From mariusz.cygan at deri.org Mon Oct 6 12:29:13 2008 From: mariusz.cygan at deri.org (Mariusz Cygan) Date: Mon, 06 Oct 2008 11:29:13 +0100 Subject: [Rdf2go-devel] Variable.ANY/null Message-ID: <48E9E879.7010601@deri.org> Hi, It looks Variable.ANY concept does not work correctly. When I use Variable.ANY everything looks good, but when I use null instead the results are just the same, and I think it shouldn't. Can you check it? -- Mariusz Cygan Research Assistant, DERI National University of Ireland, Galway From leo.sauermann at dfki.de Mon Oct 6 19:33:04 2008 From: leo.sauermann at dfki.de (Leo Sauermann) Date: Mon, 06 Oct 2008 19:33:04 +0200 Subject: [Rdf2go-devel] Variable.ANY/null In-Reply-To: <48E9E879.7010601@deri.org> References: <48E9E879.7010601@deri.org> Message-ID: <48EA4BD0.8040709@dfki.de> It was Mariusz Cygan who said at the right time 06.10.2008 12:29 the following words: > Hi, > > It looks Variable.ANY concept does not work correctly. When I use > Variable.ANY everything looks good, but when I use null instead the > results are just the same, and I think it shouldn't. Can you check it? > better that it WORKS than throwing a NullPointerException best Leo -- ____________________________________________________ DI Leo Sauermann http://www.dfki.de/~sauermann Deutsches Forschungszentrum fuer Kuenstliche Intelligenz DFKI GmbH Trippstadter Strasse 122 P.O. Box 2080 Fon: +49 631 20575-116 D-67663 Kaiserslautern Fax: +49 631 20575-102 Germany Mail: leo.sauermann at dfki.de Geschaeftsfuehrung: Prof.Dr.Dr.h.c.mult. Wolfgang Wahlster (Vorsitzender) Dr. Walter Olthoff Vorsitzender des Aufsichtsrats: Prof. Dr. h.c. Hans A. Aukes Amtsgericht Kaiserslautern, HRB 2313 ____________________________________________________ From mariusz.cygan at deri.org Mon Oct 6 19:52:16 2008 From: mariusz.cygan at deri.org (Mariusz Cygan) Date: Mon, 06 Oct 2008 18:52:16 +0100 Subject: [Rdf2go-devel] Variable.ANY/null In-Reply-To: <48EA4BD0.8040709@dfki.de> References: <48E9E879.7010601@deri.org> <48EA4BD0.8040709@dfki.de> Message-ID: <48EA5050.1080505@deri.org> So do you confirm, that Variable.Any is not needed? Mariusz Cygan Research Assistant, DERI National University of Ireland, Galway Leo Sauermann wrote: > It was Mariusz Cygan who said at the right time 06.10.2008 12:29 the > following words: >> Hi, >> >> It looks Variable.ANY concept does not work correctly. When I use >> Variable.ANY everything looks good, but when I use null instead the >> results are just the same, and I think it shouldn't. Can you check it? >> > better that it WORKS than throwing a NullPointerException > > best > Leo > > From max.at.xam.de at gmail.com Mon Oct 6 20:57:36 2008 From: max.at.xam.de at gmail.com (=?UTF-8?Q?Max_V=C3=B6lkel?=) Date: Mon, 6 Oct 2008 20:57:36 +0200 Subject: [Rdf2go-devel] Variable.ANY/null In-Reply-To: <48EA5050.1080505@deri.org> References: <48E9E879.7010601@deri.org> <48EA4BD0.8040709@dfki.de> <48EA5050.1080505@deri.org> Message-ID: Well, for clean semantics using null for values is discouraged. Imagine you have expressions likeNodeOrVariable n = ...fome function here.... which is supposed to return a node but in some cases returns null in error. It will be a hard-to-find error, as you do get results, no nullpointerexception, all seems rather ok. But isn't. Therefore we advise to use Variable.ANY. In some stores, rather by accident, e.g. in Sesame, null works like Variable.ANY. More for pragmatic reasons (usage in NEPOMUK) then for reasons of clean code, RDF2Go does not throw an exception. Any other opinions are valued. On Mon, Oct 6, 2008 at 19:52, Mariusz Cygan wrote: > So do you confirm, that Variable.Any is not needed? > > Mariusz Cygan > Research Assistant, DERI > National University of Ireland, Galway > > > Leo Sauermann wrote: > > It was Mariusz Cygan who said at the right time 06.10.2008 12:29 the > > following words: > >> Hi, > >> > >> It looks Variable.ANY concept does not work correctly. When I use > >> Variable.ANY everything looks good, but when I use null instead the > >> results are just the same, and I think it shouldn't. Can you check it? > >> > > better that it WORKS than throwing a NullPointerException > > > > best > > Leo > Kind Regards, Max V?lkel voelkel at fzi.de | http://Xam.de -- FZI Forschungszentrum Informatik an der Universit?t Karlsruhe Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe Tel.: +49-721-9654-0, Fax: +49-721-9654-959 Stiftung des b?rgerlichen Rechts, Az: 14-0563.1 Regierungspr?sidium Karlsruhe. Vorstand: Prof. Dr.