ladybird/Libraries/LibUnicode/Locale.cpp

741 lines
22 KiB
C++

/*
* Copyright (c) 2021-2024, Tim Flynn <trflynn89@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/AllOf.h>
#include <AK/GenericLexer.h>
#include <AK/HashTable.h>
#include <AK/QuickSort.h>
#include <AK/StringBuilder.h>
#include <LibUnicode/ICU.h>
#include <LibUnicode/Locale.h>
#include <unicode/localebuilder.h>
#include <unicode/locid.h>
namespace Unicode {
static bool is_key(StringView key)
{
// key = alphanum alpha
if (key.length() != 2)
return false;
return is_ascii_alphanumeric(key[0]) && is_ascii_alpha(key[1]);
}
static bool is_single_type(StringView type)
{
// type = alphanum{3,8} (sep alphanum{3,8})*
// Note: Consecutive types are not handled here, that is left to the caller.
if ((type.length() < 3) || (type.length() > 8))
return false;
return all_of(type, is_ascii_alphanumeric);
}
static bool is_attribute(StringView type)
{
// attribute = alphanum{3,8}
if ((type.length() < 3) || (type.length() > 8))
return false;
return all_of(type, is_ascii_alphanumeric);
}
static bool is_transformed_key(StringView key)
{
// tkey = alpha digit
if (key.length() != 2)
return false;
return is_ascii_alpha(key[0]) && is_ascii_digit(key[1]);
}
static bool is_single_transformed_value(StringView value)
{
// tvalue = (sep alphanum{3,8})+
// Note: Consecutive values are not handled here, that is left to the caller.
if ((value.length() < 3) || (value.length() > 8))
return false;
return all_of(value, is_ascii_alphanumeric);
}
static Optional<StringView> consume_next_segment(GenericLexer& lexer, bool with_separator = true)
{
constexpr auto is_separator = is_any_of("-_"sv);
if (with_separator) {
if (!lexer.next_is(is_separator))
return {};
lexer.ignore();
}
auto segment = lexer.consume_until(is_separator);
if (segment.is_empty()) {
lexer.retreat(with_separator);
return {};
}
return segment;
}
bool is_type_identifier(StringView identifier)
{
// type = alphanum{3,8} (sep alphanum{3,8})*
GenericLexer lexer { identifier };
while (true) {
auto type = consume_next_segment(lexer, lexer.tell() > 0);
if (!type.has_value())
break;
if (!is_single_type(*type))
return false;
}
return lexer.is_eof() && (lexer.tell() > 0);
}
static Optional<LanguageID> parse_unicode_language_id(GenericLexer& lexer)
{
// https://unicode.org/reports/tr35/#Unicode_language_identifier
//
// unicode_language_id = "root"
// OR
// unicode_language_id = ((unicode_language_subtag (sep unicode_script_subtag)?) | unicode_script_subtag)
// (sep unicode_region_subtag)?
