W3C

RDF Data Shapes Working Group Teleconference

03 Mar 2016

Agenda

See also: IRC log

Attendees

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

Contents


<scribe> scribenick: hknublau

Admin

<Arnaud> PROPOSED: Approve minutes of the 25 February 2016 Telecon: http://www.w3.org/2016/02/25-shapes-minutes.html

RESOLUTION: Approve minutes of the 25 February 2016 Telecon: http://www.w3.org/2016/02/25-shapes-minutes.html

(Missing Harold from minutes)

Disposal of Raised Issues

<Arnaud> PROPOSED: Open ISSUE-123 DirectType syntax

<simonstey> issue-123

<trackbot> issue-123 -- Shall we unify the syntax of sh:directType and sh:class? -- raised

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/123

jamsden: what was the motivation for directType anyway?

hknublau: From Arthur, OSLC

jamsden: I would prefer being consistent with inheritance
... I will talk to Shapes users to see why this is needed.
... Unintended inferencing is a different problem

<Dimitris> +1

<TallTed> +1 open it

+1 open for now

<simonstey> +1

RESOLUTION: Open ISSUE-123 DirectType syntax

Arnaud: I would like to get feedback on the status of a few issues

ISSUE-92

<trackbot> issue-92 -- Should repeated properties be interpreted as additive or conjunctive? -- open

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/92

ericP: Differences between ShEx and SHACL - properties can be disjoint by default
... we are trying to come up with an approach that works for all
... iovka may join later

ISSUE-68

<trackbot> ISSUE-68 -- pre-binding not defined in SHACL spec -- open

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/68

<kcoyle> (as I predicted, app dropped me; back on computer)

+q

<simonstey> is this about the $varname stuff?

hknublau: The proposals page is not yet up to date. The spec has a new paragraph.
... my preference would be to expose this to implementers

http://w3c.github.io/data-shapes/shacl/#pre-binding

<jamsden> It would be nice to see an example

hknublau: will send an update email, please look

ISSUE-80

<trackbot> issue-80 -- Constraint to limit IRIs against scheme/namespace, possibly with dereferencing -- open

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/80

<simonstey> +q

<Arnaud> https://www.w3.org/2015/12/17-shapes-minutes.html#item06

ericP: ShEx has a notion of URI stems
... for value matching, only gets us halfway

simonstey: Dereferencing is mentioned in Use Cases document
... people agreed this is out of scope for SHACL

kcoyle: Regex matching is similar to stemming, but stemming is very common in our use cases.

ericP: ShEx stemming construct is for convenience only.

<kcoyle> agreed

<kcoyle> We would definitely use the simpler interface

ericP: Do people support this (slightly redundant) stemming feature?

<Arnaud> ACTION: ericP to send proposal for sh:Stem in response to ISSUE-80 [recorded in http://www.w3.org/2016/03/03-shapes-minutes.html#action01]

<trackbot> Created ACTION-36 - Send proposal for sh:stem in response to issue-80 [on Eric Prud'hommeaux - due 2016-03-10].

Arnaud: Some tickets were never talked about.

ISSUE-52

<trackbot> issue-52 -- Define an Abstract Syntax for SHACL -- open

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/52

Arnaud: Since Arthur left, would anyone want to continue?

ericP: ShEx Abstract Syntax could be harvested, I could work out something

jamsden: Abstract Syntax is a good idea, but if there is only one Concrete Syntax then what is the point
... also SHACL is tied to RDF, so this feels like a nice to have only, should not delay the process

Arnaud: maybe there is value for documentation purposes, as a side project
... we are not ready to kill this off yet, let's wait for Eric's proposal

ISSUE-99

<trackbot> issue-99 -- special treatment of rdfs:Resource and rdf:List in sh:valueClass (and possibly elsewhere) -- open

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/99

<Arnaud> https://www.w3.org/2016/02/25-shapes-minutes.html#item06

hknublau: Updated proposals are on the wiki page, would be nice to see more feedback

<Dimitris> https://www.w3.org/2014/data-shapes/wiki/Proposals#ISSUE-99.5:_handling_lists_and_resources

<Arnaud> PROPOSED: No special cases for sh:class and friends. This means that Turtle lists don't validate against sh:class rdf:List and that many nodes don't validate against rdfs:Resource

<Dimitris> +1

+0.5

<TallTed> +0

<Labra> 0

<kcoyle> 0 (kinda what the hell)

<jamsden> +0

<hsolbrig> 0

<simonstey> 0

<ericP> 0 (kinda what the hell)

<simonstey> what are those "many nodes"?

hsolbrig: I am confused about Turtle lists. Why should they be different than any other list

hknublau: It's about that lists written in Turtle don't produce an rdf:type triple.

TallTed: We could solve this by adding a Shape and use sh:valueShape

Dimitris: I suggest using NodeKind

<Arnaud> PROPOSED: No special treaments of rdf:List and rdf:Resource at sh:class. This means that Turtle lists don't validate against sh:class rdf:List and that many nodes don't validate against rdfs:Resource.

