| Safe Haskell | None |
|---|---|
| Language | Haskell98 |
Lens.Family.TH
Description
Derive lenses for Lens.Family.
Example usage:
{-# LANGUAGE TemplateHaskell #-}
import Lens.Family
import Lens.Family.TH
data Foo a = Foo { _bar :: Int, _baz :: a }
deriving (Show, Read, Eq, Ord)
$(makeLenses ''Foo)- makeLenses :: Name -> Q [Dec]
- makeLensesBy :: (String -> Maybe String) -> Name -> Q [Dec]
- makeLensesFor :: [(String, String)] -> Name -> Q [Dec]
- makeTraversals :: Name -> Q [Dec]
- mkLenses :: Name -> Q [Dec]
- mkLensesBy :: (String -> Maybe String) -> Name -> Q [Dec]
- mkLensesFor :: [(String, String)] -> Name -> Q [Dec]
Documentation
makeLenses :: Name -> Q [Dec] #
Derive lenses for the record selectors in a single-constructor data declaration, or for the record selector in a newtype declaration. Lenses will only be generated for record fields which are prefixed with an underscore.
Example usage:
$(makeLenses ''Foo)
makeLensesBy :: (String -> Maybe String) -> Name -> Q [Dec] #
Derive lenses with the provided name transformation
and filtering function. Produce Just lensName to generate a lens
of the resultant name, or Nothing to not generate a lens
for the input record name.
Example usage:
$(makeLensesBy (\n -> Just (n ++ "L")) ''Foo)
makeLensesFor :: [(String, String)] -> Name -> Q [Dec] #
Derive lenses, specifying explicit pairings of (fieldName, lensName).
Example usage:
$(makeLensesFor [("_foo", "fooLens"), ("bar", "lbar")] ''Foo)makeTraversals :: Name -> Q [Dec] #
Derive traversals for each constructor in a data or newtype declaration, Traversals will be named by prefixing the constructor name with an underscore.
Example usage:
$(makeTraversals ''Foo)