W3C home > Mailing lists > Public > public-rdf-wg@w3.org > March 2011

Re: [JSON] RDF collections and JSON arrays

From: Ivan Herman <ivan@w3.org>
Date: Fri, 25 Mar 2011 09:59:51 +0100
Cc: Steve Harris <steve.harris@garlik.com>, Pat Hayes <phayes@ihmc.us>, RDF Working Group <public-rdf-wg@w3.org>
Message-Id: <036F354A-8F44-411D-83A5-374C828D6222@w3.org>
To: Andy Seaborne <andy.seaborne@epimorphics.com>

On Mar 25, 2011, at 09:57 , Andy Seaborne wrote:
> 
> RDF collections being encoded in triples are very hard to deal with generally.  Next time, make them first class objects in the data model please.
> 

Operative being 'next', not 'present' :-)

Ivan


> 	Andy
> 
> On 25/03/11 08:33, Steve Harris wrote:
>> Equally I see using [ ] just to encode multiple object for a single
>> subject and predicate as problematic, consider (in no particular
>> syntax):
>> 
>> { ... "http://example.com/alice": { "foaf:name": "Alice" },
>> "http://example.com/bob": { "foaf:name": [ "Bob", "Bob Smith" ] } }
>> 
>> That makes access to the data without a library tricky, as for every
>> "object" you read, you'll need some conditional designed to test if
>> it's an array/vector/list, or a literal value.
>> 
>> Though it makes the simple case uglier, it would probably be better
>> to always use an array to represent objects, if the aim is to allow
>> access without a library:
>> 
>> { ... "http://example.com/alice": { "foaf:name": [ "Alice" ] },
>> "http://example.com/bob": { "foaf:name": [ "Bob", "Bob Smith" ] } }
>> 
>> I'm also not keen on [[ ]] for RDF collections, but don't see a
>> sensible alternative. The triple-based representation is neither
>> machine, nor human friendly, IMHO.
>> 
>> - Steve
>> 
>> On 2011-03-25, at 08:11, Ivan Herman wrote:
>> 
>>> I agree that having a syntactic sugar for lists would be a good
>>> thing, similarly to what Turtle already has.
>>> 
>>> The problem is that the list syntax of JSON, ie, '[...]' is would
>>> be very useful for cases when we'd want to define shortcuts. Eg,
>>> the equivalent of
>>> 
>>> :a :b :c, :d .
>>> 
>>> in Turtle would make use of something like '[ :c, :d ]' and I am
>>> not sure there is an alternative for that.
>>> 
>>> So no, it is not trivial nor obvious... Hence the slightly ugly
>>> 
>>> [[ :c,:d ]]
>>> 
>>> proposal that came up on the list. I would have to hold by nose
>>> looking at that, but I do not see any radically different
>>> alternative:-(
>>> 
>>> Ivan
>>> 
>>> 
>>> 
>>> 
>>> On Mar 25, 2011, at 24:25 , Pat Hayes wrote:
>>> 
>>>> Um... I am not sure if this is trivial or obvious, but has the WG
>>>> thought about the RDF collections vocabulary in the JSON context?
>>>> Since this is supposed to correspond as nearly as possible to a
>>>> LISP list, it seems it would be 'natural' for an RDF collection
>>>> to map into a JSON array. And if this is to round-trip, then
>>>> these arrays must be somehow marked as coming from an RDF
>>>> collection so that they can be mapped back into one.
>>>> 
>>>> I wish I had something more constructive to offer on this point,
>>>> but I don't, other than to suggest it might turn out to be
>>>> important, since the collection vocabulary is used to extensively
>>>> in the OWL/RDF syntax. While OWL is not a prime target for our
>>>> WG, it would seem to be a good idea to define a JSON mapping
>>>> which does not completely screw up OWL, if at all possible.
>>>> 
>>>> Just a 2c observation.
>>>> 
>>>> Pat ------------------------------------------------------------
>>>> IHMC                                     (850)434 8903 or
>>>> (650)494 3973 40 South Alcaniz St.           (850)202 4416
>>>> office Pensacola                            (850)202 4440   fax
>>>> FL 32502                              (850)291 0667   mobile
>>>> phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>> 
>>> 
>>> ---- Ivan Herman, W3C Semantic Web Activity Lead Home:
>>> http://www.w3.org/People/Ivan/ mobile: +31-641044153 PGP Key:
>>> http://www.ivan-herman.net/pgpkey.html FOAF:
>>> http://www.ivan-herman.net/foaf.rdf
>>> 
>>> 
>>> 
>>> 
>>> 
>> 


----
Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf






Received on Friday, 25 March 2011 09:00:35 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 17:04:04 UTC