Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibJS/Runtime/Intl/PluralRules.cpp

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2022-2024, Tim Flynn <trflynn89@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/Intl/PluralRules.h>
+
+namespace JS::Intl {
+
+JS_DEFINE_ALLOCATOR(PluralRules);
+
+// 16 PluralRules Objects, https://tc39.es/ecma402/#pluralrules-objects
+PluralRules::PluralRules(Object& prototype)
+    : NumberFormatBase(prototype)
+{
+}
+
+// 16.5.4 ResolvePlural ( pluralRules, n ), https://tc39.es/ecma402/#sec-resolveplural
+Unicode::PluralCategory resolve_plural(PluralRules const& plural_rules, Value number)
+{
+    // 1. If n is not a finite Number, then
+    if (!number.is_finite_number()) {
+        // a. Let s be ! ToString(n).
+        // b. Return the Record { [[PluralCategory]]: "other", [[FormattedString]]: s }.
+        return Unicode::PluralCategory::Other;
+    }
+
+    // 2. Let locale be pluralRules.[[Locale]].
+    // 3. Let type be pluralRules.[[Type]].
+    // 4. Let res be FormatNumericToString(pluralRules, ℝ(n)).
+    // 5. Let s be res.[[FormattedString]].
+    // 6. Let operands be GetOperands(s).
+    // 7. Let p be PluralRuleSelect(locale, type, n, operands).
+    // 8. Return the Record { [[PluralCategory]]: p, [[FormattedString]]: s }.
+    return plural_rules.formatter().select_plural(number.as_double());
+}
+
+// 16.5.6 ResolvePluralRange ( pluralRules, x, y ), https://tc39.es/ecma402/#sec-resolveplural
+ThrowCompletionOr<Unicode::PluralCategory> resolve_plural_range(VM& vm, PluralRules const& plural_rules, Value start, Value end)
+{
+    // 1. If x is NaN or y is NaN, throw a RangeError exception.
+    if (start.is_nan())
+        return vm.throw_completion<RangeError>(ErrorType::NumberIsNaN, "start"sv);
+    if (end.is_nan())
+        return vm.throw_completion<RangeError>(ErrorType::NumberIsNaN, "end"sv);
+
+    // 2. Let xp be ResolvePlural(pluralRules, x).
+    // 3. Let yp be ResolvePlural(pluralRules, y).
+    // 4. If xp.[[FormattedString]] is yp.[[FormattedString]], then
+    //     a. Return xp.[[PluralCategory]].
+    // 5. Let locale be pluralRules.[[Locale]].
+    // 6. Let type be pluralRules.[[Type]].
+    // 7. Return PluralRuleSelectRange(locale, type, xp.[[PluralCategory]], yp.[[PluralCategory]]).
+    return plural_rules.formatter().select_plural_range(start.as_double(), end.as_double());
+}
+
+}