The new ARC site is coming along quite nicely. Last week I implemented two (low-level) agents that log IRC conversations and mails to ARC-DEV. RDF and SPARQL make such things incredibly easy. Today, I started writing documentation for the preview release of ARC2, and one the core changes to ARC1 is the removal of the API class for inserts and deletes in favour of an extended SPARQL, called SPARQL+ which enables aggregates, LOAD, INSERT, and DELETE, without the need for major query engine code additions.

LOAD is compatible with the LOAD operation introduced in the SPARUL proposal:

LOAD <http://example.com/> INTO <http://example.com/archive>

INSERT and DELETE are different, though. They re-use the LOAD and CONSTRUCT handlers which simplified the implementation and will hopefully make it easier for people who just learned SPARQL's standard syntax. INSERT and DELETE in SPARQL+ each support two different forms, one for explicit triples (with simple wildcards in DELETE queries), and one for dynamically CONSTRUCTed ones, e.g.

DELETE {
 <#foo> <bar> "baz" .
 <#foo2> <bar2> ?any .
}

or

INSERT INTO <http://example.com/inferred> CONSTRUCT {
  ?s foaf:knows ?o .
}
WHERE {
  ?s xfn:contact ?o .
}

More examples and detailed information about how exactly SPARQL+ extends the SPARQL grammar are available in ARC2's SPARQL+ documentation section