Re: the state of ldp-patch, and a procedural proposal

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.

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 13:12:30 UTC