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Re: [DTB] Most editor's notes addressed

From: Dave Reynolds <der@hplb.hpl.hp.com>
Date: Thu, 13 Nov 2008 09:25:50 +0000
Message-ID: <491BF29E.2030407@hplb.hpl.hp.com>
To: Axel Polleres <axel.polleres@deri.org>
CC: "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>

Axel Polleres wrote:
> Dave Reynolds wrote:
>> Hi Axel,
>>> 4)
>>> Section
>>> "== Cast Functions and Conversion Predicates for Datatypes and 
>>> <tt>rif:iri</tt> =="
>>> renamed to:
>>> "== Datatype Conversion and Datatype Checking =="
>>> in order to resolve:
>>> "Editor's Note: It was noted in discussions of the working group, 
>>> that except guard predicates, also an analogous built-in function or 
>>> predicate to SPARQL's datatype function is needed. This however has 
>>> some technical implications, see 
>>> http://lists.w3.org/Archives/Public/public-rif-wg/2008Jul/0096.html."
>>> I added a new pred:hasDatatype predicate here, please check, 
>>> especially Dave (since I didn't find your mail on that, I am not sure 
>>> whether this was how you intedned it, but this is how it makes sense 
>>> to me)!
>> That seems fine as far as it goes though it only addresses one of the 
>> four requested predicates.
>> The original email was [1] section 3.
>> Basically your pred:hasDatatype equates to my pred:isType (and I'm 
>> fine with your name).  I'd also like a negative version (isNotType, 
>> not sure hasNotDatatype reads so well but I don't care what you call it).
>> But it would also be very helpful to have the overloaded versions of 
>> the literal equality and inequality predicates.
> hmmm, I am a bit worried about, what
> hasNotDatatye(const,?X)
> should return.... somehow that looks suspicious to me.

Interesting question. It's intended use is when ?X is bound but of 
course we don't have binding patterns in DTB. Since the domain of ?X is 
rif:iri then it would return the same as:

    hasDatatype(?X, rdf:iri)

less the actual datatype IRI fo const.

So I'm not sure that adding hasNotDatatype is making things any worse.

However, we could retrict the domain the second argument to be the 
enumerated list of datatype IRIs supported by RIF (or by the particular 
RIF implementation it supports private extensions) in which case the 
return values for ?X in your example would be finite.

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Received on Thursday, 13 November 2008 09:26:38 UTC

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