-Ing. R?diger Dillmann, Dipl. Wi.-Ing. Michael Flor Prof. Dr. Dr.-Ing. Jivka Ovtcharova, Prof. Dr. rer. nat. Rudi Studer Vorsitzender des Kuratoriums: Ministerialdirigent G?nther Le?nerkraus -------------- next part -------------- An HTML attachment was scrubbed... URL: http://ontoware.org/pipermail/rdf2go-devel/attachments/20081006/6996a902/attachment.html From axel at rauschma.de Mon Oct 6 21:25:53 2008 From: axel at rauschma.de (Axel Rauschmayer) Date: Mon, 6 Oct 2008 21:25:53 +0200 Subject: [Rdf2go-devel] Variable.ANY/null In-Reply-To: References: <48E9E879.7010601@deri.org> <48EA4BD0.8040709@dfki.de> <48EA5050.1080505@deri.org> Message-ID: Failing fast is usually a good idea: One could throw NullPointerExceptions by default and have a more lenient mode that can optionally be switched on (where no NPEs are thrown). For contexts, null is a legal value, so Variable.ANY makes even more sense there (because null cannot denote a wildcard). Axel On Oct 6, 2008, at 20:57 , Max V?lkel wrote: > Well, for clean semantics using null for values is discouraged. > Imagine you have expressions like > NodeOrVariable n = ...fome function here.... which is supposed to > return a node but in some cases returns null in error. > It will be a hard-to-find error, as you do get results, no > nullpointerexception, all seems rather ok. But isn't. > Therefore we advise to use Variable.ANY. > In some stores, rather by accident, e.g. in Sesame, null works like > Variable.ANY. > More for pragmatic reasons (usage in NEPOMUK) then for reasons of > clean code, > RDF2Go does not throw an exception. > > Any other opinions are valued. > > > > On Mon, Oct 6, 2008 at 19:52, Mariusz Cygan > wrote: > So do you confirm, that Variable.Any is not needed? > > Mariusz Cygan > Research Assistant, DERI > National University of Ireland, Galway > > > Leo Sauermann wrote: > > It was Mariusz Cygan who said at the right time 06.10.2008 12:29 the > > following words: > >> Hi, > >> > >> It looks Variable.ANY concept does not work correctly. When I use > >> Variable.ANY everything looks good, but when I use null instead the > >> results are just the same, and I think it shouldn't. Can you > check it? > >> > > better that it WORKS than throwing a NullPointerException > > > > best > > Leo > > Kind Regards, > > Max V?lkel > voelkel at fzi.de | http://Xam.de > -- > FZI Forschungszentrum Informatik an der Universit?t Karlsruhe > Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe > Tel.: +49-721-9654-0, Fax: +49-721-9654-959 > Stiftung des b?rgerlichen Rechts, Az: 14-0563.1 Regierungspr?sidium > Karlsruhe. > Vorstand: Prof. Dr.-Ing. R?diger Dillmann, Dipl. Wi.-Ing. Michael Flor > Prof. Dr. Dr.-Ing. Jivka Ovtcharova, Prof. Dr. rer. nat. Rudi Studer > Vorsitzender des Kuratoriums: Ministerialdirigent G?nther Le?nerkraus > > > _______________________________________________ > Rdf2go-devel mailing list > Rdf2go-devel at ontoware.org > http://ontoware.org/mailman/listinfo/rdf2go-devel -- Axel.Rauschmayer at ifi.lmu.de http://www.pst.ifi.lmu.de/~rauschma/ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://ontoware.org/pipermail/rdf2go-devel/attachments/20081006/6c956f94/attachment-0001.html From max.at.xam.de at gmail.com Mon Oct 6 22:29:14 2008 From: max.at.xam.de at gmail.com (=?UTF-8?Q?Max_V=C3=B6lkel?=) Date: Mon, 6 Oct 2008 22:29:14 +0200 Subject: [Rdf2go-devel] Variable.ANY/null In-Reply-To: References: <48E9E879.7010601@deri.org> <48EA4BD0.8040709@dfki.de> <48EA5050.1080505@deri.org> Message-ID: On Mon, Oct 6, 2008 at 21:25, Axel Rauschmayer wrote: > Failing fast is usually a good idea: One could throw NullPointerExceptions > by default and have a more lenient mode that can optionally be switched on > (where no NPEs are thrown). > Uh, the more "modes" you have, the harder debugging becomes. As Richard Cyganiak once told me:"You can solve a problem or make it a configuration option" ;-) Seriously, I think we should try to find consensus for one option. > > For contexts, null is a legal value, so Variable.ANY makes even more sense > there (because null cannot denote a wildcard). > No I am lost, because for searches in OpenRDF natively, null is used as a wildcard, I think the empty array of type Resource denotes the default context? Well, too lazy to look up the doc now. Max V?lkel voelkel at fzi.de | http://Xam.de -- FZI Forschungszentrum Informatik an der Universit?t Karlsruhe Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe Tel.: +49-721-9654-0, Fax: +49-721-9654-959 Stiftung des b?rgerlichen Rechts, Az: 14-0563.1 Regierungspr?sidium Karlsruhe. Vorstand: Prof. Dr.