C++ ExecState::jsCallee方法代码示例

EncodedJSValue JSC_HOST_CALL constructJSWorker(ExecState& state)
{
    VM& vm = state.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    ASSERT(jsCast<DOMConstructorObject*>(state.jsCallee()));
    ASSERT(jsCast<DOMConstructorObject*>(state.jsCallee())->globalObject());
    auto& globalObject = *jsCast<DOMConstructorObject*>(state.jsCallee())->globalObject();

    if (!state.argumentCount())
        return throwVMError(&state, scope, createNotEnoughArgumentsError(&state));

    String scriptURL = state.uncheckedArgument(0).toWTFString(&state);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    // See section 4.8.2 step 14 of WebWorkers for why this is the lexicalGlobalObject.
    auto& window = asJSDOMWindow(state.lexicalGlobalObject())->wrapped();

    ASSERT(window.document());
    return JSValue::encode(toJSNewlyCreated(state, globalObject, scope, Worker::create(*window.document(), scriptURL, globalObject.runtimeFlags())));
}

EncodedJSValue JSC_HOST_CALL constructJSMutationObserver(ExecState& exec)
{
    VM& vm = exec.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    if (exec.argumentCount() < 1)
        return throwVMError(&exec, scope, createNotEnoughArgumentsError(&exec));

    JSObject* object = exec.uncheckedArgument(0).getObject();
    CallData callData;
    if (!object || object->methodTable()->getCallData(object, callData) == CallType::None)
        return throwArgumentTypeError(exec, scope, 0, "callback", "MutationObserver", nullptr, "MutationCallback");

    DOMConstructorObject* jsConstructor = jsCast<DOMConstructorObject*>(exec.jsCallee());
    auto callback = JSMutationCallback::create(object, jsConstructor->globalObject());
    JSObject* jsObserver = asObject(toJSNewlyCreated(&exec, jsConstructor->globalObject(), MutationObserver::create(WTFMove(callback))));
    PrivateName propertyName;
    jsObserver->putDirect(vm, propertyName, object);
    return JSValue::encode(jsObserver);
}

JSValue IntlNumberFormat::formatToParts(ExecState& exec, double value)
{
    VM& vm = exec.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    // FormatNumberToParts (ECMA-402)
    // https://tc39.github.io/ecma402/#sec-formatnumbertoparts
    // https://tc39.github.io/ecma402/#sec-partitionnumberpattern

    if (!m_initializedNumberFormat)
        return throwTypeError(&exec, scope, "Intl.NumberFormat.prototype.formatToParts called on value that's not an object initialized as a NumberFormat"_s);

    UErrorCode status = U_ZERO_ERROR;
    auto fieldItr = std::unique_ptr<UFieldPositionIterator, UFieldPositionIteratorDeleter>(ufieldpositer_open(&status));
    if (U_FAILURE(status))
        return throwTypeError(&exec, scope, "failed to open field position iterator"_s);

    status = U_ZERO_ERROR;
    Vector<UChar, 32> result(32);
    auto resultLength = unum_formatDoubleForFields(m_numberFormat.get(), value, result.data(), result.size(), fieldItr.get(), &status);
    if (status == U_BUFFER_OVERFLOW_ERROR) {
        status = U_ZERO_ERROR;
        result.grow(resultLength);
        unum_formatDoubleForFields(m_numberFormat.get(), value, result.data(), resultLength, fieldItr.get(), &status);
    }
    if (U_FAILURE(status))
        return throwTypeError(&exec, scope, "failed to format a number."_s);

    int32_t literalFieldType = -1;
    auto literalField = IntlNumberFormatField(literalFieldType, resultLength);
    Vector<IntlNumberFormatField> fields(resultLength, literalField);
    int32_t beginIndex = 0;
    int32_t endIndex = 0;
    auto fieldType = ufieldpositer_next(fieldItr.get(), &beginIndex, &endIndex);
    while (fieldType >= 0) {
        auto size = endIndex - beginIndex;
        for (auto i = beginIndex; i < endIndex; ++i) {
            // Only override previous value if new value is more specific.
            if (fields[i].size >= size)
                fields[i] = IntlNumberFormatField(fieldType, size);
        }
        fieldType = ufieldpositer_next(fieldItr.get(), &beginIndex, &endIndex);
    }

