Copyright	(C) 2015-2016 Edward Kmett Ryan Scott
License	BSD-style (see the file LICENSE)
Maintainer	Ryan Scott
Stability	Provisional
Portability	GHC
Safe Haskell	None
Language	Haskell98

Data.Functor.Classes.Generic

Contents

Options
Eq1
Ord1
Read1
Show1
Example

Description

Functions to generically derive Eq1, Ord1, Read1, and Show1 instances from Data.Functor.Classes.

Synopsis

newtype Options = Options {
- ghc8ShowBehavior :: Bool
}
defaultOptions :: Options
latestGHCOptions :: Options
liftEqDefault :: (GEq1 NonV4 (Rep1 f), Generic1 f) => (a -> b -> Bool) -> f a -> f b -> Bool
liftEqOptions :: (GEq1 NonV4 (Rep1 f), Generic1 f) => Options -> (a -> b -> Bool) -> f a -> f b -> Bool
liftCompareDefault :: (GOrd1 NonV4 (Rep1 f), Generic1 f) => (a -> b -> Ordering) -> f a -> f b -> Ordering
liftCompareOptions :: (GOrd1 NonV4 (Rep1 f), Generic1 f) => Options -> (a -> b -> Ordering) -> f a -> f b -> Ordering
liftReadsPrecDefault :: (GRead1 NonV4 (Rep1 f), Generic1 f) => (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (f a)
liftReadsPrecOptions :: (GRead1 NonV4 (Rep1 f), Generic1 f) => Options -> (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (f a)
liftShowsPrecDefault :: (GShow1 NonV4 (Rep1 f), Generic1 f) => (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> f a -> ShowS
liftShowsPrecOptions :: (GShow1 NonV4 (Rep1 f), Generic1 f) => Options -> (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> f a -> ShowS

Options

newtype Options #

Options that further configure how the functions in Data.Functor.Classes.Generic should behave.

Constructors

Options
Fields ghc8ShowBehavior :: Bool If `True`, a default `Show1` implementation will show hash signs (`#`) when showing unlifted types.

defaultOptions :: Options #

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

latestGHCOptions :: Options #

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

`Eq1`

liftEqDefault :: (GEq1 NonV4 (Rep1 f), Generic1 f) => (a -> b -> Bool) -> f a -> f b -> Bool #

A sensible default liftEq implementation for Generic1 instances.

liftEqOptions :: (GEq1 NonV4 (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`

liftCompareDefault :: (GOrd1 NonV4 (Rep1 f), Generic1 f) => (a -> b -> Ordering) -> f a -> f b -> Ordering #

A sensible default liftCompare implementation for Generic1 instances.

liftCompareOptions :: (GOrd1 NonV4 (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`

liftReadsPrecDefault :: (GRead1 NonV4 (Rep1 f), Generic1 f) => (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (f a) #

A sensible default liftReadsPrec implementation for Generic1 instances.

liftReadsPrecOptions :: (GRead1 NonV4 (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`

liftShowsPrecDefault :: (GShow1 NonV4 (Rep1 f), Generic1 f) => (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> f a -> ShowS #

A sensible default liftShowsPrec implementation for Generic1 instances.

liftShowsPrecOptions :: (GShow1 NonV4 (Rep1 f), Generic1 f) => Options -> (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> f a -> ShowS #

Like liftShowsPrecDefault, but with configurable Options.

Example

Note that this module exports different functions depending on which version of transformers this library is built against. Here is an example of how to use this module correctly:

{-# LANGUAGE DeriveGeneric #-}

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

data Pair a = Pair a a deriving Generic1

instance Eq1 Pair where
#if MIN_VERSION_transformers(0,4,0) && !(MIN_VERSION_transformers(0,5,0))
    eq1 = eq1Default
#else
    liftEq = liftEqDefault
#endif

instance Ord1 Pair where
#if MIN_VERSION_transformers(0,4,0) && !(MIN_VERSION_transformers(0,5,0))
    compare1 = compare1Default
#else
    liftCompare = liftCompareDefault
#endif

instance Read1 Pair where
#if MIN_VERSION_transformers(0,4,0) && !(MIN_VERSION_transformers(0,5,0))
    readsPrec1 = readsPrec1Default
#else
    liftReadsPrec = liftReadsPrecDefault
#endif

instance Show1 Pair where
#if MIN_VERSION_transformers(0,4,0) && !(MIN_VERSION_transformers(0,5,0))
    showsPrec1 = showsPrec1Default
#else
    liftShowsPrec = liftShowsPrecDefault
#endif