Cancellation Token¶

1 min read

Import: import system.core;

`CancellationToken`¶

Read-only view of a CancellationSource for cooperative checks at await boundaries. @shared (closed-graph over @shared CancellationSource) so tokens can cross into workers.

shared public class CancellationToken

`current`¶

Returns the cancellation token inherited from the current structured task.

public static get current(): Option<CancellationToken>

`resolve`¶

Explicit tokens override the current structured task; None inherits its token.

public static fun resolve(token: Option<CancellationToken>): Option<CancellationToken>

`is_cancelled`¶

True when the owning source has been cancelled.

public get is_cancelled(): bool

`wait_cancelled`¶

Suspends until cancellation and returns true. Completion or releasing a cancelled future detaches its subscription.

public fun wait_cancelled(): Future<bool>

`wait`¶

Awaits a future or cancellation using scheduler notifications. Cancellation cancels the supplied future; already performed side effects are preserved.

public fun wait<T>(future: Future<T>): Future<Result<T, CancelledError>>

`wait_void`¶

Awaits a void future or cancellation, returning true when the operation completes.

public fun wait_void(future: Future<void>): Future<Result<Unit, CancelledError>>

`throw_if_cancelled`¶

Panics with CancelledError when already cancelled.

public fun throw_if_cancelled(): void

`check`¶

Ok(Unit()) when still running; Err(CancelledError) when cancelled.

public fun check(): Result<Unit, CancelledError>

`is_cancelled_opt`¶

True when token is Some and already cancelled.

public static fun is_cancelled_opt(token: Option<CancellationToken>): bool

`throw_if_opt`¶

Panics when token is Some and already cancelled.

public static fun throw_if_opt(token: Option<CancellationToken>): void

`rejected`¶

Returns err when the explicit or inherited token is cancelled; otherwise Ok(Unit()).

public static fun rejected<E>(token: Option<CancellationToken>, err: E): Result<Unit, E>

Cancellation Token¶