GHC.Generics.Lens

Note: GHC.Generics exports a number of names that collide with Control.Lens.

You can use hiding or imports to mitigate this to an extent, and the following imports, represent a fair compromise for user code:

 import Control.Lens hiding (Rep)
 import GHC.Generics hiding (from, to)

You can use generic to replace from and to from GHC.Generics, and probably won't be explicitly referencing Rep from Control.Lens in code that uses generics.

If you're using a version of GHC older than 7.2, this module is compatible with the generic-deriving package.

Isomorphisms for GHC.Generics

generic :: Generic a => Iso' a (Rep a b)

Convert from the data type to its representation (or back)

>>> "hello"^.generic.from generic :: String
"hello"

generic1 :: Generic1 f => Iso' (f a) (Rep1 f a)

Convert from the data type to its representation (or back)

Generic Traversal

tinplate :: (Generic a, GTraversal (Rep a), Typeable b) => Traversal' a b

A Generic Traversal that visits every occurrence of something Typeable anywhere in a container.

>>> allOf tinplate (=="Hello") (1::Int,2::Double,(),"Hello",["Hello"])
True

>>> mapMOf_ tinplate putStrLn ("hello",[(2 :: Int, "world!")])
hello
world!

class GTraversal f

Used to traverse Generic data by uniplate.

Instances

GTraversal U1

(Generic a, GTraversal (Rep a), Typeable a) => GTraversal (K1 i a)

(GTraversal f, GTraversal g) => GTraversal (:+: f g)

(GTraversal f, GTraversal g) => GTraversal (:*: f g)

(Traversable f, GTraversal g) => GTraversal (:.: f g)

GTraversal a => GTraversal (M1 i c a)