Re: [netmod] Comment on draft-clacla-netmod-yang-model-update-02

[Joe Clarke <[e-mail]>]

On 11/15/17 05:38, Ladislav Lhotka wrote:
> On Wed, 2017-11-15 at 05:27 -0500, Joe Clarke wrote:
>> On 11/15/17 05:06, Ladislav Lhotka wrote:
>>>> I suppose my gut reaction to Lou's question as to whether a server
>>>> should support multiple versions was, "no."  A client may have multiple
>>>> versions loaded to support servers that support different versions.  I
>>>> may be convinced otherwise, but I feel that this will become untenable
>>>> over time (even if module names change).
>>>
>>> There are use cases for modules that are imported (i.e. not
>>> implemented): it could be that a module author wants to use some
>>> definitions from an old version of an imported module while, at the same
>>> time, other definitions from a new version.
>>>
>>> The semver-aware "import" statement should be able to deal with this.
>>
>> I think it could be, but I also think importing from different versions
>> of the same module feels messy.  How would this work with different
>> module names today?  Just use different prefixes?  Are there defined use
>> cases for this in the wild today?
> 
> Let's say a new version of a module adds new enums to two different enumeration
> types, but an implementor (for some reason) is only able to update one of them
> in the back-end and not the other.

I read implementor to be "vendor" here.  And if a vendor cannot
implement one of the enums, would they not just add a deviation?  I
don't see why they'd have to keep the old module around for this.

Joe