Re: [core] YANG to CBOR , identification of objects

[Michel Veillette <[e-mail]>]

Hi Peter

Transferring the concept of parent deltas from "draft-ietf-core-yang-cbor" to "draft-veillette-core-cool" is technically possible.
This change require some level of effort so I will prefer to get a consensus from a larger group before moving ahead.
Carsten, Alexander, Abhi, Randy, Ana, ... do you have a strong opinion about the approach proposed by Peter?

Regards,
Michel

-----Original Message-----
From: peter van der Stok [mailto:[e-mail]] 
Sent: Tuesday, July 12, 2016 6:18 AM
To: Michel Veillette <[e-mail]>
Cc: [e-mail]; Core <[e-mail]>
Subject: RE: [core] YANG to CBOR , identification of objects

Hi Michel,

Here we have a point where my vision on this document differs from yours.

> 
> Section 3: “the specification supports three types of keys.”
> I would suggest only 2: character strings and numbers.
> The use of deltas is either application (CoOL) specific or YANG to 
> CBOR mapping specific.
> If it is YANG to CBOR specific, I would encourage the use of another 
> CBOR type that specifies a delta. As specified here its use is 
> ambiguous; and forces each application to specify explicitly what is 
> meant.
> In the case that the delta is CoOL specific, I recommend to remove it 
> completely from this draft, and explain the use of Deltas in the 
> appropriate CoOL draft.
> In the latter case: What remains are two key types: number and 
> character string.
> 
> [MV] The use of delta to encode integer based keys (SIDs) is an 
> integral part of the YANG to CBOR mapping.
> [MV] This optimization is part of the encoding and independent of the 
> application.
> [MV] The document is updated to keep only 2 type of keys
> 

I am preparing a third document that describes a local numbering scheme for YANG identifiers based on discovery.
The numbers will be quite small and I like to encode them as unsigned integers.
However, with the present YANG to CBOR document some numbers must be encoded as Deltas, and that is not what I want.

Therefore I recommend that all hash conversion to CBOR goes to the yang-hash document and the SID conversion to CBOR goes to an appropriate CoOL document.
and the coming numbering conversion to CBOR also treats it in an appropriate document

This document can then specify that identifiers can be strings and numbers, where for example numbers are encoded as unsigned integers.

Greetings,

Peter