W3C

RDF Data Shapes Working Group Teleconference

24 Mar 2016

Agenda

See also: IRC log

Attendees

Present
pfps, hknublau, Arnaud, TallTed, simonstey, kcoyle, Dimitris, jamsden
Regrets
labra, ericP, hsolbrig
Chair
Arnaud
Scribe
TallTed

Contents


<scribe> scribenick: TallTed

Admin

<Arnaud> PROPOSED: Approve minutes of the 17 March 2016 Telecon: http://www.w3.org/2016/03/17-shapes-minutes.html

RESOLUTION: Approve minutes of the 17 March 2016 Telecon: http://www.w3.org/2016/03/17-shapes-minutes.html

F2F?

pfps: I don't think face- nor meeting-time is the bottleneck at the moment
... gaps in the design/spec need to be filled
... which needs external inputs and/or increased attention from some quarters

hknublau: what are the dramatic holes at the moment?

pfps: prebinding and hasShapes

Arnaud: there's been recent email traffic on prebinding

hknublau: hasShape has not been updated because we're still working on recursion, which resolution has significant impact there

[ back-and-forth about F2F impact/utility ]

hknublau: what is current timeline?

Arnaud: we are chartered until June 2017, so there should be plenty of time, even though we have not kept up with original forecast schedule

pfps: another implementation, especially one that includes the extension mechanism, would help a lot in boosting confidence

simonstey: I'm doing a fair amount of work with hknublau's draft API. do we need to re-implement that to be counted as multiple implmentations?

<Dimitris> I am planning to implement the spec

TallTed: I do expect that OpenLink will implement SHACL including extension mechanism. timing is indeterminate, but we do try to do such within CR->PR window.

Disposal of Raised Issues

<Arnaud> PROPOSED: Open ISSUE-138 Property constraints as lists, ISSUE-139 Universal applicability, ISSUE-140 Individual validation, ISSUE-141 Mixed ranges

<hknublau> +1

+1

<Dimitris> +1

<kcoyle> +1

<simonstey> +1

<pfps> I think that it would be very much better if OpenLink did an implementation before CR. This gives the WG much needed confidence that the design is workable.

<pfps> +1

RESOLUTION: Open ISSUE-138 Property constraints as lists, ISSUE-139 Universal applicability, ISSUE-140 Individual validation, ISSUE-141 Mixed ranges

<pfps> It would also be very helpful if OpenLink can contribute to the design of hasShape and pre-binding.

ISSUE-128: rdfs:range

ISSUE-128?

<trackbot> ISSUE-128 -- sh:defaultValueType is rdfs:range -- open

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/128

<Arnaud> PROPOSED: Close ISSUE-128, without action.

hknublau's email -- https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Mar/0252.html

pfps: as far as I can tell, defaultValueType is trying to mirror part of RDFS, so we don't have to put class links on some shapes, in order to support a particular version of the metamodel
... this seems to be a special purpose crutch to enable metamodel validation, and of no use elsewhere

<Arnaud> PROPOSED: Close ISSUE-128, without action.

<pfps> -1

<hknublau> +1

<simonstey> -0.5

<kcoyle> -.5

<Dimitris> 0

<jamsden> 0

+0.5

<Arnaud> PROPOSED: Close ISSUE-128, dropping sh:defaultValueType

<hknublau> -1

<pfps> +1

<kcoyle> 0

<Dimitris> 0

<simonstey> .5

<kcoyle> +q

kcoyle: I believe we've decided definitively that SHACL includes no inferencing. that makes me wonder how using rdfs:range could help us here.

hknublau: this is about pre-validation inferencing on the shapes graph
... the difference is that rdfs:range effectively always adds a type triple, while sh:defaultValueType only applies if there is no other type triple

<simonstey> sh:property [ a sh:PropertyConstraint; sh:predicate ex:property; sh:minCount 1 ] vs. sh:property [sh:predicate ex:property; sh:minCount 1 ]

simonstey: this seems to be just a bit of shorthand sugar, allowing some explicit statements to be left out

Dimitris: I think we need to finalize the metamodel before we'll know whether this is useful or not

Arnaud: do we break anything if we drop sh:defaultValueType?

hknublau: no

TallTed: what about marking it Feature At Risk?
... after this discussion, I revise my votes above to +1, -1

kcoyle: I wonder if we're not talking so much about the standard, as implementation variance

Arnaud: anyone else adjusting votes?

RESOLUTION: Close ISSUE-128, without action.

Syntax and metamodel Complexity and Possible simplifications

background https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Mar/0255.html

Dimitris: we have two considerations -- metamodel simplification, and syntax simplification. making one simpler tends to make the other more complex. do we simplify life for "engine user" or for "engine writer"?

pfps: the current design with mixed up PropertyConstraints and property paths is broken. there is some patch in consideration, but it's not clear whether that resolves the whole break.

ISSUE-41: property paths

Arnaud: in the course of this, Property Paths were raised again, and appear to be more broadly acceptable and implementable

<pfps> I don't see that closing this the other way is a possibility today.

Dimitris: ShEx people are likely to have objections here, so if we reopen, shouldn't reclose without them

<simonstey> if the extension mechanism will be dropped, we need those paths

hknublau: I wonder whether we now have solutions to a problem that doesn't really exist or isn't that important
... would probably want this to be in extension mechanism, not core

<hknublau> Yes, we could postpone it.

<Arnaud> PROPOSED: Reopen ISSUE-41, based on Peter's email https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Mar/0290.html

<simonstey> +1

<pfps> +0.5 as I find them very useful in my implementation

+1

<kcoyle> 0

<hknublau> -0

<Dimitris> +0

RESOLUTION: Reopen ISSUE-41, based on Peter's email https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Mar/0290.html

ISSUE-130: rdf dataset assumption

ISSUE-130?

<trackbot> ISSUE-130 -- SHACL should not assume that the data graph is in an RDF dataset -- open

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/130

<Zakim> pfps, you wanted to say that the current draft does not depend on datasets

<Arnaud> PROPOSED: Close ISSUE-130, as is - the latest draft doesn't require/assume a dataset

<pfps> +1

+1

<Dimitris> +1

<kcoyle> +1

<jamsden> +1

<simonstey> +1

<hknublau> 0

RESOLUTION: Close ISSUE-130, as is - the latest draft doesn't require/assume a dataset

adjourned!

<Arnaud> trackbot, end meeting

Summary of Action Items

Summary of Resolutions

  1. Approve minutes of the 17 March 2016 Telecon: http://www.w3.org/2016/03/17-shapes-minutes.html
  2. Open ISSUE-138 Property constraints as lists, ISSUE-139 Universal applicability, ISSUE-140 Individual validation, ISSUE-141 Mixed ranges
  3. Close ISSUE-128, without action.
  4. Reopen ISSUE-41, based on Peter's email https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Mar/0290.html
  5. Close ISSUE-130, as is - the latest draft doesn't require/assume a dataset
[End of minutes]

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$Date: 2016/04/01 21:16:44 $