Struct Signal

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

A reactive signal that holds a value, tracks dependencies, and triggers effects.

Signal<T> behaves similarly to a traditional “Property” (getter/setter), but on top of that, it automatically tracks which reactive computations or effects access it. When its value changes, all dependent effects are automatically re-run.

In short:

• Like a Property: provides get() and set() for accessing and updating the value.
• Adds tracking: automatically records dependencies when read inside reactive contexts, and automatically triggers dependent Effects when updated.

Type Parameters

• T: The type of the value stored in the signal. Must implement Eq + Default.

Implementations

impl<T> Signal<T>

pub fn new(value: Option<T>) -> Self

where T: Default,

Creates a new Signal with the given initial value.

If None is provided, T::default() is used.

Examples

use reactive_cache::Signal;

let signal = Signal::new(Some(10));
assert_eq!(*signal.get(), 10);

let default_signal: Signal<i32> = Signal::new(None);
assert_eq!(*default_signal.get(), 0);

pub fn get(&self) -> Ref<'_, T>

Gets a reference to the current value, tracking dependencies and effects if inside a reactive context.

Examples

use reactive_cache::Signal;

let signal = Signal::new(Some(42));
assert_eq!(*signal.get(), 42);

pub fn set(&self, value: T) -> bool

where T: Eq,

Sets the value of the signal.

Returns true if the value changed and dependent effects were triggered.

Examples

use reactive_cache::Signal;

let signal = Signal::new(Some(5));
assert_eq!(signal.set(10), true);
assert_eq!(*signal.get(), 10);

// Setting to the same value returns false
assert_eq!(signal.set(10), false);