{-# LANGUAGE CPP #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# OPTIONS_GHC -Wall #-}
module Test.QuickCheck.Classes.MonadPlus
(
#if MIN_VERSION_base(4,9,0) || MIN_VERSION_transformers(0,4,0)
monadPlusLaws
#endif
) where
import Test.QuickCheck hiding ((.&.))
#if MIN_VERSION_QuickCheck(2,10,0)
import Control.Applicative(Alternative(empty))
import Control.Monad (MonadPlus(mzero,mplus))
import Test.QuickCheck.Arbitrary (Arbitrary1(..))
#if MIN_VERSION_base(4,9,0) || MIN_VERSION_transformers(0,4,0)
import Data.Functor.Classes
#endif
#endif
import Test.QuickCheck.Property (Property)
import Test.QuickCheck.Classes.Common
#if MIN_VERSION_QuickCheck(2,10,0)
#if MIN_VERSION_base(4,9,0) || MIN_VERSION_transformers(0,4,0)
monadPlusLaws :: (MonadPlus f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Laws
monadPlusLaws p = Laws "MonadPlus"
[ ("Left Identity", monadPlusLeftIdentity p)
, ("Right Identity", monadPlusRightIdentity p)
, ("Associativity", monadPlusAssociativity p)
, ("Left Zero", monadPlusLeftZero p)
, ("Right Zero", monadPlusRightZero p)
]
monadPlusLeftIdentity :: forall proxy f. (MonadPlus f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
monadPlusLeftIdentity _ = property $ \(Apply (a :: f Integer)) -> eq1 (mplus mzero a) a
monadPlusRightIdentity :: forall proxy f. (MonadPlus f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
monadPlusRightIdentity _ = property $ \(Apply (a :: f Integer)) -> eq1 (mplus a mzero) a
monadPlusAssociativity :: forall proxy f. (MonadPlus f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
monadPlusAssociativity _ = property $ \(Apply (a :: f Integer)) (Apply (b :: f Integer)) (Apply (c :: f Integer)) -> eq1 (mplus a (mplus b c)) (mplus (mplus a b) c)
monadPlusLeftZero :: forall proxy f. (MonadPlus f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
monadPlusLeftZero _ = property $ \(k' :: LinearEquationM f) -> eq1 (mzero >>= runLinearEquationM k') mzero
monadPlusRightZero :: forall proxy f. (MonadPlus f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
monadPlusRightZero _ = property $ \(Apply (a :: f Integer)) -> eq1 (a >> (mzero :: f Integer)) mzero
#endif
#endif