Jonathan S. Shapiro wrote: > So the question is now: how do we recover objects without having > subtypes? > > Actually, this turns out to be separable into two questions: > > 1. How do we recover a suitably constrained form of existential > type (objects)? > > 2. How do we recover inheritance? > This may not be strictly related to subtyping but one other programming pattern I associate with "objects" is using them to control visibility. [...] > What we now have in mind is to introduce a new constraint: > > (has-field 'a name 'b) > I don't see how you would be able to get "protected" fields out of this. Perhaps that's fine (I've seen it mis-used quite often), but just thought I'd mention it.
The module system might be a better way to perform that kind of encapsulation anyway. Is there a module equivalent of "friend"? -Eric _______________________________________________ bitc-dev mailing list [email protected] http://www.coyotos.org/mailman/listinfo/bitc-dev
