- From: Al Gilman <asgilman@access.digex.net>
- Date: Tue, 6 Jan 1998 10:07:25 -0500 (EST)
- To: Harald.Alvestrand@maxware.no (Harald Tveit Alvestrand)
- Cc: connolly@w3.org, masinter@parc.xerox.com, leslie@bunyip.com, fielding@kiwi.ics.uci.edu, jcurran@bbn.com, harald.t.alvestrand@uninett.no, moore@cs.utk.edu, uri@bunyip.com, urn-ietf@bunyip.com
to follow up on what Harald Tveit Alvestrand said: Dan Connolly: > >Since Larry asked, I'll (re-)state the W3C opinion: we're > >heavily invested in the notion of a single, extensible universal > >address space: Al Gilman: That's one of the sources of the problem: too much emphasis on singleness. If you frame the problem as understanding a class of text strings that function as identifiers, in the context of a web of string and name classes, you will get unstuck from the impasses. Harald Alvestrand: > > The problem, to my mind, is that we really have two deep axioms > here: > > - The class of identifiers that, roughly speaking, start with > a short string and a colon, and go on in a charset-limited way. > All the URI axioms you cite are axioms of that class. > - The class of identifiers that, in addtion to being of the first > class, obey certain additional rules, such as hierarchy, > hostname representation and so on. > None of this is necessary for the URI axioms; they are vitally > necessary for today's day-to-day usage of the World Wide Web. > > (Everyone with me so far?) Al Gilman: Almost. You are very close. But you are not getting quite deep enough. It is not clear that everything that gets called an URN needs to have all the armor of your first class. There is a level of abstraction for names where the relative and absolute URLs that retrieve the same resource are viewed as variant forms of one name. We may need to link the URI documents to documents which capture this view of the naming agenda in order to have adequate documentation of what is going on. Harald A: > > If separation is not the Right Way, the issues are of course slightly > different.... Al Gilman: The Right Way is a web of sub-documents specifying a web of classes. So long as the semantics of the sub-documents is strong enough, the grouping into documents becomes a non-problem. The IETF is being materially hampered in working this situation by its failure to adopt more powerful linking and semantic modeling norms for its working documents. The canonical sub-document web for this topic is: Ancestor classes [standards track]: a string class that survives a variety of environments a name class that guarantees certain semantic properties Resource classes [BCP track]: addressing imported from the Internet platform generic hierarchy as has been used in multiple URL schemes intra-document references to named subdocuments or locations [via #fragment construct] [I may not have got them all] Scheme specifications [three tracks per URLreg plans]: Draw on the above two sets of class definitions. The URN development - should be free to define names as polymorphic and containing some forms that do not meet the hardiness requirements of the HTML/HTTP cycle. - should get with the program of scheme extension so we have one program of scheme vocabulary definition which will preserve the low cost of distinguishing things syntactically across a broad range of contexts. -- Al Gilman
Received on Tuesday, 6 January 1998 10:09:32 UTC