    {-# LANGUAGE ConstraintKinds #-}
    {-# LANGUAGE CPP #-}
    {-# LANGUAGE KindSignatures #-}
    {-# LANGUAGE ScopedTypeVariables #-}

    #if HAVE_QUANTIFIED_CONSTRAINTS
    {-# LANGUAGE QuantifiedConstraints #-}
    #endif

    {-# OPTIONS_GHC -Wall #-}

    module Test.QuickCheck.Classes.Contravariant
      (
    #if HAVE_UNARY_LAWS
        contravariantLaws
    #endif
      ) where

    import Data.Functor.Contravariant
    import Test.QuickCheck hiding ((.&.))
    #if HAVE_UNARY_LAWS
    import Test.QuickCheck.Arbitrary (Arbitrary1(..))
    import Data.Functor.Classes (Eq1,Show1)
    #endif
    import Test.QuickCheck.Property (Property)

    import Test.QuickCheck.Classes.Internal

    #if HAVE_UNARY_LAWS

    -- | Tests the following contravariant properties:
    --
    -- [/Identity/]
    --   @'contramap' 'id' ≡ 'id'@
    -- [/Composition/]
    --   @'contramap' f '.' 'contramap' g ≡ 'contramap' (g '.' f)@
    contravariantLaws ::
    #if HAVE_QUANTIFIED_CONSTRAINTS
      (Contravariant f, forall a. Eq a => Eq (f a), forall a. Show a => Show (f a), forall a. Arbitrary a => Arbitrary (f a))
    #else
      (Contravariant f, Eq1 f, Show1 f, Arbitrary1 f)
    #endif
      => proxy f
      -> Laws
    contravariantLaws :: forall (f :: * -> *) (proxy :: (* -> *) -> *).
    (Contravariant f, forall a. Eq a => Eq (f a),
     forall a. Show a => Show (f a),
     forall a. Arbitrary a => Arbitrary (f a)) =>
    proxy f -> Laws
    contravariantLaws proxy f
    p = String -> [(String, Property)] -> Laws
    Laws String
    "Contravariant"
      [ (String
    "Identity", proxy f -> Property
    forall (proxy :: (* -> *) -> *) (f :: * -> *).
    (Contravariant f, forall a. Eq a => Eq (f a),
     forall a. Show a => Show (f a),
     forall a. Arbitrary a => Arbitrary (f a)) =>
    proxy f -> Property
    contravariantIdentity proxy f
    p)
      , (String
    "Composition", proxy f -> Property
    forall (proxy :: (* -> *) -> *) (f :: * -> *).
    (Contravariant f, forall a. Eq a => Eq (f a),
     forall a. Show a => Show (f a),
     forall a. Arbitrary a => Arbitrary (f a)) =>
    proxy f -> Property
    contravariantComposition proxy f
    p)
      ]

    contravariantIdentity :: forall proxy f.
    #if HAVE_QUANTIFIED_CONSTRAINTS
      (Contravariant f, forall a. Eq a => Eq (f a), forall a. Show a => Show (f a), forall a. Arbitrary a => Arbitrary (f a))
    #else
      (Contravariant f, Eq1 f, Show1 f, Arbitrary1 f)
    #endif
      => proxy f -> Property
    contravariantIdentity :: forall (proxy :: (* -> *) -> *) (f :: * -> *).
    (Contravariant f, forall a. Eq a => Eq (f a),
     forall a. Show a => Show (f a),
     forall a. Arbitrary a => Arbitrary (f a)) =>
    proxy f -> Property
    contravariantIdentity proxy f
    _ = (Apply f Integer -> Bool) -> Property
    forall prop. Testable prop => prop -> Property
    property ((Apply f Integer -> Bool) -> Property)
    -> (Apply f Integer -> Bool) -> Property
    forall a b. (a -> b) -> a -> b
    $ \(Apply (f Integer
    a :: f Integer)) -> f Integer -> f Integer -> Bool
    forall (f :: * -> *) a.
    (forall x. Eq x => Eq (f x), Eq a) =>
    f a -> f a -> Bool
    eq1 ((Integer -> Integer) -> f Integer -> f Integer
    forall a' a. (a' -> a) -> f a -> f a'
    forall (f :: * -> *) a' a.
    Contravariant f =>
    (a' -> a) -> f a -> f a'
    contramap Integer -> Integer
    forall a. a -> a
    id f Integer
    a) f Integer
    a

    contravariantComposition :: forall proxy f.
    #if HAVE_QUANTIFIED_CONSTRAINTS
      (Contravariant f, forall a. Eq a => Eq (f a), forall a. Show a => Show (f a), forall a. Arbitrary a => Arbitrary (f a))
    #else
      (Contravariant f, Eq1 f, Show1 f, Arbitrary1 f)
    #endif
      => proxy f -> Property
    contravariantComposition :: forall (proxy :: (* -> *) -> *) (f :: * -> *).
    (Contravariant f, forall a. Eq a => Eq (f a),
     forall a. Show a => Show (f a),
     forall a. Arbitrary a => Arbitrary (f a)) =>
    proxy f -> Property
    contravariantComposition proxy f
    _ = (Apply f Integer -> QuadraticEquation -> QuadraticEquation -> Bool)
    -> Property
    forall prop. Testable prop => prop -> Property
    property ((Apply f Integer
      -> QuadraticEquation -> QuadraticEquation -> Bool)
     -> Property)
    -> (Apply f Integer
        -> QuadraticEquation -> QuadraticEquation -> Bool)
    -> Property
    forall a b. (a -> b) -> a -> b
    $ \(Apply (f Integer
    a :: f Integer)) (QuadraticEquation
    f' :: QuadraticEquation) (QuadraticEquation
    g' :: QuadraticEquation) -> do
      let f :: Integer -> Integer
    f = QuadraticEquation -> Integer -> Integer
    runQuadraticEquation QuadraticEquation
    f'
          g :: Integer -> Integer
    g = QuadraticEquation -> Integer -> Integer
    runQuadraticEquation QuadraticEquation
    g'
      f Integer -> f Integer -> Bool
    forall (f :: * -> *) a.
    (forall x. Eq x => Eq (f x), Eq a) =>
    f a -> f a -> Bool
    eq1 ((Integer -> Integer) -> f Integer -> f Integer
    forall a' a. (a' -> a) -> f a -> f a'
    forall (f :: * -> *) a' a.
    Contravariant f =>
    (a' -> a) -> f a -> f a'
    contramap Integer -> Integer
    f ((Integer -> Integer) -> f Integer -> f Integer
    forall a' a. (a' -> a) -> f a -> f a'
    forall (f :: * -> *) a' a.
    Contravariant f =>
    (a' -> a) -> f a -> f a'
    contramap Integer -> Integer
    g f Integer
    a)) ((Integer -> Integer) -> f Integer -> f Integer
    forall a' a. (a' -> a) -> f a -> f a'
    forall (f :: * -> *) a' a.
    Contravariant f =>
    (a' -> a) -> f a -> f a'
    contramap (Integer -> Integer
    g (Integer -> Integer) -> (Integer -> Integer) -> Integer -> Integer
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Integer -> Integer
    f) f Integer
    a)

    #endif