- From: Noah Mendelsohn/Cambridge/IBM <noah_mendelsohn@us.ibm.com>
- Date: Wed, 3 Apr 2002 15:58:57 -0500
- To: "Jeff Rafter" <jeffrafter@defined.net>
- Cc: xmlschema-dev@w3.org
Interesting thread. One thing to keep in mind: XML Infosets are inherently ordered, and our inheritance model is based on sequences, which tend to be ordered. In my experience with object systems, composition or mix-in (as I prefer to call it) tends to be an unordered thought: I want to know that I support interface I1 and I2, but in no sense does one come before the other. Thus, these sorts of multiple inheritance idioms are particularly tricky in XML, in which order tends to be naturally significant. Furthermore, as Jeni points out, it's quite nice to have answers that are reflected in the PSVI, so that downstream applications. This is more an intuition than a formal proposal, but if I were trying to do this sort of mix-in/multiple-inheritance/composition in schema, I might be tempted to look at something like <all> as a starting point. It validates content independent of order. Not quite sure where I'd go from there, but I thought I'd mention it. Of course, in its current form, it does nothing to sync up attributes with element content. ------------------------------------------------------------------ Noah Mendelsohn Voice: 1-617-693-4036 IBM Corporation Fax: 1-617-693-8676 One Rogers Street Cambridge, MA 02142 ------------------------------------------------------------------
Received on Wednesday, 3 April 2002 16:09:33 UTC