[xmlschemata] Support of warnings by schema languages

Hi,

Suppose I have a schema allowing zero or more "bar" elements within
"foo":

foo= element {element bar {text()} *}

and suppose I have written an implementation with my favorite
programming language which stores "bars" in an array with a length of
five.

A document with 6 bars is valid per the definition of the markup
language but my implementation will not support it correctly.

Isn't it one of the cases where it would be nice to have a notion of
"warning" and add a third state to the result of a validation which is
currently a binary true|false ?

I have been thinking about it recently and although not obvious I think
that this could be implemented at least as an extension in Relax NG by
adding an optional foreign "warning" attribute to the alternatives of a
choice: if the schema is valid per an alternative holding a warning
attribute then the warning is raised.

Anyway, before investigating further, the question is probably to know
if there is a real requirement for this feature!

What do you think?

Eric

-- 
See you in San Diego.
                               http://conferences.oreillynet.com/os2002/
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Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
(W3C) XML Schema ISBN:0-596-00252-1 http://oreilly.com/catalog/xmlschema
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