSetLens :: Int -> Lens IntSet Bool Source #