[Haskell-cafe] Instance match surprise

Tom Ellis tom-lists-haskell-cafe-2013 at jaguarpaw.co.uk
Mon Feb 1 20:30:42 UTC 2016

On Mon, Feb 01, 2016 at 09:22:31PM +0100, Wojtek Narczyński wrote:
> On 01.02.2016 20:19, Imants Cekusins wrote:
> >in
> >instance (Eq a, Eq q, Typeable a, Typeable q, AtmAcct a, Against q) =>
> >     Match a q where
> >
> >ANY is q
> >because
> >instance Against ANY
> But I require q to be Eq and Typeable, and ANY is none of those two?

Correct.  The actual reason is more subtle.  See my sibling post.


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