Sorry, maybe my reference was not exact. I was referring to reification for Anchors ( more exact link
https://docs.oasis-open-projects.org/oslc-op/link-guidance/v1.0/link-guidance.html#Anchor). In Lyo, we refer to these as “Links”.
Does ELM makes use of such reification?
From: David Honey2 <david.honey@xxxxxxx>
Sent: Monday, 21 August 2023 13:22
To: Jad El-Khoury <jad@xxxxxx>; oslc-op@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx; Andrii Berezovskyi <andriib@xxxxxx>; lyo-dev@xxxxxxxxxxx
Subject: RE: [oslc-op] RSIterator deprecation (aka RDF-star migration)
Blank nodes are different from reification.
You can use intermediate inline nodes, such as contributions, without using blank nodes. For example, in GCM, the contributions are inlined with real URIs:
@prefix process: http://jazz.net/ns/process# .
@prefix owl:
http://www.w3.org/2002/07/owl# .
@prefix oslc_acc:
http://open-services.net/ns/core/acc# .
@prefix xsd:
http://www.w3.org/2001/XMLSchema# .
@prefix rdfs:
http://www.w3.org/2000/01/rdf-schema# .
@prefix oslc_config:
http://open-services.net/ns/config# .
@prefix oslc:
http://open-services.net/ns/core# .
@prefix rtc_cm:
http://jazz.net/xmlns/prod/jazz/rtc/cm/1.0/ .
@prefix rdf:
http://www.w3.org/1999/02/22-rdf-syntax-ns# .
@prefix dcterms:
http://purl.org/dc/terms/ .
@prefix oslc_config_ext:
http://jazz.net/ns/config_ext# .
@prefix gc:
http://jazz.net/ns/gc# .
@prefix prov:
http://www.w3.org/ns/prov# .
@prefix foaf:
http://xmlns.com/foaf/0.1/ .
@prefix oslc_auto:
http://open-services.net/ns/auto# .
https://localhost:9443/gc/part/6
oslc_config:configuration
https://localhost:9443/rm/cm/stream/_XUbErJwCEe2nvM1YSnzyFQ ;
oslc_config:contributionOrder "2" .
https://localhost:9443/gc/part/5
oslc_config:configuration
https://localhost:9443/qm/oslc_config/resources/com.ibm.team.vvc.Configuration/_k5JN4JwCEe2xw5MmkuLgyg ;
oslc_config:contributionOrder "1" .
https://localhost:9443/gc/configuration/8
a oslc_config:Stream , oslc_config_ext:SharedStream , oslc_config:Configuration ;
process:projectArea
https://localhost:9443/gc/process/project-areas/_VQalgJwCEe2Z39fBbgvJ1g ;
oslc_config:acceptedBy oslc_config:Configuration ;
oslc_config:accepts oslc_config:Configuration ;
oslc_config:baselines
https://localhost:9443/gc/configuration/8/baselines ;
oslc_config:component
https://localhost:9443/gc/component/4 ;
oslc_config:contribution
https://localhost:9443/gc/part/6 ,
https://localhost:9443/gc/part/5 ;
oslc_config:previousBaseline
https://localhost:9443/gc/configuration/24 ;
oslc:archived "false"^^xsd:boolean ;
oslc:instanceShape
https://localhost:9443/gc/type/artifact/_Va5-QJwCEe2Z39fBbgvJ1g/shape ;
oslc:serviceProvider
https://localhost:9443/gc/oslc-config/serviceProvider/_VQalgJwCEe2Z39fBbgvJ1g ;
oslc:shortId "8" ;
oslc_acc:accessContext
https://localhost:9443/gc/acclist#_VQalgJwCEe2Z39fBbgvJ1g ;
dcterms:contributor
https://localhost:9443/jts/users/david ;
dcterms:created "2023-01-24T17:17:55.427Z"^^xsd:dateTime ;
dcterms:creator
https://localhost:9443/jts/users/david ;
dcterms:description "Agile component"^^rdf:XMLLiteral ;
dcterms:identifier "_qMsyNpwCEe2Z39fBbgvJ1g" ;
dcterms:modified "2023-05-15T08:42:27.141Z"^^xsd:dateTime ;
dcterms:subject "agile" ;
dcterms:title "Agile Production stream"^^rdf:XMLLiteral ;
prov:wasDerivedFrom
https://localhost:9443/gc/configuration/7 .
In the above example, the
oslc_config:contribution
property references 2 URIs
https://localhost:9443/gc/part/6 ,
https://localhost:9443/gc/part/5
that are also in the same RDF graph. This makes is possible to reference a specific contribution by URI in that graph.
Best regards,
David
David What about the use of Links (as suggested in https: //docs. oasis-open-projects. org/oslc-op/link-guidance/v1. 0/link-guidance. html) in ELM?
