Why multiply with 5 in the IRI ? Just to spread it from a hash of the IRI and its String?
It means the "hashcode of the data type" in Literal can be slightly ambiguous. Perhaps "hashcode of the #getDataType() IRI" ? It also hammers in through getDataType that every Literal has a datatype, e.g. it is always added to the hash. BTW, hashcode of the Optional language is conveniently compliant with "plus hash code of language if present", so no similar ambiguity there. https://docs.oracle.com/javase/8/docs/api/java/util/Optional.html#hashCode-- On 24 Mar 2015 12:25, "Reto Gmür" <[email protected]> wrote: On Mon, Mar 23, 2015 at 12:04 PM, Andy Seaborne <[email protected]> wrote: > On 23/03/15 10:25, Reto Gmür wrote: > >> Right now the API on Github says nothing about the identity and hascode of >> any term. In order to have interoperable it is essential to define the >> value of hashcode and the identity conditions for the rdf-terms which are >> not locally scoped, i.e. for IRIs and Literals. >> > > +1 > > >> I suggest to take the definitions from the clerezza rdf commons. >> > > Absent active JIRA at the moment, could you email here please? > > Given Peter is spending time on his implementation, this might be quite > useful to him. > > Sure. Literal: the hash code of the lexical form plus the hash code of the datatype plus if the literal has a language the hash code of the language https://git-wip-us.apache.org/repos/asf?p=clerezza-rdf-core.git;a=blob;f=api/src/main/java/org/apache/commons/rdf/Literal.java;h=cf5e1eea2d848a57e4e338a3d208f127103d39a4;hb=HEAD And the IRI: 5 + the hashcode of the string https://git-wip-us.apache.org/repos/asf?p=clerezza-rdf-core.git;a=blob;f=api/src/main/java/org/apache/commons/rdf/Iri.java;h=e1ef0f7d21a3cb668b4a3b2f2aae7e2f642b68dd;hb=HEAD Reto Andy > > > >> Reto >> >> On Mon, Mar 23, 2015 at 10:18 AM, Stian Soiland-Reyes <[email protected]> >> wrote: >> >> OK - I can see on settling BlankNode equality can take some more time >>> (also considering the SPARQL example). >>> >>> So then we must keep the "internalIdentifier" and the abstract concept >>> of the "local scope" for the next release. >>> >>> In which case this one should also be applied: >>> >>> https://github.com/commons-rdf/commons-rdf/pull/48/files >>> and perhaps: >>> https://github.com/commons-rdf/commons-rdf/pull/61/files >>> >>> >>> >>> I would then need to fix simple GraphImpl.add() to clone and change >>> the local scope of the BlankNodes: >>> .. as otherwise it would wrongly merge graph1.b1 and graph2.b1 (in >>> both having the same internalIdentifier and the abstract Local Scope >>> of being in the same Graph). This can happen if doing say a copy from >>> one graph to another. >>> >>> Raised and detailed in >>> https://github.com/commons-rdf/commons-rdf/issues/66 >>> .. adding this to the tests sounds crucial, and would help us later >>> when sorting this. >>> >>> >>> This is in no way a complete resolution. (New bugs would arise, e.g. >>> you could add a triple with a BlankNode and then not remove it >>> afterwards with the same arguments). >>> >>> >>> >>> >>> >>> On 22 March 2015 at 21:00, Peter Ansell <[email protected]> wrote: >>> >>>> +1 >>>> >>>> Although it is not urgent to release a 1.0 version, it is urgent to >>>> release (and keep releasing often) what we have changed since 0.0.2 so >>>> we can start experimenting with it, particularly since I have started >>>> more intently on Sesame 4 in the last few weeks. Stians pull requests >>>> to change the BNode situation could wait until after 0.0.3 is >>>> released, at this point. >>>> >>>> Cheers, >>>> >>>> Peter >>>> >>>> On 21 March 2015 at 22:37, Andy Seaborne <[email protected]> wrote: >>>> >>>>> I agree with Sergio that releasing something is important. >>>>> >>>>> We need to release, then independent groups can start to build on it. >>>>> We >>>>> have grounded requirements and a wider community. >>>>> >>>>> Andy >>>>> >>>>> >>>>> On 21/03/15 09:10, Reto Gmür wrote: >>>>> >>>>>> >>>>>> Hi Sergio, >>>>>> >>>>>> I don't see where an urgent agenda comes from. Several RDF APIs are >>>>>> >>>>> there >>> >>>> so a new API essentially needs to be better rather than done with >>>>>> >>>>> urgency. >>> >>>> >>>>>> The SPARQL implementation is less something that need to be part of >>>>>> the >>>>>> first release but something that helps validating the API proposal. We >>>>>> should validate our API against many possible usecases and then discus >>>>>> which are more important to support. In my opinion for an RDF API it >>>>>> is >>>>>> more important that it can be used with remote repositories over >>>>>> >>>>> standard >>> >>>> protocols than support for hadoop style processing across many machines >>>>>> [1], but maybe we can support both usecases. >>>>>> >>>>>> In any case I think its good to have prototypical implementation of >>>>>> usecases to see what API features are needed and which are >>>>>> >>>>> problematic. So >>> >>>> I would encourage to write prototype usecases where a hadoop style >>>>>> processing shows the need for exposed blank node ID or a prototype >>>>>> >>>>> showing >>> >>>> that that IRI is better an interface than a class, etc. >>>>>> >>>>>> At the end we need to decide on the API features based on the usecases >>>>>> they >>>>>> are required by respectively compatible with. But it's hard to see the >>>>>> requirements without prototypical code. >>>>>> >>>>>> Cheers, >>>>>> Reto >>>>>> >>>>>> 1. >>>>>> >>>>>> https://github.com/commons-rdf/commons-rdf/pull/48# >>> issuecomment-72689214 >>> >>>> >>>>>> On Fri, Mar 20, 2015 at 8:30 PM, Sergio Fernández <[email protected]> >>>>>> wrote: >>>>>> >>>>>> I perfectly understand what you target. But still, FMPOV still out of >>>>>>> >>>>>> our >>> >>>> urgent agenda. Not because it is not interesting, just because more >>>>>>> urgent >>>>>>> things to deal with. I think the most important think is to get >>>>>>> >>>>>> running >>> >>>> with what we have, and get a release out. But, as I said, we can >>>>>>> >>>>>> discuss >>> >>>> it. >>>>>>> >>>>>>> >>>>>>> On 20/03/15 19:10, Reto Gmür wrote: >>>>>>> >>>>>>> Just a little usage example to illustrate Stian's point: >>>>>>>> >>>>>>>> public class Main { >>>>>>>> public static void main(String... args) { >>>>>>>> Graph g = new SparqlGraph("http://dbpedia.org/sparql";); >>>>>>>> Iterator<Triple> iter = g.filter(new Iri(" >>>>>>>> http://dbpedia.org/ontology/Planet";), >>>>>>>> new >>>>>>>> Iri("http://www.w3.org/1999/02/22-rdf-syntax-ns#type >>>>>>>> "), >>>>>>>> null); >>>>>>>> while (iter.hasNext()) { >>>>>>>> System.out.println(iter.next().getObject()); >>>>>>>> } >>>>>>>> } >>>>>>>> } >>>>>>>> >>>>>>>> I think with Stian's version using streams the above could be >>>>>>>> shorter >>>>>>>> and >>>>>>>> nicer. But the important part is that the above allows to use >>>>>>>> >>>>>>> dbpedia as >>> >>>> a >>>>>>>> graph without worrying about sparql. >>>>>>>> >>>>>>>> Cheers, >>>>>>>> Reto >>>>>>>> >>>>>>>> On Fri, Mar 20, 2015 at 4:16 PM, Stian Soiland-Reyes < >>>>>>>> >>>>>>> [email protected]> >>> >>>> wrote: >>>>>>>> >>>>>>>> I think a query interface as you say is orthogonal to Reto's >>>>>>>> >>>>>>>>> >>>>>>>>> impl.sparql module - which is trying to be an implementation of RDF >>>>>>>>> Commons that is backed only by a remote SPARQL endpoint. Thus it >>>>>>>>> touches on important edges like