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Re: ISSUE-12: xs:string VS plain literals: proposed resolution

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Fri, 06 May 2011 13:32:02 +0100
Message-ID: <4DC3EA42.5060501@epimorphics.com>
To: David Wood <dpw@talis.com>
CC: Sandro Hawke <sandro@w3.org>, "public-rdf-wg@w3.org" <public-rdf-wg@w3.org>

On 06/05/11 13:16, David Wood wrote:
> On May 6, 2011, at 7:44, Sandro Hawke<sandro@w3.org>  wrote:
>> On Fri, 2011-05-06 at 09:33 +0100, Andy Seaborne wrote:
>>> I wonder if most people would be happen if we emphasised that it's
>>> the
>>> value that matters.  xsd:string and simple literal have the same
>>> value,
>>> as do 00123 and +123.
>> I guess it depends what you mean by 'emphasise'...
>> I was shocked to discover SPARQL cared about the difference, and thought
>> it was a grave mistake at the time (but I didn't notice until it was too
>> late).  I had assumed everyone already knew you should just care about
>> the value, and that every API should convert for you, hiding the
>> difference.  But I was wrong, and I don't really know how to get people
>> to use the "Semantic Web" technologies at a "semantic" level.
> +1. Of course, it would help if we standardized it that way :)

And better
"if we *had* standardized it that way"  :-)

> Regards,
> Dave
>>     -- Sandro

There are a couple of factors that matter here:

1/ Users expect what goes to be the same as what comes out.
(tools do as well sometimes)

If they read in

:x :p "foo"^^xsd:string .

and get back:

:x :p "foo" .

enough of them are surprised (=> they send email to support lists asking 
about it).

2/ SPARQL FILTERs don't care - it's graph matching that does because 
graph matching is simple entailment.  And that's what most toolkit 
provide - the direct manipulation of the RDF terms, lexical form, 
datatype and all.

:x :p "foo" .
:x :p "foo"^^xsd:string .

One triple or two?


(For the record : "foo"^^xsd:string matches "foo" in a Jena memory model 
-- there would be two triples.)
Received on Friday, 6 May 2011 12:32:35 UTC

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