IOError vs. Exception vs. IOException

[Simon Marlow]

> > Our feeling over here is that this is an unforced change, so in
> > isolation it probably wouldn't be worthwhile.  It'll break=20
> some code,
> > and the awkward squad paper will have to be updated to=20
> comply (although
> > we just noticed it is already wrong about the behaviour of
> > Prelude.catch).
> >=20
> > However, if there's concensus that folk would prefer the alternate
> > definition of IOError, then we're happy to go along with it.
>=20
> There have been three responses, all in favour of change.  What's your
> view now?  I would rather see a confusing interface fixed than force
> the other implementations to change their Preludes to implement it,
> but then I have no investment in the old interface.

Fine, I'm happy to go along with the change.

Cheers,
	Simon