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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * PluralRules internal properties.
+ *
+ * 9.1 Internal slots of Service Constructors
+ * 16.2.3 Properties of the Intl.PluralRules Constructor, Internal slots
+ *
+ * ES2024 Intl draft rev 74ca7099f103d143431b2ea422ae640c6f43e3e6
+ */
+var pluralRulesInternalProperties = {
+  localeData: pluralRulesLocaleData,
+  relevantExtensionKeys: [],
+};
+
+function pluralRulesLocaleData() {
+  // PluralRules don't support any extension keys.
+  return {};
+}
+
+/**
+ * 16.1.2 InitializePluralRules ( pluralRules, locales, options )
+ *
+ * Compute an internal properties object from |lazyPluralRulesData|.
+ *
+ * ES2024 Intl draft rev 74ca7099f103d143431b2ea422ae640c6f43e3e6
+ */
+function resolvePluralRulesInternals(lazyPluralRulesData) {
+  assert(IsObject(lazyPluralRulesData), "lazy data not an object?");
+
+  var internalProps = std_Object_create(null);
+
+  var PluralRules = pluralRulesInternalProperties;
+
+  // Compute effective locale.
+
+  // Step 9.
+  var localeData = PluralRules.localeData;
+
+  // Step 10.
+  var r = ResolveLocale(
+    "PluralRules",
+    lazyPluralRulesData.requestedLocales,
+    lazyPluralRulesData.opt,
+    PluralRules.relevantExtensionKeys,
+    localeData
+  );
+
+  // Step 11.
+  internalProps.locale = r.locale;
+
+  // Step 7.
+  internalProps.type = lazyPluralRulesData.type;
+
+  // Step 8. SetNumberFormatDigitOptions, step 6.
+  internalProps.minimumIntegerDigits = lazyPluralRulesData.minimumIntegerDigits;
+
+  // Step 8. SetNumberFormatDigitOptions, step 14.
+  internalProps.roundingIncrement = lazyPluralRulesData.roundingIncrement;
+
+  // Step 8. SetNumberFormatDigitOptions, step 15.
+  internalProps.roundingMode = lazyPluralRulesData.roundingMode;
+
+  // Step 8. SetNumberFormatDigitOptions, step 16.
+  internalProps.trailingZeroDisplay = lazyPluralRulesData.trailingZeroDisplay;
+
+  // Step 8. SetNumberFormatDigitOptions, steps 25-26.
+  if ("minimumFractionDigits" in lazyPluralRulesData) {
+    assert(
+      "maximumFractionDigits" in lazyPluralRulesData,
+      "min/max frac digits mismatch"
+    );
+    internalProps.minimumFractionDigits =
+      lazyPluralRulesData.minimumFractionDigits;
+    internalProps.maximumFractionDigits =
+      lazyPluralRulesData.maximumFractionDigits;
+  }
+
+  // Step 8. SetNumberFormatDigitOptions, steps 24 and 26.
+  if ("minimumSignificantDigits" in lazyPluralRulesData) {
+    assert(
+      "maximumSignificantDigits" in lazyPluralRulesData,
+      "min/max sig digits mismatch"
+    );
+    internalProps.minimumSignificantDigits =
+      lazyPluralRulesData.minimumSignificantDigits;
+    internalProps.maximumSignificantDigits =
+      lazyPluralRulesData.maximumSignificantDigits;
+  }
+
+  // Step 8. SetNumberFormatDigitOptions, steps 26-30.
+  internalProps.roundingPriority = lazyPluralRulesData.roundingPriority;
+
+  // `pluralCategories` is lazily computed on first access.
+  internalProps.pluralCategories = null;
+
+  return internalProps;
+}
+
+/**
+ * Returns an object containing the PluralRules internal properties of |obj|.
+ */
+function getPluralRulesInternals(obj) {
+  assert(IsObject(obj), "getPluralRulesInternals called with non-object");
+  assert(
+    intl_GuardToPluralRules(obj) !== null,
+    "getPluralRulesInternals called with non-PluralRules"
+  );
+
+  var internals = getIntlObjectInternals(obj);
+  assert(
+    internals.type === "PluralRules",
+    "bad type escaped getIntlObjectInternals"
+  );
+
+  var internalProps = maybeInternalProperties(internals);
+  if (internalProps) {
+    return internalProps;
+  }
+
+  internalProps = resolvePluralRulesInternals(internals.lazyData);
+  setInternalProperties(internals, internalProps);
+  return internalProps;
+}
+
+/**
+ * 16.1.2 InitializePluralRules ( pluralRules, locales, options )
+ *
+ * Initializes an object as a PluralRules.
+ *
+ * This method is complicated a moderate bit by its implementing initialization
+ * as a *lazy* concept.  Everything that must happen now, does -- but we defer
+ * all the work we can until the object is actually used as a PluralRules.
+ * This later work occurs in |resolvePluralRulesInternals|; steps not noted
+ * here occur there.
