kotlin-stdlib/kotlin/Throws

Throws

@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER, AnnotationTarget.CONSTRUCTOR])

expect annotation class Throws(val exceptionClasses: KClass<out Throwable>)(source)

This annotation indicates what exceptions should be declared by a function when compiled to a platform method in Kotlin/JVM and Kotlin/Native.

Since Kotlin

1.4

actual typealias Throws = Throws

@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.CONSTRUCTOR])

actual annotation class Throws(val exceptionClasses: KClass<out Throwable>)

This annotation indicates what exceptions should be declared by a function when compiled to a platform method.

When compiling to Objective-C/Swift framework, non-suspend functions having or inheriting this annotation are represented as NSError*-producing methods in Objective-C and as throws methods in Swift. Representations for suspend functions always have NSError*/Error parameter in completion handler

When Kotlin function called from Swift/Objective-C code throws an exception which is an instance of one of the exceptionClasses or their subclasses, it is propagated as NSError. Other Kotlin exceptions reaching Swift/Objective-C are considered unhandled and cause program termination.

Note: suspend functions without @Throws propagate only kotlin.coroutines.cancellation.CancellationException as NSError. Non-suspend functions without @Throws don't propagate Kotlin exceptions at all.

Since Kotlin

1.4

Constructors

Throws

expect fun Throws(vararg exceptionClasses: KClass<out Throwable>)

actual fun Throws(vararg exceptionClasses: KClass<out Throwable>)

Properties

exceptionClasses

expect val exceptionClasses: Array<out KClass<out Throwable>>

the list of checked exception classes that may be thrown by the function.

actual val exceptionClasses: Array<out KClass<out Throwable>>

the list of checked exception classes that may be thrown by the function.