Re: various issues
len bullard (cbullard@hiwaay.net)
Fri, 11 Apr 1997 12:20:33 -0500
Digitome Ltd wrote:
>
> >Peter Murray-Rust writes:
> > I think I start to understand. By 'structure' you mean the tree structure
> > of each DTD? In which case AFs are a way of providing multiple views of the
> > same document?
>
> An AF is like a virtual class in OO-speak. HyTime is a bit like a set of
> virtual class definitions. From these virtual classes you derive your own
> classes (DTDs) that inherit from their super-class(HyTime).
>
> Multiple inheritance is allowwed. That is, a given DTD can inherit from
> multiple AF super-classes.
This ties back to the thread on CTS where someone was asking about
why SGML could not inherit. Someone should explain in terms
virtual inheritance, and interface and code inheritance, how
AFs can be adopted by the OOPMen. That explanation of SGML,
architectures, and OOP technique is a missing piece of the
implementation puzzle and a considerable opportunity for a
college text.
len bullard