- From: Ian Hickson <py8ieh@bath.ac.uk>
- Date: Thu, 30 Sep 1999 23:26:48 +0100 (BST)
- To: Chris Lilley <chris@w3.org>
- cc: www-style <www-style@w3.org>, "L. David Baron" <dbaron@fas.harvard.edu>, peterl@netscape.com
On Thu, 30 Sep 1999, Chris Lilley wrote: >> When|If Schemas are pointed to by namespace URIs (as suggested in >> various packaging ideas recently), then namespaces will fill >> basically the same role as PUBLIC/SYSTEM FPIs/DTDs, and so n (where >> here n=3) namespaces will become a necessity. > So in each DTD/XSchema that uses a given vocabulary set, it has a > different namespace identifier, then there is no ability to > recognise different namespaces. Sorry, I don't follow that. > So you have made namespace declarations be an exact analogue of > doctype declarations, which already exist, and removed the ability > to identify which vocabularies are being combined in a given > document. No. The problem with DOCTYPEs is that they can only appear once in a document. The ability of identifying which vocabularies are used in a document is done by the xmlns attribute(s), which can appear as often as required. The content of these attributes is an arbitrary unique string. This string uniquely identifies a namespace. Each namespace can have a Schema (just like each FPI has a DTD). So just like the <!DOCTYPE> points to the DTD, it makes sense for the xmlns= to point to the Schema. No? If this is not the case, then what _is_ the difference between namespace declarations and doctypes? (Note -- I make two assumptions which may be flawed: 1. Schemas are basically souped up DTDs, and 2. each namespace will only have one Schema. Are these assumptions correct?) -- Ian Hickson : Is your JavaScript ready for Nav5 and IE5? : Get the latest JavaScript client sniffer at : http://developer.netscape.com/docs/examples/javascript/browser_type.html
Received on Thursday, 30 September 1999 18:26:51 UTC