W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > October to December 2005

changes in XQuery and SPARQL's use of XQuery

From: Eric Prud'hommeaux <eric@w3.org>
Date: Fri, 18 Nov 2005 04:26:08 -0500
To: public-rdf-dawg@w3.org
Message-ID: <20051118092608.GE30801@w3.org>
XQuery, XPath, and XPath F&O have changed in a number of ways since I
used them to draft the original Invocation and Effective Boolean Value
sections.
  - XQuery now has an additional type of promotion, conversion of
    xsd:untypedAtomic to the expected type for a function, (xsd:double
    for numeric arguments).
  - XQuery now has an additional type of promotion, URI promotion which
    converts xsd:anyURI to xsd:string when the latter is needed.
  - If the argument is a typed literal with a datatype of xsd:boolean or
    a derived from xsd:boolean, the EBV (effective boolean value) is the
    truth value of argument.
  - EBV rules for xsd:string apply to types derived from xsd:string.

SPARQL supports only string, double, float, integer, and
dateTime. Conspicuously absent from this list is xsd:boolean, however,
it appears in several places in the spec. I propose that, in the
interest of editorial simplicity and compatibility with XQuery, we add
xsd:boolean to the set of supported datatypes. [Note to self, uncomment
the @@s to add xsd:boolean.]

Also, our use of plain literal may be closer to XPath's use of
xsd:untypedAtomic than to xsd:xstring. Needs more thought. Related
thread:
  http://lists.w3.org/Archives/Public/public-rdf-dawg/2005OctDec/thread#230

SPARQL issues text:
  http://www.w3.org/2001/sw/DataAccess/rq23/#invocation
  http://www.w3.org/2001/sw/DataAccess/rq23/#ebv

Some XQuery et al evaluation notes:
  http://www.w3.org/2005/11/XQueryTour/
-- 
-eric

office: +81.466.49.1170 W3C, Keio Research Institute at SFC,
                        Shonan Fujisawa Campus, Keio University,
                        5322 Endo, Fujisawa, Kanagawa 252-8520
                        JAPAN
        +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA
cell:   +81.90.6533.3882

(eric@w3.org)
Feel free to forward this message to any list for any purpose other than
email address distribution.

Received on Friday, 18 November 2005 09:26:10 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:24 GMT