    JSGlobalObject* globalObject = exec.jsCallee()->globalObject(vm);
    JSArray* parts = JSArray::tryCreate(vm, globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithContiguous), 0);
    if (!parts)
        return throwOutOfMemoryError(&exec, scope);
    unsigned index = 0;

    auto resultString = String(result.data(), resultLength);
    auto typePropertyName = Identifier::fromString(&vm, "type");
    auto literalString = jsString(&exec, "literal"_s);

    int32_t currentIndex = 0;
    while (currentIndex < resultLength) {
        auto startIndex = currentIndex;
        auto fieldType = fields[currentIndex].type;
        while (currentIndex < resultLength && fields[currentIndex].type == fieldType)
            ++currentIndex;
        auto partType = fieldType == literalFieldType ? literalString : jsString(&exec, partTypeString(UNumberFormatFields(fieldType), value));
        auto partValue = jsSubstring(&vm, resultString, startIndex, currentIndex - startIndex);
        JSObject* part = constructEmptyObject(&exec);
        part->putDirect(vm, typePropertyName, partType);
        part->putDirect(vm, vm.propertyNames->value, partValue);
        parts->putDirectIndex(&exec, index++, part);
        RETURN_IF_EXCEPTION(scope, { });
    }

    return parts;
}

void IntlNumberFormat::initializeNumberFormat(ExecState& state, JSValue locales, JSValue optionsValue)
{
    VM& vm = state.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    // 11.1.2 InitializeNumberFormat (numberFormat, locales, options) (ECMA-402)
    // https://tc39.github.io/ecma402/#sec-initializenumberformat

    auto requestedLocales = canonicalizeLocaleList(state, locales);
    RETURN_IF_EXCEPTION(scope, void());

    JSObject* options;
    if (optionsValue.isUndefined())
        options = constructEmptyObject(&state, state.lexicalGlobalObject()->nullPrototypeObjectStructure());
    else {
        options = optionsValue.toObject(&state);
        RETURN_IF_EXCEPTION(scope, void());
    }

    HashMap<String, String> opt;

    String matcher = intlStringOption(state, options, vm.propertyNames->localeMatcher, { "lookup", "best fit" }, "localeMatcher must be either \"lookup\" or \"best fit\"", "best fit");
    RETURN_IF_EXCEPTION(scope, void());
    opt.add("localeMatcher"_s, matcher);

    auto& availableLocales = state.jsCallee()->globalObject(vm)->intlNumberFormatAvailableLocales();
    auto result = resolveLocale(state, availableLocales, requestedLocales, opt, relevantNumberExtensionKeys, WTF_ARRAY_LENGTH(relevantNumberExtensionKeys), IntlNFInternal::localeData);

    m_locale = result.get("locale"_s);
    if (m_locale.isEmpty()) {
        throwTypeError(&state, scope, "failed to initialize NumberFormat due to invalid locale"_s);
        return;
    }

    m_numberingSystem = result.get("nu"_s);

    String styleString = intlStringOption(state, options, Identifier::fromString(&vm, "style"), { "decimal", "percent", "currency" }, "style must be either \"decimal\", \"percent\", or \"currency\"", "decimal");
    RETURN_IF_EXCEPTION(scope, void());
    if (styleString == "decimal")
        m_style = Style::Decimal;
    else if (styleString == "percent")
        m_style = Style::Percent;
    else if (styleString == "currency")
        m_style = Style::Currency;
    else
        ASSERT_NOT_REACHED();

    String currency = intlStringOption(state, options, Identifier::fromString(&vm, "currency"), { }, nullptr, nullptr);
    RETURN_IF_EXCEPTION(scope, void());
    if (!currency.isNull()) {
        if (currency.length() != 3 || !currency.isAllSpecialCharacters<isASCIIAlpha>()) {
            throwException(&state, scope, createRangeError(&state, "currency is not a well-formed currency code"_s));
            return;
        }
    }

    unsigned currencyDigits = 0;
    if (m_style == Style::Currency) {
        if (currency.isNull()) {
            throwTypeError(&state, scope, "currency must be a string"_s);
            return;
        }

        currency = currency.convertToASCIIUppercase();
        m_currency = currency;
        currencyDigits = computeCurrencyDigits(currency);
    }

