[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Inheritance and other buzzwords
From: Tim Bray <tbray@t...> > The current namespace proposal adds one level of indirection to the names > we give document components, and includes a technique for ensuring that > the names are unique across the universe of the Internet. That's all! I think Tim is correct in trying to limit people's perception of what the namespace proposal does. The basic requirement is, more or less, to have a declaration which is as simple as possible, as non-intrusive as possible, and which does not require explicit element or attribute declarations, which will allow the RDF people to say "this element is one of our element types". Whether there is, underlying this, some more interesting structure of links derived from type names not instances (my belief), or an underlying honeycomb of parallel, mutually augmenting schemas (the architectures idea) should not be the deciding factor for the namespace proposal, to me. I think it is enough that the namespace 1.0 be expressed in a way that does not rule out an interpretation using either ot these mechanisms (or others) is enough at this stage. It was not Tim's point, but strictly I think the proposal adds two levels of indirection: prefix->ns; then ns->schema It is because of this indirection that the current proposal does not ensure unique naming: there is a possibility of an error where two fragments using the same prefix are combined under the same namespace declaration. This is particularly an issue of maintenance: where a schema is updated, perhaps to make it have a more restrictive content model. So XML tools which combine fragments with namspaces will have to be able to rewrite name prefixes. If there is <?xml:namespace ns="rick" schema="rick-v2-3-1" ?> and <?xml:namespace ns="rick" schema="rick-v2-3-2 ?> then the processing tool will have to be smart enough to, for example, relabel the second PI <?xml:namespace ns="rick-a schema="rick-v2-3-2 ?> and all the names which use this must be relabelled too in the instance. I believe the net effect of this is that prefixes will begin off simple, and end up more and more complex, more and more like partial schema URLs. Rick Jelliffe xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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