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Re: RDF-ISSUE-80 (rdf:PlainLiteral): Ask OWL and RIF WGs to update the rdf:PlainLiteral spec [RDF General]

From: Sandro Hawke <sandro@w3.org>
Date: Thu, 17 Nov 2011 16:27:34 -0500
To: Richard Cyganiak <richard@cyganiak.de>
Cc: Alex Hall <alexhall@revelytix.com>, Ivan Herman <ivan@w3.org>, RDF Working Group WG <public-rdf-wg@w3.org>
Message-ID: <1321565254.15001.48.camel@waldron>
On Thu, 2011-11-17 at 20:32 +0000, Richard Cyganiak wrote:
> On 17 Nov 2011, at 19:33, Sandro Hawke wrote:
> > I think it should actually be this group which does the revision,
> > though.  
> 
> Why?

Because RDF should be the common data model.

rdf:PlainLiteral was invented because a group of people trying to build
on top of RDF found the data model just too broken to work with.   (They
needed something simple and consistent enough on which to build
additional logics.)  So, together with everyone who was willing to help,
we came up with something that isn't pretty but that does work. 

> The rdf:PlainLiteral spec defines a datatype that's defined as being usable only *outside* of RDF graphs.

That's not a design goal, it's just an aspect of how we had to define it
to not break anything existing.    Given RDF 1.1 is willing to make some
changes to existing things, it wouldn't necessarily have to be done that
way any more.

>  It defines facets for that datatype. It defines XPath functions. None of these things are directly useful for RDF. They all make sense for, and are motivated by, RIF and OWL.

If you're going to actually define a useful XML datatype, it makes sense
to define facets and XPath functions for it.   The fact that OWL 2 can
use the facets and RIF can use the XPath functions helped motivate it,
but it seemed like one would want these things anyway.  I mean, if you
have a language tagged string, don't you want to be able to constrain
and/or act upon the language tag?   So we defined a way to do that which
happens to fit neatly into the existing XML datatype mechanisms.   They
are in no way just for RIF or OWL -- they are for anyone who wants to
use strings with language tags in RDF, using machinery from the XML
world.

Maybe XML is dead, so this doesn't matter any more?

   -- Sandro
Received on Thursday, 17 November 2011 21:27:44 GMT

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