[Haskell-cafe] bug in WinHugs Version 20051031?

[Ross Paterson]

On Fri, Jan 06, 2006 at 01:52:23PM +0300, Bulat Ziganshin wrote:
> the following program fails to load in Hugs2005 with all Haskell
> extensions enabled:
> 
> instance (CharStream m h) => ByteStream m h where ...
> instance (ByteStream m h) => CharStream m h where ...

Looks circular to me, i.e. there's no justification for inferring
instances of either class.  However recent GHC's spot the recursion
in such cases and create mutually recursive instances.