[Haskell-cafe] Existentially-quantified constructors, Eq and Show
haskell at sleepingsquirrel.org
Wed Dec 7 19:08:10 EST 2005
Joel Reymont wrote:
> Is there a less verbose way of doing this:
> data State a
> = Start
> | Stop
> | (Show a, Eq a) => State a
I'm curious, what is the difference between the above and...
data State a = Start
| State a deriving (Show, Eq)
...Does it give better error messages at compile time or something?
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