Re: different extension styles (local vs global vs invisible)

I do not know what you mean by a "global flag". The dialect name indicates
what the semantics is. It is not on a per-construct basis, but per-dialect.

You can say that the dialect name is such a global flag.  There is no any
out-of-bound communication either on a per dialect basis or on a
per construct basis.


	--michael  


> > I think rdfs:subclassOf or rdfs:type can be extended.
> 
> I think there's a design choice here.  It can be made on a case-by-case
> basis with each extension, but I think the right choice is probably the
> same almost all the time.
> 
> You have some bit of the language, say, ##, and you want to have it mean
> something different, as you've said [1].  I see three approaches:
> 
>    Option 1:  When you want the different meaning, use a different token,
>               like rif:subclass2 or ### or whatever.  (Let's call this a
>               "local extension")
> 
>    Option 2:  You use the same token (rif:subclass or ##) and add a flag
>               somewhere else in the document to indicate it has a
>               different meaning.  ("Global extension")
> 
>    Option 3:  You use the same token, and tell people out-of-band that
>               you mean it in a different sense.  ("Invisible
>               extension".)
> 
> My sense right now is that option 3 is just plain bad, and that option 1
> is better than option 2 because it's less prone to misunderstanding and
> makes it easier to merge rulesets -- it lets you use both rif:subclass
> and rif:subclass2 in the same document.
> 
>      -- Sandro
> 
> [1] http://lists.w3.org/Archives/Public/public-rif-wg/2007Oct/0094
>     (Which, honestly, I don't understand -- it seems like you're
>     conflating properties of classes with properties of instances of
>     those classes -- but that's probably not related to the extension
>     question.)
> 
>