-Ing. R?diger Dillmann, Dipl. Wi.-Ing. Michael Flor Prof. Dr. Dr.-Ing. Jivka Ovtcharova, Prof. Dr. rer. nat. Rudi Studer Vorsitzender des Kuratoriums: Ministerialdirigent G?nther Le?nerkraus -------------- next part -------------- An HTML attachment was scrubbed... URL: http://ontoware.org/pipermail/rdf2go-devel/attachments/20081006/39addebe/attachment.html From axel at rauschma.de Wed Oct 8 12:00:46 2008 From: axel at rauschma.de (Axel Rauschmayer) Date: Wed, 8 Oct 2008 12:00:46 +0200 Subject: [Rdf2go-devel] Variable.ANY/null In-Reply-To: References: <48E9E879.7010601@deri.org> <48EA4BD0.8040709@dfki.de> <48EA5050.1080505@deri.org> Message-ID: <6C3F2B87-6A71-4951-B979-234938133AAB@rauschma.de> > On Mon, Oct 6, 2008 at 21:25, Axel Rauschmayer > wrote: > Failing fast is usually a good idea: One could throw > NullPointerExceptions by default and have a more lenient mode that > can optionally be switched on (where no NPEs are thrown). > Uh, the more "modes" you have, the harder debugging becomes. As > Richard Cyganiak once told me:"You can solve a problem or make it a > configuration option" ;-) > Seriously, I think we should try to find consensus for one option. I agree. But what can you do if you have legacy software that expects that no exceptions are thrown? >> For contexts, null is a legal value, so Variable.ANY makes even >> more sense there (because null cannot denote a wildcard). > > No I am lost, because for searches in OpenRDF natively, null is used > as a wildcard, I think the empty array of type Resource denotes the > default context? > Well, too lazy to look up the doc now. True, it is a mixture: for subj, pred, obj, null is the wildcard. For the context, zero contexts means "any context", one or more contexts (of which any one can be null, denoting the anonymous context) means that any _of_those_ contexts is OK. Axel -- Axel.Rauschmayer at ifi.lmu.de http://www.pst.ifi.lmu.de/~rauschma/ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://ontoware.org/pipermail/rdf2go-devel/attachments/20081008/7246d141/attachment.html From antoni.mylka at gmail.com Tue Oct 28 04:02:53 2008 From: antoni.mylka at gmail.com (Antoni Mylka) Date: Tue, 28 Oct 2008 04:02:53 +0100 Subject: [Rdf2go-devel] announcement: Aperture 1.2.0 release Message-ID: <97d19f3c0810272002q3949958oc49c886bb5045d8e@mail.gmail.com> ANNOUNCEMENT OF Aperture 1.2.0 RELEASE Aperture is a Java framework for extracting full-text content and metadata from various information systems (e.g. file systems, web sites, mail boxes) and the file formats (e.g. documents, images) occurring in these systems. Homepage: http://aperture.sourceforge.net/ Download URL: https://sourceforge.net/project/showfiles.php?group_id=150969&package_id=166878&release_id=636375 After three years of development Aperture is stable enough to drop the .beta suffix from the release. 1.2.0 leverages architectural improvements made in 1.1.0.beta to bring support for compressed archives and to streamline email processing. A completely new service - the DataSourceDetector allows applications to provide suggestions to users about the data sources on their desktops. A host of bugfixes and minor improvements rounds the image of the leanest and meanest version of Aperture ever made. Enjoy. What's new? - a completely new Aperture service - the DataSourceDetectors - can be used to provide advice to the user about the data sources on the desktop - new subcrawlers for .zip, .gzip, tar and bzip2 compressed files - unification of the email handling - now the ImapCrawler, MboxCrawler and the MimeSubCrawler use the same code in the DataObjectFactory to convert emails to RDF. The MimeExtractor has been deprecated, switch to MimeSubCrawler - some bugfixes in the email handling code, plain text, and xml attachments are treated correctly, threads are reflected in the resulting rdf - the pdf extractor has some basic support for XMP metadata (thanks to JempBox) - a completely new XmlSafetyUtil class that helps to deal with characters that are valid in RDF, but invalid in XML thus breaking the serialization - the uris of subcrawled resources follow the pattern established by the Apache Commons VFS project. - new Sesame 2.2.1 bundled with Aperture features dramatic performance optimizations, e.g. the aperture test suite is 2 times faster, this may also be a boost for your application Best regards Leo Sauermann Christiaan Fluit Antoni Mylka