- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Wed, 24 Feb 2016 10:10:31 -0800
- To: kcoyle@kcoyle.net, public-data-shapes-wg@w3.org

More or less. "fillers of property p" = "those nodes that are the objects of s p o triples for any particular unspecified s" It may be useful to also allow inverse properties and property paths so the above rewrite would have to modified into something removed from actual triples. peter On 02/24/2016 09:53 AM, Karen Coyle wrote: > "fillers" = "values"? > > On 2/24/16 9:03 AM, Peter F. Patel-Schneider wrote: >> SHACL states property constraints in the following way >> >> for the fillers of property ex:p >> the special fillers must all belong to class ex:s, >> there must be at least one, >> there must be at least five special fillers, >> they must all be either ex:a, ex:b, ex:c, ex:d, ex:e, ex:f, ex:d, ex:h, >> ex:i, or ex:j, >> there must be at most ten, >> the identifiers used for them must match regular expression r, >> they must all belong to class ex:c, and >> there must be at most seven special fillers. >> >> but not in the following way >> >> for the fillers of property ex:p >> there must be at least one, >> they must all belong to class ex:c, >> there must be at most five, >> they must all belong to class ex:d, and >> there must be at least three. >> >> In my opinion, these features of the SHACL RDF syntax are contributing to >> the complexity of the SHACL metamodel and to the number of decisions that >> have to be made to construct the SHACL metamodel. >> >> >> If SHACL stated constraints in the following way >> >> there must be at least one filler of property ex:p, >> all the fillers of property ex:p must belong to class ex:c, >> there must be at most five fillers of property ex:p, >> all the fillers of property ex:p must belong to class ex:d, and >> there must be at least three fillers of property ex:p. >> >> then the the metamodel for SHACL constraints could have just particular >> constraints (from the clauses above and other constraint constructs). This >> would be a significant simplification of the metamodel. >> >> >> Even if SHACL permitted the second construction above and uniformly stated >> multi-part particular constraints as at the end of the following there might >> be significant simplifications of the metamodel >> >> for the fillers of property ex:p >> there must be at least one, >> they must all be either ex:a, ex:b, ex:c, ex:d, ex:e, ex:f, ex:d, ex:h, >> ex:i, or ex:j, >> there must be at most ten, >> the identifiers used for them must match regular expression r, >> they must all belong to class ex:c, and >> there must be at between five and seven fillers that belong to class ex:s. >> >> >> These simplifications would require changes to the RDF syntax of SHACL. >> >> peter >> >> >

Received on Wednesday, 24 February 2016 18:11:02 UTC