- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Thu, 6 Sep 2007 13:33:04 -0400
- To: "Seaborne, Andy" <andy.seaborne@hp.com>
- Cc: Lee Feigenbaum <lee@thefigtrees.net>, RDF Data Access Working Group <public-rdf-dawg@w3.org>
- Message-ID: <20070906173304.GF32583@w3.org>
* Seaborne, Andy <andy.seaborne@hp.com> [2007-09-06 17:53+0100] > > > > -------- Original Message -------- > > From: Eric Prud'hommeaux <mailto:eric@w3.org> > > Date: 6 September 2007 17:21 > > > > I read this as saying that in *XQuery* > > "20070906T12:08"^^xsd:dateTime is always > > > "20070906T12:07"^^xsd:dateTime (and "20070906"^^xsd:date is always > > > "20070906"^^xsd:date) > > That is, no timezone info. > > (Actually in ARQ "20070906"^^xsd:date = "20070906"^^xsd:date :-) > > > > > [[ > > C.2 Dynamic Context Components > > > > The following table describes how values are assigned to the various > > components of the dynamic context. All these components are initialized > > by mechanisms defined by the host language. For each component, > > "global" indicates that the value of the component remains constant > > throughout evaluation of the XPath expression, whereas "dynamic" > > indicates that the value of the component can be modified by the > > evaluation of subexpressions. > > > > Dynamic Context Components > > ┌──────────────────┬─────────────────────────────────────────────┐ > > │ Component │ Scope │ > > ├──────────────────┼─────────────────────────────────────────────┤ > > │Implicit timezone │global; must be initialized by implementation│ > > └──────────────────┴─────────────────────────────────────────────┘ ]] > > -- > > http://www.w3.org/TR/2007/REC-xpath20-20070123/#id-xp-evaluation-context-components > > > > - so, there can be only one implicit timezone for the evaluation of a > > query. > > > > I'd like to follow XQuery; will draft clarifying text after lunch. > > > > Does that influence your interpretation Andy? > > I'm following: > http://www.w3.org/TR/xmlschema-2/#dateTime-order > > The text you quote does not change my interpretation of the comparison text - it clarifies what happens in XPath/Xquery > > The comparisons both have no timezone so it's case B: I see no reason to deviate from XQuery in this regard. I'd like to follow XQuery's lead here and put this clarifying text above 11.3.1: [[ xsd:dateTimes that have no timezone are given an implicit time, as defined by <a href="http://www.w3.org/TR/2007/REC-xpath20-20070123/#dt-timezone">XQuery</a> ]] giving a timezone to all dateTime comparisons. I can't say what an extended implementation does with xsd:date, but wouldn't want a test case to lock us in to a behavoir that was inconsistent with XQuery without discussing the trade-offs. > [[ > B. If P and Q either both have a time zone or both do not have a time zone, compare P and Q field by field from the year field down to the second field, and return a result as soon as it can be determined. > ]] > > Cases C and D are the situation where one has a timezone, one does not. > > (ARQ uses code from Apache Xerces to actually do the comparison - it can return INDETERMINATE). > > Andy > > > -------------------------------------------- > Hewlett-Packard Limited > Registered Office: Cain Road, Bracknell, Berks RG12 1HN > Registered No: 690597 England -- -eric office: +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA mobile: +1.617.599.3509 (eric@w3.org) Feel free to forward this message to any list for any purpose other than email address distribution.
Received on Thursday, 6 September 2007 17:33:13 UTC