And just to be clear: I'm all for standardizing a canonical JSON form. In addition to my 11-year-old attempt, there have been countless others, and still no *standard*. I just want us to learn from the previous attempts and try to make something at least as good as everything which has come before, especially in terms of the various non-obvious considerations which individual implementors have discovered the hard way over the years. --scott
On Fri, Mar 16, 2018 at 1:46 PM, Mike Samuel <[email protected]> wrote: > > > On Fri, Mar 16, 2018 at 1:30 PM, Anders Rundgren < > [email protected]> wrote: > >> On 2018-03-16 18:04, Mike Samuel wrote: >> >> It is entirely unsuitable to embedding in HTML or XML though. >>> IIUC, with an implementation based on this >>> >>> JSON.canonicalize(JSON.stringify("</script>")) === `"</script>"` && >>> JSON.canonicalize(JSON.stringify("]]>")) === `"]]>"` >>> >> >> I don't know what you are trying to prove here :-) >> > > Only that canonical JSON is useful in a very narrow context. > It cannot be embedded in an HTML script tag. > It cannot be embedded in an XML or HTML foreign content context without > extra care. > If it contains a string literal that embeds a NUL it cannot be embedded in > XML period even if extra care is taken. > > > >> >> The output of JSON.canonicalize would also not be in the subset of JSON >>> that is also a subset of JavaScript's PrimaryExpression. >>> >>> JSON.canonicalize(JSON.stringify("\u2028\u2029")) === >>> `"\u2028\u2029"` >>> >>> It also is not suitable for use internally within systems that >>> internally use cstrings. >>> >>> JSON.canonicalize(JSON.stringify("\u0000")) === `"\u0000"` >>> >>> >> JSON.canonicalize() would be [almost] identical to JSON.stringify() >> > > You're correct. Many JSON producers have a web-safe version, but the > JavaScript builtin does not. > My point is that JSON.canonicalize undoes those web-safety tweaks. > > > >> JSON.canonicalize(JSON.parse('"\u2028\u2029"')) === '"\u2028\u2029"' // >> Returns true >> >> "Emulator": >> >> var canonicalize = function(object) { >> >> var buffer = ''; >> serialize(object); >> > > I thought canonicalize took in a string of JSON and produced the same. Am > I wrong? > "Canonicalize" to my mind means a function that returns the canonical > member of an > equivalence class given any member from that same equivalence class, so is > always 'a -> 'a. > > >> return buffer; >> >> function serialize(object) { >> if (object !== null && typeof object === 'object') { >> > > JSON.stringify(new Date(0)) === "\"1970-01-01T00:00:00.000Z\"" > because Date.prototype.toJSON exists. > > If you operate as a JSON_string -> JSON_string function then you > can avoid this complexity. > > if (Array.isArray(object)) { >> buffer += '['; >> let next = false; >> object.forEach((element) => { >> if (next) { >> buffer += ','; >> } >> next = true; >> serialize(element); >> }); >> buffer += ']'; >> } else { >> buffer += '{'; >> let next = false; >> Object.keys(object).sort().forEach((property) => { >> if (next) { >> buffer += ','; >> } >> next = true; > > buffer += JSON.stringify(property); >> > > I think you need a symbol check here. JSON.stringify(Symbol.for('foo')) > === undefined > > >> buffer += ':'; >> serialize(object[property]); >> }); >> buffer += '}'; >> } >> } else { >> buffer += JSON.stringify(object); >> > > This fails to distinguish non-integral numbers from integral ones, and > produces non-standard output > when object === undefined. Again, not a problem if the input is required > to be valid JSON. > > >> } >> } >> }; >> > > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
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