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RE: A question for RDF parser implementers - whitespace

From: Manuel Vázquez Acosta <manu@chasqui.cu>
Date: Wed, 28 Jul 2004 14:45:25 -0400
To: <www-rdf-interest@w3.org>
Message-Id: <20040728184542.DB36CA0D95@frink.w3.org>

Hello all:

I've been reading the whole thread and I came up with a few questions (I
will use QNames in the sake of brevity):

1. Does rdfIL("A") = rdfIL("A"^^ex:aDataType), for any rfd-interpretation
rdfI and any datatype ex:aDataType? 

I think I read somewhere on the RDF specs this doesn't hold - plain literals
are a of different order than typed literal, in fact, a typed literal's
value is given by the datatype lexical-value mapping. 
This must be applied to xds:string as well; and stated that, I don't see how
<ex:subj> <ex:prop> "A" . RDF-entails <ex:subj> <ex:prop> "A"^^xds:string .
Neither I can make any RDF rule to state this.

I'm aware that the original question was not about RDF-entailment, but
referred to a parsing problem: Should I keep the whitespaces? Nevertheless,
since some questions arisen involving RDF-entailment I started to ask myself
the question above.

Regards,
Manuel.

Lic. Manuel Vázquez Acosta.
Chasqui(r)

 
-----Original Message-----
From: www-rdf-interest-request@w3.org
[mailto:www-rdf-interest-request@w3.org] On Behalf Of Jos De_Roo
Sent: Sunday, July 11, 2004 7:27 AM
To: Graham Klyne <gk
Cc: Damian Steer; www-rdf-interest@w3.org
Subject: Re: A question for RDF parser implementers - whitespace


Graham,

I ran those test cases and found that

[[
@prefix dc:      <http://purl.org/dc/elements/1.1/> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix :        <#> .

<http://www.example.org/>
      dc:title "  The trouble with spaces   " .
]]

entails

[[
@prefix dc:      <http://purl.org/dc/elements/1.1/> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix :        <#> .

<http://www.example.org/>
      dc:title "  The trouble with spaces 
"^^<http://www.w3.org/2001/XMLSchema#string> .
]]

but that

[[
@prefix dc:      <http://purl.org/dc/elements/1.1/> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix :        <#> .

<http://www.example.org/>
      dc:title "  The trouble with spaces   "@en .
]]

does *not* entail

[[
@prefix dc:      <http://purl.org/dc/elements/1.1/> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix :        <#> .

<http://www.example.org/>
      dc:title "  The trouble with spaces 
"^^<http://www.w3.org/2001/XMLSchema#string> .
]]

and that

[[
@prefix dc:      <http://purl.org/dc/elements/1.1/> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix :        <#> .

<http://www.example.org/>
      dc:title "  The trouble with spaces   "@en-US .
]]

does *not* entail

[[
@prefix dc:      <http://purl.org/dc/elements/1.1/> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix :        <#> .

<http://www.example.org/>
      dc:title "  The trouble with spaces   "@en-GB .
]]

and that

[[
@prefix dc:      <http://purl.org/dc/elements/1.1/> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix :        <#> .

<http://www.example.org/>
      dc:title "  The trouble with spaces   "@en-GB .
]]

does *not* entail

[[
@prefix dc:      <http://purl.org/dc/elements/1.1/> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix :        <#> .

<http://www.example.org/>
      dc:title "  The trouble with spaces   " .
]]

:)

-- 
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/




Graham Klyne <gk@ninebynine.org>
Sent by: www-rdf-interest-request@w3.org
11/07/2004 12:39

 
        To:     Damian Steer <damian.steer@hp.com>
        cc:     www-rdf-interest@w3.org
        Subject:        Re: A question for RDF parser implementers -
whitespace



At 10:10 11/07/04 +0100, Damian Steer wrote:

>On 9 Jul 2004, at 14:09, Graham Klyne wrote:
>
>>
>>Hmmm.  Let's try a test case.
>>
>>Does this:
>>
>>      <dc:title>  The trouble with spaces   </dc:title>
>
>...
>
>>
>>RDF-entail this:
>>
>>      <dc:title 
>> rdf:datatype="http://www.w3.org/2001/XMLSchema#string">  The trouble 
>> with spaces   </dc:title>
>
>...
>
>>I think it should, but under your suggested regime I think it would not.
>
>I think the specs support Norm's regime here. Try this:
>
><dc:title xml:lang="en"> The trouble with spaces </dc:title>
>
>A reasonable extension of your inference would give:
>
><dc:title xml:lang="en" 
>rdf:datatype="http://www.w3.org/2001/XMLSchema#string">  The trouble with 
>spaces   </dc:title>

(Ignoring the language tags) I would not accept that as an expected 
entailment.  They are different string values.

>But (strangely, I confess) the latter is invalid rdf: only plain literals 

>can have langs.
>
>So you either maintain the orthogonality of plain- and 
datatyped-literals, 
>or you get a weird restriction on rdf entailments ("...except for 
>lang-tagged literals").

I would also say that the entailment does not hold for the same string 
with 
different language tags, or with- and without- a language tag.

#g


------------
Graham Klyne
For email:
http://www.ninebynine.org/#Contact
Received on Wednesday, 28 July 2004 14:45:46 UTC

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