Re: [netmod] Follow-up: impact of changing an import statement

Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> Sat, 01 August 2020 05:39 UTC

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Date: Sat, 1 Aug 2020 07:39:06 +0200
From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
To: "Reshad Rahman (rrahman)" <rrahman=40cisco.com@dmarc.ietf.org>
Cc: "netmod@ietf.org" <netmod@ietf.org>
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Subject: Re: [netmod] Follow-up: impact of changing an import statement
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On Sat, Aug 01, 2020 at 02:51:54AM +0000, Reshad Rahman (rrahman) wrote:
> WG,
> 
> Following up from the discussions during NETMOD meeting on Thursday. One of the main open topics is what to do when an import stmt is changed, for example
> 
>   1.  Module A (1.0.0) imports module B using “2.0.0 or derived”. There is no version 3+ for module B so module A uses 2.Y.Z
>   2.  A new revision 3.0.0 of module B is created AND there is a change in module A to import module B using “3.0.0 or derived”.

What does "2.0.0 or derived" mean? Does it mean (i) any module >=
2.0.0 or does it mean (ii) any (module >= 2.0.0 && < 3.0.0)?
 
> Authors/contributors have discussed 2 options and right now we don’t have unanimity:
> 
>   1.  Option A: depending on the impact on the importing module A, the import-stmt is deemed BC or NBC. E.g. if the only NBC change in the  imported module is  to a type which the importing module does NOT use, that’s a BC change for the importing module.
>   2.  Option B: consider the import-stmt change as a BC change and resolve this elsewhere e.g. YANG-Packages or YANG-Library.

Whether a change is BC or not always depends on which definitions have
changed, how they have changed, and how these definitions are used. So
the answer very likely must be option 1. Option 2 also seems to push
the problem elsewhere (packages, library) without providing the
details.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
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