Gary, That sounds strange, but I have no experience with RDF serializers. Consider a physical junk drawer resource, it contains a paper clip, a button, an a pad of sticky notes. There is no way to make an RDF statement that describes a list of [paper clip, button, and sticky notes] (3 nodes) without also being forced to create a fourth node for the drawer?
RDF makes a distinction between containers <https://www.w3.org/TR/rdf-schema/#ch_containervocab> and collections <https://www.w3.org/TR/rdf-schema/#ch_collectionvocab>. Based on one example <https://www.w3.org/TR/turtle/#sec-examples> (#20 <https://www.w3.org/TR/turtle/examples/example2.ttl>), the latter appears that it *might *be an anonymous list of items, i.e. items a and b have IRIs, but the collection of a and b doesn't have an IRI. Then again, I might be totally confused. If a collection is not required to be a node, then that is what I'm proposing for SpdxDocument. And if collection is not a node, the Collection class should not have an open arrow to (be a subclass of) Element, whereas if it were called Container it would. Regards, David On Wed, Jul 27, 2022 at 8:30 PM Gary O'Neall <[email protected]> wrote: > Hi David, > > > > Agree with v3 having a more expressive graph – a definite improvement. I > do recall in early days of SPDX development having an issue where RDF > serializers would drop nodes if they were not referenced which helped lead > us to having an SPDX Document as a root level node in the graph. We > included this node in the logical as well as the serialization model for > RDF. I have a feeling we may (re)discover the same issue in v3 RDF > serialization where we will need a root collection to reference all the > elements we intend to serialize. We could decide to make this root element > something not included in the logical model or we could require custom RDF > serialization libraries as alternatives. My current thinking is we have an > SPDXDocument in the model for the serializations to “contain” all the > elements we wish to serialize (in RDF, it just needs to be referenced). To > make this more flexible, we could expand the types of elements which the > SPDXDocument could “contain” (e.g. Relationships). > > > > Regards, > > Gary > -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#4716): https://lists.spdx.org/g/Spdx-tech/message/4716 Mute This Topic: https://lists.spdx.org/mt/92634687/21656 Group Owner: [email protected] Unsubscribe: https://lists.spdx.org/g/Spdx-tech/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
