Introduce constructor-like function for AutoCloseable #KT-66102

libraries/stdlib/api/js/kotlin.kt

@@ -12,6 +12,10 @@ kotlin.reflect.KProperty0<*>.isInitialized: kotlin.Boolean { get; }
 @kotlin.SinceKotlin(version = "1.4")
 public val kotlin.Throwable.suppressedExceptions: kotlin.collections.List<kotlin.Throwable> { get; }
 
+@kotlin.SinceKotlin(version = "2.0")
+@kotlin.internal.InlineOnly
+public inline fun AutoCloseable(crossinline closeAction: () -> kotlin.Unit): kotlin.AutoCloseable
+
 @kotlin.SinceKotlin(version = "1.5")
 @kotlin.WasExperimental(markerClass = {kotlin.ExperimentalStdlibApi::class})
 @kotlin.internal.InlineOnly

libraries/stdlib/jdk7/src/kotlin/AutoCloseableJVM.kt

@@ -16,6 +16,11 @@ import kotlin.contracts.contract
 @SinceKotlin("2.0")
 public actual typealias AutoCloseable = java.lang.AutoCloseable
 
+@Suppress("ACTUAL_WITHOUT_EXPECT")
+@SinceKotlin("2.0")
+@kotlin.internal.InlineOnly
+public actual inline fun AutoCloseable(crossinline closeAction: () -> Unit): AutoCloseable = java.lang.AutoCloseable { closeAction() }
+
 @Suppress("ACTUAL_WITHOUT_EXPECT")
 @SinceKotlin("1.2")
 @kotlin.internal.InlineOnly

libraries/stdlib/js/src/kotlin/AutoCloseableJs.kt

@@ -14,6 +14,12 @@ public actual interface AutoCloseable {
     public actual fun close(): Unit
 }
 
+@SinceKotlin("2.0")
+@kotlin.internal.InlineOnly
+public actual inline fun AutoCloseable(crossinline closeAction: () -> Unit): AutoCloseable = object : AutoCloseable {
+    override fun close() = closeAction()
+}
+
 @SinceKotlin("2.0")
 @WasExperimental(ExperimentalStdlibApi::class)
 @kotlin.internal.InlineOnly

libraries/stdlib/native-wasm/src/kotlin/AutoCloseable.kt

@@ -14,6 +14,12 @@ public actual interface AutoCloseable {
     public actual fun close(): Unit
 }
 
+@SinceKotlin("2.0")
+@kotlin.internal.InlineOnly
+public actual inline fun AutoCloseable(crossinline closeAction: () -> Unit): AutoCloseable = object : AutoCloseable {
+    override fun close() = closeAction()
+}
+
 @SinceKotlin("2.0")
 @WasExperimental(ExperimentalStdlibApi::class)
 @kotlin.internal.InlineOnly

libraries/stdlib/src/kotlin/AutoCloseable.kt

@@ -32,6 +32,39 @@ public expect interface AutoCloseable {
     public fun close(): Unit
 }
 
+/**
+ * Returns an [AutoCloseable] instance that executes the specified [closeAction]
+ * upon invocation of its [`close()`][AutoCloseable.close] function.
+ *
+ * This function allows specifying custom cleanup actions for resources.
+ *
+ * Note that each invocation of the `close()` function on the returned `AutoCloseable` instance executes the [closeAction].
+ * Therefore, implementers are strongly recommended to make the [closeAction] idempotent, or to prevent multiple invocations.
+ *
+ * Example:
+ *
+ * ```kotlin
+ * val autoCloseable = AutoCloseable {
+ *     // Cleanup action, e.g., closing a file or releasing a network connection
+ *     Logger.log("Releasing the network connection.")
+ *     networkConnection.release()
+ * }
+ *
+ * // Now you can pass the autoCloseable to a function or use it directly.
+ * autoCloseable.use {
+ *     // Use the connection, which will be automatically released when this scope finishes.
+ *     val content = networkConnection.readContent()
+ *     Logger.log("Network connection content: $content")
+ * }
+ * ```
+ *
+ * @See AutoCloseable.use
+ */
+@Suppress("NO_ACTUAL_FOR_EXPECT")
+@SinceKotlin("2.0")
+@kotlin.internal.InlineOnly
+public expect inline fun AutoCloseable(crossinline closeAction: () -> Unit): AutoCloseable
+
 /**
  * Executes the given [block] function on this resource and then closes it down correctly whether an exception
  * is thrown or not.

libraries/stdlib/test/autoCloseable/AutoCloseableConstructorFunctionTest.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package test.autoCloseable
+
+import kotlin.test.*
+
+class AutoCloseableConstructorFunctionTest {
+    class ResourceCloseException : Exception()
+
+    @Test
+    fun success() {
+        var isClosed = false
+        val resource = AutoCloseable(closeAction = { isClosed = true })
+        val result = resource.use { "ok" }
+        assertEquals("ok", result)
+        assertTrue(isClosed)
+    }
+
+    @Test
+    fun closeFails() {
+        assertFailsWith<ResourceCloseException> {
+            AutoCloseable { throw ResourceCloseException() }.close()
+        }
+    }
+
+    @Test
+    fun multipleCloseInvocations() {
+        var counter = 0
+        val resource = AutoCloseable { counter++ }
+        resource.use {}
+        assertEquals(1, counter)
+        resource.close()
+        resource.close()
+        assertEquals(3, counter)
+    }
+}