// (sep unicode_variant_subtag)*
LanguageID language_id {};
if (lexer.consume_specific("root"sv)) {
language_id.is_root = true;
return language_id;
}
enum class ParseState {
ParsingLanguageOrScript,
ParsingScript,
ParsingRegion,
ParsingVariant,
Done,
};
auto state = ParseState::ParsingLanguageOrScript;
while (!lexer.is_eof() && (state != ParseState::Done)) {
auto segment = consume_next_segment(lexer, state != ParseState::ParsingLanguageOrScript);
if (!segment.has_value())
return {};
switch (state) {
case ParseState::ParsingLanguageOrScript:
if (is_unicode_language_subtag(*segment)) {
state = ParseState::ParsingScript;
language_id.language = MUST(String::from_utf8(*segment));
} else if (is_unicode_script_subtag(*segment)) {
state = ParseState::ParsingRegion;
language_id.script = MUST(String::from_utf8(*segment));
} else {
return {};
}
break;
case ParseState::ParsingScript:
if (is_unicode_script_subtag(*segment)) {
state = ParseState::ParsingRegion;
language_id.script = MUST(String::from_utf8(*segment));
break;
}
state = ParseState::ParsingRegion;
[[fallthrough]];
case ParseState::ParsingRegion:
if (is_unicode_region_subtag(*segment)) {
state = ParseState::ParsingVariant;
language_id.region = MUST(String::from_utf8(*segment));
break;
}
state = ParseState::ParsingVariant;
[[fallthrough]];
case ParseState::ParsingVariant:
if (is_unicode_variant_subtag(*segment)) {
language_id.variants.append(MUST(String::from_utf8(*segment)));
} else {
lexer.retreat(segment->length() + 1);
state = ParseState::Done;
}
break;
default:
VERIFY_NOT_REACHED();
}
}
return language_id;
}
static Optional<LocaleExtension> parse_unicode_locale_extension(GenericLexer& lexer)
{
// https://unicode.org/reports/tr35/#unicode_locale_extensions
//
// unicode_locale_extensions = sep [uU] ((sep keyword)+ | (sep attribute)+ (sep keyword)*)
LocaleExtension locale_extension {};
enum class ParseState {
ParsingAttributeOrKeyword,
ParsingAttribute,
ParsingKeyword,
Done,
};
auto state = ParseState::ParsingAttributeOrKeyword;
while (!lexer.is_eof() && (state != ParseState::Done)) {
auto segment = consume_next_segment(lexer);
if (!segment.has_value())
return {};
if (state == ParseState::ParsingAttributeOrKeyword)
state = is_key(*segment) ? ParseState::ParsingKeyword : ParseState::ParsingAttribute;
switch (state) {
case ParseState::ParsingAttribute:
if (is_attribute(*segment)) {
locale_extension.attributes.append(MUST(String::from_utf8(*segment)));
break;
}
state = ParseState::ParsingKeyword;
[[fallthrough]];
case ParseState::ParsingKeyword: {
// keyword = key (sep type)?
Keyword keyword { .key = MUST(String::from_utf8(*segment)) };
Vector<StringView> keyword_values;
if (!is_key(*segment)) {
lexer.retreat(segment->length() + 1);
state = ParseState::Done;
break;
}
while (true) {
auto type = consume_next_segment(lexer);
if (!type.has_value() || !is_single_type(*type)) {
if (type.has_value())
lexer.retreat(type->length() + 1);
break;
}
keyword_values.append(*type);
}
StringBuilder builder;
builder.join('-', keyword_values);
keyword.value = MUST(builder.to_string());
locale_extension.keywords.append(move(keyword));
break;
}
default:
VERIFY_NOT_REACHED();
}
}
if (locale_extension.attributes.is_empty() && locale_extension.keywords.is_empty())
return {};
return locale_extension;
}
static Optional<TransformedExtension> parse_transformed_extension(GenericLexer& lexer)
{
// https://unicode.org/reports/tr35/#transformed_extensions
//
// transformed_extensions = sep [tT] ((sep tlang (sep tfield)*) | (sep tfield)+)
TransformedExtension transformed_extension {};
enum class ParseState {
ParsingLanguageOrField,
ParsingLanguage,
ParsingField,
Done,
};
auto state = ParseState::ParsingLanguageOrField;
while (!lexer.is_eof() && (state != ParseState::Done)) {
auto segment = consume_next_segment(lexer);
if (!segment.has_value())
return {};
if (state == ParseState::ParsingLanguageOrField)
state = is_unicode_language_subtag(*segment) ? ParseState::ParsingLanguage : ParseState::ParsingField;
switch (state) {
case ParseState::ParsingLanguage:
lexer.retreat(segment->length());
