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- /*
- * Copyright (c) 2020-2023, Linus Groh <linusg@serenityos.org>
- * Copyright (c) 2022-2023, Tim Flynn <trflynn89@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
- #include <AK/NumericLimits.h>
- #include <AK/StringBuilder.h>
- #include <AK/Time.h>
- #include <LibJS/Runtime/AbstractOperations.h>
- #include <LibJS/Runtime/Date.h>
- #include <LibJS/Runtime/GlobalObject.h>
- #include <LibJS/Runtime/Temporal/ISO8601.h>
- #include <LibTimeZone/TimeZone.h>
- #include <time.h>
- namespace JS {
- JS_DEFINE_ALLOCATOR(Date);
- static Crypto::SignedBigInteger const s_one_billion_bigint { 1'000'000'000 };
- static Crypto::SignedBigInteger const s_one_million_bigint { 1'000'000 };
- static Crypto::SignedBigInteger const s_one_thousand_bigint { 1'000 };
- Crypto::SignedBigInteger const ns_per_day_bigint { static_cast<i64>(ns_per_day) };
- NonnullGCPtr<Date> Date::create(Realm& realm, double date_value)
- {
- return realm.heap().allocate<Date>(realm, date_value, realm.intrinsics().date_prototype());
- }
- Date::Date(double date_value, Object& prototype)
- : Object(ConstructWithPrototypeTag::Tag, prototype)
- , m_date_value(date_value)
- {
- }
- ErrorOr<String> Date::iso_date_string() const
- {
- int year = year_from_time(m_date_value);
- StringBuilder builder;
- if (year < 0)
- builder.appendff("-{:06}", -year);
- else if (year > 9999)
- builder.appendff("+{:06}", year);
- else
- builder.appendff("{:04}", year);
- builder.append('-');
- builder.appendff("{:02}", month_from_time(m_date_value) + 1);
- builder.append('-');
- builder.appendff("{:02}", date_from_time(m_date_value));
- builder.append('T');
- builder.appendff("{:02}", hour_from_time(m_date_value));
- builder.append(':');
- builder.appendff("{:02}", min_from_time(m_date_value));
- builder.append(':');
- builder.appendff("{:02}", sec_from_time(m_date_value));
- builder.append('.');
- builder.appendff("{:03}", ms_from_time(m_date_value));
- builder.append('Z');
- return builder.to_string();
- }
- // 21.4.1.3 Day ( t ), https://tc39.es/ecma262/#sec-day
- double day(double time_value)
- {
- // 1. Return 𝔽(floor(ℝ(t / msPerDay))).
- return floor(time_value / ms_per_day);
- }
- // 21.4.1.4 TimeWithinDay ( t ), https://tc39.es/ecma262/#sec-timewithinday
- double time_within_day(double time)
- {
- // 1. Return 𝔽(ℝ(t) modulo ℝ(msPerDay)).
- return modulo(time, ms_per_day);
- }
- // 21.4.1.5 DaysInYear ( y ), https://tc39.es/ecma262/#sec-daysinyear
- u16 days_in_year(i32 y)
- {
- // 1. Let ry be ℝ(y).
- auto ry = static_cast<double>(y);
- // 2. If (ry modulo 400) = 0, return 366𝔽.
- if (modulo(ry, 400.0) == 0)
- return 366;
- // 3. If (ry modulo 100) = 0, return 365𝔽.
- if (modulo(ry, 100.0) == 0)
- return 365;
- // 4. If (ry modulo 4) = 0, return 366𝔽.
- if (modulo(ry, 4.0) == 0)
- return 366;
- // 5. Return 365𝔽.
- return 365;
- }
- // 21.4.1.6 DayFromYear ( y ), https://tc39.es/ecma262/#sec-dayfromyear
- double day_from_year(i32 y)
- {
- // 1. Let ry be ℝ(y).
- auto ry = static_cast<double>(y);
- // 2. NOTE: In the following steps, each _numYearsN_ is the number of years divisible by N that occur between the
- // epoch and the start of year y. (The number is negative if y is before the epoch.)
- // 3. Let numYears1 be (ry - 1970).
- auto num_years_1 = ry - 1970;
- // 4. Let numYears4 be floor((ry - 1969) / 4).
- auto num_years_4 = floor((ry - 1969) / 4.0);
- // 5. Let numYears100 be floor((ry - 1901) / 100).
