visibility of instances (was: Bug in compiling large projects ?)

[Martin Erwig]

On Dec 15, 2004, at 8:30 AM, Simon Peyton-Jones wrote:

> OK, I understand this.
>
> 1.  You really do have overlapping instances, exactly as reported in 
> the error message.
>
> 2.  The instance in Data.Graph.Inductive.Graph looks like this
> 	instance ... => Eq (gr a b)
>      This is, as you say, crazy, because it overlaps with every 
> arity-2 type constructor.
>      In particular, it overlaps with Eq (a,b)
>
>      I'm copying Martin Erwig, who is, I think the maintainer of the 
> fgl/ package, because
>      it seems to me that it should be fixed.

I will probably have some time in January 2005 to work on this and a 
couple of other
issues in the FGL.

--
Martin