Control.Lens.TH

Constructing Lenses Automatically

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

Arguments

:: (String -> Maybe String)

the name transformer

-> 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