- auto num_years_100 = floor((ry - 1901) / 100.0);
- // 6. Let numYears400 be floor((ry - 1601) / 400).
- auto num_years_400 = floor((ry - 1601) / 400.0);
- // 7. Return 𝔽(365 × numYears1 + numYears4 - numYears100 + numYears400).
- return 365.0 * num_years_1 + num_years_4 - num_years_100 + num_years_400;
- }
- // 21.4.1.7 TimeFromYear ( y ), https://tc39.es/ecma262/#sec-timefromyear
- double time_from_year(i32 y)
- {
- // 1. Return msPerDay × DayFromYear(y).
- return ms_per_day * day_from_year(y);
- }
- // 21.4.1.8 YearFromTime ( t ), https://tc39.es/ecma262/#sec-yearfromtime
- i32 year_from_time(double t)
- {
- // 1. Return the largest integral Number y (closest to +∞) such that TimeFromYear(y) ≤ t.
- if (!Value(t).is_finite_number())
- return NumericLimits<i32>::max();
- // Approximation using average number of milliseconds per year. We might have to adjust this guess afterwards.
- auto year = static_cast<i32>(floor(t / (365.2425 * ms_per_day) + 1970));
- auto year_t = time_from_year(year);
- if (year_t > t)
- year--;
- else if (year_t + days_in_year(year) * ms_per_day <= t)
- year++;
- return year;
- }
- // 21.4.1.9 DayWithinYear ( t ), https://tc39.es/ecma262/#sec-daywithinyear
- u16 day_within_year(double t)
- {
- if (!Value(t).is_finite_number())
- return 0;
- // 1. Return Day(t) - DayFromYear(YearFromTime(t)).
- return static_cast<u16>(day(t) - day_from_year(year_from_time(t)));
- }
- // 21.4.1.10 InLeapYear ( t ), https://tc39.es/ecma262/#sec-inleapyear
- bool in_leap_year(double t)
- {
- // 1. If DaysInYear(YearFromTime(t)) is 366𝔽, return 1𝔽; else return +0𝔽.
- return days_in_year(year_from_time(t)) == 366;
- }
- // 21.4.1.11 MonthFromTime ( t ), https://tc39.es/ecma262/#sec-monthfromtime
- u8 month_from_time(double t)
- {
- // 1. Let inLeapYear be InLeapYear(t).
- auto in_leap_year = static_cast<unsigned>(JS::in_leap_year(t));
- // 2. Let dayWithinYear be DayWithinYear(t).
- auto day_within_year = JS::day_within_year(t);
- // 3. If dayWithinYear < 31𝔽, return +0𝔽.
- if (day_within_year < 31)
- return 0;
- // 4. If dayWithinYear < 59𝔽 + inLeapYear, return 1𝔽.
- if (day_within_year < (59 + in_leap_year))
- return 1;
- // 5. If dayWithinYear < 90𝔽 + inLeapYear, return 2𝔽.
- if (day_within_year < (90 + in_leap_year))
- return 2;
- // 6. If dayWithinYear < 120𝔽 + inLeapYear, return 3𝔽.
- if (day_within_year < (120 + in_leap_year))
- return 3;
- // 7. If dayWithinYear < 151𝔽 + inLeapYear, return 4𝔽.
- if (day_within_year < (151 + in_leap_year))
- return 4;
- // 8. If dayWithinYear < 181𝔽 + inLeapYear, return 5𝔽.
- if (day_within_year < (181 + in_leap_year))
- return 5;
- // 9. If dayWithinYear < 212𝔽 + inLeapYear, return 6𝔽.
- if (day_within_year < (212 + in_leap_year))
- return 6;
- // 10. If dayWithinYear < 243𝔽 + inLeapYear, return 7𝔽.
- if (day_within_year < (243 + in_leap_year))
- return 7;
- // 11. If dayWithinYear < 273𝔽 + inLeapYear, return 8𝔽.
- if (day_within_year < (273 + in_leap_year))
- return 8;
- // 12. If dayWithinYear < 304𝔽 + inLeapYear, return 9𝔽.
- if (day_within_year < (304 + in_leap_year))
- return 9;
- // 13. If dayWithinYear < 334𝔽 + inLeapYear, return 10𝔽.
- if (day_within_year < (334 + in_leap_year))
- return 10;
- // 14. Assert: dayWithinYear < 365𝔽 + inLeapYear.
