ladybird/Userland/Libraries/LibLocale/DateTimeFormat.cpp
Timothy Flynn 7536648498 LibLocale+LibJS+ClockSettings: Make date time format APIs infallible
These APIs only perform small allocations, and are only used by LibJS
and the time zone settings widget. Callers which could only have failed
from these APIs are also made to be infallible here.
2023-08-23 05:29:21 +02:00

339 lines
13 KiB
C++

/*
* Copyright (c) 2021-2023, Tim Flynn <trflynn89@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Array.h>
#include <AK/StringBuilder.h>
#include <LibLocale/DateTimeFormat.h>
#include <LibLocale/Locale.h>
#include <LibLocale/NumberFormat.h>
#include <stdlib.h>
namespace Locale {
HourCycle hour_cycle_from_string(StringView hour_cycle)
{
if (hour_cycle == "h11"sv)
return HourCycle::H11;
if (hour_cycle == "h12"sv)
return HourCycle::H12;
if (hour_cycle == "h23"sv)
return HourCycle::H23;
if (hour_cycle == "h24"sv)
return HourCycle::H24;
VERIFY_NOT_REACHED();
}
StringView hour_cycle_to_string(HourCycle hour_cycle)
{
switch (hour_cycle) {
case HourCycle::H11:
return "h11"sv;
case HourCycle::H12:
return "h12"sv;
case HourCycle::H23:
return "h23"sv;
case HourCycle::H24:
return "h24"sv;
default:
VERIFY_NOT_REACHED();
}
}
CalendarPatternStyle calendar_pattern_style_from_string(StringView style)
{
if (style == "narrow"sv)
return CalendarPatternStyle::Narrow;
if (style == "short"sv)
return CalendarPatternStyle::Short;
if (style == "long"sv)
return CalendarPatternStyle::Long;
if (style == "numeric"sv)
return CalendarPatternStyle::Numeric;
if (style == "2-digit"sv)
return CalendarPatternStyle::TwoDigit;
if (style == "shortOffset"sv)
return CalendarPatternStyle::ShortOffset;
if (style == "longOffset"sv)
return CalendarPatternStyle::LongOffset;
if (style == "shortGeneric"sv)
return CalendarPatternStyle::ShortGeneric;
if (style == "longGeneric"sv)
return CalendarPatternStyle::LongGeneric;
VERIFY_NOT_REACHED();
}
StringView calendar_pattern_style_to_string(CalendarPatternStyle style)
{
switch (style) {
case CalendarPatternStyle::Narrow:
return "narrow"sv;
case CalendarPatternStyle::Short:
return "short"sv;
case CalendarPatternStyle::Long:
return "long"sv;
case CalendarPatternStyle::Numeric:
return "numeric"sv;
case CalendarPatternStyle::TwoDigit:
return "2-digit"sv;
case CalendarPatternStyle::ShortOffset:
return "shortOffset"sv;
case CalendarPatternStyle::LongOffset:
return "longOffset"sv;
case CalendarPatternStyle::ShortGeneric:
return "shortGeneric"sv;
case CalendarPatternStyle::LongGeneric:
return "longGeneric"sv;
default:
VERIFY_NOT_REACHED();
}
}
Optional<HourCycleRegion> __attribute__((weak)) hour_cycle_region_from_string(StringView) { return {}; }
Vector<HourCycle> __attribute__((weak)) get_regional_hour_cycles(StringView) { return {}; }
template<typename T, typename GetRegionalValues>
static T find_regional_values_for_locale(StringView locale, GetRegionalValues&& get_regional_values)
{
auto has_value = [](auto const& container) {
if constexpr (requires { container.has_value(); })
return container.has_value();
else
return !container.is_empty();
};
if (auto regional_values = get_regional_values(locale); has_value(regional_values))
return regional_values;
auto return_default_values = [&]() { return get_regional_values("001"sv); };
auto language = parse_unicode_language_id(locale);
if (!language.has_value())
return return_default_values();
if (!language->region.has_value())
language = add_likely_subtags(*language);
if (!language.has_value() || !language->region.has_value())
return return_default_values();
if (auto regional_values = get_regional_values(*language->region); has_value(regional_values))
return regional_values;
return return_default_values();
}
// https://unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table
Vector<HourCycle> get_locale_hour_cycles(StringView locale)
{
return find_regional_values_for_locale<Vector<HourCycle>>(locale, get_regional_hour_cycles);
}
Optional<HourCycle> get_default_regional_hour_cycle(StringView locale)
