W3C home > Mailing lists > Public > www-archive@w3.org > November 2002

Re: The emperor's new datatypes

From: Dan Connolly <connolly@w3.org>
Date: 27 Nov 2002 07:57:43 -0600
To: Graham Klyne <GK@NineByNine.org>
Cc: www-archive@w3.org, Brian McBride <bwm@hplb.hpl.hp.com>, Dan Brickley <danbri@w3.org>
Message-Id: <1038405464.7112.3058.camel@dirk>

This discussion is out of order since the question is
decided, so I'm not copying the WG...

On Wed, 2002-11-27 at 07:23, Graham Klyne wrote:
[...]
> TIDY LITERALS IN CC/PP
> ----------------------
> 
> This analysis of changes to CC/PP is predicated on tidy literals being a 
> done deal.
> 
> Dan's point, if I represent it correctly, is that we don't need typed
> literals because if we assume datatype properties relating values to
> lexical forms, we can use them as "interpretation properties".
> 
> That is, the intent of the expression:
> 
>     jenny age xsd:integer"10" .
> 
> can be equivalently expressed as:
> 
>     jenny age _:x .
>     _:x xsd:integer "10" .

While I believe that's true, that's actually not the point
of the rdfs:format proposal. In the RDFS format proposal,
it's just
	jenny age "10".

i.e. the age property takes a numeral, not a number.

The RDFS format proposal is not incompatible with
datatype properties, but it's orthogonal to it.

[...]

> So if I now refer to my thoughts about redesigning CC/PP for use with tidy
> literals [4], where I wrote:
> 
> [[
>    <prf:displayWidth
>      rdf:datatype="http://www.w3.org/2001/XMLSchema-datatypes#integer">604</prf:displayWidth>
>    <prf:displayHeight
>      rdf:datatype="http://www.w3.org/2001/XMLSchema-datatypes#integer">200</prf:displayHeight>
> ]]
> 
> I would instead write something like:


with rdfs format, you just write:

            <prf:displayWidth>604</prf:displayWidth>
            <prf:displayHeight>200</prf:displayHeight>

and change the definition of displayWidth so that
it takes numerals.

> SIMPLIFYING DANC'S PROPOSAL
> ---------------------------
> 
> In [3], DanC proposed a new construct, rdfs:format for indicating the 
> intended form of literals used as objects of a property.
> 
> [3] http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Oct/0031.html
> 
> I think a very similar effect can be achieved using other defined RDF 
> constructs:
> 
>    my:age rdfs:format xsdt:integer .
> 
> I think could equivalently be expressed as:
> 
>    my:age rdfs:range _:x .
>    xsdt:integer rdfs:range _:x .

er... let's see... xsdt:integer maps integers to literals...
so yes, those are equivalent. While I agree rdfs:format
is redudnant, I think it's probably worthwhile; especially
since the 2 triples above can't be expressed without
rdf:nodeID.

> [I think someone else suggested this on the list, but I don't know where so 
> I'm unable to cite acknowledgement -- sorry.]
> 
> which we can now express in RDF/XML thanks to the rdf:nodeId construct we 
> introduced.
[...]

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Wednesday, 27 November 2002 08:58:46 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 7 November 2012 14:17:24 GMT