- VERIFY(day_within_year < (365 + in_leap_year));
- // 15. Return 11𝔽.
- return 11;
- }
- // 21.4.1.12 DateFromTime ( t ), https://tc39.es/ecma262/#sec-datefromtime
- u8 date_from_time(double t)
- {
- // 1. Let inLeapYear be InLeapYear(t).
- auto in_leap_year = static_cast<unsigned>(JS::in_leap_year(t));
- // 2. Let dayWithinYear be DayWithinYear(t).
- auto day_within_year = JS::day_within_year(t);
- // 3. Let month be MonthFromTime(t).
- auto month = month_from_time(t);
- // 4. If month is +0𝔽, return dayWithinYear + 1𝔽.
- if (month == 0)
- return day_within_year + 1;
- // 5. If month is 1𝔽, return dayWithinYear - 30𝔽.
- if (month == 1)
- return day_within_year - 30;
- // 6. If month is 2𝔽, return dayWithinYear - 58𝔽 - inLeapYear.
- if (month == 2)
- return day_within_year - 58 - in_leap_year;
- // 7. If month is 3𝔽, return dayWithinYear - 89𝔽 - inLeapYear.
- if (month == 3)
- return day_within_year - 89 - in_leap_year;
- // 8. If month is 4𝔽, return dayWithinYear - 119𝔽 - inLeapYear.
- if (month == 4)
- return day_within_year - 119 - in_leap_year;
- // 9. If month is 5𝔽, return dayWithinYear - 150𝔽 - inLeapYear.
- if (month == 5)
- return day_within_year - 150 - in_leap_year;
- // 10. If month is 6𝔽, return dayWithinYear - 180𝔽 - inLeapYear.
- if (month == 6)
- return day_within_year - 180 - in_leap_year;
- // 11. If month is 7𝔽, return dayWithinYear - 211𝔽 - inLeapYear.
- if (month == 7)
- return day_within_year - 211 - in_leap_year;
- // 12. If month is 8𝔽, return dayWithinYear - 242𝔽 - inLeapYear.
- if (month == 8)
- return day_within_year - 242 - in_leap_year;
- // 13. If month is 9𝔽, return dayWithinYear - 272𝔽 - inLeapYear.
- if (month == 9)
- return day_within_year - 272 - in_leap_year;
- // 14. If month is 10𝔽, return dayWithinYear - 303𝔽 - inLeapYear.
- if (month == 10)
- return day_within_year - 303 - in_leap_year;
- // 15. Assert: month is 11𝔽.
- VERIFY(month == 11);
- // 16. Return dayWithinYear - 333𝔽 - inLeapYear.
- return day_within_year - 333 - in_leap_year;
- }
- // 21.4.1.13 WeekDay ( t ), https://tc39.es/ecma262/#sec-weekday
- u8 week_day(double t)
- {
- if (!Value(t).is_finite_number())
- return 0;
- // 1. Return 𝔽(ℝ(Day(t) + 4𝔽) modulo 7).
- return static_cast<u8>(modulo(day(t) + 4, 7));
- }
- // 21.4.1.14 HourFromTime ( t ), https://tc39.es/ecma262/#sec-hourfromtime
- u8 hour_from_time(double t)
- {
- if (!Value(t).is_finite_number())
- return 0;
- // 1. Return 𝔽(floor(ℝ(t / msPerHour)) modulo HoursPerDay).
- return static_cast<u8>(modulo(floor(t / ms_per_hour), hours_per_day));
- }
- // 21.4.1.15 MinFromTime ( t ), https://tc39.es/ecma262/#sec-minfromtime
- u8 min_from_time(double t)
- {
- if (!Value(t).is_finite_number())
- return 0;
- // 1. Return 𝔽(floor(ℝ(t / msPerMinute)) modulo MinutesPerHour).
- return static_cast<u8>(modulo(floor(t / ms_per_minute), minutes_per_hour));
- }
- // 21.4.1.16 SecFromTime ( t ), https://tc39.es/ecma262/#sec-secfromtime
- u8 sec_from_time(double t)
- {
- if (!Value(t).is_finite_number())
- return 0;
- // 1. Return 𝔽(floor(ℝ(t / msPerSecond)) modulo SecondsPerMinute).