    String currencyDisplayString = intlStringOption(state, options, Identifier::fromString(&vm, "currencyDisplay"), { "code", "symbol", "name" }, "currencyDisplay must be either \"code\", \"symbol\", or \"name\"", "symbol");
    RETURN_IF_EXCEPTION(scope, void());
    if (m_style == Style::Currency) {
        if (currencyDisplayString == "code")
            m_currencyDisplay = CurrencyDisplay::Code;
        else if (currencyDisplayString == "symbol")
            m_currencyDisplay = CurrencyDisplay::Symbol;
        else if (currencyDisplayString == "name")
            m_currencyDisplay = CurrencyDisplay::Name;
        else
            ASSERT_NOT_REACHED();
    }

    unsigned minimumIntegerDigits = intlNumberOption(state, options, Identifier::fromString(&vm, "minimumIntegerDigits"), 1, 21, 1);
    RETURN_IF_EXCEPTION(scope, void());
    m_minimumIntegerDigits = minimumIntegerDigits;

    unsigned minimumFractionDigitsDefault = (m_style == Style::Currency) ? currencyDigits : 0;

    unsigned minimumFractionDigits = intlNumberOption(state, options, Identifier::fromString(&vm, "minimumFractionDigits"), 0, 20, minimumFractionDigitsDefault);
    RETURN_IF_EXCEPTION(scope, void());
    m_minimumFractionDigits = minimumFractionDigits;

    unsigned maximumFractionDigitsDefault;
    if (m_style == Style::Currency)
        maximumFractionDigitsDefault = std::max(minimumFractionDigits, currencyDigits);
    else if (m_style == Style::Percent)
        maximumFractionDigitsDefault = minimumFractionDigits;
    else
        maximumFractionDigitsDefault = std::max(minimumFractionDigits, 3u);

    unsigned maximumFractionDigits = intlNumberOption(state, options, Identifier::fromString(&vm, "maximumFractionDigits"), minimumFractionDigits, 20, maximumFractionDigitsDefault);
//.........这里部分代码省略.........

EncodedJSValue JSC_HOST_CALL constructJSHTMLElement(ExecState& exec)
{
    VM& vm = exec.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    auto* jsConstructor = jsCast<JSDOMConstructorBase*>(exec.jsCallee());
    ASSERT(jsConstructor);

    auto* context = jsConstructor->scriptExecutionContext();
    if (!context)
        return throwConstructorScriptExecutionContextUnavailableError(exec, scope, "HTMLElement");
    ASSERT(context->isDocument());

    JSValue newTargetValue = exec.thisValue();
    auto* newTarget = newTargetValue.getObject();
    auto* globalObject = jsCast<JSDOMGlobalObject*>(newTarget->globalObject(vm));
    JSValue htmlElementConstructorValue = JSHTMLElement::getConstructor(vm, globalObject);
    if (newTargetValue == htmlElementConstructorValue)
        return throwVMTypeError(&exec, scope, "new.target is not a valid custom element constructor"_s);

    auto& document = downcast<Document>(*context);

    auto* window = document.domWindow();
    if (!window)
        return throwVMTypeError(&exec, scope, "new.target is not a valid custom element constructor"_s);

    auto* registry = window->customElementRegistry();
    if (!registry)
        return throwVMTypeError(&exec, scope, "new.target is not a valid custom element constructor"_s);

    auto* elementInterface = registry->findInterface(newTarget);
    if (!elementInterface)
        return throwVMTypeError(&exec, scope, "new.target does not define a custom element"_s);

    if (!elementInterface->isUpgradingElement()) {
        Structure* baseStructure = getDOMStructure<JSHTMLElement>(vm, *globalObject);
        auto* newElementStructure = InternalFunction::createSubclassStructure(&exec, newTargetValue, baseStructure);
        RETURN_IF_EXCEPTION(scope, encodedJSValue());

        Ref<HTMLElement> element = HTMLElement::create(elementInterface->name(), document);
        element->setIsDefinedCustomElement(*elementInterface);
        auto* jsElement = JSHTMLElement::create(newElementStructure, globalObject, element.get());
        cacheWrapper(globalObject->world(), element.ptr(), jsElement);
        return JSValue::encode(jsElement);
    }

