[RFC] Add IntlDateTimePatternGenerator

Hi Internals,

I would like to propose an RFC
https://wiki.php.net/rfc/intldatetimepatterngenerator to add
IntlDateTimePatternGenerator
which exposes ICU's ability to flexibly create localized date/time
formatting patterns from a skeleton.

Previous discussion: https://externals.io/message/113831
Implementation: https://github.com/php/php-src/pull/6771

Proposed signature:

class IntlDateTimePatternGenerator
{
    public function __construct(?string $locale = null) {}
 
    public static function create(?string $locale = null): 
?IntlDateTimePatternGenerator {}
 
    public function getBestPattern(string $skeleton): string|false {}
}

There is an open question about what this should be named
IntlDatePatternGenerator instead, both for brevity and to keep
consistency
with IntlDateFormatter. (Note that the underlying ICU classes are
called DateTimePatternGenerator and DateFormatter, respectively.)
I am open to switching to the shorter form.

Another open question is the signature, as currently both __construct
and create are exposed (like IntlDateFormatter).
Other classes inside the intl extension (like IntlCalendar) only
provide a static create method, and leave the __construct method
private. Is there a preferred way, or are both equivalent?

For both points, I'd say "consistency wins by default." So if the other classes in that package already skip "Time" and use ::create() instead of a constructor, you should do the same as well unless there's a very good reason not to.

(Consistency with everything else in PHP that's not that package is a possible reason not to, I grant, hence why it's somewhat subjective.)

--Larry Garfield