Re: "do not occur"

 > Incidentally, the fact that you can filter using the DATATYPE function
 > in sparql is another hint that something is amiss. By my earlier
 > analysis, the DATATYPE function should never return rdf:PlainLiteral,
 > according to our spec.

Indeed, *according to our spec*. This is why I prefer Option 2 which 
makes this point clear.

best,
Axel

Alan Ruttenberg wrote:
> On Tue, Jun 2, 2009 at 4:46 PM, Alan Ruttenberg
> <alanruttenberg@gmail.com> wrote:
>> On Tue, Jun 2, 2009 at 3:41 PM, Axel Polleres <axel.polleres@deri.org> wrote:
>>> Peter F.Patel-Schneider wrote:
>>>> From: Sandro Hawke <sandro@w3.org>
>>>> Subject: "do not occur"
>>>> Date: Tue, 2 Jun 2009 12:00:54 -0500
>>>>
>>>>> [FYI, today, SPARQL and RIF said they're okay with the current drafts;
>>>>> in RIF's case, this is modulo the name change being made in the
>>>>> builtins.]
>>>>>
>>>>> At the risk of waking sleeping dragons, Axel and I were talking about
>>>>> this delicate sentence:
>>>>>
>>>>>    Therefore, typed literals with rdf:PlainLiteral as the datatype do
>>>>>    not occur in syntaxes for RDF graphs, nor in syntaxes for SPARQL.
>>>>>
>>>>> and how it seems normative, even though it's stated as purely logical.
>>>>>
>>>>> The confusion, as I understand it, is that typed literals with the
>>>>> datatype rdf:PlainLiteral:
>>>>>
>>>>>        - DO NOT occur in the syntax, which means they
>>>>>        - MUST NOT occur in the documents.
>>>>>
>>>>> This is a little confusing.
>>>>>
>>>>> Option 1:
>>>>>
>>>>>    leave it as is
>>>>>
>>>>>     (my vote: +0)
>>>> +1
>>> -1
>>>
>>> To me this last sentence indicates that if I now go out and publish a graph.
>>>
>>>     :s :p "gotcha, haha"^^rdf:PlainLiteral.
>> Here's my interpretation of the spec: "haha"^^rdf:PlainLiteral is not
>> a typed rdf:PlainLiteral literal.
>> It means something, just not what you think. That's because the only
>> syntax for rdf:PlainLiteral literals is that of plain literals.
> 
> Incidentally, the fact that you can filter using the DATATYPE function
> in sparql is another hint that something is amiss. By my earlier
> analysis, the DATATYPE function should never return rdf:PlainLiteral,
> according to our spec.
> 
> -Alan
> 
>> -Alan
>>
>>> I consequently yield the whole spec invalid (by ex falso quod libet)....
>>>
>>> There is no guarantee that there is no such graph published out there
>>> already.  Current RDF APIs swallow that graph without trouble, I can even
>>> write SPARQL queries against it that filter the datatype rdf:PlainLiteral
>>> with current implementations) and it is totally compliant with RDF. So, the
>>> sentence as it stands just doesn't make sense to me.
>>>
>>>
>>>> I put the sentence in to emphasize the previous sentence, which provides
>>>> the normative force.  That sentence as well does not use a MUST, also by
>>>> design.  The rationale is that this is the way that things are.
>>> Let us have a look at the previous sentence again:
>>>
>>> "To eliminate another source of syntactic redundancy and to retain a large
>>> degree of interoperability with applications that do not understand the
>>> rdf:PlainLiteral datatype, the form of rdf:PlainLiteral literals in syntaxes
>>> for RDF graphs and for SPARQL is the already existing syntax for the
>>> corresponding plain literal, not the syntax for a typed literal."
>>>
>>> Hmm, to my understanding that sentence indicates only that a
>>> rdf:PlainLiteral typed literal is not a plain literal in the sense of this
>>> spec not that rdf:PlainLiteral typed literals
>>> do not exist - which however the other sentence does say. At the very least,
>>> I find the second sentence more confusing than enlightning in its current
>>> state.
>>>
>>>
>>>> A MUST
>>>> would be directives to implementations, and this is not that.
>>>>> Option 2:
>>>>>
>>>>>    rephrase as: Therefore, typed literals with rdf:PlainLiteral as the
>>>>>    datatype are considered by this specification to be not valid in
>>>>>    syntaxes for RDF graphs or SPARQL.
>>>>>
>>>>>    (my vote: -0)
>>>
>>> +1
>>>
>>> This is precise and on the safe side. I have a much better feeling with
>>> that.
>>>
>>>> +0
>>>>
>>>>> Option 3:
>>>>>
>>>>>    (just drop the sentence; it's doesn't add much itself.)
>>>>>
>>>>>    (my vote: +1)
>>>> +0
>>> +0 I can live with that, although indeed the sense of the sentence before is
>>> a bit lost with that, i.e. it doesn't say anything about explicitly
>>> rdf:PlainLiteral typed literals.
>>>
>>>>> That's it.  (Dear sleeping dragons: If you're going to breath fire,
>>>>> please give me time to run away first.)
>>>> But sleeping dragons don't work that way.  :-)
>>> (I guess after that mail, you are safe Sandro, they'll run after me :-))
>>>
>>> Axel
>>>
>>>>>       -- Sandro
>>>> peter
>>>>
>>>>
>>>
>>> --
>>> Dr. Axel Polleres
>>> Digital Enterprise Research Institute, National University of Ireland,
>>> Galway
>>> email: axel.polleres@deri.org  url: http://www.polleres.net/
>>>
>>>
>>>


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

Received on Tuesday, 2 June 2009 21:00:25 UTC