Re: $variables

On 7/11/16 3:50 PM, Andy Seaborne wrote:
> Section 1.1 already has a link to RDF term in RDF 1.1.
>
> (originally from https://www.w3.org/TR/sparql11-query/#defn_RDFTerm
> which was adopted by RDF 1.1).
>
> "Node" is the role that an RDF term is used for - the subject/object
> role (position) : standard graph theory of vertex/node, not an edge.
>
> The set of nodes is the set of RDF terms used in subject or object
> position.
>
> (Blank node is a misnomer in "generalised RDF" :
> https://www.w3.org/TR/rdf11-concepts/#section-generalized-rdf)
>
> Having SHACL-defined versions of terminology will only lead to comments
> like "are they the same thing?".
>
> It might be useful to split the terminolgy into terminology that are
> used from elsewhere, and terminology that is defined by this document,
> including different styling.
>
> I would find it clearer if the URL for the definition when to the to the
> definition title (ie. the id should be on the title text), not into the
> body of the text If nothing else, clicking on a definition link then
> puts the box in the right place, not top-truncated (Firefox and Chrome).
>
> Karen - do you have example of where "node" is used to include
> predicates? I don't know my way round the spec but looking through it, I
> don't see any but I only jumped around the doc for a while.

It doesn't say that in the spec, but this is how I interpreted Holger's 
response here:[1]. If I'm interpreting that wrong, please let me know. 
However, if scopenode only applies to nodes, then I wonder how one can 
"scope" triples in which the term of interest is the predicate.

