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

[Joel Reymont]

I was also hoping that something like this would let me avoid  
quantifying a in functions downstream but alas, it does not happen. I  
have to use (Eq a, Show a) => a ... everywhere else.

On Dec 7, 2005, at 11:14 PM, Bulat Ziganshin wrote:

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

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