RE: Nate's objections to Motion 42
Michel Hack wrote:
> Nate Hayes replied to me:
> > > > If an implementation throws exceptions, a user will always be
alerted
> > > > as soon as the invalid construction is encountered, regardless what
> > > > the decoration scheme is. So it's a moot point.
> > >
> > > Not it's not: we want to allow the two kinds of Empty to have
different
> > > propagation rules, so that ILL will not be lost, but EMP could under
> > > certain circumstances be absorbed. In the absence of exceptions this
> > > should allow validity tests to be deferred longer.
> >
> > If you're talking strictly about arithmetic operations, why would you
ever
> > want an emp decoration (or an empty set, for that matter) to be
absorbed?
>
> I said that Motion 42 decorations were *primarily* about arithmetic
> operations, not *strictly*. In fact there are deliberate exceptions
> to the general rule even for arithmetic expressions, e.g. case().
Ok. So what I hear you saying is that for arithmetic operations, you never
want or expect an emp decoration (or an empty set) to be absorbed. Right?
Nate