Re: [netmod] yang-data-ext issues

Ladislav Lhotka <lhotka@nic.cz> Tue, 24 April 2018 14:25 UTC

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From: Ladislav Lhotka <lhotka@nic.cz>
To: Robert Varga <nite@hq.sk>, netmod@ietf.org
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Date: Tue, 24 Apr 2018 16:25:57 +0200
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Subject: Re: [netmod] yang-data-ext issues
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Robert Varga <nite@hq.sk>; writes:

> On 23/04/18 18:51, Juergen Schoenwaelder wrote:
>> Some people will say that the cost of a new language version is high.
>> (Well, when we did 1.1, some people said it will never be deployed.)
>> Anyway, not bumping the YANG version number but having instead several
>> (optional) language extensions is just hiding the version number
>> change under the carpet.
>
> Not quite, as extensions allow for modular/incremental evolution, as an
> implementer I do not have to go through a long development cycle where I
> need to rewire language aspects just to get the features my users need
> for their models...

But what prevents you from forking YANG, indicating it in the
"yang-version" string and implementing your new statements as built-ins?

It is tempting to think about extensions as a magic for adding modular
extensions but it breaks down as soon as such extensions interfere with
the YANG core (with and each other, or both).

Lada

>
> Regards,
> Robert
>

-- 
Ladislav Lhotka
Head, CZ.NIC Labs
PGP Key ID: 0xB8F92B08A9F76C67