- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Mon, 10 Nov 2014 12:53:35 -0500
- To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
- Cc: Arthur Ryman <ryman@ca.ibm.com>, public-data-shapes-wg@w3.org
* Peter F. Patel-Schneider <pfpschneider@gmail.com> [2014-11-10 07:54-0800] > RDF graphs are defined without respect to XML datatypes. For > example, "1"^^^xsd:integer and "01"^^xsd:integer are different as > far as RDF graphs are concerned. > > Of course, there is a close relationship between these two literals, > but that is (mostly) defined in the RDF semantics. > > So is it then the case that OSLC goes beyond RDF graphs? I suspect that the only place you can detect this is if a _defined_property_ has an oslc:allowedValue property. Data: <X> :foo "01"^^xsd:integer . ShExC Schema: :Xshape { :foo (1 2 3) . } Resource Shapes: :Xshape rs:property [ rs:name "foo" ; rs:propertyDefinition :foo ; rs:allowedValue 1, 2, 3 ; rs:occurs rs:Exactly-one ] . > peter > > > On 11/10/2014 07:38 AM, Arthur Ryman wrote: > >Eric, > > > >Yes. RDF includes the built-in XML datatypes. > >_________________________________________________________ > >Arthur Ryman > >Chief Data Officer > >SWG | Rational > >905.413.3077 (phone) | 416.939.5063 (cell) > >IBM InterConnect 2015 > > > > > > > > > >From: "Eric Prud'hommeaux" <eric@w3.org> > >To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>, > >Cc: Arthur Ryman/Toronto/IBM@IBMCA, public-data-shapes-wg@w3.org > >Date: 11/07/2014 08:46 AM > >Subject: Re: Shapes, Individuals, and Classes - OSLC Motivations > > > > > > > >* Peter F. Patel-Schneider <pfpschneider@gmail.com> [2014-11-06 > >20:36-0800] > >>So your view is that all that counts is the graph? Nothing about > >>datatypes, or RDF, or RDFS? > > > >I suspect that OSLC wants datatypes, noting that Resource Shapes has > >an oslc:valueType predicate for identifying the datatype of a literal. > > > > http://www.w3.org/Submission/2014/SUBM-shapes-20140211/#valueType > > > > > >>peter > >> > >> > >>On 11/06/2014 12:01 PM, Arthur Ryman wrote: > >>>Peter, > >>> > >>>Commenting on your proposed wording of how to express the "decoupling" > >>>requirement. I'd go further and demote the notion of class to being > >more > >>>like just another property and view the shape/constraints as applying > >to > >>>the RDF representation of an information resource, i.e. to a set of > >>>triples (aka an RDF graph). Some of the triples will have rdf:type as > >the > >>>predicate and those triples are useful for locating certain subject > >nodes > >>>that we want to say more things about, e.g that they are the subjects > >of > >>>triples that have certain other predicates, etc. > >>>_________________________________________________________ > >>>Arthur Ryman > >>>Chief Data Officer > >>>SWG | Rational > >>>905.413.3077 (phone) | 416.939.5063 (cell) > >>>IBM InterConnect 2015 > >>> > >>> > >>> > >>> > >>>From: "Peter F. Patel-Schneider" <pfpschneider@gmail.com> > >>>To: Arthur Ryman/Toronto/IBM@IBMCA, > >>>Cc: public-data-shapes-wg@w3.org > >>>Date: 11/06/2014 12:14 PM > >>>Subject: Re: Shapes, Individuals, and Classes - OSLC Motivations > >>> > >>> > >>> > >>>I still don't know what "custom" means here with respect to RDF. As > >far > >>>as I > >>>can tell any bit of an ontology, or class, or property, or constraint, > >or > >>>shape could be called "custom". Now it may be that within OSLC there > >is > >>>some > >>>notion of custom vs non-custom, but how can that notion be removed from > >>>OSLC > >>>so that it can be used elsewhere? > >>> > >>>Similarly, the notions of "specification", "implementation", "project", > >>>etc., > >>>appear to me to be specific to OSLC, and particular to the design > >>>methodology > >>>you outline below, and using them to drive a spec could, I think, tie > >that > >>> > >>>spec quite closely to the design methodology. > >>> > >>> > >>> > >>>As a contrast, here is what I believe should be used to say that > >classes > >>>and > >>>shapes/constraints are decoupled. > >>> > >>>Definition: Classes and shapes/constraints are decoupled if the > >>>specification > >>>can use different sets of shapes/constraints on the same class. For > >>>example, > >>>if the specification permits the ontology > >>> ex:Person rdf:type