    Element* elementToUpgrade = elementInterface->lastElementInConstructionStack();
    if (!elementToUpgrade) {
        throwInvalidStateError(exec, scope, "Cannot instantiate a custom element inside its own constructor during upgrades"_s);
        return JSValue::encode(jsUndefined());
    }

    JSValue elementWrapperValue = toJS(&exec, jsConstructor->globalObject(), *elementToUpgrade);
    ASSERT(elementWrapperValue.isObject());

    JSValue newPrototype = newTarget->get(&exec, vm.propertyNames->prototype);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    JSObject* elementWrapperObject = asObject(elementWrapperValue);
    JSObject::setPrototype(elementWrapperObject, &exec, newPrototype, true /* shouldThrowIfCantSet */);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    elementInterface->didUpgradeLastElementInConstructionStack();

    return JSValue::encode(elementWrapperValue);
}

void IntlDateTimeFormat::initializeDateTimeFormat(ExecState& exec, JSValue locales, JSValue originalOptions)
{
    VM& vm = exec.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    // 12.1.1 InitializeDateTimeFormat (dateTimeFormat, locales, options) (ECMA-402 2.0)
    // 1. If dateTimeFormat.[[initializedIntlObject]] is true, throw a TypeError exception.
    // 2. Set dateTimeFormat.[[initializedIntlObject]] to true.

    // 3. Let requestedLocales be CanonicalizeLocaleList(locales).
    Vector<String> requestedLocales = canonicalizeLocaleList(exec, locales);
    // 4. ReturnIfAbrupt(requestedLocales),
    RETURN_IF_EXCEPTION(scope, void());

    // 5. Let options be ToDateTimeOptions(options, "any", "date").
    JSObject* options = toDateTimeOptionsAnyDate(exec, originalOptions);
    // 6. ReturnIfAbrupt(options).
    RETURN_IF_EXCEPTION(scope, void());

    // 7. Let opt be a new Record.
    HashMap<String, String> localeOpt;

    // 8. Let matcher be GetOption(options, "localeMatcher", "string", «"lookup", "best fit"», "best fit").
    String localeMatcher = intlStringOption(exec, options, vm.propertyNames->localeMatcher, { "lookup", "best fit" }, "localeMatcher must be either \"lookup\" or \"best fit\"", "best fit");
    // 9. ReturnIfAbrupt(matcher).
    RETURN_IF_EXCEPTION(scope, void());
    // 10. Set opt.[[localeMatcher]] to matcher.
    localeOpt.add(vm.propertyNames->localeMatcher.string(), localeMatcher);

    // 11. Let localeData be the value of %DateTimeFormat%.[[localeData]].
    // 12. Let r be ResolveLocale( %DateTimeFormat%.[[availableLocales]], requestedLocales, opt, %DateTimeFormat%.[[relevantExtensionKeys]], localeData).
    const HashSet<String> availableLocales = exec.jsCallee()->globalObject()->intlDateTimeFormatAvailableLocales();
    HashMap<String, String> resolved = resolveLocale(exec, availableLocales, requestedLocales, localeOpt, relevantExtensionKeys, WTF_ARRAY_LENGTH(relevantExtensionKeys), localeData);

    // 13. Set dateTimeFormat.[[locale]] to the value of r.[[locale]].
    m_locale = resolved.get(vm.propertyNames->locale.string());
    if (m_locale.isEmpty()) {
        throwTypeError(&exec, scope, ASCIILiteral("failed to initialize DateTimeFormat due to invalid locale"));
        return;
    }
    // 14. Set dateTimeFormat.[[calendar]] to the value of r.[[ca]].
    m_calendar = resolved.get(ASCIILiteral("ca"));
    // Switch to preferred aliases.
    if (m_calendar == "gregory")
        m_calendar = ASCIILiteral("gregorian");
    else if (m_calendar == "islamicc")
        m_calendar = ASCIILiteral("islamic-civil");
    else if (m_calendar == "ethioaa")
        m_calendar = ASCIILiteral("ethiopic-amete-alem");
    // 15. Set dateTimeFormat.[[numberingSystem]] to the value of r.[[nu]].
    m_numberingSystem = resolved.get(ASCIILiteral("nu"));
    // 16. Let dataLocale be the value of r.[[dataLocale]].
    String dataLocale = resolved.get(ASCIILiteral("dataLocale"));

