Struct CancelToken 

pub struct CancelToken(/* private fields */);

A cooperative cancellation signal for a single engine call.

Cancellation is checked at engine checkpoints during both target preparation and evaluation. Setting it does not abort work in progress; it causes the next checkpoint to return ExcelErrorKind::Cancelled.

The token is a handle: cloning shares one signal, so a caller can hold a clone and cancel from another thread.

use formualizer_eval::engine::CancelToken;

let token = CancelToken::new();
let remote = token.clone();
assert!(!token.is_cancelled());
remote.cancel();
assert!(token.is_cancelled());

The underlying representation is deliberately private so that richer cancellation (cancellation reasons, linked child tokens) can be added without a breaking change. Use CancelToken::from_flag to adopt a flag you already own.

Implementations

impl CancelToken

pub fn new() -> Self

Creates a token that has not been cancelled.

pub fn cancel(&self)

Signals cancellation. Idempotent, and safe to call from another thread.

pub fn is_cancelled(&self) -> bool

Returns whether cancellation has been signalled.

pub fn from_flag(flag: Arc<AtomicBool>) -> Self

Adopts an existing flag, for callers that already own one or share it with non-engine code.

pub fn as_flag(&self) -> &Arc<AtomicBool>

Borrows the underlying flag as a legacy/interoperability bridge.

New code should poll CancelToken::is_cancelled instead. The raw flag may not represent future richer cancellation semantics.

Trait Implementations

impl Clone for CancelToken

fn clone(&self) -> CancelToken

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CancelToken

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for CancelToken

fn default() -> CancelToken

Returns the “default value” for a type.

impl From<Arc<Atomic<bool>>> for CancelToken

fn from(flag: Arc<AtomicBool>) -> Self

Converts to this type from the input type.