W3C home > Mailing lists > Public > public-data-shapes-wg@w3.org > January 2015

Re: Definition of Shape

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Sat, 24 Jan 2015 08:48:58 -0800
Message-ID: <54C3CCFA.9000802@gmail.com>
To: kcoyle@kcoyle.net, public-data-shapes-wg@w3.org
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

The glossary that I put together was at least partly an attempt to answer
these sorts of questions.

In the glossary a shape (or unscoped constraint) is something that can only
be evaluated against something, e.g., people with at least two friends would
be a shape.  A scoped constraint includes both a shape and an indication of
how it is to be applied, e.g., all people must be people with at least two
friends would be a scoped constraint.  I would actually prefer to use just
"constraint" for scoped constraints but I was trying not to push this
particular preference for the meaning of constraint.

peter


On 01/24/2015 08:08 AM, Karen Coyle wrote:
> 
> 
> On 1/23/15 10:34 PM, Jose Emilio Labra Gayo wrote:
>> On Fri, Jan 23, 2015 at 8:30 PM, Peter F. Patel-Schneider 
>> <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> wrote:
>> 
> The glossary already contains a stab as this:
>>> 
>>> https://www.w3.org/2014/data-shapes/wiki/Glossary#Unscoped_Constraint.2FShape
>
>>> 
> 
>>> Yes, but I think we should have a simple definition of what a Shape
>>> is and I think this definition could be it.
> 
>> +1 for simple definition
> 
>> I also think that in the
>>> context of this group we can differentiate between a constraint and
>>> a shape, saying that a shape is a set of constraints on some RDF
>>> node.
> 
>> Does the shape constrain? or does it define? In the Dublin Core work
>> the "shape" was called a "description" -- it describes the graph and
>> the desired rules for the graph. Whether one uses those rules to
>> constrain, or to inform, or to reject, or to simply shake one's head in
>> dismay is a matter for the application that applies the rules. "Shape
>> expressions" is very close to this meaning, and is looked on favorably
>> within the DC community.
> 
>> kc
> 
> 
> 
>>> Apart from that, we can maintain the definitions of "constraint", 
>>> "scoped constraint" and "unscoped constraint" which I also think
>>> they make sense.
> 
>>> Best regards, Jose Labra
> 
> peter
> 
> 
> On 01/23/2015 10:10 AM, Jose Emilio Labra Gayo wrote:
>> I edited the Glossary page to add a possible definition of shape as:
> 
>> "A Shape is a set of constraints over the properties and objects
> of an
>> RDF node"
> 
>> I think it is in accordance with the use of the term in the WG
> and does
>> not enter in conflict with other terms.
> 
>> -- Saludos, Labra
>> 
>> 
>> 
>> 
>> -- Saludos, Labra
> 
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1

iQEcBAEBAgAGBQJUw8z6AAoJECjN6+QThfjzx3oH/1ED2hwHUZX6C94Ph6MW19fM
IYMUu3vS+s4XwwtPFPkqnMG8BrwtyzYKolWX5Eocd2Q+X7dAJrJMdeHQIX/EmjIZ
4kWFjh6fBsN8GzfDCy4qfUkVhGNf4Bzl/sKM3q2UbapNRX/VId96xSVPc/cC1jDL
h6nRktcRuQIQx9W4Jg457nO8S+34ny6yV7t6J0CRziIyw5n5L4XgEOULblp5/mMT
FmrDgoo7t++stZeP1HM8BSCgKmDr8dVDE9yS0+QggJU2GtpCpdrTxWqaA54rR38b
P2SJlrd1VLJDg69vOs+KKlqNcoX2CIjOvbidur6inqBc0Ki/2prn6YSokqkiku0=
=0HPS
-----END PGP SIGNATURE-----
Received on Saturday, 24 January 2015 16:49:31 UTC

This archive was generated by hypermail 2.3.1 : Saturday, 24 January 2015 16:49:32 UTC