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Re: [JSON] RDF collections and JSON arrays

From: Ivan Herman <ivan@w3.org>
Date: Fri, 25 Mar 2011 15:01:40 +0100
Cc: Andy Seaborne <andy.seaborne@epimorphics.com>, Steve Harris <steve.harris@garlik.com>, RDF Working Group <public-rdf-wg@w3.org>
Message-Id: <67D42638-79B6-4FCB-B354-E013EEA9744A@w3.org>
To: Pat Hayes <phayes@ihmc.us>

On Mar 25, 2011, at 14:37 , Pat Hayes wrote:

> 
> On Mar 25, 2011, at 3:59 AM, Ivan Herman wrote:
> 
>> 
>> 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' :-)
> 
> Awwww, you are no fun. 

:-)

I.


> 
> Pat
> 
>> 
>> 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
>> 
>> 
>> 
>> 
>> 
> 
> ------------------------------------------------------------
> 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






Received on Friday, 25 March 2011 14:02:06 UTC

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