Struct Source 

pub struct Source<T> { /* private fields */ }

A watchable event channel with no current value.

Subscribers receive Signal::Value when emit is called and Signal::Complete when complete is called. There is no get() and no last-value storage — this is the entire point of Source vs. Cell.

Implementations

impl<T: CellValue> Source<T>

pub fn new() -> Self

Create a new source with no subscribers.

pub fn downgrade(&self) -> WeakSource<T>

Create a weak reference to this source.

pub fn own(&self, guard: SubscriptionGuard)

Take ownership of a subscription guard, dropping it when this source is dropped.

pub fn is_complete(&self) -> bool

Returns true if this source has completed.

pub fn with_name(self, _name: impl Into<Arc<str>>) -> Self

Builder-style name attachment, kept for API compatibility with Cell::with_name. Source carries no name field, so this is a no-op.

pub fn subscribe( &self, callback: impl Fn(&Signal<T>) + Send + Sync + 'static, ) -> SubscriptionGuard

Subscribe to all signals. Returns a guard that unsubscribes when dropped.

Unlike Cell::subscribe, Source::subscribe does not invoke the callback synchronously with a current value — there is no current value. The callback fires only on subsequent emit or complete calls.

pub fn emit(&self, value: T)

Emit a value to all subscribers. Does not store the value — there is no .get() on Source.

This is the hot path. Compared to Cell::set it skips the value: ArcSwap<T> store and the associated Debt::pay_all drop on the previous value. Useful when emission rate is high (timers, clocks, ticks).

pub fn complete(&self)

Mark this source as completed. Subsequent emit calls are dropped silently.

Trait Implementations

impl<T> Clone for Source<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: CellValue> Default for Source<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Send + Sync> DepNode for Source<T>

fn id(&self) -> Uuid

fn name(&self) -> Option<String>

fn deps(&self) -> Vec<Arc<dyn DepNode>>

Returns the dependencies of this node.

fn subscriber_count(&self) -> usize

Returns the number of active subscribers to this node.

fn owned_count(&self) -> usize

Returns the number of subscription guards owned by this node.

fn display_name(&self) -> String

fn dependency_count(&self) -> usize

fn has_dependencies(&self) -> bool

fn dependency_tree(&self) -> String

where Self: Sized,

fn print_dependency_tree(&self)

where Self: Sized,

impl<T: CellValue> Pipeline<T, Empty> for Source<T>