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Re: LDP-Server - Issue-57

From: Henry Story <henry.story@bblfish.net>
Date: Fri, 14 Jun 2013 17:57:49 +0200
Cc: Arnaud Le Hors <lehors@us.ibm.com>, "public-ldp-wg@w3.org" <public-ldp-wg@w3.org>
Message-Id: <33A736C4-6172-4096-98A5-D9CCA9B6CEEB@bblfish.net>
To: "Wilde, Erik" <Erik.Wilde@emc.com>

On 14 Jun 2013, at 17:31, "Wilde, Erik" <Erik.Wilde@emc.com> wrote:

> hello arnaud.
> 
> On 2013-06-14 8:12 , "Arnaud Le Hors" <lehors@us.ibm.com> wrote:
>>> Do you think that we have here one of those differences that goes beyond
>>> language? That we have here a notion so subtle that there remains no
>>> way to tell the difference in language itself?
>> I think the difference really lies into whether you see the interaction
>> model and the RDF type as inseparable or not.
> 
> very well put. to spice things up a little (sorry arnaud :-)... no,
> seriously, please don't respond to this (i promise i won't), but maybe use
> it as a little thought experiment for yourself:
> 
> we theoretically should be able to "re-encode" LDP in JSON, saying clearly
> which hypermedia affordances clients really need to know about, and then
> we encode those in JSON. the payload of the JSON-guided interactions then
> is RDF (because that's what we're shipping back and forth), but the
> service is driven by LDP interactions that can be represented any way we
> choose.
> 
> for RDF-minded clients, of course that would be inconvenient and thus we
> very don't want this. it's pretty much always a bad idea to mix metamodels
> in a service, it makes processing hard (you need two processing
> machineries) and is more complex than serializing everything in the same
> way.
> 
> but as arnaud rightly pointed out: if somebody took off and said "i love
> LDP, but i really want to build a JSON flavor of it", they should be able
> to fairly easily extract the interaction model, represent it in a way that
> makes JSON-LDP consumers happy, and then wrap that set of interactions
> around the RDF that's being exchanged.

RDF just makes other models explicit: it's just logic! ( Just compare
RDF Semantics to Zermelo–Fraenkel set theory for example, you'll see how
close these are ) So whatever you do in JSON is like doing it in RDF, but 
less explicit, therefore on the whole less capable of expanding fully 
to the web, which as you know is structured in such a way as to make 
it impossible to rely on contexts. 

> so, please *do not* respond ;-) but i think arnaud made an excellent
> comment here, pointing out a very helpful separation of concerns (service
> model vs. data model).

That's a completely different point.  Note that logic allows you to model
anything you can speak about - there is no serious categorical distinction 
between a service model and a datamodel. Both could be expressed in RDF and
furthermore they can like anything be linked. 

So is this the branch you folks want to hold onto? I am running to get the 
rescue team to pump up a big air bed for you to fall onto when the branch
breaks. You'll see it's that dot all the way down there . Just head straight
for it, you'll be safe.

;-)

See you in Madrid.

> 
> cheers,
> 
> dret.
> 

Social Web Architect
http://bblfish.net/
Received on Friday, 14 June 2013 15:58:23 UTC

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