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Linkeddata Release 3.1.2 and RDF.rb Release 3.1.2 from Gregg Kellogg on 2020-05-30 (public-rdf-ruby@w3.org from May 2020)

From: Gregg Kellogg <gregg@greggkellogg.net>
Date: Sun, 31 May 2020 12:39:10 -0700
Message-Id: <03F64FC7-675A-4356-8EB9-FDEE0D6F2C45@greggkellogg.net>
Cc: Pierre-Antoine Champin <pchampin@liris.cnrs.fr>
To: public-rdf-star@w3.org
As mentioned on the RDF Ruby mailing list [1], the Ruby RDF toolset has been updated to provisional support for RDF* (N-Triples/Quads, Turtle, and SPARQL) [2]. We followed the lead of RDF4J in results representation.

There is some initial implementation in a branch of my JSON-LD implementation as well [3], although this is highly speculative and is under active discussion between myself and Pierre-Antoine.

As an example of what I implemented [4]:

{
  "@id": {
    "@context": {"foaf": "http://xmlns.com/foaf/0.1/"},
    "@index": "ignored",
    "@id": "bob",
    "foaf:age" 23
  },
  "ex:certainty": 0.9
}

This allowed the value of @id to be a node object with the provision that it MUST describe just a single relationship, but there is support for arbitrary levels of subject or object embedding.

The Turtle/TriG and N-Triples/Quads implementations can be tested using my distiller [5], by setting the “rdfstar” field to either “SA” or “PG” (Separate Assertions or Property Graph).

There are other proposals for introducing a new keyword @triples, which would be a replacement for @id, or @object, which changes the interpretation of the enclosing node to have an embedded subject, which we are also considering.

As well, there is more discussion of how closely this model seems like N3 formulae, with a restriction on their contents. The JSON-LD style of named graphs is already very close to how N3 formulae are used, there the formula is the subject or object of a triple in another formulae; in JSON-LD, named graphs are often named by an identifier which is the object of another triple. We’ll be exploring this further in the JSON-LD Community Group.

> [1] https://lists.w3.org/Archives/Public/public-rdf-ruby/2020May/0000.html <https://lists.w3.org/Archives/Public/public-rdf-ruby/2020May/0000.html>
[2] https://github.com/ruby-rdf/linkeddata/releases/tag/3.1.2
[3] https://github.com/ruby-rdf/json-ld/tree/feature/json-ld-star 
[4] https://github.com/ruby-rdf/json-ld/tree/feature/json-ld-star#json-ld-rdfstar
[5] http://rdf.greggkellogg.net/distiller?command=serialize&format=turtle&output_format=ntriples&rdfstar=SA

Gregg Kellogg
gregg@greggkellogg.net
Received on Sunday, 31 May 2020 19:39:27 UTC

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