+ *
+ * ES2024 Intl draft rev 74ca7099f103d143431b2ea422ae640c6f43e3e6
+ */
+function InitializePluralRules(pluralRules, locales, options) {
+  assert(IsObject(pluralRules), "InitializePluralRules called with non-object");
+  assert(
+    intl_GuardToPluralRules(pluralRules) !== null,
+    "InitializePluralRules called with non-PluralRules"
+  );
+
+  // Lazy PluralRules data has the following structure:
+  //
+  //   {
+  //     requestedLocales: List of locales,
+  //     type: "cardinal" / "ordinal",
+  //
+  //     opt: // opt object computer in InitializePluralRules
+  //       {
+  //         localeMatcher: "lookup" / "best fit",
+  //       }
+  //
+  //     minimumIntegerDigits: integer ∈ [1, 21],
+  //
+  //     // optional, mutually exclusive with the significant-digits option
+  //     minimumFractionDigits: integer ∈ [0, 100],
+  //     maximumFractionDigits: integer ∈ [0, 100],
+  //
+  //     // optional, mutually exclusive with the fraction-digits option
+  //     minimumSignificantDigits: integer ∈ [1, 21],
+  //     maximumSignificantDigits: integer ∈ [1, 21],
+  //
+  //     roundingPriority: "auto" / "lessPrecision" / "morePrecision",
+  //
+  //     trailingZeroDisplay: "auto" / "stripIfInteger",
+  //
+  //     roundingIncrement: integer ∈ (1, 2, 5,
+  //                                   10, 20, 25, 50,
+  //                                   100, 200, 250, 500,
+  //                                   1000, 2000, 2500, 5000),
+  //
+  //     roundingMode: "ceil" / "floor" / "expand" / "trunc" /
+  //                   "halfCeil" / "halfFloor" / "halfExpand" / "halfTrunc" / "halfEven",
+  //   }
+  //
+  // Note that lazy data is only installed as a final step of initialization,
+  // so every PluralRules lazy data object has *all* these properties, never a
+  // subset of them.
+  var lazyPluralRulesData = std_Object_create(null);
+
+  // Step 1.
+  var requestedLocales = CanonicalizeLocaleList(locales);
+  lazyPluralRulesData.requestedLocales = requestedLocales;
+
+  // Step 2. (Inlined call to CoerceOptionsToObject.)
+  if (options === undefined) {
+    options = std_Object_create(null);
+  } else {
+    options = ToObject(options);
+  }
+
+  // Step 3.
+  var opt = new_Record();
+  lazyPluralRulesData.opt = opt;
+
+  // Steps 4-5.
+  var matcher = GetOption(
+    options,
+    "localeMatcher",
+    "string",
+    ["lookup", "best fit"],
+    "best fit"
+  );
+  opt.localeMatcher = matcher;
+
+  // Steps 6-7.
+  var type = GetOption(
+    options,
+    "type",
+    "string",
+    ["cardinal", "ordinal"],
+    "cardinal"
+  );
+  lazyPluralRulesData.type = type;
+
+  // Step 8.
+  SetNumberFormatDigitOptions(lazyPluralRulesData, options, 0, 3, "standard");
+
+  // Step 12.
+  //
+  // We've done everything that must be done now: mark the lazy data as fully
+  // computed and install it.
+  initializeIntlObject(pluralRules, "PluralRules", lazyPluralRulesData);
+}
+
+/**
+ * 16.2.2 Intl.PluralRules.supportedLocalesOf ( locales [ , options ] )
+ *
+ * Returns the subset of the given locale list for which this locale list has a
+ * matching (possibly fallback) locale. Locales appear in the same order in the
+ * returned list as in the input list.
+ *
+ * ES2024 Intl draft rev 74ca7099f103d143431b2ea422ae640c6f43e3e6
+ */
+function Intl_PluralRules_supportedLocalesOf(locales /*, options*/) {
+  var options = ArgumentsLength() > 1 ? GetArgument(1) : undefined;
+
+  // Step 1.
+  var availableLocales = "PluralRules";
+
+  // Step 2.
+  var requestedLocales = CanonicalizeLocaleList(locales);
+
+  // Step 3.
+  return SupportedLocales(availableLocales, requestedLocales, options);
+}
+
+/**
+ * 16.3.3 Intl.PluralRules.prototype.select ( value )
+ *
+ * Returns a String value representing the plural category matching
+ * the number passed as value according to the
+ * effective locale and the formatting options of this PluralRules.
+ *
+ * ES2024 Intl draft rev 74ca7099f103d143431b2ea422ae640c6f43e3e6
+ */
+function Intl_PluralRules_select(value) {
+  // Step 1.
+  var pluralRules = this;
+
+  // Step 2.
+  if (
+    !IsObject(pluralRules) ||
+    (pluralRules = intl_GuardToPluralRules(pluralRules)) === null
+  ) {
+    return callFunction(
+      intl_CallPluralRulesMethodIfWrapped,
+      this,
+      value,
+      "Intl_PluralRules_select"
+    );
+  }
+
+  // Step 3.
