[apps-discuss] Identifier comparison in draft-ietf-appsawg-json-pointer, was: Feedback on draft-ietf-appsawg-json-pointer-00

[Julian Reschke <[e-mail]>]

On 2012-03-01 21:14, Mike Acar wrote:
> Hi,
>
> I've been asked to review the JSON Pointer and Patch draft RFCs. I've
> had some discussion about them off-list, and have been advised to bring
> my issues to the list. And so, I am. :)
>
> I've scanned the archived list discussion of the patch and pointer RFCs,
> so I don't think these issues have come up here already. Let me know if
> they have.
>
> The first issue is comparing Unicode strings. Section 4 of
> http://tools.ietf.org/html/draft-ietf-appsawg-json-pointer-00 says
>
> If the currently referenced value is a JSON object, the new
> referenced value is the object member with the name identified by
> the reference token.
>
> That is, if the reference token equals the name of some value within the
> object, move to that value. However, the tokens and values are Unicode
> strings; I'm not an expert in Unicode, but my impression is that testing
> Unicode strings for equality is not as simple as comparing sequences of
> bytes. For example, there are linguistic considerations: I believe
> German ö and oe are considered identical.

No, they aren't.

The spec could be made a bit clearer by saying "code point by code 
point", but I would think that's the default unless otherwise stated.

> There's also the question of JSON documents with different encodings;
> UTF8 is the default, but UTF-16 and -32 with both endiannesses are also
> supported. Presumably this question will disappear in practice, since
> implementations will operate on deserialized data structures, not on
> JSON texts.

Indeed.

> ...

Best regards, Julian