kc

[1] 
https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Jun/0125.html

>
>     Andy
>
>
> On 11/07/16 22:58, Karen Coyle wrote:
>> Andy, I also wondered about that. RDF term seems to be saying that any
>> "thing" in a triple is an RDF term, Whereas "node" is a subject or an
>> object. However, I don't hear "RDF term" used much so if we use it in
>> SHACL then we will definitely need to define it in the SHACL document
>> where it is used.
>>
>> kc
>>
>>
>> On 7/11/16 1:29 PM, Andy Seaborne wrote:
>>> Is this the right terminology:
>>>
>>> RDF 1.1 Concepts:
>>>
>>> https://www.w3.org/TR/rdf11-concepts/#h2_section-rdf-graph
>>> [[
>>> IRIs <https://www.w3.org/TR/rdf11-concepts/#dfn-iri>, literals
>>> <https://www.w3.org/TR/rdf11-concepts/#dfn-literal> and blank nodes
>>> <https://www.w3.org/TR/rdf11-concepts/#dfn-blank-node> are collectively
>>> known as RDF terms.
>>> ]]
>>>
>>>
>>>
>>> On 08/07/16 16:56, Karen Coyle wrote:
>>>> "Any node in the data graph that is equal to/the same as/matches (pick
>>>> one) the value of sh:nodescope in the SHACL graph is 'in scope'."
>>>>
>>>> That said, the RDF Concepts document[1] describes a triple as two
>>>> nodes (" node-arc-node "). Therefore "node" does not include the
>>>> predicate of a triple. Could someone confirm that is the case?
>>>>
>>>> kc
>>>> [1] https://www.w3.org/TR/2014/REC-rdf11-concepts-20140225/
>>>>
>>>> On 7/8/16 8:11 AM, Arnaud Le Hors wrote:
>>>>> Ok, but this isn't just a matter of hiding this when SPARQL is
>>>>> hidden. I
>>>>> still want to understand what that sentence means when SPARQL isn't
>>>>> hiddene. So, can you tell me what this sentence is supposed to be
>>>>> saying?
>>>>>
>>>>> A node scope with value $scopeNode, defines $scopeNode as the node
>>>>> in-scope in the data graph.
>>>>>
>>>>> The way it reads to me is that a node scope has a variable
>>>>> $scopeNode as
>>>>> a value, and that this defines the variable as the "node in-scope".
>>>>> What
>>>>> does it mean for a scope node to have a value? And How does a node
>>>>> scope
>>>>> with a value define the value as the "node in-scope"? And shouldn't
>>>>> that
>>>>> rather be "node in scope"??
>>>>>
>>>>> As I said I just can't parse this sentence. I'd appreciate if someone
>>>>> could rephrase.
>>>>>
>>>>> Unfortunately the spec remains hard to read and understand because of
>>>>> stuff like this so I second the sentiment Karen conveys from the
>>>>> community she represents. I understand English isn't the editors'
>>>>> primary language and that's ok but given that I strongly encourage
>>>>> them
>>>>> to welcome comments pointing these problems out.
>>>>>
>>>>> Thanks.
>>>>> --
>>>>> Arnaud  Le Hors - Senior Technical Staff Member, Open Web
>>>>> Technologies -
>>>>> IBM Cloud
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> From:        Dimitris Kontokostas
>>>>> <kontokostas@informatik.uni-leipzig.de>
>>>>> To:        Arnaud Le Hors/Cupertino/IBM@IBMUS
>>>>> Cc:        Karen Coyle <kcoyle@kcoyle.net>, public-data-shapes-wg
>>>>> <public-data-shapes-wg@w3.org>
>>>>> Date:        07/08/2016 01:38 AM
>>>>> Subject:        Re: $variables
>>>>> ------------------------------------------------------------------------
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> You are right,
>>>>> although the button exists we the spec does not flow well in some
>>>>> cases
>>>>> when the sparql definitions are hidden
>>>>> Holger created an issue to track this and we will try to have it ready
>>>>> for review by the next call
>>>>>
>>>>> On Fri, Jul 8, 2016 at 8:09 AM, Arnaud Le Hors <_lehors@us.ibm.com_
>>>>> <mailto:lehors@us.ibm.com>> wrote:
>>>>> I have to agree with Karen. In fact, I will admit that I don't
>>>>> understand what this sentence means:
>>>>>
>>>>> A node scope with value $scopeNode, defines $scopeNode as the node
>>>>> in-scope in the data graph.
>>>>>
>>>>> Actually, I can't even quite parse this sentence. What's with that
>>>>> comma? What's the subject of "defines"?
>>>>>
>>>>> I do understand the following:
>>>>>
>>>>> Node scopes are defined with the sh:scopeNode predicate. The values of
>>>>> sh:scopeNode can be a IRIs or literals.
>>>>>
>>>>> Although the "a" seems to be a typo.
>>>>> --
>>>>> Arnaud  Le Hors - Senior Technical Staff Member, Open Web
>>>>> Technologies -
>>>>> IBM Cloud
>>>>>
>>>>>
>>>>> Karen Coyle <_kcoyle@kcoyle.net_ <mailto:kcoyle@kcoyle.net>> wrote on
>>>>> 07/07/2016 08:52:00 PM:
>>>>>
>>>>>> From: Karen Coyle <_kcoyle@kcoyle.net_ <mailto:kcoyle@kcoyle.net>>
>>>>>> To: _public-data-shapes-wg@w3.org_
>>>>>> <mailto:public-data-shapes-wg@w3.org>
>>>>>> Date: 07/07/2016 08:53 PM
>>>>>> Subject: Re: $variables
>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 7/7/16 4:59 PM, Holger Knublauch wrote:
>>>>>> >
>>>>>> >
>>>>>> > On 8/07/2016 9:45, Karen Coyle wrote:
>>>>>> >>
>>>>>> >>
>>>>>> >> On 7/7/16 3:42 PM, Holger Knublauch wrote:
>>>>>> >>>
>>>>>> >>>
>>>>>> >>> On 8/07/2016 8:35, Karen Coyle wrote:
>>>>>> >>>> On the call today I was told that the way to avoid the
>>>>> complication of
>>>>>> >>>> the $variables in the spec is to choose not to view the SPARQL
>>>>>> in the
>>>>>> >>>> draft. However, even with the SPARQL hidden, the $variables are
>>>>>> still
