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From: Brian Rosen <br@brianrosen.net>
In-Reply-To: <d2ab505d-bc99-482d-a8e5-694f67ce932b@www.fastmail.com>
Date: Wed, 15 Jul 2020 08:37:39 -0400
Cc: dispatch@ietf.org
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Message-Id: <1C9B201D-7DB6-4A8D-8750-475981DB5863@brianrosen.net>
References: <159467093010.19477.7181341398452455173@ietfa.amsl.com>
 <77B617C1-2148-4AE6-8428-DAD43D01FBC5@tzi.org>
 <d2ab505d-bc99-482d-a8e5-694f67ce932b@www.fastmail.com>
To: Martin Thomson <mt@lowentropy.net>
Archived-At: <https://mailarchive.ietf.org/arch/msg/dispatch/x1bVs5oEwOvPiO-joVAwCxlpmtw>
Subject: Re: [dispatch] draft-goessner-dispatch-jsonpath-00.txt
Precedence: list

I haven=E2=80=99t seen json pointer in the wild, pretty much ever.  =
I=E2=80=99ve seen A LOT of jsonpath. =20
But I=E2=80=99m not exactly doing mainstream interfaces.

Brian

> On Jul 15, 2020, at 5:40 AM, Martin Thomson <mt@lowentropy.net> wrote:
>=20
> I see three major differences here from JSON pointer:
>=20
> 1. this selects multiple values in the same way that XPath does, so =
this includes // and * and other such things
> 2. predicates (the execution of script is a major concern and really =
begs for a security model), which is largely a consequence of having =
multiple values but not strictly
> 3. syntax
>=20
> Of these, the syntax difference seems gratuitous.  JSON pointer isn't =
exactly awesome~1but it has fewer variants and it isn't inclined toward =
implementation by eval(), which is an anti-feature.
>=20
> Personally, I would much rather see a new JSON pointer developed, =
which would be evolutionary rather than revolutionary; more version 2 =
than competition.  It would be relatively simple to add multi-value and =
relative evaluation to JSON pointer if those are the key use cases.  =
That said, I don't have a lot of insight into what the implementation =
landscape is.  If JSON pointer is moribund, then we might want to =
acknowledge that.  My sense is that it has some relatively wide support, =
including modifications for relative references =
(https://json-schema.org/draft/2019-09/relative-json-pointer.html).
>=20
> Predicates are where this gets tricky, but I would suggest that you =
need to decide the question of whether they are included from the =
outset.  Personally, these seem like they could be a big risk and I =
would defer their addition if not cut them out, but I don't know what =
sort of use cases are driving this.
>=20
> This seems big enough to be a working group (particularly if you put =
the predicate stuff in scope).
>=20
>=20
> On Tue, Jul 14, 2020, at 15:14, Carsten Bormann wrote:
>> (Reply-To set to dispatch@ietf.org)
>>=20
>> I would like to initiate discussion for =
draft-goessner-dispatch-jsonpath:
>>=20
>> https://www.ietf.org/id/draft-goessner-dispatch-jsonpath-00.html
>>=20
>> It says:
>>=20
>>> This document picks up the popular JSONPath specification dated
>>> 2007-02-21 and provides a more normative definition for it.
>>> It is intended as a submission to the IETF DISPATCH WG, in order to
>>> find the right way to complete standardization of this =
specification.
>>> In its current state, it is a strawman document showing what needs =
to
>>> be covered.
>>=20
>> (For some reason the abstract landed in the Contributing note; =
typical=20
>> Internet-Draft deadline day botch.)
>>=20
>> This is a widely implemented specification that has been around for=20=

>> more than a decade; now may be a good opportunity to finally go ahead=20=

>> and turn it into a proper Internet standards document.  The immediate=20=

>> cause for writing this up now is that some IoT discovery work (some =
of=20
>> which happens in W3C) can make good use of JSONPath.  Clearly, we=20
>> already have JSON Pointer (RFC 6901) for a more limited set of=20
>> applications; the specification would do good in defining how these =
two=20
>> fit together.
>>=20
>> There is no active WG that immediately fits this work.
>>=20
>> Eventually CDDL may pick JSONPath up in the form of a predicate=20
>> operator; this might make the CBOR WG the right group (which probably=20=

>> would then go ahead and write up another specification that makes=20
>> JSONPath useful for querying CBOR instances that go beyond the JSON=20=

>> generic data model).
>>=20
>> Reopening the JSON WG may be another approach, as may be creating a=20=

>> short-lived targeted WG.
>>=20
>> Please discuss!
>>=20
>> Gr=C3=BC=C3=9Fe, Carsten
>>=20
>>=20
>>=20
>>> Begin forwarded message:
>>>=20
>>> From: internet-drafts@ietf.org
>>> Subject: New Version Notification for =
draft-goessner-dispatch-jsonpath-00.txt
>>> Date: 2020-07-13 at 22:08:50 CEST
>>> To: "Stefan G=C3=B6ssner" <stefan.goessner@fh-dortmund.de>, "Stefan =
Gossner" <stefan.goessner@fh-dortmund.de>, "Carsten Bormann" =
<cabo@tzi.org>
>>>=20
>>>=20
>>> A new version of I-D, draft-goessner-dispatch-jsonpath-00.txt
>>> has been successfully submitted by Carsten Bormann and posted to the
>>> IETF repository.
>>>=20
>>> Name:		draft-goessner-dispatch-jsonpath
>>> Revision:	00
>>> Title:		JSONPath -- XPath for JSON
>>> Document date:	2020-07-12
>>> Group:		Individual Submission
>>> Pages:		14
>>> URL:            =
https://www.ietf.org/internet-drafts/draft-goessner-dispatch-jsonpath-00.t=
xt
>>> Status:         =
https://datatracker.ietf.org/doc/draft-goessner-dispatch-jsonpath/
>>> Htmlized:       =
https://tools.ietf.org/html/draft-goessner-dispatch-jsonpath-00
>>> Htmlized:       =
https://datatracker.ietf.org/doc/html/draft-goessner-dispatch-jsonpath
>>>=20
>>>=20
>>> Abstract:
>>>  insert abstract here
>>>=20
>>>=20
>>>=20
>>>=20
>>> Please note that it may take a couple of minutes from the time of =
submission
>>> until the htmlized version and diff are available at tools.ietf.org.
>>>=20
>>> The IETF Secretariat
>>>=20
>>>=20
>>=20
>> _______________________________________________
>> dispatch mailing list
>> dispatch@ietf.org
>> https://www.ietf.org/mailman/listinfo/dispatch
>>=20
>=20
> _______________________________________________
> dispatch mailing list
> dispatch@ietf.org
> https://www.ietf.org/mailman/listinfo/dispatch