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[Bug 1231] New: Pattern facet for ordered durations can and should be simplified

From: <bugzilla@wiggum.w3.org>
Date: Sat, 09 Apr 2005 02:17:08 +0000
To: public-qt-comments@w3.org
Message-Id: <E1DK5X2-0002kR-RS@wiggum.w3.org>


           Summary: Pattern facet for ordered durations can and should be
           Product: XPath / XQuery / XSLT
           Version: Last Call drafts
          Platform: PC
               URL: http://www.w3.org/XML/Group/2004/06/xmlschema-
        OS/Version: Linux
            Status: NEW
          Severity: minor
          Priority: P4
         Component: Data Model
        AssignedTo: ndw@nwalsh.com
        ReportedBy: cmsmcq@w3.org
         QAContact: public-qt-comments@w3.org

In appendix C (http://www.w3.org/TR/2005/WD-xpath-datamodel-20050404/#xdtschema),
declarations are given of the types yearMonthDuration and dayTimeDuration.

In each, a pattern facet is given which seeks (as far as I can tell) 
to provide a regular expression which defines the lexical space of 
the new types.

Since all lexical forms for values in these types must ALSO be legal 
lexical forms for the parent duration type, it's not really necessary 
to recapitulate all the constraints of that type.  The patterns 
may be simplified to "[^DT]*" for yearMonthDuration and 
"[^YM]*(T.*)?" for dayTimeDuration. (The lexical space defined by
these is the same as that defined by the current declarations,
if my work with Grail is reliable.)

If the WGs prefer to use patterns which fully capture all the
constraints on lexical forms, the bug in the dayTimeDuration
facet which allows forms like "P2HS" and "P2H.S" should
be fixed.
Received on Saturday, 9 April 2005 02:17:10 UTC

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