[Bug 3245] Equality of strings

http://www.w3.org/Bugs/Public/show_bug.cgi?id=3245





------- Comment #2 from cmsmcq@w3.org  2007-04-20 15:36 -------
Thank you; the point about possibly equating strings which have the same
normalized form is an interesting one.

Changing identity constraints to use equality rather than identity
has been discussed, but if all schema tests use equality rather 
than identity, then the distinction between identity and equality
is lost, and we are back where we were in XML Schema 1.0, trying
to square the circle and resolve the conflicting desire to have 
certain things (or pairs of things) be both the same and not the same.
The Working Group has not made any final decision on the issue,
but it is safe to say that discussions have not so far shown consensus
on the idea.

It would be possible, without backward compatibility problems, to
define equality for strings as involving Unicode normalization, but
(as the originators of the comment are aware) since strings are
not ordered by XML Schema, equality of strings is not appealed to at
any point in schema validity assessment.  If it would be useful to
others using XML Schema (e.g. XSL, XQuery, XForms, ...) for XSD
to define string equality in this way, without changing the behavior
of enumerations etc., then please let us know.

Received on Friday, 20 April 2007 15:36:36 UTC