- return static_cast<u8>(modulo(floor(t / ms_per_second), seconds_per_minute));
- }
- // 21.4.1.17 msFromTime ( t ), https://tc39.es/ecma262/#sec-msfromtime
- u16 ms_from_time(double t)
- {
- if (!Value(t).is_finite_number())
- return 0;
- // 1. Return 𝔽(ℝ(t) modulo ℝ(msPerSecond)).
- return static_cast<u16>(modulo(t, ms_per_second));
- }
- // 21.4.1.18 GetUTCEpochNanoseconds ( year, month, day, hour, minute, second, millisecond, microsecond, nanosecond ), https://tc39.es/ecma262/#sec-getutcepochnanoseconds
- Crypto::SignedBigInteger get_utc_epoch_nanoseconds(i32 year, u8 month, u8 day, u8 hour, u8 minute, u8 second, u16 millisecond, u16 microsecond, u16 nanosecond)
- {
- // 1. Let date be MakeDay(𝔽(year), 𝔽(month - 1), 𝔽(day)).
- auto date = make_day(year, month - 1, day);
- // 2. Let time be MakeTime(𝔽(hour), 𝔽(minute), 𝔽(second), 𝔽(millisecond)).
- auto time = make_time(hour, minute, second, millisecond);
- // 3. Let ms be MakeDate(date, time).
- auto ms = make_date(date, time);
- // 4. Assert: ms is an integral Number.
- VERIFY(ms == trunc(ms));
- // 5. Return ℤ(ℝ(ms) × 10^6 + microsecond × 10^3 + nanosecond).
- auto result = Crypto::SignedBigInteger { ms }.multiplied_by(s_one_million_bigint);
- result = result.plus(Crypto::SignedBigInteger { static_cast<i32>(microsecond) }.multiplied_by(s_one_thousand_bigint));
- result = result.plus(Crypto::SignedBigInteger { static_cast<i32>(nanosecond) });
- return result;
- }
- static i64 clip_bigint_to_sane_time(Crypto::SignedBigInteger const& value)
- {
- static Crypto::SignedBigInteger const min_bigint { NumericLimits<i64>::min() };
- static Crypto::SignedBigInteger const max_bigint { NumericLimits<i64>::max() };
- // The provided epoch (nano)seconds value is potentially out of range for AK::Duration and subsequently
- // get_time_zone_offset(). We can safely assume that the TZDB has no useful information that far
- // into the past and future anyway, so clamp it to the i64 range.
- if (value < min_bigint)
- return NumericLimits<i64>::min();
- if (value > max_bigint)
- return NumericLimits<i64>::max();
- // FIXME: Can we do this without string conversion?
- return value.to_base_deprecated(10).to_number<i64>().value();
- }
- // 21.4.1.20 GetNamedTimeZoneEpochNanoseconds ( timeZoneIdentifier, year, month, day, hour, minute, second, millisecond, microsecond, nanosecond ), https://tc39.es/ecma262/#sec-getnamedtimezoneepochnanoseconds
- Vector<Crypto::SignedBigInteger> get_named_time_zone_epoch_nanoseconds(StringView time_zone_identifier, i32 year, u8 month, u8 day, u8 hour, u8 minute, u8 second, u16 millisecond, u16 microsecond, u16 nanosecond)
- {
- auto local_nanoseconds = get_utc_epoch_nanoseconds(year, month, day, hour, minute, second, millisecond, microsecond, nanosecond);
- auto local_time = UnixDateTime::from_nanoseconds_since_epoch(clip_bigint_to_sane_time(local_nanoseconds));
- // FIXME: LibTimeZone does not behave exactly as the spec expects. It does not consider repeated or skipped time points.
- auto offset = TimeZone::get_time_zone_offset(time_zone_identifier, local_time);
- // Can only fail if the time zone identifier is invalid, which cannot be the case here.
- VERIFY(offset.has_value());
- return { local_nanoseconds.minus(Crypto::SignedBigInteger { offset->seconds }.multiplied_by(s_one_billion_bigint)) };
- }
- // 21.4.1.21 GetNamedTimeZoneOffsetNanoseconds ( timeZoneIdentifier, epochNanoseconds ), https://tc39.es/ecma262/#sec-getnamedtimezoneoffsetnanoseconds
- i64 get_named_time_zone_offset_nanoseconds(StringView time_zone_identifier, Crypto::SignedBigInteger const& epoch_nanoseconds)
- {
- // Only called with validated time zone identifier as argument.