{
if (auto hour_cycles = get_locale_hour_cycles(locale); !hour_cycles.is_empty())
return hour_cycles.first();
return {};
}
Optional<MinimumDaysRegion> __attribute__((weak)) minimum_days_region_from_string(StringView) { return {}; }
Optional<u8> __attribute__((weak)) get_regional_minimum_days(StringView) { return {}; }
Optional<u8> get_locale_minimum_days(StringView locale)
{
return find_regional_values_for_locale<Optional<u8>>(locale, get_regional_minimum_days);
}
Optional<FirstDayRegion> __attribute__((weak)) first_day_region_from_string(StringView) { return {}; }
Optional<Weekday> __attribute__((weak)) get_regional_first_day(StringView) { return {}; }
Optional<Weekday> get_locale_first_day(StringView locale)
{
return find_regional_values_for_locale<Optional<Weekday>>(locale, get_regional_first_day);
}
Optional<WeekendStartRegion> __attribute__((weak)) weekend_start_region_from_string(StringView) { return {}; }
Optional<Weekday> __attribute__((weak)) get_regional_weekend_start(StringView) { return {}; }
Optional<Weekday> get_locale_weekend_start(StringView locale)
{
return find_regional_values_for_locale<Optional<Weekday>>(locale, get_regional_weekend_start);
}
Optional<WeekendEndRegion> __attribute__((weak)) weekend_end_region_from_string(StringView) { return {}; }
Optional<Weekday> __attribute__((weak)) get_regional_weekend_end(StringView) { return {}; }
Optional<Weekday> get_locale_weekend_end(StringView locale)
{
return find_regional_values_for_locale<Optional<Weekday>>(locale, get_regional_weekend_end);
}
String combine_skeletons(StringView first, StringView second)
{
// https://unicode.org/reports/tr35/tr35-dates.html#availableFormats_appendItems
constexpr auto field_order = Array {
"G"sv, // Era
"yYuUr"sv, // Year
"ML"sv, // Month
"dDFg"sv, // Day
"Eec"sv, // Weekday
"abB"sv, // Period
"hHKk"sv, // Hour
"m"sv, // Minute
"sSA"sv, // Second
"zZOvVXx"sv, // Zone
};
StringBuilder builder;
auto append_from_skeleton = [&](auto skeleton, auto ch) {
auto first_index = skeleton.find(ch);
if (!first_index.has_value())
return false;
auto last_index = skeleton.find_last(ch);
builder.append(skeleton.substring_view(*first_index, *last_index - *first_index + 1));
return true;
};
for (auto fields : field_order) {
for (auto ch : fields) {
if (append_from_skeleton(first, ch))
break;
if (append_from_skeleton(second, ch))
break;
}
}
return MUST(builder.to_string());
}
Optional<CalendarFormat> __attribute__((weak)) get_calendar_date_format(StringView, StringView) { return {}; }
Optional<CalendarFormat> __attribute__((weak)) get_calendar_time_format(StringView, StringView) { return {}; }
Optional<CalendarFormat> __attribute__((weak)) get_calendar_date_time_format(StringView, StringView) { return {}; }
Optional<CalendarFormat> get_calendar_format(StringView locale, StringView calendar, CalendarFormatType type)
{
switch (type) {
case CalendarFormatType::Date:
return get_calendar_date_format(locale, calendar);
case CalendarFormatType::Time:
return get_calendar_time_format(locale, calendar);
case CalendarFormatType::DateTime:
return get_calendar_date_time_format(locale, calendar);
default:
VERIFY_NOT_REACHED();
}
}
Vector<CalendarPattern> __attribute__((weak)) get_calendar_available_formats(StringView, StringView) { return {}; }
Optional<CalendarRangePattern> __attribute__((weak)) get_calendar_default_range_format(StringView, StringView) { return {}; }
Vector<CalendarRangePattern> __attribute__((weak)) get_calendar_range_formats(StringView, StringView, StringView) { return {}; }
Vector<CalendarRangePattern> __attribute__((weak)) get_calendar_range12_formats(StringView, StringView, StringView) { return {}; }
Optional<StringView> __attribute__((weak)) get_calendar_era_symbol(StringView, StringView, CalendarPatternStyle, Era) { return {}; }
Optional<StringView> __attribute__((weak)) get_calendar_month_symbol(StringView, StringView, CalendarPatternStyle, Month) { return {}; }
