- From: <bugzilla@wiggum.w3.org>
- Date: Wed, 04 Feb 2009 15:41:40 +0000
- To: www-xml-schema-comments@w3.org
http://www.w3.org/Bugs/Public/show_bug.cgi?id=6522 --- Comment #8 from Michael Kay <mike@saxonica.com> 2009-02-04 15:41:39 --- >We should note that--as currently defined--a datatype does not have a name. Technically this is true, we say: "Different simple type definitions with different selections of facets can describe the same datatype. " So, for example, a restriction of xs:string with the pattern facet "x|y" describes the same datatype as a restriction of xs:string with the enumeration facet ("x", "y"). Fortunately, however, this is a fact that we never take advantage of; we never require a processor to detect that these are the same datatype (in general, it may be impossible to do so). This means that the fact that they are the same has no observable consequences and therefore should probably not have been stated in the specification. Any use of reflection or introspection, as I discussed in comment #5, would almost certainly relate to type definitions rather than datatypes per se. In any processing system that annotates values with types, the annotation is likely in practice to be a type definition rather than a "pure" datatype. And of course the relations such as "is derived from" are properties of type definitions, not to datatypes. So the fact remains, that having two type definitions that are "identical except in name" causes us problems. -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the QA contact for the bug.
Received on Wednesday, 4 February 2009 15:41:48 UTC