- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Thu, 2 Apr 2015 21:24:14 +0100
- To: Arthur Ryman <arthur.ryman@gmail.com>
- Cc: "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
> On 2 Apr 2015, at 20:48, Arthur Ryman <arthur.ryman@gmail.com> wrote: > > Richard, > > Seems like a useful idea. In the case that the extension language is > SPARQL this requirement is implicitly satisfied since we are defining > the semantics of 1) using SPARQL. However, even in SPARQL, the only > way to reuse a query is to copy it, maybe as a subquery of a larger > query. Are you proposing a way to package SPARQL queries so they are > callable from SPARQL? In Holger’s draft, there’s a facility to invoke SHACL evaluation as a SPARQL function. So you can ask in a SPARQL function if a certain node validates against a certain shape. This function is central to the way sh:valueShape is handled in Holger’s draft. This function would have to be implemented as a custom user function in the SPARQL engine. (This should be trivial in any SPARQL engine that supports user-defined functions.) In Peter’s draft, there’s no such facility, and sh:valueShape would instead be handled by syntactically expanding the query. I raised the issue hoping that somebody will say something that can inform discussion of the differences between these two proposals. Best, Richard > > -- Arthur > > On Sat, Mar 28, 2015 at 4:17 PM, RDF Data Shapes Working Group Issue > Tracker <sysbot+tracker@w3.org> wrote: >> shapes-ISSUE-26 (invoke-highlevel): Can extensions invoke the high-level language? [SHACL Spec] >> >> http://www.w3.org/2014/data-shapes/track/issues/26 >> >> Raised by: Richard Cyganiak >> On product: SHACL Spec >> >> It looks like SHACL will be split into two parts: >> >> 1) A high-level “Core/Lite” language consisting of things like cardinality constraints, datatype constraints, conjunctions and disjunctions >> 2) An extension mechanism that relies on embedded expressions in a more expressive language >> >> Can the embedded expressions in 2) invoke named expressions defined using 1)? >> >> >> >
Received on Thursday, 2 April 2015 20:24:39 UTC