Re: [Cbor] hildjj/cbor-map-entries: Explicit Map datatype for CBOR, in array format

Michael Richardson <mcr+ietf@sandelman.ca> Thu, 18 February 2021 17:43 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: Laurence Lundblade <lgl@island-resort.com>
cc: Kio Smallwood <kio@mothers-arms.co.uk>, Joe Hildebrand <hildjj@cursive.net>, Carsten Bormann <cabo@tzi.org>, "Dale R. Worley" <worley@ariadne.com>, cbor@ietf.org
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Date: Thu, 18 Feb 2021 12:43:13 -0500
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Subject: Re: [Cbor] hildjj/cbor-map-entries: Explicit Map datatype for CBOR, in array format
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Laurence Lundblade <lgl@island-resort.com> wrote:
    > This is semi-related and maybe something I’m a little confused about.

    > My understanding is that map keys/labels can be anything in CBOR
    > including a map or array.

yes, that's allowed, but probably unwise to write into a CBOR Protocol.

    > This is nye impossible to write general map
    > handling code for — code like lookup up by label and duplicate
    > detection. They will not translate to other map data structures in
    > other languages and serialization formats.

    > Further, this seems like an
    > exotic feature of little practical use (though I’m sure someone could
    > do something very cool and clever with it for entertainment purposes).

    > What to do?

I think that you got it right in QCBOR: you declare what you support, and
that's it.

    > - Don’t standardize any IETF protocols that use exotic map keys?

I would expect that anyone that tried to do this would get pushback.
So, we lead by example.

Such a hard-to-implem,ent protocol would probably be a terrible failure.
We can't really keep people that are intent on shooting their feet from
obtaining some kind of foot canon.

    > - Add text to Kio’s proposal to restrict map keys to text string, byte string
    > and integer?

no, it doesn't belong there.

--
Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide