On Thu, Dec 15, 2011 at 06:49:13PM +1000, Gregory Crosswhite wrote:
>
> So at the end of the day... what is the point of even making Maybe and []
> instances of Alternative?
The Alternative and Monoid instances for [] are equivalent. However,
the Alternative and Monoid instances for Maybe are not. To wit:
> (Just (Sum 4)) <|> (Just (Sum 3))
Just (Sum {getSum = 4})
> (Just (Sum 4)) `mappend` (Just (Sum 3))
Just (Sum {getSum = 7})
-Brent
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