[Nml-wg] NML-NSI integration

[Jerry Sobieski]

Guys-

If you are considering which parsers will process the constructs then 
you are already way past where you need to be.

I would implore you to make the specification so simple that the 
standard is not based on nor is concerned about parser implementations.

Jerry



On 2/17/12 10:45 AM, Roman Łapacz wrote:
> W dniu 2012-02-17 16:28, Freek Dijkstra pisze:
>> Hi all,
>>
>> A port can have many properties. It can be abstract, Ethernet, (NSI)
>> domain boundary port, have restricted access, be part of a link bundle.
>>
>> What I want to avoid is having to deal with namespaces and objects such
>> as<nml-nsi-ethernet-restricted-lacp:port>
>>
>>> If we allow adding new tags as extensions in any place in the structure
>>> then we don't have too much control over the structure. Generic parsers
>>> will not know how to interpret such unexpected (not included in the 
>>> base
>>> NML schema) changes. On the contrary, namespaces as extensions allow
>>> parsers to, at least, understand their standard properties, others 
>>> would
>>> be ignored. The structures defined in the base NML schema are still
>>> followed. (Of course it is possible to define a schema in such way that
>>> any element could be inserted in any place but I don't think it's the
>>> right direction).
>> The RNC schema you created last year DID allow arbitrary elements inside
>> NML elements.
>>
>> I think I misunderstand you. In particular, I do not understand the
>> sentence "namespaces as extensions allow parsers to, at least,
>> understand their standard properties."
>>
>
> a very simple example
>
> <nml-ext:x>
> <nml:y></nml:y>
> <nml-ext:z></nml-ext:z>
> </nml-ext:x>
>
> A parser which does not understand the nml-ext extension/namespace 
> would treat x as nml:x (of course if nml:x exsits) and ignore nml-ext:z.
>
>
> Roman
>
>
>> Are you talking about chameleon namespaces?
>>
>> I assume that:
>>
>> * NML elements can contain arbitrary child elements, from the NML or
>> other namespace
>> * if a parser encounters an unknown element from a known namespace, it
>> should stop and return an error
>> * if a parser encounters an element from a unknown namespace, it should
>> ignore it (or -if we define chameleon namespaces- interpret as if it was
>> part of the base namespace)
>> (Note that in this case, I'm unclear how a parser should distinguish
>> between a chameleon namespace and a proprietary namespace which can
>> safely be ignored.)
>>
>> Could you perhaps give an example of a message containing NML and NSI
>> information, and explain how a parser which only understands NML sees
>> it, and how a parsers understands both NML and NSI sees it, and if
>> either should ignore unknown elements or stop and return an error?
>>
>> Freek
>> _______________________________________________
>> nml-wg mailing list
>> nml-wg at ogf.org
>> https://www.ogf.org/mailman/listinfo/nml-wg
>
> _______________________________________________
> nml-wg mailing list
> nml-wg at ogf.org
> https://www.ogf.org/mailman/listinfo/nml-wg