Re: [netmod] [Technical Errata Reported] RFC7950 (6031)

["Rob Wilton (rwilton)" <[e-mail]>]

> -----Original Message-----
> From: netmod <[e-mail]> On Behalf Of Juergen Schoenwaelder
> Sent: 27 March 2020 16:13
> To: Martin Björklund <[e-mail]>
> Cc: [e-mail]; [e-mail]; [e-mail]; rfc-
> [e-mail]
> Subject: Re: [netmod] [Technical Errata Reported] RFC7950 (6031)
> 
> On Fri, Mar 27, 2020 at 04:35:44PM +0100, Martin Björklund wrote:
> > [re-sent w/ correct address]
> >
> > Juergen Schoenwaelder <[e-mail]> wrote:
> > > Hi,
> > >
> > > two comments:
> > >
> > > - It is unclear to me whether this really qualifies as an errata.
> > >
> > > - If we add this, then there should probably text about which
> > >   combinations are allowed. For example, for pattern and ranges, there
> > >   is explicit text that says further restrictions of the value space
> > >   are possible, bot not expansions. If we follow that logic, then
> > >
> > >   typedef a {
> > >     type leaf-ref {
> > >       path "/some/thing";
> > >       require-instance true;
> > >     }
> > >   }
> > >
> > >   typedef b {
> > >     type a {
> > >       require-instance false;
> > >     }
> > >   }
> > >
> > >   might be illegal since b has a larger value space than a.
> >
> > The value space of b is the same as for a. "require-instance" doesn't
> > change the value space; it changes semantic validation of the given
> > values ((see my mail from 17 Mar, "Require-instance problem").
> >
> > /martin
> 
> OK. If we consider require-instance a constraint and not a restriction,
> then the motivation for this errata is at least
> confusing:
> 
>   Since no one argued against this understanding, this errata changes
>   the text to the same form as in other restrictions applicable to
>   derived types.
> 
> Simply put: Do you think it is OK to overwrite a require-instance true
> with a require-instance false in a derived type?
[RW] 
I'm not sure, but going in the other direction seems plausible.

E.g. you start with a typedef that is explicitly require-instance false that is then refined by a typedef to be require-instance true.

Regards,
Rob


> 
> /js
> 
> --
> Juergen Schoenwaelder           Jacobs University Bremen gGmbH
> Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
> Fax:   [phone]         <https://www.jacobs-university.de/>
> 
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