#485: Replace TimeZoneRulesImpl with TimeZoneRules for some return values

Author: DmitryNekrasov

core/androidNative/src/internal/TzdbBionic.kt

@@ -10,13 +10,13 @@
 package kotlinx.datetime.internal
 
 private class TzdbBionic(private val rules: Map<String, Entry>) : TimeZoneDatabase {
-    override fun rulesForId(id: String): TimeZoneRulesImpl =
+    override fun rulesForId(id: String): TimeZoneRules =
         rules[id]?.readRules() ?: throw IllegalStateException("Unknown time zone $id")
 
     override fun availableTimeZoneIds(): Set<String> = rules.keys
 
     class Entry(val file: ByteArray, val offset: Int, val length: Int) {
-        fun readRules(): TimeZoneRulesImpl = readTzFile(file.copyOfRange(offset, offset + length)).toTimeZoneRules()
+        fun readRules(): TimeZoneRules = readTzFile(file.copyOfRange(offset, offset + length)).toTimeZoneRules()
     }
 }
 

core/commonJs/src/internal/Platform.kt

@@ -60,7 +60,7 @@ private val tzdb: Result<TimeZoneDatabase?> = runCatching {
         return (wholeMinutes * SECONDS_PER_MINUTE + seconds) * sign
     }
 
-    val zones = mutableMapOf<String, TimeZoneRulesImpl>()
+    val zones = mutableMapOf<String, TimeZoneRules>()
     val (zonesPacked, linksPacked) = readTzdb() ?: return@runCatching null
     for (zone in zonesPacked) {
         val components = zone.split('|')
@@ -84,7 +84,7 @@ private val tzdb: Result<TimeZoneDatabase?> = runCatching {
         }
     }
     object : TimeZoneDatabase {
-        override fun rulesForId(id: String): TimeZoneRulesImpl =
+        override fun rulesForId(id: String): TimeZoneRules =
             zones[id] ?: throw IllegalTimeZoneException("Unknown time zone: $id")
 
         override fun availableTimeZoneIds(): Set<String> = zones.keys
@@ -134,7 +134,7 @@ internal actual fun timeZoneById(zoneId: String): TimeZone {
     throw IllegalTimeZoneException("js-joda timezone database is not available")
 }
 
-internal fun rulesForId(zoneId: String): TimeZoneRulesImpl? = tzdb.getOrThrow()?.rulesForId(zoneId)
+internal fun rulesForId(zoneId: String): TimeZoneRules? = tzdb.getOrThrow()?.rulesForId(zoneId)
 
 internal actual fun getAvailableZoneIds(): Set<String> =
     tzdb.getOrThrow()?.availableTimeZoneIds() ?: setOf("UTC")

core/commonKotlin/src/internal/RegionTimeZone.kt

@@ -7,7 +7,7 @@ package kotlinx.datetime.internal
 
 import kotlinx.datetime.*
 
-internal class RegionTimeZone(private val tzid: TimeZoneRulesImpl, override val id: String) : TimeZone() {
+internal class RegionTimeZone(private val tzid: TimeZoneRules, override val id: String) : TimeZone() {
 
     override fun atStartOfDay(date: LocalDate): Instant {
         val ldt = LocalDateTime(date, LocalTime.MIN)

core/commonKotlin/src/internal/TimeZoneDatabase.kt

@@ -6,6 +6,6 @@
 package kotlinx.datetime.internal
 
 internal interface TimeZoneDatabase {
-    fun rulesForId(id: String): TimeZoneRulesImpl
+    fun rulesForId(id: String): TimeZoneRules
     fun availableTimeZoneIds(): Set<String>
 }

core/commonKotlin/src/internal/Tzfile.kt

@@ -40,7 +40,7 @@ internal class TzFileData(
 }
 
 internal class TzFile(val data: TzFileData, val rules: PosixTzString?) {
-    fun toTimeZoneRules(): TimeZoneRulesImpl {
+    fun toTimeZoneRules(): TimeZoneRules {
         val tzOffsets = buildList {
             add(data.states[0].offset)
             data.transitions.forEach { add(data.states[it.stateIndex].offset) }

core/commonKotlin/test/TimeZoneRulesTest.kt

@@ -12,7 +12,7 @@ import kotlin.test.*
 class TimeZoneRulesTest {
     @Test
     fun ruleStrings() {
-        val rules = readTzFile(EuropeBerlinTzFile2023c).toTimeZoneRules()
+        val rules = readTzFile(EuropeBerlinTzFile2023c).toTimeZoneRules() as TimeZoneRulesImpl
         // first, check that for the future, there are no explicitly defined transitions
         assertTrue(rules.transitionEpochSeconds.all {
             Instant.fromEpochSeconds(it) < LocalDateTime(2038, 1, 1, 0, 0).toInstant(UtcOffset.ZERO)

core/tzdbOnFilesystem/src/internal/TzdbOnFilesystem.kt

@@ -11,7 +11,7 @@ internal class TzdbOnFilesystem(defaultTzdbPath: Path? = null): TimeZoneDatabase
         tabPaths.any { path.containsFile(it) }
     } ?: throw IllegalStateException("Could not find the path to the timezone database")
 
-    override fun rulesForId(id: String): TimeZoneRulesImpl {
+    override fun rulesForId(id: String): TimeZoneRules {
         val idAsPath = Path.fromString(id)
         require(!idAsPath.isAbsolute) { "Timezone ID '$idAsPath' must not begin with a '/'" }
         require(idAsPath.components.none { it == ".." }) { "'$idAsPath' must not contain '..' as a component" }

core/windows/src/internal/TzdbInRegistry.kt

@@ -14,7 +14,7 @@ internal class TzdbInRegistry: TimeZoneDatabase {
 
     // TODO: starting version 1703 of Windows 10, the ICU library is also bundled, with more accurate/ timezone information.
     // When Kotlin/Native drops support for Windows 7, we should investigate moving to the ICU.
-    private val windowsToRules: Map<String, TimeZoneRulesImpl> = buildMap {
+    private val windowsToRules: Map<String, TimeZoneRules> = buildMap {
         processTimeZonesInRegistry { name, recurring, historic ->
             val recurringRules = RecurringZoneRules(recurring.transitions)
             val rules = run {
@@ -76,7 +76,7 @@ internal class TzdbInRegistry: TimeZoneDatabase {
         }
     }
 
-    override fun rulesForId(id: String): TimeZoneRulesImpl {
+    override fun rulesForId(id: String): TimeZoneRules {
         val standardName = standardToWindows[id] ?: throw IllegalTimeZoneException("Unknown time zone $id")
         return windowsToRules[standardName]
                 ?: throw IllegalTimeZoneException("The rules for time zone $id are absent in the Windows registry")