- auto time_zone = TimeZone::time_zone_from_string(time_zone_identifier);
- VERIFY(time_zone.has_value());
- // Since UnixDateTime::from_seconds_since_epoch() and UnixDateTime::from_nanoseconds_since_epoch() both take an i64, converting to
- // seconds first gives us a greater range. The TZDB doesn't have sub-second offsets.
- auto seconds = epoch_nanoseconds.divided_by(s_one_billion_bigint).quotient;
- auto time = UnixDateTime::from_seconds_since_epoch(clip_bigint_to_sane_time(seconds));
- auto offset = TimeZone::get_time_zone_offset(*time_zone, time);
- VERIFY(offset.has_value());
- return offset->seconds * 1'000'000'000;
- }
- // 21.4.1.23 AvailableNamedTimeZoneIdentifiers ( ), https://tc39.es/ecma262/#sec-time-zone-identifier-record
- Vector<TimeZoneIdentifier> available_named_time_zone_identifiers()
- {
- // 1. If the implementation does not include local political rules for any time zones, then
- // a. Return « the Time Zone Identifier Record { [[Identifier]]: "UTC", [[PrimaryIdentifier]]: "UTC" } ».
- // NOTE: This step is not applicable as LibTimeZone will always return at least UTC, even if the TZDB is disabled.
- // 2. Let identifiers be the List of unique available named time zone identifiers.
- auto identifiers = TimeZone::all_time_zones();
- // 3. Sort identifiers into the same order as if an Array of the same values had been sorted using %Array.prototype.sort% with undefined as comparefn.
- // NOTE: LibTimeZone provides the identifiers already sorted.
- // 4. Let result be a new empty List.
- Vector<TimeZoneIdentifier> result;
- result.ensure_capacity(identifiers.size());
- bool found_utc = false;
- // 5. For each element identifier of identifiers, do
- for (auto identifier : identifiers) {
- // a. Let primary be identifier.
- auto primary = identifier.name;
- // b. If identifier is a non-primary time zone identifier in this implementation and identifier is not "UTC", then
- if (identifier.is_link == TimeZone::IsLink::Yes && identifier.name != "UTC"sv) {
- // i. Set primary to the primary time zone identifier associated with identifier.
- // ii. NOTE: An implementation may need to resolve identifier iteratively to obtain the primary time zone identifier.
- primary = TimeZone::canonicalize_time_zone(identifier.name).value();
- }
- // c. Let record be the Time Zone Identifier Record { [[Identifier]]: identifier, [[PrimaryIdentifier]]: primary }.
- TimeZoneIdentifier record { .identifier = identifier.name, .primary_identifier = primary };
- // d. Append record to result.
- result.unchecked_append(record);
- if (!found_utc && identifier.name == "UTC"sv && primary == "UTC"sv)
- found_utc = true;
- }
- // 6. Assert: result contains a Time Zone Identifier Record r such that r.[[Identifier]] is "UTC" and r.[[PrimaryIdentifier]] is "UTC".
- VERIFY(found_utc);
- // 7. Return result.
- return result;
- }
- // 21.4.1.24 SystemTimeZoneIdentifier ( ), https://tc39.es/ecma262/#sec-systemtimezoneidentifier
- StringView system_time_zone_identifier()
- {
- return TimeZone::current_time_zone();
- }
- // 21.4.1.25 LocalTime ( t ), https://tc39.es/ecma262/#sec-localtime
- double local_time(double time)
- {
- // 1. Let systemTimeZoneIdentifier be SystemTimeZoneIdentifier().
- auto system_time_zone_identifier = JS::system_time_zone_identifier();
- double offset_nanoseconds { 0 };
- // 2. If IsTimeZoneOffsetString(systemTimeZoneIdentifier) is true, then
- if (is_time_zone_offset_string(system_time_zone_identifier)) {
- // a. Let offsetNs be ParseTimeZoneOffsetString(systemTimeZoneIdentifier).
- offset_nanoseconds = parse_time_zone_offset_string(system_time_zone_identifier);
- }
- // 3. Else,
- else {
- // a. Let offsetNs be GetNamedTimeZoneOffsetNanoseconds(systemTimeZoneIdentifier, ℤ(ℝ(t) × 10^6)).
- auto time_bigint = Crypto::SignedBigInteger { time }.multiplied_by(s_one_million_bigint);
- offset_nanoseconds = get_named_time_zone_offset_nanoseconds(system_time_zone_identifier, time_bigint);
- }
- // 4. Let offsetMs be truncate(offsetNs / 10^6).
