Remove kotlinx.datetime.Instant and kotlinx.datetime.Clock

core/common/src/DeprecatedClock.kt

@@ -1,137 +1,23 @@
 /*
- * Copyright 2019-2024 JetBrains s.r.o. and contributors.
+ * Copyright 2019-2025 JetBrains s.r.o. and contributors.
  * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
  */
 
-@file:Suppress("DEPRECATION")
-@file:JvmMultifileClass
-@file:JvmName("ClockKt")
 package kotlinx.datetime
 
-import kotlin.jvm.JvmMultifileClass
-import kotlin.jvm.JvmName
-import kotlin.time.ExperimentalTime
-import kotlin.time.TimeMark
-import kotlin.time.TimeSource
-
-/**
- * Creates a [kotlin.time.Clock] (the standard library version of `Clock`) delegating to `this`.
- */
-public fun Clock.toStdlibClock(): kotlin.time.Clock =
-    (this as? DateTimeClock)?.clock ?: StdlibClock(this)
-
 /**
- * Creates a [kotlinx.datetime.Clock] delegating to the version of `Clock` from the standard library.
- */
-public fun kotlin.time.Clock.toDeprecatedClock(): Clock =
-    (this as? StdlibClock)?.clock ?: DateTimeClock(this)
-
-private class DateTimeClock(val clock: kotlin.time.Clock): kotlinx.datetime.Clock {
-    override fun now(): Instant = clock.now().toDeprecatedInstant()
-}
-
-private class StdlibClock(val clock: Clock): kotlin.time.Clock {
-    override fun now(): kotlin.time.Instant = clock.now().toStdlibInstant()
-}
-
-/**
- * The `kotlinx-datetime` version of [kotlin.time.Clock].
+ * This is a deprecated type alias for `kotlinx.datetime.Clock`.
  *
- * Using this interface is discouraged in favor of the standard library version, [kotlin.time.Clock].
- * Initially, `Instant` and `Clock` were introduced in `kotlinx-datetime`,
- * but it turned out they were useful even in contexts where no datetime processing was needed.
- * As a result, starting from 2.1.20, Kotlin's standard library includes its own `Instant` and `Clock` classes.
+ * Before 0.7.0, this type was used to represent a clock in the `kotlinx.datetime` library.
+ * However, in Kotlin 2.1.20,
+ * the `kotlin.time.Clock` type was introduced and is now the preferred way to represent a clock.
  *
- * `kotlinx.datetime.Clock` is still available for compatibility reasons in the compatibility artifact of
- * `kotlinx-datetime`, but it is deprecated.
- * In the normal release artifact, it is replaced by `kotlin.time.Clock`.
- * See [https://github.com/Kotlin/kotlinx-datetime?tab=readme-ov-file#deprecation-of-instant] for more information.
+ * This type alias is kept for making sure the existing code that uses `kotlinx.datetime.Clock` compiles.
+ * For ensuring binary compatibility instead of source compatibility,
+ * see <https://github.com/Kotlin/kotlinx-datetime?tab=readme-ov-file#deprecation-of-instant>.
  */
 @Deprecated(
-    "Use kotlin.time.Clock instead",
-    ReplaceWith("kotlin.time.Clock", "kotlin.time.Clock"),
-    level = DeprecationLevel.WARNING
-)
-public interface Clock {
-    /**
-     * Returns the [Instant] corresponding to the current time, according to this clock.
-     *
-     * Calling [now] later is not guaranteed to return a larger [Instant].
-     * In particular, for [Clock.System], the opposite is completely expected,
-     * and it must be taken into account.
-     * See the [System] documentation for details.
-     *
-     * Even though [Instant] is defined to be on the UTC-SLS time scale, which enforces a specific way of handling
-     * leap seconds, [now] is not guaranteed to handle leap seconds in any specific way.
-     */
-    public fun now(): Instant
-
-    /**
-     * The [Clock] instance that queries the platform-specific system clock as its source of time knowledge.
-     *
-     * Successive calls to [now] will not necessarily return increasing [Instant] values, and when they do,
-     * these increases will not necessarily correspond to the elapsed time.
-     *
-     * For example, when using [Clock.System], the following could happen:
-     * - [now] returns `2023-01-02T22:35:01Z`.
-     * - The system queries the Internet and recognizes that its clock needs adjusting.
-     * - [now] returns `2023-01-02T22:32:05Z`.
-     *
-     * When you need predictable intervals between successive measurements, consider using [TimeSource.Monotonic].
-     *
-     * For improved testability, you should avoid using [Clock.System] directly in the implementation
-     * and pass a [Clock] explicitly instead. For example:
-     *
-     * @sample kotlinx.datetime.test.samples.ClockSamples.system
-     * @sample kotlinx.datetime.test.samples.ClockSamples.dependencyInjection
-     */
-    public object System : Clock {
-        override fun now(): Instant = kotlin.time.Clock.System.now().toDeprecatedInstant()
-    }
-
-    /** A companion object used purely for namespacing. */
-    public companion object {
-
-    }
-}
-
-/**
- * Returns the current date at the given [time zone][timeZone], according to [this Clock][this].
- *
- * The time zone is important because the current date is not the same in all time zones at the same instant.
- *
- * @sample kotlinx.datetime.test.samples.ClockSamples.todayIn
- */
-@Deprecated("kotlin.datetime.Clock is superseded by kotlin.time.Clock",
-    level = DeprecationLevel.WARNING,
-    replaceWith = ReplaceWith("this.toStdlibClock().todayIn(timeZone)")
-)
-public fun Clock.todayIn(timeZone: TimeZone): LocalDate =
-    toStdlibClock().todayIn(timeZone)
-
-/**
- * Returns a [TimeSource] that uses this [Clock] to mark a time instant and to find the amount of time elapsed since that mark.
- *
- * **Pitfall**: using this function with [Clock.System] is error-prone
- * because [Clock.System] is not well suited for measuring time intervals.
- * Please only use this conversion function on the [Clock] instances that are fully controlled programmatically.
- */
-@ExperimentalTime
-@Deprecated("kotlin.datetime.Clock is superseded by kotlin.time.Clock",
+    "This type is deprecated in favor of `kotlin.time.Clock`.",
     level = DeprecationLevel.WARNING,
-    replaceWith = ReplaceWith("this.toStdlibClock().asTimeSource()")
-)
-public fun Clock.asTimeSource(): TimeSource.WithComparableMarks = toStdlibClock().asTimeSource()
-
-@Deprecated("Use Clock.todayIn instead", ReplaceWith("this.toStdlibClock().todayIn(timeZone)"), DeprecationLevel.WARNING)
-public fun Clock.todayAt(timeZone: TimeZone): LocalDate = todayIn(timeZone)
-
-@Deprecated(
-    "kotlin.datetime.Clock is superseded by kotlin.time.Clock",
-    ReplaceWith("this.asClock(origin.toStdlibInstant()).toDeprecatedClock()"),
-    level = DeprecationLevel.WARNING
-)
-public fun TimeSource.asClock(origin: kotlinx.datetime.Instant): kotlinx.datetime.Clock = object : Clock {
-    private val startMark: TimeMark = markNow()
-    override fun now() = origin + startMark.elapsedNow()
-}
+    replaceWith = ReplaceWith("kotlin.time.Clock", "kotlin.time.Clock"))
+public typealias Clock = kotlin.time.Clock