Y Combinator in Haskell

Question

Is it possible to write the Y Combinator in Haskell?

It seems like it would have an infinitely recursive type.

 Y :: f -> b -> c
 where f :: (f -         


        

Answer 1

Here's a non-recursive definition of the y-combinator in haskell:

newtype Mu a = Mu (Mu a -> a)
y f = (\h -> h $ Mu h) (\x -> f . (\(Mu g) -> g) x $ x)

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