Share PluralRuleList with languages with the same rule

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/intl/PluralRuleList.kt

@@ -22,7 +22,7 @@ internal class PluralRuleList(private val rules: Array<PluralRule>) {
 
     companion object {
         private val cacheMutex = Mutex()
-        private val cache = mutableMapOf<String, Deferred<PluralRuleList>>()
+        private val cache = Array<Deferred<PluralRuleList>?>(cldrPluralRuleLists.size) { null }
         private val emptyList = PluralRuleList(emptyArray())
 
         @OptIn(InternalResourceApi::class)
@@ -31,13 +31,19 @@ internal class PluralRuleList(private val rules: Array<PluralRule>) {
             regionQualifier: RegionQualifier,
         ): PluralRuleList {
             val cldrLocaleName = buildCldrLocaleName(languageQualifier, regionQualifier) ?: return emptyList
+            return getInstance(cldrLocaleName)
+        }
+
+        suspend fun getInstance(cldrLocaleName: String): PluralRuleList {
+            val listIndex = cldrPluralRuleListIndexByLocale[cldrLocaleName]!!
             return coroutineScope {
                 val deferred = cacheMutex.withLock {
-                    cache.getOrPut(cldrLocaleName) {
-                        async(start = CoroutineStart.LAZY) {
-                            createInstance(cldrLocaleName)
+                    if (cache[listIndex] == null) {
+                        cache[listIndex] = async(start = CoroutineStart.LAZY) {
+                            createInstance(listIndex)
                         }
                     }
+                    cache[listIndex]!!
                 }
                 deferred.await()
             }
@@ -58,8 +64,7 @@ internal class PluralRuleList(private val rules: Array<PluralRule>) {
             return null
         }
 
-        internal fun createInstance(cldrLocaleName: String): PluralRuleList {
-            val cldrPluralRuleListIndex = cldrPluralRuleListIndexByLocale[cldrLocaleName]!!
+        private fun createInstance(cldrPluralRuleListIndex: Int): PluralRuleList {
             val cldrPluralRuleList = cldrPluralRuleLists[cldrPluralRuleListIndex]
             val pluralRules = cldrPluralRuleList.map { PluralRule(it.first, it.second) }
             return PluralRuleList(pluralRules.toTypedArray())

components/resources/library/src/commonTest/kotlin/org/jetbrains/compose/resources/PluralRulesTest.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.compose.resources
 
+import kotlinx.coroutines.test.runTest
 import org.jetbrains.compose.resources.intl.PluralCategory
 import org.jetbrains.compose.resources.intl.PluralRuleList
 import kotlin.test.*
@@ -17,9 +18,9 @@ class PluralRulesTest {
      * Tests the actual language pluralization rules with the integer samples given by Unicode.
      */
     @Test
-    fun testIntegerSamples() {
+    fun testIntegerSamples() = runTest {
         for ((locale, samplesByCategory) in cldrPluralRuleIntegerSamples) {
-            val pluralRuleList = PluralRuleList.createInstance(locale)
+            val pluralRuleList = PluralRuleList.getInstance(locale)
             for ((category, samples) in samplesByCategory) {
                 for (sample in parsePluralSamples(samples)) {
                     assertEquals(category, pluralRuleList.getCategory(sample))