streaming and blank node >>>>>>>>> identities. >>>>>>>>> >>>>>>>>> It's not a SPARQL endpoint backed by RDF Commons! :-) >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> On 20 March 2015 at 10:58, Sergio Fernández <[email protected]> >>>>>>>>> >>>>>>>> wrote: >>> >>>> >>>>>>>>> Hi Reto, >>>>>>>>>> >>>>>>>>>> yes, that was a deliberated decision on early phases. I'd need to >>>>>>>>>> >>>>>>>>> look >>> >>>> it >>>>>>>>>> up, I do not remember the concrete issue. >>>>>>>>>> >>>>>>>>>> Just going a bit deeper into the topic, in querying we are talking >>>>>>>>>> >>>>>>>>> not >>> >>>> >>>>>>>>>> only >>>>>>>>> >>>>>>>>> about providing native support to query Graph instance, but also >>>>>>>>>> to >>>>>>>>>> >>>>>>>>>> provide >>>>>>>>> >>>>>>>>> common interfaces to interact with the results. >>>>>>>>>> >>>>>>>>>> The idea was to keep the focus on RDF 1.1 concepts before moving >>>>>>>>>> to >>>>>>>>>> >>>>>>>>>> query. >>>>>>>>> >>>>>>>>> Personally I'd prefer to keep that scope for the first incubator >>>>>>>>>> release, >>>>>>>>>> and then start to open discussions about such kind of threads. But >>>>>>>>>> >>>>>>>>> of >>> >>>> >>>>>>>>>> course >>>>>>>>> >>>>>>>>> we can vote to change that approach. >>>>>>>>>> >>>>>>>>>> Cheers, >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On 17/03/15 11:05, Reto Gmür wrote: >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> Hi Sergio, >>>>>>>>>>> >>>>>>>>>>> I'm not sure which deliberate decision you are referring to, is >>>>>>>>>>> it >>>>>>>>>>> Issue >>>>>>>>>>> #35 in Github? >>>>>>>>>>> >>>>>>>>>>> Anyway, the impl.sparql code is not about extending the API to >>>>>>>>>>> >>>>>>>>>> allow >>> >>>> running queries on a graph, in fact the API isn't extended at all. >>>>>>>>>>> It's >>>>>>>>>>> >>>>>>>>>>> an >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> implementation of the API which is backed by a SPARQL endpoint. >>>>>>>>>> >>>>>>>>> Very >>> >>>> >>>>>>>>>>> >>>>>>>>>>> often >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> the triple store doesn't run in the same VM as the client and so >>>>>>>>>> >>>>>>>>> it is >>> >>>> >>>>>>>>>>> necessary that implementation of the API speak to a remote triple >>>>>>>>>>> store. >>>>>>>>>>> This can use some proprietary protocols or standard SPARQL, this >>>>>>>>>>> >>>>>>>>>> is >>> >>>> an >>>>>>>>>>> implementation for SPARQL and can thus be used against any SPARQL >>>>>>>>>>> endpoint. >>>>>>>>>>> >>>>>>>>>>> Cheers, >>>>>>>>>>> Reto >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> On Tue, Mar 17, 2015 at 7:41 AM, Sergio Fernández < >>>>>>>>>>> >>>>>>>>>> [email protected]> >>> >>>> wrote: >>>>>>>>>>> >>>>>>>>>>> Hi Reto, >>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> thanks for updating us with the status from Clerezza. >>>>>>>>>>>> >>>>>>>>>>>> In the current Commons RDF API we delivery skipped querying for >>>>>>>>>>>> >>>>>>>>>>> the >>> >>>> >>>>>>>>>>>> early >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> versions. >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Although I'd prefer to keep this approach in the initial steps >>>>>>>>>>>> at >>>>>>>>>>>> ASF >>>>>>>>>>>> >>>>>>>>>>>> (I >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> hope we can import the code soon...), that's for sure one of the >>>>>>>>>> >>>>>>>>> next >>> >>>> >>>>>>>>>>>> points to discuss in the project, where all that experience is >>>>>>>>>>>> >>>>>>>>>>>> valuable. >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>>> Cheers, >>>>>>>>>>>> >>>>>>>>>>>> On 16/03/15 13:02, Reto Gmür wrote: >>>>>>>>>>>> >>>>>>>>>>>> Hello, >>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> With the new