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Re: ISSUE-105: Graph vs. dataset syntaxes

From: Sandro Hawke <sandro@w3.org>
Date: Thu, 13 Dec 2012 12:28:21 -0500
Message-ID: <50CA1035.1090301@w3.org>
To: Ivan Herman <ivan@w3.org>
CC: Markus Lanthaler <markus.lanthaler@gmx.net>, public-rdf-wg@w3.org
On 12/13/2012 06:35 AM, Ivan Herman wrote:
> I find this a sensible compromise...

Me too.   It seems to me basically what SPARQL does, and why it's called 
the "default graph".

> For Trig/Turtle this may not be formally relevant because, afaik, Trig will have its own media type. But, for example, if an extension of RDFa is defined some day including facilities for graphs, this is probably an approach to follow.

If we agree with this resolution of ISSUE-105, I might suggest this is 
new information and warrants briefly re-visiting this issue:

    *RESOLVED:* In TriG, triples of the dataset's default graph MUST be
    surrounded by curly braces.

    http://www.w3.org/2011/rdf-wg/meeting/2012-10-17#resolution_2

... because with this approach it's much more natural to treat the 
name-graph pairs as an ignorable addition to turtle.

      -- Sandro

> Ivan
>
> On Dec 5, 2012, at 13:13 , Markus Lanthaler wrote:
>
>> While JSON-LD is a dataset syntax we expect that in most cases it will be
>> used to express simple graphs. This might become problematic if a consumer
>> is unable to process datasets -- even in the case where the dataset consists
>> of only the default graph. In JSON-LD we resolved this issue by specifying
>> that a consumer expecting a graph, MUST ignore everything but the default
>> graph.
>>
>> This allows publishers to expose their graphs in, e.g., both JSON-LD and
>> Turtle. Summarized, the behavior of a consumer would be as follows:
>>
>> Exposed  |  Expected  |  behavior
>> ---------+------------+-----------
>> Data set |  graph     |  use default graph as graph, ignore rest
>> Data set |  data set  |  exposed = expected
>> Graph    |  data set  |  use graph as default graph in dataset
>> Graph    |  graph     |  exposed = expected
>>
>>
>> This might have consequences on how data should be modeled (what should be
>> put in the default graph and what in a named graph) but that's beyond the
>> scope of a syntax.
>>
>> I would therefore like to propose to standardize this behavior for all RDF
>> data set syntaxes.
>>
>>
>> Regards,
>> Markus
>>
>>
>> --
>> Markus Lanthaler
>> @markuslanthaler
>>
>>
>
> ----
> Ivan Herman, W3C Semantic Web Activity Lead
> Home: http://www.w3.org/People/Ivan/
> mobile: +31-641044153
> FOAF: http://www.ivan-herman.net/foaf.rdf
>
>
>
>
>
Received on Thursday, 13 December 2012 17:28:33 GMT

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