rdfs:Class . > >>> ex:name rdf:type rdf:Property . > >>> ex:name rdfs:domain ex:Person . > >>>to be used with the constraint set > >>> ex:Person < exists ex:name > >>>(every person has a "known" value for its name) > >>>or used with the constraint set > >>> ex:Person < all ex:name xsd:string > >>>(all "known" names of people are strings) > >>>then it will be said to allow the decoupling of constraints/shapes and > >>>classes. > >>> > >>> > >>>A stronger notion would be that shapes/constraints are independent of > >>>classes. > >>> This could be defined as: > >>> > >>>Definition: Classes and shapes/constraints are independent if some > >>>shapes/constraints do not use class membership in their definition. For > >>>example, the following constraint is class-independent: > >>> exists ex:name < exactly 1 ex:name > >>>(if something has a "known" name then it has exactly one "known" name) > >>> > >>> > >>>peter > >>> > >>> > >>> > >>> > >>>On 11/06/2014 04:59 AM, Arthur Ryman wrote: > >>>>Peter, > >>>> > >>>>OSLC defines specification for RDF representation of resources in > >>>several > >>>>domains, e.g. Requirements, Quality, Change Management etc. A > >>>>specification typically defines a class and several properties. > >>>>Implementations are allowed to add new RDF properties but they don't > >>>>necessarily introduce new RDF classes. Furthermore, within an > >>>>implementation, users may add custom RDF properties on a > >>>>project-by-project basis, but that doesn't change the RDF class. > >>>Therefore > >>>>different projects use different Shapes but the Shapes only differ by > >>>RDF > >>>>properties, not RDF classes. That is what I mean by decoupling Shapes > >>>and > >>>>Classes. > >>>> > >>>>I will elaborate this on the wiki. > >>>>_________________________________________________________ > >>>>Arthur Ryman > >>>>Chief Data Officer > >>>>SWG | Rational > >>>>905.413.3077 (phone) | 416.939.5063 (cell) > >>>>IBM InterConnect 2015 > >>>> > >>>> > >>>> > >>>> > >>>>From: "Peter F. Patel-Schneider" <pfpschneider@gmail.com> > >>>>To: Arthur Ryman/Toronto/IBM@IBMCA, public-data-shapes-wg@w3.org, > >>>>Date: 11/05/2014 05:27 PM > >>>>Subject: Re: Shapes, Individuals, and Classes - OSLC > >Motivations > >>>> > >>>> > >>>> > >>>>I'm still wondering what you think it means to decouple shapes and > >>>>classes. > >>>>The first motivation you provide is supported by both SPIN and OWL > >>>>constraints. I can't figure out what custom properties have to do > >with > >>>>classes, or constraints, or shapes. The behaviour you appear to be > >>>>looking > >>>>for in your second paragraph is also supported by both SPIN and OWL > >>>>constraints. > >>>> > >>>>I had thought that this was ironed out at the Face-to-Face, but I > >guess > >>>>not. > >>>> > >>>>peter > >>>> > >>>> > >>>>On 11/05/2014 01:47 PM, Arthur Ryman wrote: > >>>>>There are a few motivations for decoupling shapes and classes. One is > >>>>that > >>>>>the creation shape may be different than the update shape. Another > >has > >>>>to > >>>>>do with custom properties. I'll write up the following in the wiki. > >>>>> > >>>>>OSLC supports an open content model for resources. It is common for > >>>>tools > >>>>>to add their own custom properties, and for projects within a tool to > >>>>have > >>>>>different user-defined properties. For example, consider a bug > >tracking > >>>>>tool. Project A may add a custom property foo and project B may add > >>>bar. > >>>>>All projects use the same RDF type for bug resources, e.g. > >>>>>oslc_cm:ChangeRequest. However, the shape for resources in project A > >>>>>differs for the shape for project B. > >>>>>_________________________________________________________ > >>>>>Arthur Ryman > >>>>>Chief Data Officer > >>>>>SWG | Rational > >>>>>905.413.3077 (phone) | 416.939.5063 (cell) > >>>>>IBM InterConnect 2015 > >>>>> > >>>>> > >>>> > >>>> > >>>> > >>> > >>> > >>> > >> > > -- -ericP office: +1.617.599.3509 mobile: +33.6.80.80.35.59 (eric@w3.org) Feel free to forward this message to any list for any purpose other than email address distribution. There are subtle nuances encoded in font variation and clever layout which can only be seen by printing this message on high-clay paper.
Received on Monday, 10 November 2014 17:53:40 UTC