Enum Flow 

pub enum Flow {
    Continue,
    Stop,
}

Whether an observer still accepts events, as reported by Observer::on_next.

This is the only way an observer can tell the source that is pushing into it to stop, while that push is running. It matters most for a synchronous source, which delivers its whole sequence before subscribe returns: until it does, nobody holds the subscription yet, so disposing it is not yet possible, and an infinite synchronous source would never end.

It does not replace disposal, and no source may rely on it alone: an observer can also go away between two events, which no return value can report. See the variants for what each one promises.

Variants

Continue

The observer is not known to have stopped, so the source may keep pushing.

This is a hint, not a guarantee: it means “no stop has been observed here”, and the observer may still be disposed before the next event, or already have been disposed somewhere this call could not see — a value queued behind a delivery running elsewhere is reported as Continue even when that delivery is about to stop. A source must therefore still honor its disposal; treating Continue as proof that downstream is alive is wrong.

Stop

The observer will never accept another event.

The caller must not call Observer::on_next again, must not call Observer::on_termination, and should drop the observer instead: it has either already delivered its own termination downstream or been disposed, so a termination sent now would be a second one. Unlike Flow::Continue, this is a guarantee, never a hint.

Implementations

impl Flow

pub fn is_continue(self) -> bool

Returns whether this is Flow::Continue.

pub fn is_stop(self) -> bool

Returns whether this is Flow::Stop.

Trait Implementations

impl Clone for Flow

fn clone(&self) -> Flow

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Flow

impl Debug for Flow

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

Formats the value using the given formatter.

impl Eq for Flow

impl IntoFlow for Flow

fn into_flow(self) -> Flow

impl PartialEq for Flow

fn eq(&self, other: &Flow) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Flow