[Haskell-cafe] Re: Type System (Was: Currying and Partial Evaluation)

"Alfonso Acosta" wrote:

On Jan 9, 2008 1:07 AM, Achim Schneider wrote:

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Beg pardon? Are you referring to the type of y being described with 'b' instead of 'a'?

Yes.

"(a -> a) -> a" and "(b -> b) -> b" are equivalent.

For some reason ^^^^^^^^^^^^^^^

Yes, exactly that wire which isn't obscured by the boiler plate has kindled my interest.

ghc uses b instead of a if you are picky about it, just provide a type signature explicitly.

Prelude> let {y :: (a -> a) -> a ; y f = f $ y f} Prelude> :t y y :: (a -> a) -> a

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