[core] Artart last call review of draft-ietf-core-links-json-07

[Mark Nottingham <[e-mail]>]

Reviewer: Mark Nottingham
Review result: Ready with Issues

This specification is a relatively straightforward mapping of the
format described in RFC6690 (itself a serialisation of RFC5988bis
links) into JSON and CBOR. I don't have deep knowledge of CBOR, but
given the editorship of the document, I trust it's seen adequate
review in that regard.

The only potential issue is how this is achieved. Rather than defining
two new serialisations of RFC5988bis links (into JSON and CBOR), it
describes how to re-serialise RFC6690 documents into JSON and CBOR.
This means that any constraints upon RFC6690 documents are also
mirrored into these formats; e.g., the target IRI is constrained to be
a URI in 6690, and therefore can also only be a URI in JSON and CBOR,
despite these formats' ability to easily convey non-ASCII content.

In other words, the specification currently defines these link formats
in terms of the Link header (as defined in section 5 of RFC5988) --
along with all of the foibles of HTTP header syntax -- rather than
their abstract model (defined in Section 3).

Whether or not this is a problem depends on what's desired; if 6690 is
seen as effectively a profile of 5988, then it makes sense to express
it in those terms. If the full range of links capable of being
expressed in 5988 is desired, creating new serialisations of 5988
links (without a hop through 6690) is preferable.

If the current approach is kept, it'd be nice to clarify this
situation a bit in the Introduction.