    // 17. Let tz be Get(options, "timeZone").
    JSValue tzValue = options->get(&exec, vm.propertyNames->timeZone);
    // 18. ReturnIfAbrupt(tz).
    RETURN_IF_EXCEPTION(scope, void());

    // 19. If tz is not undefined, then
    String tz;
    if (!tzValue.isUndefined()) {
        // a. Let tz be ToString(tz).
        String originalTz = tzValue.toWTFString(&exec);
        // b. ReturnIfAbrupt(tz).
        RETURN_IF_EXCEPTION(scope, void());
        // c. If the result of IsValidTimeZoneName(tz) is false, then i. Throw a RangeError exception.
        // d. Let tz be CanonicalizeTimeZoneName(tz).
        tz = canonicalizeTimeZoneName(originalTz);
        if (tz.isNull()) {
            throwRangeError(&exec, scope, String::format("invalid time zone: %s", originalTz.utf8().data()));
            return;
        }
    } else {
        // 20. Else,
        // a. Let tz be DefaultTimeZone().
        tz = defaultTimeZone();
    }

    // 21. Set dateTimeFormat.[[timeZone]] to tz.
    m_timeZone = tz;

    // 22. Let opt be a new Record.
    // Rather than building a record, build the skeleton pattern.
    StringBuilder skeletonBuilder;

    // 23. For each row of Table 3, except the header row, do:
    // a. Let prop be the name given in the Property column of the row.
    // b. Let value be GetOption(options, prop, "string", «the strings given in the Values column of the row», undefined).
    // c. ReturnIfAbrupt(value).
    // d. Set opt.[[<prop>]] to value.
    auto narrowShortLong = { "narrow", "short", "long" };
    auto twoDigitNumeric = { "2-digit", "numeric" };
    auto twoDigitNumericNarrowShortLong = { "2-digit", "numeric", "narrow", "short", "long" };
    auto shortLong = { "short", "long" };

    String weekday = intlStringOption(exec, options, vm.propertyNames->weekday, narrowShortLong, "weekday must be \"narrow\", \"short\", or \"long\"", nullptr);
    RETURN_IF_EXCEPTION(scope, void());
    if (!weekday.isNull()) {
        if (weekday == "narrow")
//.........这里部分代码省略.........

void IntlPluralRules::initializePluralRules(ExecState& exec, JSValue locales, JSValue optionsValue)
{
    VM& vm = exec.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    // 13.1.1 InitializePluralRules (pluralRules, locales, options)
    // https://tc39.github.io/ecma402/#sec-initializepluralrules
    Vector<String> requestedLocales = canonicalizeLocaleList(exec, locales);
    RETURN_IF_EXCEPTION(scope, void());

    JSObject* options;
    if (optionsValue.isUndefined())
        options = constructEmptyObject(&exec, exec.lexicalGlobalObject()->nullPrototypeObjectStructure());
    else {
        options = optionsValue.toObject(&exec);
        RETURN_IF_EXCEPTION(scope, void());
    }

    HashMap<String, String> localeOpt;
    String localeMatcher = intlStringOption(exec, options, vm.propertyNames->localeMatcher, { "lookup", "best fit" }, "localeMatcher must be either \"lookup\" or \"best fit\"", "best fit");
    RETURN_IF_EXCEPTION(scope, void());
    localeOpt.add(vm.propertyNames->localeMatcher.string(), localeMatcher);

    const HashSet<String> availableLocales = exec.jsCallee()->globalObject(vm)->intlNumberFormatAvailableLocales();
    HashMap<String, String> resolved = resolveLocale(exec, availableLocales, requestedLocales, localeOpt, nullptr, 0, IntlPRInternal::localeData);
    m_locale = resolved.get(vm.propertyNames->locale.string());
    if (m_locale.isEmpty()) {
        throwTypeError(&exec, scope, "failed to initialize PluralRules due to invalid locale"_s);
        return;
    }

