- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Thu, 29 Oct 2015 10:29:50 -0700
- To: Holger Knublauch <holger@topquadrant.com>, public-data-shapes-wg@w3.org
On 10/28/2015 10:29 PM, Holger Knublauch wrote:
> On 10/29/2015 14:14, Peter F. Patel-Schneider wrote:
[...]
>> I here propose several changes the normative bits of the version of Part 2
>> that was prepared for ISSUE-95,
>> http://w3c.github.io/data-shapes/shacl/index-ISSUE-95.html, that fix many of
>> the problems there. I have not proposed changes for any of the bits marked
>> non-normative or any of the examples.
>>
>>
>> 6.2
>>
>> The SPARQL queries linked to a constraint via sh:sparql must be string
>> literals that can be parsed into legal SPARQL 1.1 queries of the query form
>> SELECT.
>> ->
>> The values for sh:sparql must be either the empty string literal ("") or
>> string literals that are can be parsed into legal SPARQL 1.1 queries of the
>> query form SELECT. The empty string literal indicates a vacuous constraint,
>> i.e., one that never produces any violations.
>
> Could you clarify why the "" literals are needed? Why not use no value instead?
That would be fine by me. The only reason to have "" is to explicitly say
that a constraint is vacuous.
peter
Received on Thursday, 29 October 2015 17:30:25 UTC