This was an oversight in e42d954743.
These fields should always follow the locale preference in the CLDR.
Overriding these fields would permit formats like "h:mm:ss" to result in
strings like "1:2:3" instead of "1:02:03".
TR-35's Matching Skeleton algorithm dictates how user requests including
fractional second digits should be handled when the CLDR format pattern
does not include that field. When the format pattern contains {second},
but does not contain {fractionalSecondDigits}, generate a second pattern
which appends "{decimal}{fractionalSecondDigits}" to the {second} field.
ECMA-402 doesn't explicitly handle a note in the TR-35 spec related to
expanding field lengths based on user-provided options. Instead, it
assumes the "implementation defined" locale data includes the possible
values.
LibUnicode does not generate every possible combination of field lengths
in its implementation of TR-35's "Missing Skeleton Fields", because the
number of generated patterns would grow out of control. Instead, it's
much simpler to handle this difference at runtime.
Other implementations unconditionally initialize [[pattern12]] from
[[pattern]] regardless of whether [[pattern]] has an hour pattern of h11
or h12. LibUnicode does not do this. So when InitializeDateTimeFormat
defaults the hour cycle to the locale's preferred hour cycle, if the
best format didn't have an equivalent hour pattern, [[pattern12]] will
be empty.
This adds plumbing for the Intl.DateTimeFormat object, constructor, and
prototype.
Note that unlike other Intl objects, the Intl.DateTimeFormat object has
a LibUnicode structure as a base. This is to prevent wild amounts of
code duplication between LibUnicode, Intl.DateTimeFormat, and other
not-yet-defined Intl structures, because there's 12 fields shared
between them.
Currently, we generate separate data files for locale and number format
related tables/methods, but provide public accessors for all of the data
in one Locale.h file. Rather than continuing this trend for date-time,
relative time, etc. formatting, it's a bit easier to reason about if the
public accessors are also in separate files.
Allocating a Vector for each of these invocations is a bit silly when
the values are basically all compile-time arrays. This AO is used even
more heavily by Intl.DateTimeFormat, so change it to accept a Span to
reduce its cost.
This also adds an overload to accept a fixed-size C-array so callers do
not have to be prefixed with AK::Array, i.e. this:
get_option(..., AK::Array { "a"sv, "b"sv }, ...);
Reduces to:
get_option(..., { "a"sv, "b"sv }, ...);
(Which is how all call sites were already written to construct a Vector
in place).
Since AsyncIteratorClose and IteratorClose differ only in that the async
version awaits the inner value we just implement them with an enum flag
to switch just that behavior.
This is required for Temporal.Duration.prototype.round(). Subsequently,
this now returns ThrowCompletionOr<Optional<String>>, which brings the
signature in line with that of to_smallest_temporal_unit().
Much nicer! :^)