if (auto language_id = parse_unicode_language_id(lexer); language_id.has_value()) {
transformed_extension.language = language_id.release_value();
state = ParseState::ParsingField;
break;
}
return {};
case ParseState::ParsingField: {
// tfield = tkey tvalue;
TransformedField field { .key = MUST(String::from_utf8(*segment)) };
Vector<StringView> field_values;
if (!is_transformed_key(*segment)) {
lexer.retreat(segment->length() + 1);
state = ParseState::Done;
break;
}
while (true) {
auto value = consume_next_segment(lexer);
if (!value.has_value() || !is_single_transformed_value(*value)) {
if (value.has_value())
lexer.retreat(value->length() + 1);
break;
}
field_values.append(*value);
}
if (field_values.is_empty())
return {};
StringBuilder builder;
builder.join('-', field_values);
field.value = MUST(builder.to_string());
transformed_extension.fields.append(move(field));
break;
}
default:
VERIFY_NOT_REACHED();
}
}
if (!transformed_extension.language.has_value() && transformed_extension.fields.is_empty())
return {};
return transformed_extension;
}
static Optional<OtherExtension> parse_other_extension(char key, GenericLexer& lexer)
{
// https://unicode.org/reports/tr35/#other_extensions
//
// other_extensions = sep [alphanum-[tTuUxX]] (sep alphanum{2,8})+ ;
OtherExtension other_extension { .key = key };
Vector<StringView> other_values;
if (!is_ascii_alphanumeric(key) || (key == 'x') || (key == 'X'))
return {};
while (true) {
auto segment = consume_next_segment(lexer);
if (!segment.has_value())
break;
if ((segment->length() < 2) || (segment->length() > 8) || !all_of(*segment, is_ascii_alphanumeric)) {
lexer.retreat(segment->length() + 1);
break;
}
other_values.append(*segment);
}
if (other_values.is_empty())
return {};
StringBuilder builder;
builder.join('-', other_values);
other_extension.value = MUST(builder.to_string());
return other_extension;
}
static Optional<Extension> parse_extension(GenericLexer& lexer)
{
// https://unicode.org/reports/tr35/#extensions
//
// extensions = unicode_locale_extensions | transformed_extensions | other_extensions
size_t starting_position = lexer.tell();
if (auto header = consume_next_segment(lexer); header.has_value() && (header->length() == 1)) {
switch (char key = (*header)[0]) {
case 'u':
case 'U':
if (auto extension = parse_unicode_locale_extension(lexer); extension.has_value())
return Extension { extension.release_value() };
break;
case 't':
case 'T':
if (auto extension = parse_transformed_extension(lexer); extension.has_value())
return Extension { extension.release_value() };
break;
default:
if (auto extension = parse_other_extension(key, lexer); extension.has_value())
return Extension { extension.release_value() };
break;
}
}
lexer.retreat(lexer.tell() - starting_position);
return {};
}
static Vector<String> parse_private_use_extensions(GenericLexer& lexer)
{
// https://unicode.org/reports/tr35/#pu_extensions
//
// pu_extensions = = sep [xX] (sep alphanum{1,8})+ ;
size_t starting_position = lexer.tell();
auto header = consume_next_segment(lexer);
if (!header.has_value())
return {};
auto parse_values = [&]() {
Vector<String> extensions;
while (true) {
auto segment = consume_next_segment(lexer);
if (!segment.has_value())
break;
if ((segment->length() < 1) || (segment->length() > 8) || !all_of(*segment, is_ascii_alphanumeric)) {
lexer.retreat(segment->length() + 1);
break;
}
extensions.append(MUST(String::from_utf8(*segment)));
}
return extensions;
};
if ((header->length() == 1) && (((*header)[0] == 'x') || ((*header)[0] == 'X'))) {
if (auto extensions = parse_values(); !extensions.is_empty())
return extensions;
}
lexer.retreat(lexer.tell() - starting_position);
return {};
}
Optional<LanguageID> parse_unicode_language_id(StringView language)
{
GenericLexer lexer { language };
auto language_id = parse_unicode_language_id(lexer);
if (!lexer.is_eof())
return {};
return language_id;
}
Optional<LocaleID> parse_unicode_locale_id(StringView locale)
{
GenericLexer lexer { locale };
// https://unicode.org/reports/tr35/#Unicode_locale_identifier
//
// unicode_locale_id = unicode_language_id
// extensions*
// pu_extensions?
