Types.hs

{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE StandaloneDeriving #-}

module Types where

import qualified Data.Map as Map
import Data.Data
import Data.Text
import GHC.Generics
import Test.QuickCheck (Property, counterexample)

data Foo = Foo {
      fooInt :: Int
    , fooDouble :: Double
    , fooTuple :: (String, Text, Int)
    -- This definition causes an infinite loop in genericTo and genericFrom!
    -- , fooMap :: Map.Map String Foo
    , fooMap :: Map.Map String (Text,Int)
    } deriving (Show, Typeable, Data)

data UFoo = UFoo {
      _UFooInt :: Int
    , uFooInt :: Int
    } deriving (Show, Eq, Data, Typeable)

data OneConstructor = OneConstructor
                      deriving (Show, Eq, Typeable, Data)

data Product2 a b = Product2 a b
                    deriving (Show, Eq, Typeable, Data)

data Product6 a b c d e f = Product6 a b c d e f
                    deriving (Show, Eq, Typeable, Data)

data Sum4 a b c d = Alt1 a | Alt2 b | Alt3 c | Alt4 d
                    deriving (Show, Eq, Typeable, Data)

class ApproxEq a where
    (=~) :: a -> a -> Bool

newtype Approx a = Approx { fromApprox :: a }
    deriving (Show, Data, Typeable, ApproxEq, Num)

instance (ApproxEq a) => Eq (Approx a) where
    Approx a == Approx b = a =~ b

data Nullary = C1 | C2 | C3 deriving (Eq, Show)

data SomeType a = Nullary
                | Unary Int
                | Product String (Maybe Char) a
                | Record { testOne   :: Double
                         , testTwo   :: Maybe Bool
                         , testThree :: Maybe a
                         } deriving (Eq, Show)

data GADT a where
    GADT :: { gadt :: String } -> GADT String
  deriving Typeable

deriving instance Data (GADT String)
deriving instance Eq   (GADT a)
deriving instance Show (GADT a)

deriving instance Generic Foo
deriving instance Generic UFoo
deriving instance Generic OneConstructor
deriving instance Generic (Product2 a b)
deriving instance Generic (Product6 a b c d e f)
deriving instance Generic (Sum4 a b c d)
deriving instance Generic (Approx a)
deriving instance Generic Nullary
deriving instance Generic (SomeType a)

failure :: Show a => String -> String -> a -> Property
failure func msg v = counterexample
                     (func ++ " failed: " ++ msg ++ ", " ++ show v) False