<kcoyle> +.5

<simonstey> +0.9

0.5

<Labra> +0.5

<Dimitris> +1

<hsolbrig> 0.5

<TallTed> +0.5

<ericP> 0 (kinda what the hell)

<jamsden> +0.5

<ericP> +1 -kinda what the hell

RESOLUTION: No special treaments of rdf:List and rdf:Resource at sh:class. This means that Turtle lists don't validate against sh:class rdf:List and that many nodes don't validate against rdfs:Resource.

TallTed: This WG is best suitable to define a standard Shape for well-formed rdf:Lists

<simonstey> https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Feb/0045.html

<simonstey> +q

simonstey: Special construct was asked for by various use cases. I would prefer to have such a feature. But we left this to future work.

<simonstey> issue-119

<trackbot> issue-119 -- Defining constraints on (values of) rdf:Lists -- closed

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/119

hknublau: We could leave this to a general rdf:List library that can be created by 3rd parties

kcoyle: Many people hate rdf:Lists, but it's basic RDF standard, so we need to do something about it.

hknublau: if we are to add a standard Shape, someone needs to produce a draft
... We should however add three NodeKinds, esp for BlankNodeOrIRI

<Arnaud> PROPOSED: sh:NodeKind should be extended with sh:BlankNodeOrIRI (and the two other combinations)

+1

<jamsden> These aren't well enouth specified for me to adequately assess them

<Dimitris> +1 but indeed we should enumerate all options

<simonstey> +-0

hknublau: The three new terms could be sh:BlankNodeOrIRI, sh:BlankNodeOrLiteral, sh:IRIorLiteral

<Arnaud> http://w3c.github.io/data-shapes/shacl/#AbstractNodeKindPropertyConstraint

<Dimitris> i would suggest to add only sh:NonLiteral + the old ones (sh:IRI, sh;BlankNode, sh:Literal)

@Dimitris, I have seen use cases for sh:NonBlankNode (aka IRIOrLiteral).

<Dimitris> we can use sh:or for special cases I think but I don;t mind to add more if needed

<kcoyle> can they not be combined as individuals?

<Dimitris> sh:IRI, sh;BlankNode, sh:Literal, sh:NonIRI, sh;NonBlankNode, sh:NonLiteral ?

<simonstey> sh:not ?

<simonstey> +1 to Karen's concerns

<Arnaud> PROPOSED: sh:NodeKind should be extended with sh:BlankNodeOrIRI, sh:BlankNodeOrLiteral, sh:IRIorLiteral

<ericP> and any node would be blurlteral?

<hsolbrig> +1

<ericP> +1

<kcoyle> +1

+1 (But Dimitr's syntax would be fine too)

<Dimitris> +1

<jamsden> I don't undestand how this would be used to constrain the list, so can't vote intelligently

<iovka_> +1

<Labra> +0.5 (I would prefer NonLiteral)

<simonstey> sh:not [ sh:property [ sh:predicate ex:prop; sh:nodekind sh:Literal ] ]

<TallTed> +0.5

<simonstey> +0.5

<TallTed> I like Dimitris alternative sugar, too

RESOLUTION: sh:NodeKind should be extended with sh:BlankNodeOrIRI, sh:BlankNodeOrLiteral, sh:IRIorLiteral

<Arnaud> PROPOSED: change possible values of sh:NodeKind to sh:IRI, sh;BlankNode, sh:Literal, sh:NonIRI, sh;NonBlankNode, sh:NonLiteral

+0

<Arnaud> PROPOSED: change possible values of sh:NodeKind to sh:IRI, sh:BlankNode, sh:Literal, sh:NonIRI, sh:NonBlankNode, sh:NonLiteral

<hsolbrig> +0

<Dimitris> +1

<simonstey> +0,5

<kcoyle> -.5

<TallTed> +0.5 (shorter strings, same meaning, I think will fit thinking more often)

<Labra> +0.8

<ericP> +1

kcoyle: Not would be better than Non.

<TallTed> Non is perfectly valid English usage...

<ericP> +1 to naan

<TallTed> BlankNode should all become Blanknode -- everywhere

<Dimitris> NonBlanknode with lower n

<kcoyle> -1

<TallTed> TallTed: inappropriate camelcasing on Blanknode should be undone. `BlankNode` should all become `Blanknode`.

<Arnaud> trackbot, end meeting

Summary of Action Items

[NEW] ACTION: ericP to send proposal for sh:Stem in response to ISSUE-80 [recorded in http://www.w3.org/2016/03/03-shapes-minutes.html#action01]
 

Summary of Resolutions

  1. Approve minutes of the 25 February 2016 Telecon: http://www.w3.org/2016/02/25-shapes-minutes.html
  2. Open ISSUE-123 DirectType syntax
  3. No special treaments of rdf:List and rdf:Resource at sh:class. This means that Turtle lists don't validate against sh:class rdf:List and that many nodes don't validate against rdfs:Resource.
  4. sh:NodeKind should be extended with sh:BlankNodeOrIRI, sh:BlankNodeOrLiteral, sh:IRIorLiteral
[End of minutes]

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$Date: 2016/03/14 19:58:39 $