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chris-martin/ConjList.hs

Created January 18, 2017 06:20
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ConjList.hs
newtype ConjList a = ConjList [a] deriving Show
instance Monoid a => Monoid (ConjList a) where
mempty = ConjList $ repeat mempty
mappend (ConjList x) (ConjList y) = ConjList $ zipWith mappend x y
λ> mappend (ConjList ["ab", "cd"]) (ConjList ["xc", "xy", "xp"])
ConjList ["abxc","cdxy"]
it :: (Monoid a, Data.String.IsString a) => ConjList a
λ> mappend (ConjList ["ab", "cd"]) mempty
ConjList ["ab","cd"]
it :: (Monoid a, Data.String.IsString a) => ConjList a
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