- From: Adrian Giurca <giurca@tu-cottbus.de>
- Date: Fri, 07 Dec 2007 10:38:39 +0100
- To: "David Z. Hirtle" <dhirtle@cs.uwaterloo.ca>
- CC: "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>
Hi David, David Z. Hirtle wrote: > Hi Adrian, > > >> I read them but I don't see why <formula>, <declare> are necessary. I >> understand the need for <op> and <object> for example... >> > > The <formula> and <declare> elements are there because the XML syntax > is fully-striped (as explained at the beginning 2.1.1.6.). A > stripe-skipped version of the XSDs is also possible, of course. > I do not understand why the XML syntax has apparently not been derived from the (normative?) EBNF in a principled manner and that it therefore seems to contain design flaws. The concepts such as "fully-stripped" or "stripe-skipped" a re not very clear in the argumentation from 2.1.1.6. > >> You are right. I was in hurry and therefore wrong. Below is the proposed >> design: >> >> <xs:element name="CONDITION" type="CONDITION.type" abstract="true"/> >> <xs:complexType name="CONDITION.type" abstract="true"/> >> <xs:element name="And" type="And.Type" substitutionGroup="CONDITION"/> >> > > I still don't think that will work because CONDITION and And are of > different types. Have you tested it with, say, XSV? > (http://www.w3.org/2001/03/webdata/xsv) > Of course. This is the design we have in R2ML. Moreover, the above UML diagram (which is in the BLD ) comes into this approach. > Another advantage of groups is that they are nicely modular, and can > be used with xs:redefine. Because the XSDs are so far stand-alone > ("monolithic"), this hasn't been taken advantage of, but it may be > important in the future. > > This is an approach which can be discussed. The need for redefine comes if you want to define dialects as in RuleML but it might not be the only solution. xs:group is equivalent to "parameter entities", which have been used in DTDs to simulate something like derivation/specialization. But since XMLS has a true derivation mechanism, it's not a good idea to stick to the old DTD practice of simulating derivation. >> I know the document but there is about DTD modularization and it might >> not be the same case for an XMLS. >> > > See appendices A - C of the document for the XML Schemas. > > David > > Adrian
Received on Friday, 7 December 2007 09:37:02 UTC