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Re: SHACL syntax and metamodel complexity

From: Karen Coyle <kcoyle@kcoyle.net>
Date: Mon, 7 Mar 2016 17:45:21 -0800
To: public-data-shapes-wg@w3.org
Message-ID: <56DE2EB1.8080607@kcoyle.net>


On 3/7/16 2:58 PM, Holger Knublauch wrote:
> Peter's proposal does not have the same functionality and is not simpler
> or easier to learn. Neither would simplicity necessarily be an argument
> to prefer it. There are good reasons why the current draft and proposal
> 3 have their structure.

I asked earlier if there were differences in functionality. Peter said 
no; you now say yes. If there are, then I think we need to enumerate 
them. It's not enough to just Y/N with nothing further.

kc

>
> As an analogy, take the difference between a "simple" weakly-typed
> language (e.g. JavaScript) and a "complex" strongly-typed language (e.g.
> Java). Some developers prefer JavaScript, others Java. The difference is
> that the more structured languages (like Java) allow for additional
> support at edit time, compile time and static analysis, and typically
> lead to more maintainable code in the long term. If SHACL is supposed to
> support data longevity, then I'd certainly prefer a more structured
> approach.
>
> Holger
>
>
> On 8/03/2016 6:19, Karen Coyle wrote:
>> If Peter's proposal has the same or similar functionality but is
>> simpler and easier to learn, then that is enough to make it
>> preferable. If we hope that SHACL will be widely used, even by
>> developers with minimal technical acumen, then we must aim for
>> simplicity. Fewer constructs, if they can be combined to create the
>> necessary functionality, is better, IMO, than many specific
>> properties. We should follow the "principle of least effort." [1]
>>
>> kc
>> [1] Zipf, George K. Human Behavior and the Principle of Least Effort:
>> An Introduction to Human Ecology. Cambridge, Mass: Addison-Wesley
>> Press, 1949
>>
>> On 3/6/16 8:04 PM, Holger Knublauch wrote:
>>>  From what I have seen so far, your alternative proposal has at least as
>>> many irregularities and constructs as the current drafts, while
>>> introducing many new problems. I will send a list of problems that I
>>> have already found at some stage. Many of these design decisions are
>>> basically a matter of taste and of a different world-view.
>>>
>>> I believe as long there is no list of real ISSUEs that you are trying to
>>> solve here, all this looks like a solution in search of a problem.
>>>
>>> Holger
>>>
>>>
>>> On 7/03/2016 13:21, Peter F. Patel-Schneider wrote:
>>>> I don't see this as a radical change.  A radical change would scrap
>>>> most of
>>>> the syntax and require non-local changes to shapes and constraints.
>>>>
>>>> What is broken in the current syntax is that there are too many
>>>> constructs and
>>>> too many irregularities.  Refactoring results in fewer constructs and
>>>> more
>>>> regularity.  This will result in a language that is easier to use.
>>>>
>>>> peter
>>>>
>>>>
>>>> On 03/06/2016 06:24 PM, Holger Knublauch wrote:
>>>>> Peter,
>>>>>
>>>>> I understand this is largely just a sketch and you may be "thinking
>>>>> out loud".
>>>>> Yet I don't have sufficient information on how all this is supposed
>>>>> to work,
>>>>> e.g. with SPARQL generation. It would help if you could provide some
>>>>> examples
>>>>> of how this vocabulary would be used to define some built-in and
>>>>> extension
>>>>> constraint types. On
>>>>>
>>>>> https://www.w3.org/2014/data-shapes/wiki/ISSUE-95:_Metamodel_simplifications#Proposal_3
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> I am presenting snippets illustrating the definitions of
>>>>> ex:LanguageConstraintType, sh:PatternConstraintType and
>>>>> sh:ClassConstraintType. Would you mind creating similar examples in
>>>>> your
>>>>> metamodel?
>>>>>
>>>>> Furthermore, I am unclear what problem you are trying to solve. What
>>>>> is broken
>>>>> in the current SHACL syntax that motivates your (radical) changes?
>>>>> Have any
>>>>> users complained or are there any related ISSUEs recorded? Of course
>>>>> we can
>>>>> come up with any number of syntaxes for SHACL and I could certainly
>>>>> make up
>>>>> plenty of variations, too.
>>>>>
>>>>> Thanks,
>>>>> Holger
>>>>>
>>>>>
>>>>> On 5/03/2016 13:32, Peter F. Patel-Schneider wrote:
>>>>>> I fixed up some silly syntax errors and added prefix
>>>>>> declarations.  The
>>>>>> attached file looks OK to the syntax checker I grabbed.
>>>>>>
>>>>>> peter
>>>>>>
>>>>>>
>>>>>> On 03/04/2016 04:29 PM, Holger Knublauch wrote:
>>>>>>> Turtle file doesn't parse. Could you fix this?
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Holger
>>>>>>>
>>>>>>>
>>>>>>> On 5/03/2016 10:17, Peter F. Patel-Schneider wrote:
>>>>>>>> On 03/03/2016 04:20 PM, Holger Knublauch wrote:
>>>>>>>>> If you want this to be
>>>>>>>>> seriously considered, please work out the details, including
>>>>>>>>> Turtle files
>>>>>>>>> etc.
>>>>>>>>> Holger
>>>>>>>> OK, since you asked so nicely, see the two attached files.
>>>>>>>>
>>>>>>>> peter
>>>>>>>>
>>>>>
>>>
>>>
>>>
>>
>
>
>

-- 
Karen Coyle
kcoyle@kcoyle.net http://kcoyle.net
m: 1-510-435-8234
skype: kcoylenet/+1-510-984-3600
Received on Tuesday, 8 March 2016 01:45:43 UTC

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