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RE: details of rdf:datatype?

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Mon, 14 Oct 2002 14:52:03 +0200
To: "Dan Connolly" <connolly@w3.org>, <w3c-rdfcore-wg@w3.org>
Message-ID: <BHEGLCKMOHGLGNOKPGHDEEFOCAAA.jjc@hpl.hp.com>


This (Dan's examples) is what I wanted, and I thought I lost a crucial
(straw poll) vote.

http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Sep/0178.html
item 11 -
ACTION: 2002-09-13#8 jjc update the abstract data model in concepts doc to
reflect the pair denoting a datatype literal

We decided that in the abstract syntax the datatyped values would be
represented as pairs (uri and lexical value). I am not sure when the
lexical=>value mapping takes place (it might be in Pat's court, but I got
the impression he had lobbed it out of play).

It is clear that some aspects of the decision require systems to *know* the
datatypes in question, and if they don't they cannot compare non-lexically
identically values.
I believe we have clarified that the point at which that knowledge is needed
is not syntactic. Whether it is in the model theory or somehow after I still
don't know.

Jeremy


(I will do the abstract syntax update today or tomorrow - Graham can I have
a lock on the file?)

> -----Original Message-----
> From: w3c-rdfcore-wg-request@w3.org
> [mailto:w3c-rdfcore-wg-request@w3.org]On Behalf Of Dan Connolly
> Sent: 14 October 2002 14:40
> To: w3c-rdfcore-wg@w3.org
> Subject: details of rdf:datatype?
>
>
>
> I'm puzzling thru the details of the [6Sep] decision.
>
> It seems to specify that this holds:
>
> 	:jenny :age <...#integer>"10".
> =>
> 	:jenny :age <...#decimal>"10".
>
>
> since those two literals denote the same value.
>
> and this one holds:
>
> 	:jenny :age <...#decimal>"010".
> =>
> 	:jenny :age <...#decimal>"10".
>
> If somebody would please confirm, I'd appreciate it.
>
> But I don't see how this works for an open-ended set
> of datatypes. Does this hold?
>
> 	:jenny :age <http://example/vocab#type1>"hello".
> =>
> 	:jenny :age <http://example/vocab#type2>"hello".
>
> If type1 and type2 map hello to the same value, it does hold.
>
> Likewise, if type1 maps hello1 and hello2 to the
> same value, then the following holds:
>
> 	:jenny :age <http://example/vocab#type1>"hello1".
> =>
> 	:jenny :age <http://example/vocab#type1>"hello2".
>
> It seems to me that a parser should raise an exception
> if it sees rdf:datatype used with a value it doesn't
> recognize. Recognizing datatypes is a parse-time thing;
> you can't do lazy-evaluation of the type-uri/string-val
> pair.
>
> Is that the design folks have in mind?
>
>
> [6Sep] Draft minutes: telecon 2002-09-06 Jan Grant (Fri, Sep 06 2002)
> http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Sep/0081.html
>
> =>
> http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Aug/0257.html
>
> =>
> http://www-nrc.nokia.com/sw/rdf-datatyping.html
> http://lists.w3.org/Archives/Public/www-archive/2002Aug/0111.html
>
>
> --
> Dan Connolly, W3C http://www.w3.org/People/Connolly/
>
>
>
Received on Monday, 14 October 2002 08:52:21 EDT

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