[Haskell-cafe] Re: Existencial quantification and polymorphic datatypes (actually, components...)

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4294967296 :: Integer (...) In the above you can see the polymorphism of the return type of fromInteger, it returns a Int8 or a Int32.

You can see the polymorphism of the argument of "show", it takes an Int8 or Int32 or Integer.

The latest ghc-6.10.1 also allows avoiding use of SomeNum, see impredicative-polymorphism: http://www.haskell.org/ghc/docs/latest/html/users_guide/other-type-extension...

Great, thanks! I'm enlightened :) But how is this: data SomeNum = forall a. SN a different from: data SomeNum = SN (forall a. a) ? Maurício