[RFC] IntlRelativeDateTimeFormatter

Here my two cents, - I would be in favor of an enum instead for the constants. - I would be in favor of an appropriate namespace to avoid conflicts. - It seems there are missing parts, e.g. how do you plan (or do you plan to) express the 2nd argument of ureldateformat_open(). There is probably more to it, just surface level first impressions. Cheers.

Hi Ignace, David, Thanks for the feedback. IMHO I tend to not accept Duration object as a parameter.  IntlRelativeDateTimeFormatter formats a caller-selected offset and unit. Time\Duration represents stopwatch time as seconds and nanoseconds. This cause a huge amount of issue which immediately comes into my head when thinking of this.  The API looks like $fmt->format(3, UNIT_DAY);    // in 3 days $fmt->format(2, UNIT_MONTH);  // in 2 months $fmt->format(-1, UNIT_SUNDAY);// last Sunday If we are now accepting Durations, they look like Time\Duration::fromMinutes(90) We don't know how to deal with 90 minutes here. It can be 90 minutes or 1.5 hour. Nevertheless, what about weekdays? things like UNIT_SUNDAY are not durations. Not to mention months, quarters, and years need calendar context. For enums and namespaces: I kept class constants and the global Intl* class name to stay consistent with the existing ext/intl API, such as IntlDateFormatter, IntlListFormatter IntlNumberRangeFormatter, and IntlDatePatternGenerator. I don't want to make IntlRelativeDateTimeFormatter somehow special here just because this is added later. I agree that enums and namespaces would be nicer in isolation, *indeed*. But,  introducing them for only this one formatter would make the API inconsistent with the rest of ext/intl. For the second argument of ureldatefmt_open(): the initial implementation will pass NULL, so ICU uses the default number formatter for the selected locale. *This is intended.* Exposing a custom NumberFormatter is possible future scope, but it needs extra care because ICU adopts ownership of the supplied UNumberFormat, so PHP would need to clone the underlying formatter before passing it to ICU. What do you think? Cheers, Weilin