- auto offset_milliseconds = trunc(offset_nanoseconds / 1e6);
- // 5. Return t + 𝔽(offsetMs).
- return time + offset_milliseconds;
- }
- // 21.4.1.26 UTC ( t ), https://tc39.es/ecma262/#sec-utc-t
- double utc_time(double time)
- {
- // 1. Let systemTimeZoneIdentifier be SystemTimeZoneIdentifier().
- auto system_time_zone_identifier = JS::system_time_zone_identifier();
- double offset_nanoseconds { 0 };
- // 2. If IsTimeZoneOffsetString(systemTimeZoneIdentifier) is true, then
- if (is_time_zone_offset_string(system_time_zone_identifier)) {
- // a. Let offsetNs be ParseTimeZoneOffsetString(systemTimeZoneIdentifier).
- offset_nanoseconds = parse_time_zone_offset_string(system_time_zone_identifier);
- }
- // 3. Else,
- else {
- // a. Let possibleInstants be GetNamedTimeZoneEpochNanoseconds(systemTimeZoneIdentifier, ℝ(YearFromTime(t)), ℝ(MonthFromTime(t)) + 1, ℝ(DateFromTime(t)), ℝ(HourFromTime(t)), ℝ(MinFromTime(t)), ℝ(SecFromTime(t)), ℝ(msFromTime(t)), 0, 0).
- auto possible_instants = get_named_time_zone_epoch_nanoseconds(system_time_zone_identifier, year_from_time(time), month_from_time(time) + 1, date_from_time(time), hour_from_time(time), min_from_time(time), sec_from_time(time), ms_from_time(time), 0, 0);
- // b. NOTE: The following steps ensure that when t represents local time repeating multiple times at a negative time zone transition (e.g. when the daylight saving time ends or the time zone offset is decreased due to a time zone rule change) or skipped local time at a positive time zone transition (e.g. when the daylight saving time starts or the time zone offset is increased due to a time zone rule change), t is interpreted using the time zone offset before the transition.
- Crypto::SignedBigInteger disambiguated_instant;
- // c. If possibleInstants is not empty, then
- if (!possible_instants.is_empty()) {
- // i. Let disambiguatedInstant be possibleInstants[0].
- disambiguated_instant = move(possible_instants.first());
- }
- // d. Else,
- else {
- // i. NOTE: t represents a local time skipped at a positive time zone transition (e.g. due to daylight saving time starting or a time zone rule change increasing the UTC offset).
- // ii. Let possibleInstantsBefore be GetNamedTimeZoneEpochNanoseconds(systemTimeZoneIdentifier, ℝ(YearFromTime(tBefore)), ℝ(MonthFromTime(tBefore)) + 1, ℝ(DateFromTime(tBefore)), ℝ(HourFromTime(tBefore)), ℝ(MinFromTime(tBefore)), ℝ(SecFromTime(tBefore)), ℝ(msFromTime(tBefore)), 0, 0), where tBefore is the largest integral Number < t for which possibleInstantsBefore is not empty (i.e., tBefore represents the last local time before the transition).
- // iii. Let disambiguatedInstant be the last element of possibleInstantsBefore.
- // FIXME: This branch currently cannot be reached with our implementation, because LibTimeZone does not handle skipped time points.
- // When GetNamedTimeZoneEpochNanoseconds is updated to use a LibTimeZone API which does handle them, implement these steps.
- VERIFY_NOT_REACHED();
- }
- // e. Let offsetNs be GetNamedTimeZoneOffsetNanoseconds(systemTimeZoneIdentifier, disambiguatedInstant).
- offset_nanoseconds = get_named_time_zone_offset_nanoseconds(system_time_zone_identifier, disambiguated_instant);
- }
- // 4. Let offsetMs be truncate(offsetNs / 10^6).
- auto offset_milliseconds = trunc(offset_nanoseconds / 1e6);
- // 5. Return t - 𝔽(offsetMs).
- return time - offset_milliseconds;
- }
- // 21.4.1.27 MakeTime ( hour, min, sec, ms ), https://tc39.es/ecma262/#sec-maketime
- double make_time(double hour, double min, double sec, double ms)
- {
- // 1. If hour is not finite or min is not finite or sec is not finite or ms is not finite, return NaN.
- if (!isfinite(hour) || !isfinite(min) || !isfinite(sec) || !isfinite(ms))
- return NAN;
- // 2. Let h be 𝔽(! ToIntegerOrInfinity(hour)).
