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Re: [netmod] RFC 7951 - JSON encoding of empty lists

Kent Watsen <kent+ietf@watsen.net> Tue, 29 March 2022 17:14 UTC

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From: Kent Watsen <kent+ietf@watsen.net>
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Date: Tue, 29 Mar 2022 17:14:13 +0000
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To: Jack Rickard <jack.rickard=40microsoft.com@dmarc.ietf.org>
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Subject: Re: [netmod] RFC 7951 - JSON encoding of empty lists
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#1 is an empty list (or leaf-list).  This is what you want.

#2 is a list containing one element, which is an empty container (or, in Python term's, an empty 'dict').

Yanglint 1.x used to accept #1, kinks are being worked out on the 2.x branch.

Kent // contributor


> On Mar 29, 2022, at 10:21 AM, Jack Rickard <jack.rickard=40microsoft.com@dmarc.ietf.org> wrote:
> 
> Hi,
>  
> I think I’ve found an ambiguity in RFC 7951, and I’d like your input on what was intended and what the best behaviour to exhibit is.
>  
> Section 5.3 and 5.4 of RFC 7951 - JSON Encoding of Data Modeled with YANG (ietf.org) <https://datatracker.ietf.org/doc/html/rfc7951#section-5.3> describe the encoding of leaf-lists and lists, however it’s unclear how an empty list should be encoded. Should it be encoded as:
> An empty array: {“list”: []}
> A missing field: {}
>  
> I’ve seen libraries go either way, libyang only accepts 2 but the python yangson library accepts both (I’m not sure which is the default).
>  
> Thanks,
> Jack Rickard 
> he/him 
> Software Engineer 
> jack.rickard@microsoft.com <mailto:jack.rickard@microsoft.com> 
> 
> <image001.png>
>  
>  
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