repository the clerezza rdf commons previously in >>>>>>>>>>>>> >>>>>>>>>>>> the >>> >>>> commons >>>>>>>>>>>>> sandbox are now at: >>>>>>>>>>>>> >>>>>>>>>>>>> https://git-wip-us.apache.org/repos/asf/clerezza-rdf-core.git >>>>>>>>>>>>> >>>>>>>>>>>>> I will compare that code with the current status of the code in >>>>>>>>>>>>> >>>>>>>>>>>> the >>> >>>> incubating rdf-commons project in a later mail. >>>>>>>>>>>>> >>>>>>>>>>>>> Now I would like to point to your attention a big step forward >>>>>>>>>>>>> towards >>>>>>>>>>>>> CLEREZZA-856. The impl.sparql modules provide an implementation >>>>>>>>>>>>> >>>>>>>>>>>> of >>> >>>> the >>>>>>>>>>>>> API >>>>>>>>>>>>> on top of a SPARQL endpoint. Currently it only supports read >>>>>>>>>>>>> access. >>>>>>>>>>>>> >>>>>>>>>>>>> For >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>> >>>>>>>>> usage example see the tests in >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>>> /src/test/java/org/apache/commons/rdf/impl/sparql ( >>>>>>>>>>>>> https://git-wip-us.apache.org/repos/asf?p=clerezza-rdf-core. >>>>>>>>>>>>> git;a=tree;f=impl.sparql/src/test/java/org/apache/commons/ >>>>>>>>>>>>> >>>>>>>>>>>>> rdf/impl/sparql;h=cb9c98bcf427452392e74cd162c08a >>> b308359c13;hb=HEAD >>> >>>> ) >>>>>>>>>>>>> >>>>>>>>>>>>> The hard part was supporting BlankNodes. The current >>>>>>>>>>>>> >>>>>>>>>>>> implementation >>> >>>> handles >>>>>>>>>>>>> them correctly even in tricky situations, however the current >>>>>>>>>>>>> >>>>>>>>>>>> code >>> >>>> is >>>>>>>>>>>>> not >>>>>>>>>>>>> optimized for performance yet. As soon as BlankNodes are >>>>>>>>>>>>> >>>>>>>>>>>> involved >>> >>>> many >>>>>>>>>>>>> queries have to be sent to the backend. I'm sure some SPARQL >>>>>>>>>>>>> >>>>>>>>>>>> wizard >>> >>>> could >>>>>>>>>>>>> help making things more efficient. >>>>>>>>>>>>> >>>>>>>>>>>>> Since SPARQL is the only standardized methods to query RDF >>>>>>>>>>>>> >>>>>>>>>>>> data, I >>> >>>> >>>>>>>>>>>>> think >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>> >>>>>>>>> being able to façade an RDF Graph accessible via SPARQL is an >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> important >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>> >>>>>>>>> usecase for an RDF API, so it would be good to also have an SPARQL >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>>> backed >>>>>>>>>>>>> implementation of the API proposal in the incubating >>>>>>>>>>>>> commons-rdf >>>>>>>>>>>>> repository. >>>>>>>>>>>>> >>>>>>>>>>>>> Cheers, >>>>>>>>>>>>> Reto >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> -- >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Sergio Fernández >>>>>>>>>>>> Partner Technology Manager >>>>>>>>>>>> Redlink GmbH >>>>>>>>>>>> m: +43 660 2747 925 >>>>>>>>>>>> e: [email protected] >>>>>>>>>>>> w: http://redlink.co >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>> -- >>>>>>>>>> Sergio Fernández >>>>>>>>>> Partner Technology Manager >>>>>>>>>> Redlink GmbH >>>>>>>>>> m: +43 660 2747 925 >>>>>>>>>> e: [email protected] >>>>>>>>>> w: http://redlink.co >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> -- >>>>>>>>> Stian Soiland-Reyes >>>>>>>>> Apache Taverna (incubating), Apache Commons RDF (incubating) >>>>>>>>> http://orcid.org/0000-0001-9842-9718 >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> -- >>>>>>> Sergio Fernández >>>>>>> Partner Technology Manager >>>>>>> Redlink GmbH >>>>>>> m: +43 660 2747 925 >>>>>>> e: [email protected] >>>>>>> w: http://redlink.co >>>>>>> >>>>>>> >>>>>> >>>>> >>> >>> >>> -- >>> Stian Soiland-Reyes >>> Apache Taverna (incubating), Apache Commons RDF (incubating) >>> http://orcid.org/0000-0001-9842-9718 >>> >>> >> >