auto language_id = parse_unicode_language_id(lexer);
if (!language_id.has_value())
return {};
LocaleID locale_id { language_id.release_value() };
while (true) {
auto extension = parse_extension(lexer);
if (!extension.has_value())
break;
locale_id.extensions.append(extension.release_value());
}
locale_id.private_use_extensions = parse_private_use_extensions(lexer);
if (!lexer.is_eof())
return {};
return locale_id;
}
String canonicalize_unicode_locale_id(StringView locale)
{
UErrorCode status = U_ZERO_ERROR;
auto locale_data = LocaleData::for_locale(locale);
VERIFY(locale_data.has_value());
locale_data->locale().canonicalize(status);
VERIFY(icu_success(status));
return locale_data->to_string();
}
String canonicalize_unicode_extension_values(StringView key, StringView value)
{
UErrorCode status = U_ZERO_ERROR;
icu::LocaleBuilder builder;
builder.setUnicodeLocaleKeyword(icu_string_piece(key), icu_string_piece(value));
auto locale = builder.build(status);
VERIFY(icu_success(status));
locale.canonicalize(status);
VERIFY(icu_success(status));
auto result = locale.getUnicodeKeywordValue<StringBuilder>(icu_string_piece(key), status);
VERIFY(icu_success(status));
return MUST(result.to_string());
}
StringView default_locale()
{
return "en"sv;
}
static void define_locales_without_scripts(HashTable<String>& locales)
{
// https://tc39.es/ecma402/#sec-internal-slots
// For locales that include a script subtag in addition to language and region, the corresponding locale without a
// script subtag must also be supported.
HashTable<String> new_locales;
auto append_locale_without_script = [&](auto const& locale) {
auto parsed_locale = parse_unicode_language_id(locale);
if (!parsed_locale.has_value())
return;
if (!parsed_locale->language.has_value() || !parsed_locale->script.has_value() || !parsed_locale->region.has_value())
return;
auto locale_without_script = MUST(String::formatted("{}-{}", *parsed_locale->language, *parsed_locale->region));
new_locales.set(move(locale_without_script));
};
for (auto const& locale : locales)
append_locale_without_script(locale);
for (auto const& new_locale : new_locales)
locales.set(new_locale);
}
bool is_locale_available(StringView locale)
{
static auto available_locales = []() {
i32 count = 0;
auto const* locale_list = icu::Locale::getAvailableLocales(count);
HashTable<String> available_locales;
available_locales.ensure_capacity(static_cast<size_t>(count));
for (i32 i = 0; i < count; ++i) {
UErrorCode status = U_ZERO_ERROR;
auto locale_name = locale_list[i].toLanguageTag<StringBuilder>(status);
if (icu_failure(status))
continue;
available_locales.set(MUST(locale_name.to_string()));
}
define_locales_without_scripts(available_locales);
return available_locales;
}();
return available_locales.contains(locale);
}
Style style_from_string(StringView style)
{
if (style == "narrow"sv)
return Style::Narrow;
if (style == "short"sv)
return Style::Short;
if (style == "long"sv)
return Style::Long;
VERIFY_NOT_REACHED();
}
StringView style_to_string(Style style)
{
switch (style) {
case Style::Narrow:
return "narrow"sv;
case Style::Short:
return "short"sv;
case Style::Long:
return "long"sv;
default:
VERIFY_NOT_REACHED();
}
}
static void apply_extensions_to_locale(icu::Locale& locale, icu::Locale const& locale_with_extensions)
{
UErrorCode status = U_ZERO_ERROR;
icu::LocaleBuilder builder;
builder.setLocale(locale_with_extensions);
builder.setLanguage(locale.getLanguage());
builder.setRegion(locale.getCountry());
builder.setScript(locale.getScript());
builder.setVariant(locale.getVariant());
locale = builder.build(status);
VERIFY(icu_success(status));
}
Optional<String> add_likely_subtags(StringView locale)
{
UErrorCode status = U_ZERO_ERROR;
auto locale_data = LocaleData::for_locale(locale);
if (!locale_data.has_value())
return {};
// ICU doesn't seem to handle maximizing locales that have keywords. For example, "und-x-private" should become
// "en-Latn-US-x-private" (in the same manner that "und" becomes "en-Latn-US"). So here, we maximize the locale
// without keywords, then add them back if needed.
