Re: RFC: Extending method specializers

Pascal Costanza <pc@xxxxxxxxx> writes:

You could start by restricting the predicates to the kinds of
predicates that describe strict subset relationships, and for example,
reject a method on oddp when a method on primep already exists, or
vice versa. But this requires you to (a) either analyze the predicate
to find out what it does, or (b) restrict the predicates to a fixed
set of predefined ones.
That's a false dilemma. For situations where priority cannot be
clearly determined you could keep track of the method definition order
and evaluate the predicates in that order, selecting the first one
that passes (ML-style). You could add a protocol step and require the
programmer to specify the priority explicitly. You could even pick a
predicate based on the alphabetical order of its name :)

With a little thought, I'm sure it's possible to come up with a
practical and theoretically sound solution. This doesn't have to be
reduced to the halting problem :)

--
Regards,
Slava Akhmechet.
.