Re: XSchema Spec, Sections 2.0 and 2.1 (Draft 1)
Simon St. Laurent wrote: > PP> Resources (namespaces, characters, entities, etc.) are one thing. > PP> Constraints are another. I'd like to keep them separate. > > JC>And I would like to keep them together. A matter of taste. > > Unfortunately, I think it's a lot more than a matter of taste. Making XSchemas > perform text substitutions requires a much more complex processing model. It's also a matter of what our goals are. My original hopes for XSchema were relatively modest -- I wanted a standard way to explore DTDs. A side-effect was that parsers could use the information for validation. I also had some vague hopes for schema reuse and laying a foundation for strong typing. When John pointed out that you couldn't validate an XML document without entities and notations, I had to agree and added both to my DTD. It simply didn't occur to me that such validation would be done outside the parser -- the back-and-forth between XML applications and parsers described by John and Paul. I just assumed that validating parsers would, in the future, read XSchemas as they now read DTDs. Having now read the multitudinous arguments on each side, I have come to the conclusion that entities don't belong in XSchema for two reasons: 1) Requiring that a parser include information (an entity definition) from an XSchema document just to get a well-formed document is a bad mistake. Evolutionary steps that require you to throw away existing software don't have much chance of success. 2) I find the view of XSchema-as-schema far more compelling than XSchema-as-DTD. Although both fit my original goal (DTD exploration), XSchema-as-DTD is a dead end, while XSchema-as-schema is a building block for the future. -- Ron Bourret 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...)
PURCHASE STYLUS STUDIO ONLINE TODAY!
Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!
Download The World's Best XML IDE!
Accelerate XML development with our award-winning XML IDE - Download a free trial today!
Subscribe in XML format