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Constant Applicative
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| newtype Constant a b = Constant { getConstant :: a } deriving (Eq, Ord, Show) | |
| instance Functor (Constant a) where | |
| fmap _ (Constant a) = Constant a | |
| instance Monoid a => Applicative (Constant a) where | |
| pure x = Constant mempty | |
| (<*>) (Constant a) (Constant b) = Constant (a <> b) |
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