- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Sat, 1 Oct 2016 08:19:42 -0700
- To: Dimitris Kontokostas <kontokostas@informatik.uni-leipzig.de>
- Cc: Karen Coyle <kcoyle@kcoyle.net>, "public-rdf-sha." <public-rdf-shapes@w3.org>
OK, that fixes the point about loose terminology. However, does it introduce a change to SHACL that should be approved by the working group as a whole? peter On 09/28/2016 11:30 PM, Dimitris Kontokostas wrote: > Thanks Peter, > > I tried to come up with a better wording as well but ended up deleting the > paragraph completely > https://github.com/w3c/data-shapes/commit/139f7de173b0ee6e054c4f250f33e18a6dac78fd#diff-69303a57193e6c2d7327c8de0fc977caL1069 > > We already have a definition of how filters & validation work in section 4 > which, IIRC came from you: > A node validates against a shape iff either it does not validate against some > filter of the shape or none of the constraints in the shape produce a > validation result or a failure for the node. > > This definition also covers the filter ordering as well as how node failure is > handled. > I am not sure if there is a need to handle other kinds of failure that may > arise from the different order of evaluation, even though these cases are > probably not common. > > Best, > Dimitris > > On Thu, Sep 29, 2016 at 1:09 AM, Peter F. Patel-Schneider > <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> wrote: > > So, yes, I have two problems with the current wording: > > 1/ It is yet another case of loose terminology. > 2/ It is the wrong way to do things. > > There are two reasons that it is wrong: > a) It prevents optimization of the SPARQL processing. > b) It even prevents translation of entire SHACL shapes to single SPARQL > queries, *requiring* something like sh:hasShape in *every* SHACL > implementation. > > I think that the order in which I discovered these issues was 2a, then 1, then > 2b. > > The net result is that I believe that the entire sentence needs to be > completely scrapped, and thus I don't see that there is any utility in > wordsmithing the sentence to fix problem 1. > > Peter F. Patel-Schneider > Nuance Communications > > > On 09/28/2016 02:41 PM, Karen Coyle wrote: > > Oh, I should have included the link to the diagram: > > > > > https://www.w3.org/TR/2016/WD-shacl-20160814/images/SHACL-Validation-Process.png > <https://www.w3.org/TR/2016/WD-shacl-20160814/images/SHACL-Validation-Process.png> > > > > That's a quick read. - kc > > > > On 9/28/16 2:38 PM, Karen Coyle wrote: > >> > >> > >> On 9/28/16 1:56 PM, Peter F. Patel-Schneider wrote: > >>> My view is that there should be no requirement that focus nodes are > >>> validated > >>> against the filter shapes of a shape before they are validated against > >>> the > >>> constraints of the shape. I have previously mentioned several reasons > >>> that > >>> led me to this view. > >> > >> OK. This is a different objection to what I had previously understood. I > >> thought your objection was to saying that they are "validated". > >> > >> In the introduction to section 2.0 of SHACL there is a diagram that > >> shows what I have taken to be an execution flow: > >> > >> data graph -> targets are used to select focus nodes -> Filters are used > >> to eliminate some focus nodes -> Constraints are used to produce > >> validation results. > >> > >> Is it this flow that you are objecting to? > >> > >> If so, can you either point to or reiterate your reasons? > >> > >> Thanks, > >> kc > >> > >> > >>> > >>> Peter F. Patel-Schneider > >>> Nuance Communications > >>> > >>> > >>> On 09/28/2016 06:40 AM, Karen Coyle wrote: > >>>> Peter, how would you describe the action that takes place then? > >>>> Because there > >>>> is an implied action and work flow. Implemented? executed? enforced? > >>>> resolved? > >>>> (I'm running through the thesaurus entries.) > >>>> > >>>> kc > >>>> > >>>> On 9/27/16 3:43 PM, Peter F. Patel-Schneider wrote: > >>>>> For starters, filter shapes are not "applied to the data graph", so, > >>>>> no. > >>>>> > >>>>> peter > >>>>> > >>>>> > >>>>> On 09/27/2016 03:38 PM, Holger Knublauch wrote: > >>>>>> Peter, would this suggestion work better for you? I assume someone > >>>>>> could argue > >>>>>> that "applied" is not defined. > >>>>>> > >>>>>> Holger > >>>>>> > >>>>>> > >>>>>> > >>>>>> On 28/09/2016 1:44, Karen Coyle wrote: > >>>>>>> Filter shapes must be ... > >>>>>>> - applied to the data graph > >>>>>>> ... before validating.... > >>>>>>> > >>>>>>> > >>>>>>> On 9/26/16 4:38 PM, Holger Knublauch wrote: > >>>>>>>> Does anyone else find this sentence unclear? If yes, could someone > >>>>>>>> suggest alternative wording? > >>>>>>>> > >>>>>>>> "Filter shapes MUST be validated before validating the associated > >>>>>>>> shapes > >>>>>>>> or constraints." > >>>>>>>> > >>>>>>>> Thanks, > >>>>>>>> Holger > >>>>>>>> > >>>>>>>> > >>>>>>>> On 27/09/2016 1:52, Peter F. Patel-Schneider wrote: > >>>>>>>>> How is a shape "validated"? > >>>>>>>>> > >>>>>>>>> This problem even affects the second half of the sentence I > >>>>>>>>> initially > >>>>>>>>> quoted. > >>>>>>>>> > >>>>>>>>> peter > >>>>>>>>> > >>>>>>>>> On 09/26/2016 12:18 AM, Holger Knublauch wrote: > >>>>>>>>>> Replaced with "validated": > >>>>>>>>>> > >>>>>>>>>> > https://github.com/w3c/data-shapes/commit/d4fbdebd7044cd79f35985a75a54994ea3facde9 > <https://github.com/w3c/data-shapes/commit/d4fbdebd7044cd79f35985a75a54994ea3facde9> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> Holger > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> On 26/09/2016 15:59, Peter F. Patel-Schneider wrote: > >>>>>>>>>>> "Filter shapes MUST be evaluated before validating the associated > >>>>>>>>>>> shapes or > >>>>>>>>>>> constraints." > >>>>>>>>>>> > >>>>>>>>>>> Evaluation is not defined. > >>>>>>>>>>> > >>>>>>>>>>> > >>>>>>>>>>> peter > >>>>>>>>>>> > >>>>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>> > >>>>>> > >>>>>> > >>>>> > >>>>> > >>>> > >>> > >> > > > > > > > -- > Dimitris Kontokostas > Department of Computer Science, University of Leipzig & DBpedia Association > Projects: http://dbpedia.org, http://rdfunit.aksw.org, http://aligned-project.eu > Homepage: http://aksw.org/DimitrisKontokostas > Research Group: AKSW/KILT http://aksw.org/Groups/KILT >
Received on Saturday, 1 October 2016 15:20:14 UTC