    String typeString = intlStringOption(exec, options, Identifier::fromString(&vm, "type"), { "cardinal", "ordinal" }, "type must be \"cardinal\" or \"ordinal\"", "cardinal");
    RETURN_IF_EXCEPTION(scope, void());
    m_type = typeString == "ordinal" ? UPLURAL_TYPE_ORDINAL : UPLURAL_TYPE_CARDINAL;

    unsigned minimumIntegerDigits = intlNumberOption(exec, options, Identifier::fromString(&vm, "minimumIntegerDigits"), 1, 21, 1);
    RETURN_IF_EXCEPTION(scope, void());
    m_minimumIntegerDigits = minimumIntegerDigits;

    unsigned minimumFractionDigitsDefault = 0;
    unsigned minimumFractionDigits = intlNumberOption(exec, options, Identifier::fromString(&vm, "minimumFractionDigits"), 0, 20, minimumFractionDigitsDefault);
    RETURN_IF_EXCEPTION(scope, void());
    m_minimumFractionDigits = minimumFractionDigits;

    unsigned maximumFractionDigitsDefault = std::max(minimumFractionDigits, 3u);
    unsigned maximumFractionDigits = intlNumberOption(exec, options, Identifier::fromString(&vm, "maximumFractionDigits"), minimumFractionDigits, 20, maximumFractionDigitsDefault);
    RETURN_IF_EXCEPTION(scope, void());
    m_maximumFractionDigits = maximumFractionDigits;

    JSValue minimumSignificantDigitsValue = options->get(&exec, Identifier::fromString(&vm, "minimumSignificantDigits"));
    RETURN_IF_EXCEPTION(scope, void());

    JSValue maximumSignificantDigitsValue = options->get(&exec, Identifier::fromString(&vm, "maximumSignificantDigits"));
    RETURN_IF_EXCEPTION(scope, void());

    if (!minimumSignificantDigitsValue.isUndefined() || !maximumSignificantDigitsValue.isUndefined()) {
        unsigned minimumSignificantDigits = intlNumberOption(exec, options, Identifier::fromString(&vm, "minimumSignificantDigits"), 1, 21, 1);
        RETURN_IF_EXCEPTION(scope, void());
        unsigned maximumSignificantDigits = intlNumberOption(exec, options, Identifier::fromString(&vm, "maximumSignificantDigits"), minimumSignificantDigits, 21, 21);
        RETURN_IF_EXCEPTION(scope, void());
        m_minimumSignificantDigits = minimumSignificantDigits;
        m_maximumSignificantDigits = maximumSignificantDigits;
    }

    UErrorCode status = U_ZERO_ERROR;
    m_numberFormat = std::unique_ptr<UNumberFormat, UNumberFormatDeleter>(unum_open(UNUM_DECIMAL, nullptr, 0, m_locale.utf8().data(), nullptr, &status));
    if (U_FAILURE(status)) {
        throwTypeError(&exec, scope, "failed to initialize PluralRules"_s);
        return;
    }

    if (m_minimumSignificantDigits) {
        unum_setAttribute(m_numberFormat.get(), UNUM_SIGNIFICANT_DIGITS_USED, true);
        unum_setAttribute(m_numberFormat.get(), UNUM_MIN_SIGNIFICANT_DIGITS, m_minimumSignificantDigits.value());
        unum_setAttribute(m_numberFormat.get(), UNUM_MAX_SIGNIFICANT_DIGITS, m_maximumSignificantDigits.value());
    } else {
        unum_setAttribute(m_numberFormat.get(), UNUM_MIN_INTEGER_DIGITS, m_minimumIntegerDigits);
        unum_setAttribute(m_numberFormat.get(), UNUM_MIN_FRACTION_DIGITS, m_minimumFractionDigits);
        unum_setAttribute(m_numberFormat.get(), UNUM_MAX_FRACTION_DIGITS, m_maximumFractionDigits);
    }

    status = U_ZERO_ERROR;
    m_pluralRules = std::unique_ptr<UPluralRules, UPluralRulesDeleter>(uplrules_openForType(m_locale.utf8().data(), m_type, &status));
    if (U_FAILURE(status)) {
        throwTypeError(&exec, scope, "failed to initialize PluralRules"_s);
        return;
    }

    m_initializedPluralRules = true;
}