+  var n = ToNumber(value);
+
+  // Ensure the PluralRules internals are resolved.
+  getPluralRulesInternals(pluralRules);
+
+  // Step 4.
+  return intl_SelectPluralRule(pluralRules, n);
+}
+
+/**
+ * 16.3.4 Intl.PluralRules.prototype.selectRange ( start, end )
+ *
+ * Returns a String value representing the plural category matching the input
+ * number range according to the effective locale and the formatting options
+ * of this PluralRules.
+ *
+ * ES2024 Intl draft rev 74ca7099f103d143431b2ea422ae640c6f43e3e6
+ */
+function Intl_PluralRules_selectRange(start, end) {
+  // Step 1.
+  var pluralRules = this;
+
+  // Step 2.
+  if (
+    !IsObject(pluralRules) ||
+    (pluralRules = intl_GuardToPluralRules(pluralRules)) === null
+  ) {
+    return callFunction(
+      intl_CallPluralRulesMethodIfWrapped,
+      this,
+      start,
+      end,
+      "Intl_PluralRules_selectRange"
+    );
+  }
+
+  // Step 3.
+  if (start === undefined || end === undefined) {
+    ThrowTypeError(
+      JSMSG_UNDEFINED_NUMBER,
+      start === undefined ? "start" : "end",
+      "PluralRules",
+      "selectRange"
+    );
+  }
+
+  // Step 4.
+  var x = ToNumber(start);
+
+  // Step 5.
+  var y = ToNumber(end);
+
+  // Step 6.
+  return intl_SelectPluralRuleRange(pluralRules, x, y);
+}
+
+/**
+ * 16.3.5 Intl.PluralRules.prototype.resolvedOptions ( )
+ *
+ * Returns the resolved options for a PluralRules object.
+ *
+ * ES2024 Intl draft rev 74ca7099f103d143431b2ea422ae640c6f43e3e6
+ */
+function Intl_PluralRules_resolvedOptions() {
+  // Step 1.
+  var pluralRules = this;
+
+  // Step 2.
+  if (
+    !IsObject(pluralRules) ||
+    (pluralRules = intl_GuardToPluralRules(pluralRules)) === null
+  ) {
+    return callFunction(
+      intl_CallPluralRulesMethodIfWrapped,
+      this,
+      "Intl_PluralRules_resolvedOptions"
+    );
+  }
+
+  var internals = getPluralRulesInternals(pluralRules);
+
+  // Steps 3-4.
+  var result = {
+    locale: internals.locale,
+    type: internals.type,
+    minimumIntegerDigits: internals.minimumIntegerDigits,
+  };
+
+  // Min/Max fraction digits are either both present or not present at all.
+  assert(
+    hasOwn("minimumFractionDigits", internals) ===
+      hasOwn("maximumFractionDigits", internals),
+    "minimumFractionDigits is present iff maximumFractionDigits is present"
+  );
+
+  if (hasOwn("minimumFractionDigits", internals)) {
+    DefineDataProperty(
+      result,
+      "minimumFractionDigits",
+      internals.minimumFractionDigits
+    );
+    DefineDataProperty(
+      result,
+      "maximumFractionDigits",
+      internals.maximumFractionDigits
+    );
+  }
+
+  // Min/Max significant digits are either both present or not present at all.
+  assert(
+    hasOwn("minimumSignificantDigits", internals) ===
+      hasOwn("maximumSignificantDigits", internals),
+    "minimumSignificantDigits is present iff maximumSignificantDigits is present"
+  );
+
+  if (hasOwn("minimumSignificantDigits", internals)) {
+    DefineDataProperty(
+      result,
+      "minimumSignificantDigits",
+      internals.minimumSignificantDigits
+    );
+    DefineDataProperty(
+      result,
+      "maximumSignificantDigits",
+      internals.maximumSignificantDigits
+    );
+  }
+
+  DefineDataProperty(result, "roundingMode", internals.roundingMode);
+  DefineDataProperty(result, "roundingIncrement", internals.roundingIncrement);
+  DefineDataProperty(
+    result,
+    "trailingZeroDisplay",
+    internals.trailingZeroDisplay
+  );
+
+  // Step 5.
+  var internalsPluralCategories = internals.pluralCategories;
+  if (internalsPluralCategories === null) {
+    internalsPluralCategories = intl_GetPluralCategories(pluralRules);
+    internals.pluralCategories = internalsPluralCategories;
+  }
+
+  var pluralCategories = [];
+  for (var i = 0; i < internalsPluralCategories.length; i++) {
+    DefineDataProperty(pluralCategories, i, internalsPluralCategories[i]);
+  }
+
+  // Step 6.
+  DefineDataProperty(result, "pluralCategories", pluralCategories);
+
+  // Steps 7-9.
+  //
+  // Our implementation doesn't use [[RoundingType]], but instead directly
+  // stores the computed `roundingPriority` value.
+  DefineDataProperty(result, "roundingPriority", internals.roundingPriority);
+
+  // Step 10.
+  return result;
+}