Regards Jad From: oslc-op@ lists. oasis-open-projects. org <oslc-op@ lists. oasis-open-projects. org>
|
This Message Is From an External Sender
|
|
This message came from outside your organization.
|
|
|
David
What about the use of Links (as suggested in
https://docs.oasis-open-projects.org/oslc-op/link-guidance/v1.0/link-guidance.html) in ELM?
Regards
Jad
From an OSLC standpoint, we have discouraged the use of reification in OSLC representations. I don’t think we use it any of the OSLC specifications. That was the main
reason why an intermediate oslc_config:Contribution resource was introduced in
the OSLC Configuration Management specification. You cannot query for reified data using OSLC Query. We also cannot describe such reified data in OSLC resource shapes. Having said that, I know of some cases in IBM Rational ELM where reification is present
in the public RDF of resources. An example is EWM work items.
Best regards,
David
Hello, This is an FYI that Apache Jena seems to be (from what I understood) moving quite aggressively to drop RDF 1. 1 reification in favor of RDF-star
[1]. How many users of Lyo require RDF 1. 1 reification and are unable to switch to RDF-star?
|
This Message Is From an External Sender
|
|
This message came from outside your organization.
|
|
|
Hello,
This is an FYI that Apache Jena seems to be (from what I understood) moving quite aggressively to drop RDF 1.1 reification in favor of RDF-star [1].
How many users of Lyo require RDF 1.1 reification and are unable to switch to RDF-star? Also, should we amend the OSLC Link Guidance to cover RDF-star and encourage it over RDF 1.1 reification?
RDF-star is indeed a better approach, with a significant support from the industry and academia.
Subject: Re: RSIterator deprecation
Date:
16 August 2023 at 18:19:08 CEST
Thanks Andy,
On 15 Aug 2023, at 10:12, Andy Seaborne <andy@xxxxxxxxxx> wrote:
That's quite a long method!
Yes, not proudest part of Lyo. To my shame, I was reluctant to refactor it since I took over the project. Looks like you are providing us with a necessary push.
What is reification used for in Lyo?
Do quoted triples provide the same capability?
Lyo provides support for implementing OASIS OSLC standards. To be brief, OSLC (Core) is both a predecessor and a superset to the W3C LDP. OSLC allows metadata to be placed on link triples using RDF 1.1 reification [1].
Assuming that by quoted triples you refer to RDF-star, yes, they provide the same capability and would fully cover OSLC needs. However, Lyo still needs to support what is standardized in OSLC. Additionally, I was under impression that RDF-star haven't reached
W3C Recommendation status and OASIS discourages citing documents that haven't reached the standard/recommendation status in its standards-track specs. Regardless, OSLC standards try to maintain backwards compat, which means the committee will only vote to
add RDF-star support to the standard (e.g., via a SHOULD clause) but not remove RDF 1.1 reification for backwards compatibility reasons.
Reification support is all calculation library code - it's a way to
present reification. It does not affect storage.
Jena2 had variations of reification which did impact storage - these
have not existed in releases for a long time.
The library that backs the reification support is ReifierStd and it will
be available in jena5. ReifierStd works on graphs, not models. Writing
companion code to provide the functionality for the Model API
equivalents would be possible. Contributions welcome.
RSIterator isn't necessary. It's a "typed next()" iterator that came
about in the pre-generics times.
I am not quite sure I understand the impact of the change. Do we need to implement any support if we need RDF 1.1 reification and are ready to switch to Graph and ReifierStd APIs, and drop the use of RSIterator?
To be clear : this is not RDF-star quoted triples.
To be clear from our side too, we are certainly interested in adopting RDF-star quoted triples in the future. We are not ready to drop RDF 1.1 reification until/unless RDF 1.2 drops it (when it reaches W3C Rec).
Also, do I understand correctly that the removal is planned for Jena 5.x after JDK 21 release?
Yes, sometime after Java21. Jena5 will require Java17, in line with
supporting two LTS versions of Java.
Jena is already built and tested on Java17 as part of our CI. Users can
switch to java17 in deployments now. It is a bit faster and has Java
improvements and fixes not backported to Java11.
We've been testing Lyo on JDK 11, 17, 20, and 21-ea. We are ready for the JDK 17 migration, it's just that some of the Lyo users use it in legacy environments, but we've communicated to them that Lyo will drop JDK 11 support when Jena does.
–Andrew.
[1]:
https://oslc-op.github.io/oslc-specs/notes/link-guidance.html#Anchor
Unless otherwise stated above:
IBM United Kingdom Limited
Registered in England and Wales with number 741598
Registered office: PO Box 41, North Harbour, Portsmouth, Hants. PO6 3AU
Links:
You receive all messages sent to this group.
View/Reply Online (#1337) |
Reply To Group |
Reply To Sender |
Mute This Topic |
New Topic
Your Subscription |
Contact Group Owner |
Unsubscribe [jad@xxxxxx]
Unless otherwise stated above:
IBM United Kingdom Limited
Registered in England and Wales with number 741598
Registered office: PO Box 41, North Harbour, Portsmouth, Hants. PO6 3AU
