Data.Functor.Classes.Generic · transformers-compat-0.8

Options

3 declarations

datadata Options

Options that further configure how the functions in Data.Functor.Classes.Generic should behave. Currently, the Options have no effect (but this may change in the future).

Options

valuedefaultOptions :: Options

#

Options that match the behavior of the installed version of GHC.

valuelatestGHCOptions :: Options

#

Options that match the behavior of the most recent GHC release.

`Eq1`

2 declarations

valueliftEqDefault

:: (GEq1 (Rep1 f), Generic1 f)
=> a -> b -> Bool
-> f a
-> f b
-> Bool

#

A sensible default liftEq implementation for Generic1 instances.

valueliftEqOptions

:: (GEq1 (Rep1 f), Generic1 f)
=> Options
-> a -> b -> Bool
-> f a
-> f b
-> Bool

#

Like liftEqDefault, but with configurable Options. Currently, the Options have no effect (but this may change in the future).

`Ord1`

2 declarations

valueliftCompareDefault

:: (GOrd1 (Rep1 f), Generic1 f)
=> a -> b -> Ordering
-> f a
-> f b
-> Ordering

#

A sensible default liftCompare implementation for Generic1 instances.

valueliftCompareOptions

:: (GOrd1 (Rep1 f), Generic1 f)
=> Options
-> a -> b -> Ordering
-> f a
-> f b
-> Ordering

#

Like liftCompareDefault, but with configurable Options. Currently, the Options have no effect (but this may change in the future).

`Read1`

2 declarations

valueliftReadsPrecDefault

:: (GRead1 (Rep1 f), Generic1 f)
=> Int -> ReadS a
-> ReadS [a]
-> Int
-> ReadS (f a)

#

A sensible default liftReadsPrec implementation for Generic1 instances.

valueliftReadsPrecOptions

:: (GRead1 (Rep1 f), Generic1 f)
=> Options
-> Int -> ReadS a
-> ReadS [a]
-> Int
-> ReadS (f a)

#

Like liftReadsPrecDefault, but with configurable Options. Currently, the Options have no effect (but this may change in the future).

`Show1`

2 declarations

valueliftShowsPrecDefault

:: (GShow1 (Rep1 f), Generic1 f)
=> Int -> a -> ShowS
-> [a] -> ShowS
-> Int
-> f a
-> ShowS

#

A sensible default liftShowsPrec implementation for Generic1 instances.

valueliftShowsPrecOptions

:: (GShow1 (Rep1 f), Generic1 f)
=> Options
-> Int -> a -> ShowS
-> [a] -> ShowS
-> Int
-> f a
-> ShowS

#

Like liftShowsPrecDefault, but with configurable Options. Currently, the Options have no effect (but this may change in the future).

`GenericFunctorClasses`

1 declaration

newtypenewtype FunctorClassesDefault (f :: Type -> Type) a

#

An adapter newtype, suitable for DerivingVia. Its Eq1, Ord1, Read1, and Show1 instances leverage Generic1-based defaults.

Constructors

FunctorClassesDefault
- getFunctorClassesDefault :: f a

Instances8Eq1, Ord1, Read1, Show1, Eq, Ord, …

(GEq1 (Rep1 f), Generic1 f) => Eq1 (FunctorClassesDefault f)Defined in transformers-compat-0.8 · Data.Functor.Classes.Generic.Internal
(GOrd1 (Rep1 f), Generic1 f) => Ord1 (FunctorClassesDefault f)Defined in transformers-compat-0.8 · Data.Functor.Classes.Generic.Internal
(GRead1 (Rep1 f), Generic1 f) => Read1 (FunctorClassesDefault f)Defined in transformers-compat-0.8 · Data.Functor.Classes.Generic.Internal
(GShow1 (Rep1 f), Generic1 f) => Show1 (FunctorClassesDefault f)Defined in transformers-compat-0.8 · Data.Functor.Classes.Generic.Internal
(GEq (Rep1 f a), Generic1 f) => Eq (FunctorClassesDefault f a)Defined in transformers-compat-0.8 · Data.Functor.Classes.Generic.Internal
(GOrd (Rep1 f a), Generic1 f) => Ord (FunctorClassesDefault f a)Defined in transformers-compat-0.8 · Data.Functor.Classes.Generic.Internal
(GRead (Rep1 f a), Generic1 f) => Read (FunctorClassesDefault f a)Defined in transformers-compat-0.8 · Data.Functor.Classes.Generic.Internal
(GShow (Rep1 f a), Generic1 f) => Show (FunctorClassesDefault f a)Defined in transformers-compat-0.8 · Data.Functor.Classes.Generic.Internal

Example

0 declarations

The most straightforward way to use the defaults in this module is to use DerivingVia on GHC 8.6 or later. For example:

{-# LANGUAGE DeriveGeneric, DerivingVia #-}

import Data.Functor.Classes
import Data.Functor.Classes.Generic
import GHC.Generics

data Pair a = Pair a a
  deriving stock Generic1
  deriving (Eq1, Ord1, Read1, Show1)
           via FunctorClassesDefault Pair

If using an older version of GHC, then one can also define instances manually. Here is an example:

{-# LANGUAGE DeriveGeneric #-}

import Data.Functor.Classes
import Data.Functor.Classes.Generic
import GHC.Generics

data Pair a = Pair a a deriving Generic1

instance C.Eq1 Pair where
    C.liftEq = liftEqDefault

instance C.Ord1 Pair where
    C.liftCompare = liftCompareDefault

instance C.Read1 Pair where
    C.liftReadsPrec = liftReadsPrecDefault

instance C.Show1 Pair where
    C.liftShowsPrec = liftShowsPrecDefault