You're right, throwing is probably too much of a breaking change
Norbert Lindenberg <[email protected]> wrote: >If throwing an exception from Date.prototype.toLocaleString is allowed, then I >think that would be the best solution. I thought that would be considered an >incompatible change since the spec doesn't mention it and no implementation >(that I've tested with) does it. > >Norbert > > >On Jun 22, 2012, at 9:25 , Allen Wirfs-Brock wrote: > >> #3 is also the alternative that seems right to me although since the >> "Invalid Date" behavior isn't in the standard and also isn't universal we >> could change the behavior of Date toLocaleString for ES6 and in the I18N API >> spec. to also throw. >> >> "Invalid Date" doesn't seems to me like a debugging message and not >> something that requires or is intended for end-user localization. > >doesn't seems -> seems? > >> Allen >> >> >> >> >> On Jun 21, 2012, at 10:33 PM, Brendan Eich wrote: >> >>> Eric Albright wrote: >>>> I think detection of programming errors is important enough that I favor >>>> option 3. Next in line is option 1. >>> >>> Agreed. >>> >>> /be >>>> >>>> ________________________________________ >>>> From: [email protected] [[email protected]] on >>>> behalf of Norbert Lindenberg [[email protected]] >>>> Sent: Thursday, June 21, 2012 4:23 PM >>>> To: es-discuss >>>> Subject: Internationalization: NaN and Infinity in date formatting >>>> >>>> The ECMAScript Internationalization API Specification currently requires >>>> that Intl.DateTimeFormat.prototype.format(date) throws an exception if >>>> ToNumber(date) is not a finite Number (i.e., it's NaN or +/- Infinity). >>>> This is incompatible with the specification of >>>> Date.prototype.toLocale(|Date|Time)String, which unconditionally requires >>>> that a String value is returned. >>>> >>>> Most existing implementations of Date.prototype.toLocale(|Date|Time)String >>>> return "Invalid Date" for NaN (Infinity is mapped to NaN in the Date >>>> constructor). Safari tries to produce something in the format of a date >>>> string, with limited success: >>>> Mac OS 10.6.8: "December -2147483629, 1969 -596:-31:-23 GMT-08:00" >>>> iOS 5.1.1 German: "1. Januar 1970 00:00:00 GMT-07:52:58" >>>> >>>> Internationalization libraries usually use integer-based representations >>>> of date and time and therefore don't deal with NaN and Infinity. >>>> >>>> I see the following options: >>>> >>>> 1) Change Intl.DateTimeFormat.prototype.format to return a localized form >>>> of "Invalid Date" for non-finite values. Pro: Most compatible with current >>>> implementations. Con: Internationalization libraries probably don't >>>> provide these localized strings, so the wrapper implementing the >>>> ECMAScript Internationalization API has to provide them. >>>> >>>> 2) Change Intl.DateTimeFormat.prototype.format to return >>>> Intl.NumberFormat.prototype.format(ToNumber(date)) for non-finite values. >>>> Pro: Relies on existing functionality. Con: Less descriptive and less >>>> compatible than 1. >>>> >>>> 3) Leave Intl.DateTimeFormat.prototype.format as is (i.e., throw an >>>> exception for non-finite values); specify >>>> Date.prototype.toLocale(|Date|Time)String to handle NaN directly before >>>> calling Intl.DateTimeFormat.prototype.format with other values. Pro: >>>> Easier detection of programming errors when using format(). Con: format() >>>> and toLocaleString() start to drift apart. >>>> >>>> I lean towards option 1). >>>> >>>> Comments? >>>> >>>> Thanks, >>>> Norbert >>>> >>>> _______________________________________________ >>>> es-discuss mailing list >>>> [email protected] >>>> https://mail.mozilla.org/listinfo/es-discuss >>>> _______________________________________________ >>>> es-discuss mailing list >>>> [email protected] >>>> https://mail.mozilla.org/listinfo/es-discuss >>>> >>> _______________________________________________ >>> es-discuss mailing list >>> [email protected] >>> https://mail.mozilla.org/listinfo/es-discuss >>> >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss > > _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
