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Re: XPath: what's the answre to True >= False

• To: michael.h.kay@n...
• Subject: Re: XPath: what's the answre to True >= False
• From: Uche Ogbuji <uche.ogbuji@f...>
• Date: Fri, 06 Dec 2002 13:08:01 -0700
• Cc: "'Berend de Boer'" <berend@x...>, "'xml-dev'" <xml-dev@l...>
• In-reply-to: Message from "Michael Kay" <michael.h.kay@n...> of "Fri, 06 Dec 2002 11:09:46 GMT." <000001c29d17$fcc6a280$6401a8c0@pcukmka>
• Sender: Uche Ogbuji <uche.ogbuji@f...>

> > When trying to create another XPath implementation I stumbled 
> > upon the 
> > somewhat complex conversion in paragraph 3.5: Booleans. To compare a 
> > boolean and a node-set, both are converted to Booleans. For all 
> > operators, including >= and <=. Can anyone tell me what:
> > 
> >     True >= False
> >     False >= True
> > 
> Section 3.4 says "When neither object to be compared is a node-set and
> the operator is <=, <, >= or >, then the objects are compared by
> converting both operands to numbers and comparing the numbers according
> to IEEE 754.
> 
> False <= True, because number(false()) = 0 and number(true()) = 1.
> 
> Suggestions as to how XPath 1.0 could have been improved are somewhat
> academic at this point...

No they aren't.  I think work will be continuing on XPath 1.0 (or on alternate 
forks from XPath 1.0 to technologies other than W3C XPath 2.0) for quite some 
time.  This might include notes that clarify aspects of XPath 1.0.


-- 
Uche Ogbuji                                    Fourthought, Inc.
http://uche.ogbuji.net    http://4Suite.org    http://fourthought.com
Tour of 4Suite - http://www.xml.com/pub/a/2002/10/16/py-xml.html
Proper XML Output in Python - http://www.xml.com/pub/a/2002/11/13/py-xml.html
RSS for Python - http://www-106.ibm.com/developerworks/webservices/library/ws-p
yth11.html
Debug XSLT on the fly - http://www-106.ibm.com/developerworks/xml/library/x-deb
ugxs.html

• References:
  • RE: XPath: what's the answre to True >= False
    • From: "Michael Kay" <michael.h.kay@n...>

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