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.

Examples

Basic usage

use std::rc::Rc;
use reactive_cache::Signal;

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

signal.set(20);
assert_eq!(*signal.get(), 20);

Using inside a struct

use std::rc::Rc;
use reactive_cache::Signal;

struct ViewModel {
    counter: Rc<Signal<i32>>,
    name: Rc<Signal<String>>,
}

let vm = ViewModel {
    counter: Signal::new(0).into(),
    name: Signal::new("Alice".to_string()).into(),
};

assert_eq!(*vm.counter.get(), 0);
assert_eq!(*vm.name.get(), "Alice");

vm.counter.set(1);
vm.name.set("Bob".into());

assert_eq!(*vm.counter.get(), 1);
assert_eq!(*vm.name.get(), "Bob");

Implementations

impl<T> Signal<T>

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

Creates a new Signal with the given initial value.

Examples

Basic usage:

use std::rc::Rc;
use reactive_cache::Signal;

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

Using inside a struct:

use std::rc::Rc;
use reactive_cache::Signal;

struct ViewModel {
    counter: Rc<Signal<i32>>,
    name: Rc<Signal<String>>,
}

let vm = ViewModel {
    counter: Signal::new(0),
    name: Signal::new("Alice".to_string()),
};

assert_eq!(*vm.counter.get(), 0);
assert_eq!(*vm.name.get(), "Alice");

// Update values
assert!(vm.counter.set(1));
assert!(vm.name.set("Bob".into()));

assert_eq!(*vm.counter.get(), 1);
assert_eq!(*vm.name.get(), "Bob");

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(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, all dependent memos are invalidated and dependent effects were triggered.

Examples

use reactive_cache::Signal;

let signal = Signal::new(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);