Re: ACTION: ericP to send proposal for sh:Stem in response to ISSUE-80

• From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
• Date: Thu, 31 Mar 2016 08:55:19 -0700
• To: Eric Prud'hommeaux <eric@w3.org>, public-data-shapes-wg@w3.org
• Message-ID: <56FD4867.7070604@gmail.com>

On 03/30/2016 03:03 PM, Eric Prud'hommeaux wrote:

> PROPOSAL: write stems in shacl like:
> 
> <http://a.example/S1> a sh:Shape;
>    sh:propValues (
>      <http://a.example/p1> [
>        sh:values [
>          a sh:StemRange;
>          shex:stem <http://a.example/v>
>        ]
>      ]
>    ).
> 
> This matches { <s1> <http://a.example/p1> <http://a.example/v123> }
>          and { <s1> <http://a.example/p1> <http://a.example/v> }
>    but fails { <s1> <http://a.example/p1> <http://a.example/uv> }

The following syntax might be better:

ex:S1 a sh:Shape;
   sh:propValues (
     <http://a.example/p1>
     [ a sh:Shape ;
       sh:stem <http://a.example/v>
     ] ) .

or, in the current SHACL syntax:

ex:S1 a sh:Shape;
   sh:property
     [ a sh:Shape ;
       sh:predicate <http://a.example/p1> ;
       sh:stem <http://a.example/v>
     ].

I appears to me that this is equivalent to

ex:S1 a sh:Shape;
    sh:property
      [ a sh:Shape ;
        sh:predicate <http://a.example/p1> ;
        sh:nodeKind sh:IRI ;
        sh:pattern "^http://a.example/v"
      ].


> PROPOSAL: write exclusions in shacl like:
> 
> <http://a.example/S1> a sh:Shape;
>    sh:propValues (
>      <http://a.example/p1> [
>        sh:values [
>          a sh:StemRange;
>          shex:stem <http://a.example/v>
>          sh:exclusions: (
>            [ "type": "Stem", "stem": <http://a.example/v1> ],
>            [ "type": "Stem", "stem": <http://a.example/v2> ],
>            [ "type": "Stem", "stem": <http://a.example/v3> ]
>          )
>        ]
>      ]
>    ).
> 
> This matches { <s1> <http://a.example/p1> <http://a.example/v4> }
>          and { <s1> <http://a.example/p1> <http://a.example/v456> }
>    but fails { <s1> <http://a.example/p1> <http://a.example/v2> }
>          and { <s1> <http://a.example/p1> <http://a.example/v234> }

It appears to me that this is equivalent to

ex:S1 a sh:Shape;
  sh:propValues ( <http://a.example/p1>
    [ a sh:Shape ;
      sh:nodeKind sh:IRI ;
      sh:pattern "^http://a.example/v" ;
      sh:not [ a sh:Shape ; sh:pattern "^http://a.example/v1" ] ;
      sh:not [ a sh:Shape ; sh:pattern "^http://a.example/v2" ] ;
      sh:not [ a sh:Shape ; sh:pattern "^http://a.example/v3" ]
    ] ) .

(because of the repeated sh:not the current syntax for this would be quite large).


>> You can find the stem tests in <http://raw.githubusercontent.com/shexSpec/shexTest/master/validation/manifest.ttl> with
>>
>>   SELECT * { ?s <http://www.w3.org/ns/shacl/test-suite#trait> <http://www.w3.org/ns/shacl/test-suite#Stem> }
>>
>> Gotta put my child to bed. will try to write to formalize later.
>> -- 
>> -ericP
>

Received on Thursday, 31 March 2016 15:55:48 UTC