On 09/11/12 09:56, Rupert Westenthaler wrote:
RDF libs:
====
Out of the viewpoint of Apache Stanbol one needs to ask the Question
if it makes sense to manage an own RDF API. I expect the Semantic Web
Standards to evolve quite a bit in the coming years and I do have
concern that the Clerezza RDF modules will be updated/extended to
provide implementations of those. One example of such an situation is
SPARQL 1.1 that is around for quite some time and is still not
supported by Clerezza. While I do like the small API, the flexibility
to use different TripleStores and that Clerezza comes with OSGI
support I think given the current situation we would need to discuss
all options and those do also include a switch to Apache Jena or
Sesame. Especially Sesame would be an attractive option as their RDF
Graph API [1] is very similar to what Clerezza uses. Apache Jena's
counterparts (Model [2] and Graph [3]) are considerable different and
more complex interfaces. In addition Jena will only change to
org.apache packages with the next major release so a switch before
that release would mean two incompatible API changes.
Jena isn't changing the packaging as such -- what we've discussed is
providing a package for the current API and then a new, org.apache API.
The new API may be much the same as the existing one or it may be
different - that depends on contributions made!
I'd like to hear more about your experiences esp. with Graph API as that
is supposed to be quite simple - it's targeted at storage extensions as
well as supporting the richer Model API. Personally, aside from the
fact that Clerreza enforces slot constraints (no literals as subjects),
the Jena Graph API and Clerezza RDF core API seem reasonably aligned.
(for generalised systems such as rules engine - and for SPARQL - triples
can arise with extras like literals as subjects; they get removed later)
Andy
