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-- DataKinds is needed for deriveAll0 calls on GHC 8
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeFamilies #-}
module DataFamilies.Types (module DataFamilies.Types) where
import Prelude.Compat
import Generics.Deriving.TH (deriveAll0)
import Types (ApproxEq(..))
data family Nullary a
data instance Nullary Int = C1 | C2 | C3 deriving (Eq, Show)
data instance Nullary Char = C4 deriving (Eq, Show)
data family SomeType a b c
data instance SomeType c () a = Nullary
| Unary Int
| Product String (Maybe Char) a
| Record { testOne :: Double
, testTwo :: Maybe Bool
, testThree :: Maybe a
}
| List [a]
deriving (Eq, Show)
data family Approx a
newtype instance Approx a = Approx { fromApprox :: a }
deriving (Show, ApproxEq, Num)
instance (ApproxEq a) => Eq (Approx a) where
Approx a == Approx b = a =~ b
data family GADT a
data instance GADT a where
GADT :: { gadt :: String } -> GADT String
deriving instance Eq (GADT a)
deriving instance Show (GADT a)
-- We use generic-deriving to be able to derive Generic instances for
-- data families on GHC 7.4.
$(deriveAll0 'C1)
$(deriveAll0 'C4)
$(deriveAll0 'Approx)
$(deriveAll0 'Nullary)
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