Re: VSS instantiation discussion

Hi Ulf,

Thanks for your input. From the discussions, I think we’re getting closer to a point where we can decide how we move forward. Before I answer to your comments, I’ll put a couple of points I took away from yesterday:


  *   CSV is important for listing, understanding and flatten all nodes, so that the dot-notated identifier is apparent
  *   YAML is obviously the single point of truth and the interpretation in form of the different serializations through the tools shows one way of doing so
  *   But at the same time ppl rather look at the serialization instead of the yaml, because there’s less room for interpretations (includes, etc)
  *   Many of my particular concerns can be solved with wildcards as well, instead of changing anything. Even though in my opinion it’s not a really clean solution
  *   More examples are necessary

I hope most of us can stand behind those takeaways from the discussion 😊

> YAML MUST unambiguously specify the path to a leaf node.
> Translations from YAML to other formats MUST preserve the path definitions.

Yes, but does it have to do so unambiguously for leaf nodes including or not including the instances?  As said, I think something like the CSV should serve as a list of all dot-notated elements in the tree, including the instance definition. But that doesn’t mean that it has to do so for every translation. I think if you separate the core tree (without instances) from root to leaf, your request is very well possible. If you have the instances in the path, it gets really hard to achieve.

> All metadata from a node in YAML MUST be preserved in the translations, except for instantiation metadata that MUST not be present.

Why would that help? In the CSV the information is not a problem, and even in the json it would not hurt, if that’s just additional information to the rest, which is presented in a way, which is easily parseable. I would vote against this strict rule.


Best regards,
Daniel

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From: Ulf Bjorkengren <ulfbjorkengren@geotab.com>
Date: Tuesday, 7 July 2020 at 22:19
To: public-automotive <public-automotive@w3.org>
Subject: VSS instantiation discussion
Resent-From: <public-automotive@w3.org>
Resent-Date: Tuesday, 7 July 2020 at 22:19

Regarding the VSS instantiation discussion I think we need to establish a few ground rules, in order to not get lost. Below is my attempt on a few rules for such a list.

- YAML MUST unambiguously specify the path to a leaf node.
- Translations from YAML to other formats MUST preserve the path definitions.
- All metadata from a node in YAML MUST be preserved in the translations, except for instantiation metadata that MUST not be present.

Regarding Gen2 and JSON I would say that Gen2 is agnostic to what format the VSS tree uses. Gen2 uses JSON as payload format, but that has nothing to do with what format the VSS tree is represented in. In the Gen2 impl project the VSS tree is represented in the native C format, as an example.

BR
Ulf
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Ulf Bjorkengren

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