Martynas, > this is a very simple answer that I have given you before: a shape of > RDF data is defined as SPARQL query. There are no two ways about it.
Hmm, the list of deliverables of the data shapes wg [1] mentions an RDF vocabulary to describe shapes, a set of semantics _possibly_ defined as SPARQL operations, etc. It says that one possibility is to use SPARQL queries to evaluate shapes against RDF graphs. At least to me, that doesn't mean that the shape is defined as a SPARQL query, but as an RDF graph. [1] http://www.w3.org/2014/data-shapes/charter#deliverables Best, Lars > On Tue, May 12, 2015 at 2:18 PM, Svensson, Lars <l.svens...@dnb.de> wrote: > > Kingsley, > > > > On Monday, May 11, 2015 9:00 PM, Kingsley Idehen wrote: > > > >> We have to be careful here. RDF Language sentences/statements have a > >> defined syntax as per RDF Abstract Syntax i.e., 3-tuples organized in > >> subject, > >> predicate, object based structure. RDF Shapes (as far as I know) has > >> nothing > to > >> do with the subject, predicate, object structural syntax of an RDF > >> statement/sentence. Basically, it's supposed to provide a mechanism for > >> constraining the entity type (class instances) of RDF statement's subject > >> and > >> object, when creating RDF statements/sentences in documents. Think of this > as > >> having more to do with what's regarded as data-entry validation and > control, in > >> other RDBMS quarters. > > > > The charter of the data shapes WG [1] says that "the product of the RDF Data > Shapes WG will enable the definition of graph topologies for interface > specification, code development, and data verification", so it's not _only_ > about > validation etc. My understanding is that it's somewhat similar to XML schema > and thus is essentially a description of the graph structure. As such, it can > of > course be used for validation, but that is only one purpose. > > > >> The function of the "profile" I believe you (and others that support this) > >> are > >> seeking has more to do with enabling clients and servers (that don't > necessarily > >> understand or care about RDF's implicit semantics) exchange hints about the > >> nature of RDF document content (e.g., does it conform to Linked Data > >> principles re. entity naming [denotation + connotation] ). > > > > No, my use of "profile" is really a "shape" in the sense of the data shapes > > wg. > Some of their motivations are what I'm envisioning, too, e.g. > > > > * Developers of each data-consuming application could define the shapes > their software needs to find in each feed, in order to work properly, with > optional elements it can use to work better. > > * Developers of data-providing systems can read the shape definitions (and > possibly related RDF Vocabulary definitions) to learn what they need to > provide > > > >> Cut long story short, a "profile" hint is about the nature of the RDF > >> content > (in > >> regards to entity names and name interpretation), not its shape (which is > >> defined by RDF syntax). > > > > OK, I stand corrected: My question is: How can clients and servers negotiate > shape information? > > > > Best, > > > > Lars
