RE: Request for help with semantics of XML Schema Datatypes

"3.2"^^xsd:float and "3.2"^^xsd:decimal will compare equal.
Decimal gets promoted to float.  

All the best, Ashok


-----Original Message-----
From: Jeremy Carroll [mailto:jjc@hplb.hpl.hp.com]
Sent: Tuesday, October 05, 2004 2:56 AM
To: Ashok Malhotra
Cc: w3c-xml-query-wg@w3.org; w3c-xsl-wg@w3.org; SWBPD list
Subject: Re: Request for help with semantics of XML Schema Datatypes


Thanks, a few inline comments ...


> 
> "3.2"^^xsd:float the same as or different from "3.2"^^xsd:int
> [AM] There is no legal value such as "3.2"^^xsd:int.  Are you thinking
> of some kind of truncation semantics?

No sorry I mistyped I meant "3.2"^^xsd:decimal, the point being, if I 
understand correctly that these compare different becase 
"3.2"^^xsd:float is the nearest number in the float value space to 3.2, 
whereas "3.2"^^xsd:decimal is precise.

> 
> "http://www.example.org/"^^xsd:string the same as or different from 
> "http://www.example.org/"^^xsd:anyURI
> [AM] This is currently under discussion.  I can let you know when
> we have a firm position.
> 
> where the ^^ denotes the value arising from the lexical form on the left 
> according to the datatype on the right.
> 
> I have looked at F&O and the XPath 2.0 WDs and believe that an answer 
> offered by your WGs is the eq operator in XPath. (Modulo difficulties to 
> do with NaN, and numeric approximation). This would suggest that all the 
> numeric types have a shared value space of numbers, understood as in 
> mathematics; whereas all the other datatypes are disjoint, and 
> understood more as in a sorted type system (is that the right term?). I 
> haven't yet understood the rules for dates under eq.
> [AM] In XML Schema you cannot compare values from different datatypes
> but the F&O defines ordering and equality semantics for some of them.
> 

In SW the equality function is what really matters, ordering is a bonus.

> This message is to ask whether:
> - any participants of either XSLT or XQuery WGs would like to 
> participate in this Task Force
> [AM] I'm not sure how much time I can commit to, but I can certainly answer questions.
> - you would like me to attend one of your telecons to explain in more 
> detail what are the concerns
> 

anyone else?

> BTW, the Semantic Web Best Practices and Deployment WG, will be having a 
> face to face in Bristol on 1st and 2nd Nov. For this TF, the f2f goal is 
> to agree an outline first note, outlining the issues and possible solutions.
> 

A possible way forward would be if your groups could comment on our 
first note, which will be replaced by a second note, once we have 
processed feedback ... It may become clearer what value the 
participation of your WG in the process would be.

Jeremy

Received on Tuesday, 5 October 2004 12:08:26 UTC