On 2018-03-18 15:47, Michał Wadas wrote:
JSON supports arbitrary precision numbers that can't be properly represented as 64 bit floats. This includes numbers like eg. 1e9999 or 1/1e9999.
rfc7159: Since software that implements IEEE 754-2008 binary64 (double precision) numbers [IEEE754] is generally available and widely used, good interoperability can be achieved by implementations that expect no more precision or range than these provide, in the sense that implementations will approximate JSON numbers within the expected precision If interoperability is not an issue you are free to do whatever you feel useful. Targeting a 0.001% customer base with standards, I gladly leave to others to cater for. The de-facto standard featured in any number of applications, is putting unusual/binary/whatever stuff in text strings. Anders
On Sun, 18 Mar 2018, 15:30 Anders Rundgren, <[email protected] <mailto:[email protected]>> wrote: On 2018-03-18 15:08, Richard Gibson wrote:On Sunday, March 18, 2018, Anders Rundgren <[email protected] <mailto:[email protected]>> wrote: On 2018-03-16 20:24, Richard Gibson wrote:Though ECMAScript JSON.stringify may suffice for certain Javascript-centric use cases or otherwise restricted subsets thereof as addressed by JOSE, it is not suitable for producing canonical/hashable/etc. JSON, which requires a fully general solution such as [1]. Both its number serialization [2] and string serialization [3] specify aspects that harm compatibility (the former having arbitrary branches dependent upon the value of numbers, the latter being capable of producing invalid UTF-8 octet sequences that represent unpaired surrogate code points—unacceptable for exchange outside of a closed ecosystem [4]). JSON is a general /language-agnostic/interchange format, and ECMAScript JSON.stringify is *not*a JSON canonicalization solution. [1]: _http://gibson042.github.io/canonicaljson-spec/_ [2]: http://ecma-international.org/ecma-262/7.0/#sec-tostring-applied-to-the-number-type [3]: http://ecma-international.org/ecma-262/7.0/#sec-quotejsonstring [4]: https://tools.ietf.org/html/rfc8259#section-8.1Richard, I may be wrong but AFAICT, our respective canoncalization schemes are in fact principally IDENTICAL. In that they have the same goal, yes. In that they both achieve that goal, no. I'm not married to choices like exponential notation and uppercase escapes, but a JSON canonicalization scheme MUST cover all of JSON.Here it gets interesting... What in JSON cannot be expressed through JS and JSON.stringify()?That the number serialization provided by JSON.stringify() is unacceptable, is not generally taken as a fact. I also think it looks a bit weird, but that's just a matter of esthetics. Compatibility is an entirely different issue. I concede this point. The modified algorithm is sufficient, but note that a canonicalization scheme will remain static even if ECMAScript changes.Agreed.Sorting on Unicode Code Points is of course "technically 100% right" but strictly put not necessary. Certain scenarios call for different systems to _independently_ generate equivalent data structures, and it is a necessary property of canonical serialization that it yields identical results for equivalent data structures. JSON does not specify significance of object member ordering, so member ordering does not distinguish otherwise equivalent objects, so canonicalization MUST specify member ordering that is deterministic with respect to all valid data.Violently agree but do not understand (I guess I'm just dumb...) why (for example) sorting on UCS2/UTF-16 Code Units would not achieve the same goal (although the result would differ).Your claim about uppercase Unicode escapes is incorrect, there is no such requirement: https://tools.ietf.org/html/rfc8259#section-7 I don't recall ever making a claim about uppercase Unicode escapes, other than observing that it is the preferred form for examples in the JSON RFCs... what are you talking about?You're right, I found it it in the https://gibson042.github.io/canonicaljson-spec/#changelog Thanx, Anders _______________________________________________ es-discuss mailing list [email protected] <mailto:[email protected]> https://mail.mozilla.org/listinfo/es-discuss
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
