[Haskell-cafe] Existentially-quantified constructors, Eq and Show

[Tomasz Zielonka]

On Wed, Dec 07, 2005 at 04:09:31PM -0800, John Meacham wrote:
> you arn't using existential types here. an example with an existential
> type would be (in ghc syntax)
> 
> > data forall a . State
> >     = Start
> >     | Stop
> >     | (Show a, Eq a) => State a

Shouldn't it be:

> data State
>     = Start
>     | Stop
>     | forall a . (Show a, Eq a) => State a

?

Best regards
Tomasz

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