Re: [netmod] Next steps for draft-ietf-netmod-rfc8407bis

[Christian Hopps <[e-mail]>]

Jan Lindblad <[e-mail]> writes:

> Med, author team,
>
> Thank you for taking the time to get this work done, and well done!
> This is one of those fundamental bricks that saves time and improves
> quality for the entire YANG community.
>
> I read the -09 version and like what I see. I have a couple of minor
> suggestions you might consider.
>
> + In section 3.4 about tree diagrams, the section text is already
> advocating intermixing smaller tree snippets with explanations (which
> is great), but I wish we could say that
> tree diagrams of entire modules SHOULD NOT be included. Just a waste
> of forest and attention span, imho.

The full tree diagram is literally the thing I read first and most in almost every YANG RFC/draft. Please do not get rid of it.

> + In section 4.11.5 regarding booleans, it is said that booleans can
> take values true and false. This is true in mathematics :-) but in
> YANG a boolean leaf can additionally take the "value" of "not set".
> Actually, "not set" is a possibility for leafs in general, unless it
> is declared mandatory true, or has a default. In my experience, one
> of the most common YANG modeling issues is when people model a leaf
> foo, which isn't mandatory, has no default and the description
> statement does not say what happens if the leaf is not set. In many
> cases, there is a sort of natural meaning, but with booleans leafs in
> particular, the absence of the leaf is typically highly ambiguous. I
> think this hole merits a recommendation clause in the I-D.

I think this general idea of the author having a clear understanding of not-set for all non-mandatory nodes, and that it is communicated to the user if need be, is a really good one.

Though for the particular case of booleans I would think not-set just implies false. Maybe that should be codified if it isn't already. :)

Thanks,
Chris.

> Best Regards,
> /jan