auto maximized = icu::Locale::createFromName(locale_data->locale().getBaseName());
maximized.addLikelySubtags(status);
if (icu_failure(status))
return {};
if (strlen(locale_data->locale().getName()) != strlen(locale_data->locale().getBaseName()))
apply_extensions_to_locale(maximized, locale_data->locale());
auto result = maximized.toLanguageTag<StringBuilder>(status);
if (icu_failure(status))
return {};
return MUST(result.to_string());
}
Optional<String> remove_likely_subtags(StringView locale)
{
UErrorCode status = U_ZERO_ERROR;
auto locale_data = LocaleData::for_locale(locale);
if (!locale_data.has_value())
return {};
// ICU doesn't seem to handle minimizing locales that have keywords. For example, "und-x-private" should become
// "en-x-private" (in the same manner that "und" becomes "en"). So here, we minimize the locale without keywords,
// then add them back if needed.
auto minimized = icu::Locale::createFromName(locale_data->locale().getBaseName());
minimized.minimizeSubtags(status);
if (icu_failure(status))
return {};
if (strlen(locale_data->locale().getName()) != strlen(locale_data->locale().getBaseName()))
apply_extensions_to_locale(minimized, locale_data->locale());
auto result = minimized.toLanguageTag<StringBuilder>(status);
if (icu_failure(status))
return {};
return MUST(result.to_string());
}
bool is_locale_character_ordering_right_to_left(StringView locale)
{
auto locale_data = LocaleData::for_locale(locale);
if (!locale_data.has_value())
return false; // Default to left-to-right
return static_cast<bool>(locale_data->locale().isRightToLeft());
}
String LanguageID::to_string() const
{
StringBuilder builder;
auto append_segment = [&](Optional<String> const& segment) {
if (!segment.has_value())
return;
if (!builder.is_empty())
builder.append('-');
builder.append(*segment);
};
append_segment(language);
append_segment(script);
append_segment(region);
for (auto const& variant : variants)
append_segment(variant);
return MUST(builder.to_string());
}
String LocaleID::to_string() const
{
StringBuilder builder;
auto append_segment = [&](auto const& segment) {
if (segment.is_empty())
return;
if (!builder.is_empty())
builder.append('-');
builder.append(segment);
};
append_segment(language_id.to_string());
for (auto const& extension : extensions) {
extension.visit(
[&](LocaleExtension const& ext) {
builder.append("-u"sv);
for (auto const& attribute : ext.attributes)
append_segment(attribute);
for (auto const& keyword : ext.keywords) {
append_segment(keyword.key);
append_segment(keyword.value);
}
},
[&](TransformedExtension const& ext) {
builder.append("-t"sv);
if (ext.language.has_value())
append_segment(ext.language->to_string());
for (auto const& field : ext.fields) {
append_segment(field.key);
append_segment(field.value);
}
},
[&](OtherExtension const& ext) {
builder.appendff("-{}", ext.key);
append_segment(ext.value);
});
}
if (!private_use_extensions.is_empty()) {
builder.append("-x"sv);
for (auto const& extension : private_use_extensions)
append_segment(extension);
}
return MUST(builder.to_string());
}
}