Safe Haskell	Safe-Inferred
Language	Haskell2010

GHC.Toolchain.Lens

Description

A very simple Lens implementation

Synopsis

data Lens a b = Lens {
- view :: a -> b
- set :: b -> a -> a
}
(%) :: Lens a b -> Lens b c -> Lens a c
over :: Lens a b -> (b -> b) -> a -> a
(%++) :: Lens a [b] -> b -> a -> a
(&) :: a -> (a -> b) -> b

Documentation

data Lens a b Source #

Constructors

Lens
Fields view :: a -> b set :: b -> a -> a

(%) :: Lens a b -> Lens b c -> Lens a c Source #

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

(%++) :: Lens a [b] -> b -> a -> a Source #

Append b to [b]

Example usage: @cc & _ccProgram % _prgFlags %++ "-U__i686"@

(&) :: a -> (a -> b) -> b infixl 1 Source #

& is a reverse application operator. This provides notational convenience. Its precedence is one higher than that of the forward application operator $, which allows & to be nested in $.

>>> 5 & (+1) & show
"6"

Since: base-4.8.0.0