Re: [netmod] augment and if-feature

[Juergen Schoenwaelder <[e-mail]>]

On Thu, Mar 16, 2017 at 09:54:14AM +0000, Robert Wilton wrote:

> In short, I think that if-feature statements work better if they act on the
> given node and all descendant nodes, regardless of which module those
> descendants are defined in.

I think there is something important here. The augment does not really
make a difference. What seems to be the root of the issue is whether
an if-feature on say a container or list applies down the hierarchy.
RFC 7950 is not very specific about this. It only says:

   The "if-feature" statement makes its parent statement conditional.

Of course, if a container or list is conditional, then everything
inside will only exist if the feature is supported, so I think it is
reasonable to assume that the if-feature applies down the hierarchy
but this is not explicitly stated (but it seems to be the only
reasonable way to implement this). Anyway, once we have clarified
this, the augment behaviour falls out of this.

That said, as a service to readers, it might still be useful to repeat
the if-feature definition in augmenting modules but this would purely
be a service to the readers, not something that is required by the
language itself.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
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