Haskell-book/18/Instance/src/Nope.hs


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module Nope where

import Test.QuickCheck
import Test.QuickCheck.Checkers

data Nope a = NopeDotJpg deriving (Show, Eq)

instance Functor Nope where
    fmap _ _ = NopeDotJpg

instance Applicative Nope where
    pure _ = NopeDotJpg
    _ <*> _ = NopeDotJpg

instance Monad Nope where
    return _ = NopeDotJpg
    _ >>= _ = NopeDotJpg

instance Arbitrary (Nope a) where
    arbitrary = return NopeDotJpg

instance EqProp (Nope a) where
    (=-=) = eq