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Re: "Simple Lists" (was Re: ISSUE-77: Should we mark rdf:Seq as archaic (cf ISSUE-24))

From: Steve Harris <steve.harris@garlik.com>
Date: Mon, 17 Oct 2011 09:53:52 +0100
Cc: Pat Hayes <phayes@ihmc.us>, Andy Seaborne <andy.seaborne@epimorphics.com>, public-rdf-wg@w3.org
Message-Id: <DCA76DA5-3D28-41C3-9D00-20B6EB20519E@garlik.com>
To: Sandro Hawke <sandro@w3.org>
On 17 Oct 2011, at 04:20, Sandro Hawke wrote:
>> Hmm. I thought that the whole point of the RDF Collection vocabulary was to allow what are basically LISP S-expressions to be stored and transmitted as triples, so that everything can be send down a 'RDF pipe'.  Changing a triples-based version of Sexpressions into some other kind of Sexpression representation doesnt seem to gain anything much in utility or performance, but destroys the compatibility (or requires the whole world to invent new ways to transmit RDF from place to place.) What is being gained here? 
> 
> It's a wave *and* a particle.
> 
> I'm picturing something that can fit into plain triples but can also be
> treated as a decent list type.   The best of both worlds, although with
> some costs.   

I'm not convinced that it is the best of both worlds. It's the triple representation of RDF Collections that's the problem.

> I think just adding a decent list type -- that can't be viewed as
> triples -- might be too big a change for some people to accept, and
> might not be so good for the model.  But I'm not sure, and I'm in favor
> of exploring the idea further.    There's also the idea Andy mentioned,
> which sounded like this but more so ... something more than lists ...
> but I'm not sure what that might be.    Dictionaries?

I've never had an issue representing dictionaries in RDF myself, but then I rarely have to model any particularly complex data structures.

It's ordered things that have been difficult.

A lexical representation of a list could be as simple as a CSV encoded row, e.g. '1,2,3' or '"Alice Foo","Bob Bar","Carol Baz"'. It just has to be something that will be encoded in one literal, and can easily be parsed by a consumer. CSV handling libraries are very common.

Other candidates could be JSON format, tab separated, obscure unicode (☃) separated, whatever. As long as Turtle has some friendly syntax for it, it doesn't really matter.

- Steve
Received on Monday, 17 October 2011 08:54:21 GMT

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