Re: SHACL Compact Syntax, was Re: Fwd: Transition Request: 3 FPWGNOTE documents

I also agree to defer a compact syntax for shacl to a later CG/WG.

Best,
Dimitris

Typed by thumb. Please forgive brevity, errors.

On May 24, 2017 9:28 PM, "simon.steyskal" <simon.steyskal@wu.ac.at> wrote:

Hi!

I second that. Trying to get our own compact syntax published now will
cause more harm than good.

br simon

(sorry for missing out on today's call.. I've totally forgotten about it)

-------- Original message --------
From: Sandro Hawke <sandro@w3.org>
Date: 5/24/17 20:17 (GMT+01:00)
To: Irene Polikoff <irene@topquadrant.com>, Data Shapes WG <
public-data-shapes-wg@w3.org>
Cc: Ralph Hodgson <rhodgson@topquadrant.com>
Subject: SHACL Compact Syntax, was Re: Fwd: Transition Request: 3 FPWGNOTE
documents

Tom's email, to which Irene is replying, was send to a W3C Member
Confidential mailing list (chairs@w3.org).  She accidentally included it in
her reply, perhaps not knowing the list's confidentiality (which is not
obvious).   Here's my to reply to that list, which bears on this this group:

My sincere apologies, Tom.  You mentioned this concern to me earlier, and
then I completely forgot about it in the flurry of documents.  That was a
serious error on my part.

I agree, it's a very bad architectural practice to design languages such
that a non-trivial document could be syntactically valid in multiple
languages while having different semantics.   We pretty much only see this
in a few notoriously bad situations, like "1/2/2017" being either
2017-01-02 or 2017-02-01, depending on the locale.

I suggest the Data Shapes Working Group withdraw its decision to publish
this (or the Director not approve it), and instead delegate to an expected
new SHACL CG to figure out a way to make the syntax disjoint from ShExC in
at least the cases where the semantics are distinct, [then] publish it as a
CG Report, much like ShExC, instead of a WG Note (since the WG will
presumably have expired by then).


Does that sound like a reasonably path forward?

I guess another option would be to make a trivial change to the syntax
(before next week) to make it disjoint, but I believe the community would
be far better served by having the syntax be the same in places where the
semantics are the same.  If that's possible, it seems worthwhile to take
the time in a CG to figure that out in concert with ShEx folks.

Thoughts?

      -- Sandro


On 05/24/2017 11:57 AM, Irene Polikoff wrote:

I really do not think ShEx has a “copywrite" on an idea of a compact
syntax. Its syntax itself was itself influenced by many different
syntaxes/previous works, I am sure.

Further, the syntaxes are not identical. They are similar. For example,
SHACL has target declarations and it is supported in the syntax. The way
cardinalities are expressed is different.

I guess one option would be to modify the syntax to be even less similar.
But I can’t think what could be done to make it significantly more
different - because the information it is trying to express is very similar
and it is expressed in an obvious way as a “property”, then a list of
constraints for the values such as the data type, cardinality, etc. There
is nothing novel or special in this format.

I suppose one could change delimiters. However, many delimiters are quite
standard and making them into something else would be very peculiar e.g.,
the use of ‘|” for ‘or’; the use of “;”  as a separator. These are used by
many-many languages. With this, I am not sure what changes would be
sufficient to ensure that SHACL and ShEx compact syntax can’t be confused.
Should SHACL WG members object to the ShEx CG use of the words ‘shape’,
‘node shape’, etc.? Because this will be confusing to potential users -
when they hear or see shape, they wouldn’t know which one.

Overall, this sounds like an attempt to prevent SHACL from having a compact
syntax so that for those who want a compact syntax, ShEx will be an only
option. This is not good for the community and, to me, sounds like a desire
to block progress and deprive users of SHACL of features. No one should
have a right to do this, especially not on the open web.


Begin forwarded message:

*From: *Tom Baker <tom@tombaker.org>
*Subject: **Re: Transition Request: 3 FPWGNOTE documents*
*Date: *May 24, 2017 at 11:05:47 AM EDT

...