Concerning Time.TimeDiff

[Simon Marlow]

=20
> > in any case, since a pair of Int64's is not a clear win and=20
> an Integer
> > definatly is a clear win in terms of usability then I=20
> believe we should
> > go for that.
>=20
> It's a radical idea but... Maybe we could avoid all these=20
> issues by using an=20
> abstract type with all sensible instances (including Num=20
> though it is only=20
> semi-sensible for times).
>
> Internally, we might use Integer or two Int64s or we might=20
> even add Int128 to=20
> our compilers.  Externally it looks like an Integral (or=20
> Fractional?) type.

Yes, I think that's a reasonable compromise.  The accuracy is still
specified to be picoseconds, but the representation is hidden.

Any objections?

Cheers,
	Simon