Optional<StringView> __attribute__((weak)) get_calendar_weekday_symbol(StringView, StringView, CalendarPatternStyle, Weekday) { return {}; }
Optional<StringView> __attribute__((weak)) get_calendar_day_period_symbol(StringView, StringView, CalendarPatternStyle, DayPeriod) { return {}; }
Optional<StringView> __attribute__((weak)) get_calendar_day_period_symbol_for_hour(StringView, StringView, CalendarPatternStyle, u8) { return {}; }
Optional<StringView> __attribute__((weak)) get_time_zone_name(StringView, StringView, CalendarPatternStyle, TimeZone::InDST) { return {}; }
Optional<TimeZoneFormat> __attribute__((weak)) get_time_zone_format(StringView) { return {}; }
static Optional<String> format_time_zone_offset(StringView locale, CalendarPatternStyle style, i64 offset_seconds)
{
auto formats = get_time_zone_format(locale);
if (!formats.has_value())
return {};
auto number_system = get_preferred_keyword_value_for_locale(locale, "nu"sv);
if (!number_system.has_value())
return {};
if (offset_seconds == 0)
return MUST(String::from_utf8(formats->gmt_zero_format));
auto sign = offset_seconds > 0 ? formats->symbol_ahead_sign : formats->symbol_behind_sign;
auto separator = offset_seconds > 0 ? formats->symbol_ahead_separator : formats->symbol_behind_separator;
offset_seconds = llabs(offset_seconds);
auto offset_hours = offset_seconds / 3'600;
offset_seconds %= 3'600;
auto offset_minutes = offset_seconds / 60;
offset_seconds %= 60;
StringBuilder builder;
builder.append(sign);
switch (style) {
// The long format always uses 2-digit hours field and minutes field, with optional 2-digit seconds field.
case CalendarPatternStyle::LongOffset:
builder.appendff("{:02}{}{:02}", offset_hours, separator, offset_minutes);
if (offset_seconds > 0)
builder.appendff("{}{:02}", separator, offset_seconds);
break;
// The short format is intended for the shortest representation and uses hour fields without leading zero, with optional 2-digit minutes and seconds fields.
case CalendarPatternStyle::ShortOffset:
builder.appendff("{}", offset_hours);
if (offset_minutes > 0) {
builder.appendff("{}{:02}", separator, offset_minutes);
if (offset_seconds > 0)
builder.appendff("{}{:02}", separator, offset_seconds);
}
break;
default:
VERIFY_NOT_REACHED();
}
// The digits used for hours, minutes and seconds fields in this format are the locale's default decimal digits.
auto result = replace_digits_for_number_system(*number_system, builder.string_view());
return MUST(MUST(String::from_utf8(formats->gmt_format)).replace("{0}"sv, result, ReplaceMode::FirstOnly));
}
// https://unicode.org/reports/tr35/tr35-dates.html#Time_Zone_Format_Terminology
String format_time_zone(StringView locale, StringView time_zone, CalendarPatternStyle style, AK::UnixDateTime time)
{
auto offset = TimeZone::get_time_zone_offset(time_zone, time);
if (!offset.has_value())
return MUST(String::from_utf8(time_zone));
switch (style) {
case CalendarPatternStyle::Short:
case CalendarPatternStyle::Long:
case CalendarPatternStyle::ShortGeneric:
case CalendarPatternStyle::LongGeneric:
if (auto name = get_time_zone_name(locale, time_zone, style, offset->in_dst); name.has_value())
return MUST(String::from_utf8(*name));
break;
case CalendarPatternStyle::ShortOffset:
case CalendarPatternStyle::LongOffset:
if (auto formatted_offset = format_time_zone_offset(locale, style, offset->seconds); formatted_offset.has_value())
return formatted_offset.release_value();
return MUST(String::from_utf8(time_zone));
default:
VERIFY_NOT_REACHED();
}
// If more styles are added, consult the following table to ensure always falling back to GMT offset is still correct:
// https://unicode.org/reports/tr35/tr35-dates.html#dfst-zone
switch (style) {
case CalendarPatternStyle::Short:
case CalendarPatternStyle::ShortGeneric:
return format_time_zone(locale, time_zone, CalendarPatternStyle::ShortOffset, time);
case CalendarPatternStyle::Long:
case CalendarPatternStyle::LongGeneric:
return format_time_zone(locale, time_zone, CalendarPatternStyle::LongOffset, time);
default:
VERIFY_NOT_REACHED();
}
}
}