>>>>>> >>>> visible since they are part of the explanatory text. So this
>>>>>> does not
>>>>>> >>>> solve the problem, and in fact it probably makes it worse
>>>>>> because
>>>>>> >>>> without the SPARQL the $variables make even less sense. For
>>>>>> example,
>>>>>> >>>> with SPARQL definitions hidden, you see:
>>>>>> >>>>
>>>>>> >>>> **********
>>>>>> >>>>
>>>>>> >>>> 2.1.1 Node scopes (sh:scopeNode)
>>>>>> >>>>
>>>>>> >>>> A node scope with value $scopeNode, defines $scopeNode as the
>>>>>> node
>>>>>> >>>> in-scope in the data graph.
>>>>>> >>>>
>>>>>> >>>> Node scopes are defined with the sh:scopeNode predicate. The
>>>>> values of
>>>>>> >>>> sh:scopeNode can be a IRIs or literals.
>>>>>> >>>>
>>>>>> >>>> *************
>>>>>> >>>>
>>>>>> >>>> I think they need to be removed from the text, and moved into
>>>>>> the
>>>>>> >>>> SPARQL code area, and the text should be complete without using
>>>>>> them.
>>>>>> >>>
>>>>>> >>> That would be fine with me. I had used the values in
>>>>>> SPARQL-like $
>>>>>> >>> notation to make it easier to read for those who are familiar
>>>>>> with
>>>>>> >>> SPARQL because the SPARQL query and its description would match.
>>>>> But if
>>>>>> >>> the WG thinks this is too geeky, we can just drop the $ sign and
>>>>> change
>>>>>> >>> the CSS style around these variables.
>>>>>> >>>
>>>>>> >>> I do wonder what audience are we talking about here? What in
>>>>> particular
>>>>>> >>> is difficult to understand about the $ variables? The spec is
>>>>>> not a
>>>>>> >>> tutorial...
>>>>>> >>>
>>>>>> >>> Holger
>>>>>> >>
>>>>>> >> Holger, you always trot out this "not a tutorial" like anyone who
>>>>>> has
>>>>>> >> any problem with the spec is some kind of backward dunce. I
>>>>>> wish you
>>>>>> >> would be less condescending and more open to hearing suggestions.
>>>>>> The
>>>>>> >> folks who brought this up are key RDF programmers on projects like
>>>>>> >> Europeana and DPLA. Hardly novices. But believe them when they say
>>>>>> >> that it makes the reading and comprehension more difficult. Do not
>>>>>> >> disparage them.
>>>>>> >
>>>>>> > The suggested change here is to drop the $ character before
>>>>>> variable
>>>>>> > names in the scope section. I am really surprised this would make a
>>>>>> > difference, but said I have no problems with that.
>>>>>>
>>>>>> I'm pretty sure it isn't just a matter of dropping the $ - it doesn't
>>>>>> make sense to say:
>>>>>>
>>>>>> "A node scope with value scopeNode, defines scopeNode as the node
>>>>>> in-scope in the data graph."
>>>>>>
>>>>>> So some more adjustment of the text is going to be needed. Especially
>>>>>> because there is sometimes more about SPARQL in the text, such as:
>>>>>>
>>>>>> *********
>>>>>> 2.1.1 Node scopes (sh:scopeNode)
>>>>>>
>>>>>> A node scope with value $scopeNode, defines $scopeNode as the node
>>>>>> in-scope in the data graph.
>>>>>>
>>>>>> Node scopes are defined with the sh:scopeNode predicate. The
>>>>>> values of
>>>>>> sh:scopeNode can be a IRIs or literals.
>>>>>>
>>>>>> The following SPARQL query specifies the semantics of node scopes.
>>>>>> The
>>>>>> variable $scopeNode is assumed to be pre-bound to the given value of
>>>>>> sh:scopeNode.
>>>>>>
>>>>>> *******
>>>>>>
>>>>>> It doesn't make sense to say "The following SPARQL query...." when
>>>>>> the
>>>>>> SPARQL query is hidden.
>>>>>>
>>>>>> If we can agree on parameters of the edits, I'd be happy to pitch
>>>>>> in a
>>>>>> do some or all of the work. I'd say that the last paragraph belongs
>>>>>> with
>>>>>> the SPARQL code, and the first sentence needs a different value
>>>>>> example,
>>>>>> which should be uniform throughout where possible.
>>>>>>
>>>>>> I'd also reverse the first two paragraphs, which I think increases
>>>>>> readability.
>>>>>>
>>>>>> kc
>>>>>>
>>>>>> >
>>>>>> > What else would be needed to make the document more readable for
>>>>>> the
>>>>>> > audience you are referring to?
>>>>>> >
>>>>>> > Anyway, I think you are over-reacting in your personal criticism.
>>>>>> I am
>>>>>> > merely collecting information to help me fulfill my editing role.
>>>>>> If I
>>>>>> > were to accept every single viewpoint without asking for
>>>>>> clarifications
>>>>>> > we would never reach a fixpoint - there are just too many different
>>>>>> > viewpoints and potential audiences here.
>>>>>> >
>>>>>> > Holger
>>>>>> >
>>>>>> >
>>>>>> >
>>>>>>
>>>>>> --
>>>>>> Karen Coyle
>>>>>> _kcoyle@kcoyle.net_ <mailto:kcoyle@kcoyle.net>_http://kcoyle.net_
>>>>> <http://kcoyle.net/>
>>>>>> m: 1-510-435-8234
>>>>>> skype: kcoylenet/_+1-510-984-3600_ <tel:%2B1-510-984-3600>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Dimitris Kontokostas
>>>>> Department of Computer Science, University of Leipzig & DBpedia
>>>>> Association
>>>>> Projects: _http://dbpedia.org_ <http://dbpedia.org/>,
>>>>> _http://rdfunit.aksw.org_ <http://rdfunit.aksw.org/>,
>>>>> _http://aligned-project.eu_ <http://aligned-project.eu/>
>>>>> Homepage: _http://aksw.org/DimitrisKontokostas_
>>>>> Research Group: AKSW/KILT _http://aksw.org/Groups/KILT_
>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>>
>>
>
>
>

-- 
Karen Coyle
kcoyle@kcoyle.net http://kcoyle.net
m: 1-510-435-8234
skype: kcoylenet/+1-510-984-3600

Received on Tuesday, 12 July 2016 00:25:22 UTC