- From: Alexandre Bertails <bertails@w3.org>
- Date: Fri, 18 Oct 2013 10:10:50 -0400
- To: James Leigh <james@3roundstones.com>
- CC: Sandro Hawke <sandro@w3.org>, public-ldp-patch@w3.org, Eric Prud'hommeaux <eric@w3.org>, Tim Berners-Lee <timbl@w3.org>, Linked Data Platform WG <public-ldp-wg@w3.org>
On 10/18/2013 09:11 AM, James Leigh wrote:
> On Thu, 2013-10-17 at 22:57 -0400, Alexandre Bertails wrote:
>> TurtlePatch
>> -----------
>>
>> Champion: Sandro
>>
>> Summary: subset of SPARQL Update with INSERT and DELETE clauses.
>>
>> Example:
>>
>> [[
>> PREFIX foaf <http://xmlns.com/foaf/0.1/>
>> PREFIX s <http://www.w3.org/2000/01/rdf-schema#>
>> DELETE DATA {
>> <http://www.w3.org/People/Berners-Lee/card#i> foaf:mbox
>> <mailto:timbl@w3.org>
>> }
>> INSERT DATA {
>> <http://www.w3.org/People/Berners-Lee/card#i> foaf:mbox
>> <mailto:timbl@hushmail.com>
>> <http://www.w3.org/People/Berners-Lee/card> s:comment "This is my
>> general description of myself.\n\nI try to keep data here up to date and
>> it should be considered authoritative."
>> }
>> ]]
>>
>> Pros:
>> * can be implemented using full SPARQL implementation
>> * easy to implement from scratch (parser + runtime)
>>
>> Cons:
>> * no support for bnodes
>>
>> Status:
>> * I implemented this approach in Banana-RDF
>>
>> Remark: Sandro talked about "TurtlePatch plus variables" but I'm not
>> sure what that means exactly by reading his spec. Until I see a
>> solution properly considering bnodes, it will be a -1 for me.
>
> While "no support for bnodes" is technically true for this format, LDP
> does permit skolemization[1]. I personally don't expect this group to
> agree on any PATCH format that includes blank nodes and I think the only
> acceptable solution is to give them blank node identifiers through a
> skolemization process as Sandro suggested earlier.
I guess there is a tension between how much LDP PATCH should influence
LDP for its handling of bnodes. Adding the skolemization constraint
over LDP is pretty huge and this will have an impact of graph
serializations.
I've added your comment to [2].
[2] http://www.w3.org/2012/ldp/wiki/LDP_PATCH_Proposals#TurtlePatch
>
> With blank node identifiers, the above solution handles blank nodes
> quite well, IMHO, without any of the NP problems other solutions have.
>
> [1] http://www.w3.org/TR/rdf11-concepts/#section-skolemization
>
> Regards,
> James
>
>
Received on Friday, 18 October 2013 14:10:51 UTC