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Re: property path length restrictions [was: Re: A review of extension functions in current implementatations]

From: Jerven Tjalling Bolleman <Jerven.Bolleman@sib.swiss>
Date: Mon, 08 Apr 2019 11:47:24 +0200
To: Christian Chiarcos <chiarcos@informatik.uni-frankfurt.de>
Cc: public-sparql-12@w3.org
Message-ID: <949af22d835b397a9f693f6d1f4c8812@bell.isb-sib.ch>
Hi Christian,

I think this can be added as an github issue.

https://github.com/w3c/sparql-12/issues

As you are not the only one whom would like this.

Regards,
Jerven
On 2019-04-08 11:22, Christian Chiarcos wrote:
> Dear all,
> 
> something I find myself missing almost every time I work with SPARQL
> is the path length feature in the early property graph drafts:
> 
> 		_elt{n,m}_
> 		 A path between n and m occurrences of _elt_.
> 
> What I normally use instead is aggegation and counting of intermediate
> nodes, in order to have it portable, so I didn't check for current
> implementations. Not sure whether this qualifies for the wiki, thus,
> but there used to be implementations 10 years ago:
> https://www.w3.org/2009/sparql/wiki/Feature:PathLength
> 
> The aggregation solution works in most cases (it is slow, though), but
> this is a pain to write and to teach -- and a needless one if path
> length would be implemented just as syntactic sugar for
> aggregate+count.
> 
> Best,
> 
> Christian
> 
> Am .04.2019, 23:51 Uhr, schrieb Jeen Broekstra
> <jeen.broekstra@gmail.com>:
> 
>> Thanks for this Jerven.
>> 
>> I added a short list of things I could think of from the top of my
>> head that RDF4J currently adds as SPARQL extensions. I also
>> mentioned GeoSPARQL for completeness sake, although I think we
>> should probably consider such an elaborate feature (with its own set
>> of specs) out of scope. Feel free to extend, correct, or ask for
>> clarification (I've been rather terse in my examples).
>> 
>> Jeen
>> 
>> On Thu, Apr 4, 2019 at 5:54 AM Jerven Tjalling Bolleman
>> <Jerven.Bolleman@sib.swiss> wrote:
>> 
>>> Hi Adrian, Bob, All,
>>> 
>>> I created a wiki page at
>>> 
>> 
> https://github.com/w3c/sparql-12/wiki/Inventory-of-existing-extensions-to-SPARQL-1.1
>>> 
>>> That you can start with.
>>> 
>>> Adrian, I added you as a collaborator in case that is needed.
>>> 
>>> Bob, I don't know your github account so please let me know if me
>>> or
>>> Andy needs to do some
>>> admin work for you.
>>> 
>>> This goes for anyone whom would like to work on this and can't due
>>> to
>>> permissions.
>>> 
>>> Regards,
>>> Jerven
>>> 
>>> On 2019-04-03 19:38, Adrian Gschwend wrote:
>>>> On 03.04.19 18:58, bob@snee.com wrote:
>>>> 
>>>> Hi Bob,
>>>> 
>>>>> Instead of assigning a single person to do an inventory of
>>> these
>>>>> functions someone (I'd be happy to) could serve as an editor of
>>> a
>>>>> summary document with content provided by those implementors.
>>> If there
>>>>> is no place under
>>>>> https://lists.w3.org/Archives/Public/public-sparql-12/
>>>>> where we can put a page to store such a document perhaps git
>>> would be
>>>>> the best place for it.
>>>> 
>>>> that definitely makes sense! And if you volunteer you get a +1
>>> from me
>>>> :) Would add some stuff I have in mind as well.
>>>> 
>>>> regards
>>>> 
>>>> Adrian
>>> 
>>> --
>>> Jerven Tjalling Bolleman
>>> SIB | Swiss Institute of Bioinformatics
>>> CMU - 1, rue Michel Servet - 1211 Geneva 4
>>> t: +41 22 379 58 85 - f: +41 22 379 58 58
>>> Jerven.Bolleman@sib.swiss - http://www.sib.swiss
> 
> --
> Prof. Dr. Christian Chiarcos
> Applied Computational Linguistics
> Johann Wolfgang Goethe Universit├Ąt Frankfurt a. M.
> 60054 Frankfurt am Main, Germany
> 
> office: Robert-Mayer-Str. 11-15, #107
> mail: chiarcos@informatik.uni-frankfurt.de
> web: http://acoli.cs.uni-frankfurt.de
> tel: +49-(0)69-798-22463
> fax: +49-(0)69-798-28334

-- 
Jerven Tjalling Bolleman
SIB | Swiss Institute of Bioinformatics
CMU - 1, rue Michel Servet - 1211 Geneva 4
t: +41 22 379 58 85 - f: +41 22 379 58 58
Jerven.Bolleman@sib.swiss - http://www.sib.swiss
Received on Monday, 8 April 2019 09:48:03 UTC

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