Struct PendingEvents 

pub struct PendingEvents<T, E> { /* private fields */ }

The events waiting to be delivered to an observer.

A termination is the last event of a stream, so it is queued last and nothing is queued after it. Queuing anything after it gives the event back instead of accepting it: the caller drops it outside of the lock that guards this queue, because dropping a value can run arbitrary code that re-enters that lock.

Implementations

impl<T, E> PendingEvents<T, E>

pub fn new() -> Self

pub fn with_capacity(capacity: usize) -> Self

pub fn from_batch(events: EventBatch<T, E>) -> (Option<T>, Self)

Splits events into the value to deliver first and the queue holding what follows it.

The queue is built here, so it is never already terminated and nothing can be given back. The first value is handed to the caller instead of being queued, so a batch carrying a single value leaves the queue empty and never allocates it.

pub fn is_terminated(&self) -> bool

Returns whether the last event has been queued, after which nothing can be queued anymore.

pub fn is_empty(&self) -> bool

Returns whether there is nothing left to deliver.

pub fn push(&mut self, event: Event<T, E>) -> Option<Event<T, E>>

Queues event, or gives it back when the last event has already been queued.

pub fn push_batch( &mut self, events: EventBatch<T, E>, ) -> Option<EventBatch<T, E>>

Queues events, or gives them back when the last event has already been queued.

A batch is queued as a whole: it holds at most one termination and queues it last, so no event of a batch can be rejected on its own.

pub fn pop(&mut self) -> Option<Event<T, E>>

Takes the next event to deliver, which is the termination once no value is left.

pub fn pop_next(&mut self) -> Option<T>

Takes the next value to deliver, leaving the termination in place.

pub fn take_termination(&mut self) -> Option<Termination<E>>

Takes the last event, whether or not values are still queued before it.

Trait Implementations

impl<T, E> Debug for PendingEvents<T, E>

where VecDeque<T>: Debug, Option<Termination<E>>: Debug,

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

Formats the value using the given formatter.

impl<T, E> Default for PendingEvents<T, E>

fn default() -> Self

Returns the “default value” for a type.