- auto h = to_integer_or_infinity(hour);
- // 3. Let m be 𝔽(! ToIntegerOrInfinity(min)).
- auto m = to_integer_or_infinity(min);
- // 4. Let s be 𝔽(! ToIntegerOrInfinity(sec)).
- auto s = to_integer_or_infinity(sec);
- // 5. Let milli be 𝔽(! ToIntegerOrInfinity(ms)).
- auto milli = to_integer_or_infinity(ms);
- // 6. Let t be ((h * msPerHour + m * msPerMinute) + s * msPerSecond) + milli, performing the arithmetic according to IEEE 754-2019 rules (that is, as if using the ECMAScript operators * and +).
- // NOTE: C++ arithmetic abides by IEEE 754 rules
- auto t = ((h * ms_per_hour + m * ms_per_minute) + s * ms_per_second) + milli;
- // 7. Return t.
- return t;
- }
- // 21.4.1.28 MakeDay ( year, month, date ), https://tc39.es/ecma262/#sec-makeday
- double make_day(double year, double month, double date)
- {
- // 1. If year is not finite or month is not finite or date is not finite, return NaN.
- if (!isfinite(year) || !isfinite(month) || !isfinite(date))
- return NAN;
- // 2. Let y be 𝔽(! ToIntegerOrInfinity(year)).
- auto y = to_integer_or_infinity(year);
- // 3. Let m be 𝔽(! ToIntegerOrInfinity(month)).
- auto m = to_integer_or_infinity(month);
- // 4. Let dt be 𝔽(! ToIntegerOrInfinity(date)).
- auto dt = to_integer_or_infinity(date);
- // 5. Let ym be y + 𝔽(floor(ℝ(m) / 12)).
- auto ym = y + floor(m / 12);
- // 6. If ym is not finite, return NaN.
- if (!isfinite(ym))
- return NAN;
- // 7. Let mn be 𝔽(ℝ(m) modulo 12).
- auto mn = modulo(m, 12);
- // 8. Find a finite time value t such that YearFromTime(t) is ym and MonthFromTime(t) is mn and DateFromTime(t) is 1𝔽; but if this is not possible (because some argument is out of range), return NaN.
- if (!AK::is_within_range<int>(ym) || !AK::is_within_range<int>(mn + 1))
- return NAN;
- auto t = days_since_epoch(static_cast<int>(ym), static_cast<int>(mn) + 1, 1) * ms_per_day;
- // 9. Return Day(t) + dt - 1𝔽.
- return day(static_cast<double>(t)) + dt - 1;
- }
- // 21.4.1.29 MakeDate ( day, time ), https://tc39.es/ecma262/#sec-makedate
- double make_date(double day, double time)
- {
- // 1. If day is not finite or time is not finite, return NaN.
- if (!isfinite(day) || !isfinite(time))
- return NAN;
- // 2. Let tv be day × msPerDay + time.
- auto tv = day * ms_per_day + time;
- // 3. If tv is not finite, return NaN.
- if (!isfinite(tv))
- return NAN;
- // 4. Return tv.
- return tv;
- }
- // 21.4.1.31 TimeClip ( time ), https://tc39.es/ecma262/#sec-timeclip
- double time_clip(double time)
- {
- // 1. If time is not finite, return NaN.
- if (!isfinite(time))
- return NAN;
- // 2. If abs(ℝ(time)) > 8.64 × 10^15, return NaN.
- if (fabs(time) > 8.64E15)
- return NAN;
- // 3. Return 𝔽(! ToIntegerOrInfinity(time)).
- return to_integer_or_infinity(time);
- }
- // 21.4.1.33.1 IsTimeZoneOffsetString ( offsetString ), https://tc39.es/ecma262/#sec-istimezoneoffsetstring
- bool is_time_zone_offset_string(StringView offset_string)
- {
- // 1. Let parseResult be ParseText(StringToCodePoints(offsetString), UTCOffset).
- auto parse_result = Temporal::parse_iso8601(Temporal::Production::TimeZoneNumericUTCOffset, offset_string);
- // 2. If parseResult is a List of errors, return false.
- // 3. Return true.
- return parse_result.has_value();
- }
- // 21.4.1.33.2 ParseTimeZoneOffsetString ( offsetString ), https://tc39.es/ecma262/#sec-parsetimezoneoffsetstring
- double parse_time_zone_offset_string(StringView offset_string)
- {
- // 1. Let parseResult be ParseText(StringToCodePoints(offsetString), UTCOffset).
- auto parse_result = Temporal::parse_iso8601(Temporal::Production::TimeZoneNumericUTCOffset, offset_string);
- // 2. Assert: parseResult is not a List of errors.
- VERIFY(parse_result.has_value());
- // 3. Assert: parseResult contains a TemporalSign Parse Node.
- VERIFY(parse_result->time_zone_utc_offset_sign.has_value());
- // 4. Let parsedSign be the source text matched by the TemporalSign Parse Node contained within parseResult.
- auto parsed_sign = *parse_result->time_zone_utc_offset_sign;
- i8 sign { 0 };
- // 5. If parsedSign is the single code point U+002D (HYPHEN-MINUS) or U+2212 (MINUS SIGN), then
- if (parsed_sign.is_one_of("-"sv, "\xE2\x88\x92"sv)) {
- // a. Let sign be -1.
- sign = -1;
- }
- // 6. Else,
- else {
- // a. Let sign be 1.
- sign = 1;
- }
- // 7. NOTE: Applications of StringToNumber below do not lose precision, since each of the parsed values is guaranteed to be a sufficiently short string of decimal digits.
- // 8. Assert: parseResult contains an Hour Parse Node.
- VERIFY(parse_result->time_zone_utc_offset_hour.has_value());
- // 9. Let parsedHours be the source text matched by the Hour Parse Node contained within parseResult.
- auto parsed_hours = *parse_result->time_zone_utc_offset_hour;
- // 10. Let hours be ℝ(StringToNumber(CodePointsToString(parsedHours))).
- auto hours = string_to_number(parsed_hours);
- double minutes { 0 };
- double seconds { 0 };
- double nanoseconds { 0 };
- // 11. If parseResult does not contain a MinuteSecond Parse Node, then
- if (!parse_result->time_zone_utc_offset_minute.has_value()) {
- // a. Let minutes be 0.
- minutes = 0;
- }
- // 12. Else,
- else {
- // a. Let parsedMinutes be the source text matched by the first MinuteSecond Parse Node contained within parseResult.
- auto parsed_minutes = *parse_result->time_zone_utc_offset_minute;
- // b. Let minutes be ℝ(StringToNumber(CodePointsToString(parsedMinutes))).
- minutes = string_to_number(parsed_minutes);
- }
- // 13. If parseResult does not contain two MinuteSecond Parse Nodes, then
- if (!parse_result->time_zone_utc_offset_second.has_value()) {
- // a. Let seconds be 0.
- seconds = 0;
- }
- // 14. Else,
- else {
- // a. Let parsedSeconds be the source text matched by the second secondSecond Parse Node contained within parseResult.
- auto parsed_seconds = *parse_result->time_zone_utc_offset_second;
- // b. Let seconds be ℝ(StringToNumber(CodePointsToString(parsedSeconds))).
- seconds = string_to_number(parsed_seconds);
- }
- // 15. If parseResult does not contain a TemporalDecimalFraction Parse Node, then
- if (!parse_result->time_zone_utc_offset_fraction.has_value()) {
- // a. Let nanoseconds be 0.
- nanoseconds = 0;
- }
- // 16. Else,
- else {
- // a. Let parsedFraction be the source text matched by the TemporalDecimalFraction Parse Node contained within parseResult.
- auto parsed_fraction = *parse_result->time_zone_utc_offset_fraction;
- // b. Let fraction be the string-concatenation of CodePointsToString(parsedFraction) and "000000000".
- auto fraction = ByteString::formatted("{}000000000", parsed_fraction);
- // c. Let nanosecondsString be the substring of fraction from 1 to 10.
- auto nanoseconds_string = fraction.substring_view(1, 9);
- // d. Let nanoseconds be ℝ(StringToNumber(nanosecondsString)).
- nanoseconds = string_to_number(nanoseconds_string);
- }
- // 17. Return sign × (((hours × 60 + minutes) × 60 + seconds) × 10^9 + nanoseconds).
- // NOTE: Using scientific notation (1e9) ensures the result of this expression is a double,
- // which is important - otherwise it's all integers and the result overflows!
- return sign * (((hours * 60 + minutes) * 60 + seconds) * 1e9 + nanoseconds);
- }
- }
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