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Re: [DTB] Action 681 completed

From: Jos de Bruijn <debruijn@inf.unibz.it>
Date: Mon, 02 Feb 2009 14:59:44 +0100
Message-ID: <4986FC50.4030401@inf.unibz.it>
To: Axel Polleres <axel.polleres@deri.org>
CC: "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>
<snip/>

>>> Note (also an editor's note in the document):
>>>  I assumed the second argument of isLiteralOfType to be a rif:iri at the
>>> moment. As we defined a datatype identifier just as a unicode string
>>> representing an IRI in the definition of symbol spaces, it might be
>>> better to restrict the domain of the second argument to strings, yes?
>>
>> I disagree. A rif:iri constant can denote an actual datatype, so you can
>> speak about actual datatypes when speaking about the types of literals.
> 
> This is what we say so far:
> http://www.w3.org/2005/rules/wiki/DTB#Symbol_Spaces
> 
> "The identifier of a symbol space is a sequence of Unicode characters
> that form an absolute IRI."
> 
> It is not an IRI constant, although the current definitions of
> isLiteralOfType  and isLiteralNotOfType talk about IRI constants as the
> second argument.

that's fine.

> 
> I am happy with either keeping it like that or changing it, just wanted
> to point out that there are two options.
> 
> 
>> In fact, it would have been best if in BLD semantic structures the IRIs
>> of datatypes are mapped to the corresponding datatypes, e.g., xsd:string
>> is mapped to the XML schema string datatype.  One could then, in DTB,
>> speak only about values and datatypes, which will be much more
>> convenient and much more elegant.
> 
> I am not sure what you want to say here, can you explain/maybe
> illustrate with an example?

I propose to extend the definition of semantic structure [1] by adding
the following conditions to point 1 of the definition:
- If a constant c \in Const is an IRI constant "d"^^rif:iri and d is a
datatype identifier, i.e., d \in DTS, then I_C(d) is the datatype [2]
identified by d.

Thinking again about this, we might get away with this change without
redoing last call.  The only real implication it has is that equality
statements of the form

xsd:integer=xsd:string

are currently not inconsistent, but with the proposed change they do
become inconsistent.
But we anyway don't want people to write this kind of statement; in
fact, people should not use datatype identifiers outside of constants
and isLiteralOfType/isLiteralNotOfType statements.

Best, Jos

[1] http://www.w3.org/2005/rules/wiki/BLD#Semantic_Structures

> 
> Thanks,
> Axel
> 
>> We should not have moved BLD to last call before finalizing DTB :-(
>> I now think we should probably redo BLD last call, after finalizing DTB.
>>
>>> Moreover, I think by dropping the specific guard predicates, we can get
>>> rid of the definition of short names for symbol spaces as well.
>>
>> Yes.
>>
>>
>> Best, Jos
>>
>>>
>>> Axel
>>>
>>
> 
> 

-- 
Jos de Bruijn            debruijn@inf.unibz.it
+390471016224         http://www.debruijn.net/
----------------------------------------------
No one who cannot rejoice in the discovery of
his own mistakes deserves to be called a
scholar.
  - Donald Foster


Received on Monday, 2 February 2009 13:59:54 GMT

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