Re: Proposal to close ISSUE-76 stating that execution order matters

Holger,
I don't think it is productive to accuse others of being dishonest or 
having a hidden agenda. I would appreciate that everyone keeps the 
discussion civil.
Thank you.
--
Arnaud  Le Hors - Senior Technical Staff Member, Open Web Technologies - 
IBM Software Group


"Peter F. Patel-Schneider" <pfpschneider@gmail.com> wrote on 07/29/2015 
07:13:27 AM:

> From: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
> To: Holger Knublauch <holger@topquadrant.com>, RDF Data Shapes 
> Working Group <public-data-shapes-wg@w3.org>
> Date: 07/29/2015 08:04 AM
> Subject: Re: Proposal to close ISSUE-76 stating that execution order 
matters
> 
> I raised this issue because I believe that there are excellent reasons 
for not
> requiring a particular order for the execution of the operands of the 
boolean
> operators.  Some of these reasons are even independent of the treatment 
of
> constraint violations that produce non-boolean results, although such 
results
> do make it more difficult to come up with a good solution.
> 
> To me this is not a pseudo argument in any way, shape, or form nor do I
> believe that I have been dishonest at all here.
> 
> Peter F. Patel-Schneider
> Nuance Communications
> 
> On 07/28/2015 04:18 PM, Holger Knublauch wrote:
> > On 7/29/2015 9:02, Peter F. Patel-Schneider wrote:
> >> I would say instead that the *most relevant* computer languages, 
> e.g., SQL and
> >> SPARQL, do not work this way.  I believe that most users of SHACL
> will not see
> >> that the connection to programming languages is so strong as to 
dictate how
> >> SHACL works.
> >>
> >> In general, users cannot tell which constraint is most restrictive.
> > 
> > In many cases they can. Why else do languages like SPARQL have ( ... )
> > brackets to control the execution order. According to your logic, 
> those should
> > be removed from SPARQL too.
> > 
> > Frankly, I believe the whole point of opening this ticket was to try 
to make
> > it as hard as possible for us to make recursion work - the 
> execution order is
> > needed for error handling there. I would prefer an honest discussion 
instead
> > of hiding behind pseudo arguments.
> > 
> > Thanks,
> > Holger
> > 
> > 
> >>    This is a
> >> job better done by the analog of query optimizers.  Requiring a 
particular
> >> order of evaluation will inhibit such optimiizations.
> >>
> >> peter
> >>
> >>
> >> On 07/27/2015 05:27 PM, Holger Knublauch wrote:
> >>> ISSUE-76 [1] is about whether the order of AND and OR operands 
> should matter.
> >>> I believe the order should matter, because this is how most 
> computer languages
> >>> work and therefore matches the expectation that users can put the 
most
> >>> restrictive operands first to avoid unnecessary evaluations. It also 
helps
> >>> produce consistent results in the face of errors. sh:AndConstraint 
and
> >>> sh:OrConstraint use rdf:Lists for that reason.
> >>>
> >>> Holger
> >>>
> >>> [1] http://www.w3.org/2014/data-shapes/track/issues/76
> >>>
> > 
> > 
>