Copyright	(C) 2015-2017 Ryan Scott
License	BSD-style (see the file LICENSE)
Maintainer	Ryan Scott
Portability	Template Haskell
Safe Haskell	None
Language	Haskell2010

Data.Functor.Deriving

Contents

Description

Exports functions to mechanically derive Functor instances.

For more info on how deriving Functor works, see this GHC wiki page.

Synopsis

`Functor`

Generates a Functor instance declaration for the given data type or data family instance.

Like deriveFunctor, but takes an FFTOptions argument.

Generates a lambda expression which behaves like fmap (without requiring a Functor instance).

Like makeFmap, but takes an FFTOptions argument.

`FFTOptions`

Options that further configure how the functions in Data.Functor.Deriving should behave. (FFT stands for 'Functor'/'Foldable'/'Traversable'.)

Constructors

FFTOptions
Fields fftEmptyCaseBehavior :: Bool If `True`, derived instances for empty data types (i.e., ones with no data constructors) will use the `EmptyCase` language extension. If `False`, derived instances will simply use `seq` instead. (This has no effect on GHCs before 7.8, since `EmptyCase` is only available in 7.8 or later.)

Instances

Eq FFTOptions Source #
Instance details Defined in Data.Functor.Deriving.Internal Methods (==) :: FFTOptions -> FFTOptions -> Bool # (/=) :: FFTOptions -> FFTOptions -> Bool #
Ord FFTOptions Source #
Instance details Defined in Data.Functor.Deriving.Internal Methods compare :: FFTOptions -> FFTOptions -> Ordering # (<) :: FFTOptions -> FFTOptions -> Bool # (<=) :: FFTOptions -> FFTOptions -> Bool # (>) :: FFTOptions -> FFTOptions -> Bool # (>=) :: FFTOptions -> FFTOptions -> Bool # max :: FFTOptions -> FFTOptions -> FFTOptions # min :: FFTOptions -> FFTOptions -> FFTOptions #
Read FFTOptions Source #
Instance details Defined in Data.Functor.Deriving.Internal Methods readsPrec :: Int -> ReadS FFTOptions # readList :: ReadS [FFTOptions] # readPrec :: ReadPrec FFTOptions # readListPrec :: ReadPrec [FFTOptions] #
Show FFTOptions Source #
Instance details Defined in Data.Functor.Deriving.Internal Methods showsPrec :: Int -> FFTOptions -> ShowS # show :: FFTOptions -> String # showList :: [FFTOptions] -> ShowS #

Conservative FFTOptions that doesn't attempt to use EmptyCase (to prevent users from having to enable that extension at use sites.)

Be aware of the following potential gotchas:

Type variables of kind * -> * are assumed to have Functor constraints. If this is not desirable, use makeFmap.