Re: SHACL to SPARQL

These may be useful:

https://shape-fragments.github.io/shape-fragments-spec/
https://github.com/Shape-Fragments/SHACL2SPARQL
https://github.com/MaximeJakubowski/ssf_project
https://github.com/MaximeJakubowski/sls_project


On Mon, Sep 23, 2024 at 2:57 PM David Habgood <dcchabgood@gmail.com> wrote:

> Hi all,
>
> I have a library which generates SPARQL queries from SHACL, mostly to
> support two use cases. The first is listing sets of items, or focus nodes,
> with constraints on which items are selected. I find this one quite
> straightforward in SHACL. The second is describing individual objects, i.e.
> which properties should be included/and or excluded when describing an
> individual focus node. This one I find less clear - I can see there are a
> series of SHACL predicates which are relevant, but it's unclear to me if
> there's a "canonical" way this should be done.
>
> My question is whether there's a canonical way to do Use Case 2, and if
> not, should this form part of the use cases SHACL covers in future or be a
> part of a SHACL extension.
>
> In detail my use cases are:
>
> Use Case 1:
> I want to describe the selection of a set of focus nodes, based on one or
> a combination of the following focus node attributes:
> - the class of the focus nodes
> - the focus nodes' relationship to a specified node (e.g. is member of x)
> - the focus nodes' relationship to nodes of a specified class (e.g. the
> dcat:Catalogs that contain any dcat:Dataset, dcat:Resource etc.)
> - the presence or abscence of properties on the focus nodes, including via
> path relations (inverse, sequence etc.)
>
> Use Case 2:
> I want to describe a focus node by choosing one of the following two
> methods:
> 1.
> a. including all direct properties, except:
> - excluding any properties explicitly stated including via path relations
> (inverse, sequence etc.). (e.g. when describing a dcat:Dataset, not listing
> it's large number of members)
> - including any properties explicitly stated via "indirect" path relations
> (inverse, sequence etc.)
> b. inclusion of blank nodes to a specified depth
>
> 2.
> a. excluding all direct/indirect properties, except:
> - including any properties explicitly stated via direct and indirect path
> relations (inverse, sequence etc.)
> b. inclusion of blank nodes to a specified depth
>
> If SHACL predicates are reused across both use cases I want a clear way to
> distinguish which they are being used for. E.g. is a SHACL expression which
> in some way specifies dcterms:hasPart being used to describe how to select
> a set of focus nodes, or how to describe each focus node. At present I've
> used extension predicates for the blank node depth and "include all
> properties" concepts.
>
> Thanks,
> David
>