import/instance bug

[Sigbjorn Finne]

Conal Elliott conal@microsoft.com writes:
>
> In Zeep.hs:
> 
>    module Zeep where
>    instance Eq [(Int, Int)]
>
> In tst.hs:
>
>    import Zeep
>   import IOExts
>
> The result:
....
> ERROR "c:\hugs98/lib\Array.hs":60 - Cannot justify constraints in
> instance member binding
> *** Expression    : (==)
> *** Type          : Eq (Array a b) => Array a b -> Array a b ->Bool
> *** Given context : Eq (Array a b)
> *** Constraints   : Eq [(a,b)]

Not really a bug, see Jeff's response (&cure) to a very similar bug
report:

 http://haskell.org/pipermail/hugs-bugs/2001-December/000545.html

--sigbjorn