module Test.QuickCheck.Property.Common.Internal (
Equal(..)
, runEqual
, Equalable(..)
) where
data Equal a = Equal a a
| NotE (Equal a)
| AndE (Equal a) (Equal a)
| OrE (Equal a) (Equal a)
runEqual :: (a -> a -> Bool) -> Equal a -> Bool
runEqual f (Equal a b) = f a b
runEqual f (NotE e) = not $ runEqual f e
runEqual f (AndE e g) = runEqual f e && runEqual f g
runEqual f (OrE e g) = runEqual f e && runEqual f g
class Equalable a where
type Result a :: *
type Compared a :: *
equalWith :: (Result a -> Result a -> Bool) -> a -> Compared a
mapEqual :: (Equal (Result a) -> Equal (Result a)) -> a -> a
zipEquals :: (Equal (Result a) -> Equal (Result a) -> Equal (Result a)) -> a -> a -> a
instance Equalable (Equal a) where
type Result (Equal a) = a
type Compared (Equal a) = Bool
equalWith = runEqual
mapEqual = id
zipEquals = id
instance Equalable a => Equalable (x -> a) where
type Result (x -> a) = Result a
type Compared (x -> a) = x -> Compared a
equalWith f fun = equalWith f . fun
mapEqual f fun = mapEqual f . fun
zipEquals f fun1 fun2 = \x -> zipEquals f (fun1 x) (fun2 x)