Re: enforcing the prohibition

Pat Hayes wrote:
> 
> On May 22, 2009, at 1:31 PM, Axel Polleres wrote:
> 
>> Maybe I missed that in the thread, but as for defining D-entailment 
>> for SPARQL, we should be fine, because we can restrict BGP matching 
>> extension accordingly, right?  We can just say that graphs with 
>> explicit rdf:PlainLiteral typed literals aren't well-formed.
> 
> We can say that, yes, but there is nothing in the current RDF or SPARQL 
> specs that say this. 

just wanted to make sure with you that this is a feasible approach...

> So what should a conforming SPARQL/RDF engine do, 
> if it comes across one? Apart from reporting it to the OWL/RIF militia, 
> that is. That is why I think having a named 'convention' that engines 
> can say they support, or not, is useful. An engine which does can flag 
> this as an error with a clear conscience, and its owners can cite the 
> relevant W3C document when challenged, and nobody has to refer to OWL or 
> RIF (inviting the response: so what, I'm not using those, just RDF...) 
> Note, just saying that you support {rdf:text}-entailment isn't going to 
> be enough.

... just as SPARQLOWL entailment migt refuse graphs containing graphs 
that comprise incomplete OWL axioms (e.g. having malformed RDF lists, etc.)

> 
> Pat
> 
>>
>> Axel
>>
>> Eric Prud'hommeaux wrote:
>>> On Fri, May 22, 2009 at 09:55:03AM +0000, Seaborne, Andy wrote:
>>>>
>>>>> -----Original Message-----
>>>>> From: public-rdf-text-request@w3.org [mailto:public-rdf-text-
>>>>> request@w3.org] On Behalf Of Sandro Hawke
>>>>> Sent: 22 May 2009 01:27
>>>>> To: Pat Hayes
>>>>> Cc: Axel Polleres; public-rdf-text@w3.org
>>>>> Subject: enforcing the prohibition
>>>>>
>>>>>
>>>>>>> One thing I am not sure still: It was pointed out that we cannot
>>>>>>> prevent people from writing graphs using rdf:text as a datatype
>>>>>>> explicitly.
>>>>>>> Is that a problem?
>>>>>> Well, I think we can very actively discourage them from doing so, and
>>>>>> warning them to expect trouble, and exactly what to expect, if they
>>>>>> do. In fact, nothing will actually break if they do, unless they
>>>>>> expect these things to mean the same as plain literals without using
>>>>>> datatype entailment. Its more likely that they, the publishers. won't
>>>>>> have any problems, but some poor schmuk the other side of the world
>>>>>> won't get their queries answered properly. But if the spec has 
>>>>>> plainly
>>>>>> said this using rdf:text (or whatever) as a dataype will cause these
>>>>>> problems, and it does, then its going to be easy for people to find
>>>>>> the culprit, which I think is all that we really need to do. Social
>>>>>> pressure will do the rest: blogs will immediately point out that 
>>>>>> XXX's
>>>>>> RDF is corrupted with the forbidden datatype, etc..
>>>>> I'm neutral on this option, but one more stick we *could* use is to
>>>>> require RIF systems to reject RDF graphs that use rdf:text as a
>>>>> datatype.
>>>> This seems harsh.  "Be liberal with what you accept."
>>> i have a similar conclusion, but my arguments are:
>>>  1 don't add a new graph validation layer, burden for implementors.
>>>  2 someone may have clever ideas for it in the future.
>>>>     Andy
>>>>
>>>>
>>>>> RIF already does this with the rif:iri, to try to make sure
>>>>> it doesn't leak out.
>>>>>
>>>>>     ...documents importing RDF graphs containing typed literals of the
>>>>>     form "http://iri"^^rif:iri must be rejected.
>>>>>
>>>>>            -- http://www.w3.org/2005/rules/wiki/SWC
>>>>>
>>>>> We haven't yet added any ImportsRejectionTests to check on this, 
>>>>> but we
>>>>> plan to.  I don't think OWL 2 such a notion, and I wouldn't want to 
>>>>> add
>>>>> it just for this.
>>>>>
>>>>>      -- Sandro
>>
>>
>> -- 
>> Dr. Axel Polleres
>> Digital Enterprise Research Institute, National University of Ireland, 
>> Galway
>> email: axel.polleres@deri.org  url: http://www.polleres.net/
>>
>>
> 
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> 
> 


-- 
Dr. Axel Polleres
Digital Enterprise Research Institute, National University of Ireland, 
Galway
email: axel.polleres@deri.org  url: http://www.polleres.net/

Received on Saturday, 23 May 2009 00:17:26 UTC