HORIZON HASKELLDocslts/ghc-9.14.xd82dee82026-10-12Search names, modules, packages, or :: a typeCtrl K

GHC 9.14.1 · lts/ghc-9.14.x · d82dee8 · 2026-10-12

Modulederiving-compat-0.6.8Haskell2010

Data.Functor.Deriving

Exports functions to mechanically derive Functor instances.

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

  • 1 type
  • 7 values

Functor

6 declarations

FFTOptions

2 declarations
newtypenewtype FFTOptions
#

Options that further configure how the functions in Data.Functor.Deriving should behave. (FFT stands for FunctorFoldableTraversable.)

Constructors

  • FFTOptions
    • 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.)

Instances4Eq, Ord, Read, Show
  • Eq FFTOptionsDefined in deriving-compat-0.6.8 · Data.Functor.Deriving.Internal
  • Ord FFTOptionsDefined in deriving-compat-0.6.8 · Data.Functor.Deriving.Internal
  • Read FFTOptionsDefined in deriving-compat-0.6.8 · Data.Functor.Deriving.Internal
  • Show FFTOptionsDefined in deriving-compat-0.6.8 · Data.Functor.Deriving.Internal

deriveFunctor limitations

0 declarations

Be aware of the following potential gotchas:

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