[Haskell-cafe] a bunch of newbie questions

Brian Hulley brianh at metamilk.com
Fri Aug 4 17:32:22 EDT 2006


Bulat Ziganshin wrote:
> Hello Brian,
>
> Friday, August 4, 2006, 8:50:25 PM, you wrote:
>
>>         class Bar a b where
>>             bar :: a -> b
>
>> (*) But there's one exception: you can't use typeclasses to resolve
>> overloadings between values and functions because non-function
>> values don't have a type of the form A -> B:
>
>>         cool :: Int
>>         cool :: Char -> String
>
>>         class Cool -- Ooops! fundamental problem encountered ;-)
>
> class Cool a where
>    cool :: a
>
> instance Cool Int
> instance Cool (Char -> String)
>
> ?

Yes thanks - someone else pointed this out to me off-list as well.
I think that mental block must have been caused by watching too many 
episodes of Star Trek yesterday!
Ok I give up, there's just no excuse... ;-)

Brian.

-- 
Logic empowers us and Love gives us purpose.
Yet still phantoms restless for eras long past,
congealed in the present in unthought forms,
strive mightily unseen to destroy us.

http://www.metamilk.com 



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