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view similer.hs @ 0:7a82a5e50499

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Initial commit. define to Functor for Similer
author Yasutaka Higa <e115763@ie.u-ryukyu.ac.jp>
date Sun, 31 Aug 2014 16:48:45 +0900
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children 878d1e271709
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data Similer a f b = Similer a (a -> b) b

instance Functor (Similer a f) where
  fmap g (Similer a f b) = Similer a (g . f) $ g b

eta :: a -> Similer a (a -> a) a
eta a = Similer a id a

--mu :: (Eq a, Eq b, Eq c) => Similer a (a -> b) (Similer b (b -> c) c) -> Similer b (b -> c) c
--mu (Similer a f (Similer b g c)) = if ((f a) == b) then Similer b g c else undefined
--mu (Similer a f (Similer b g c)) = if ((f a) == b) then Similer b g c else undefined