Struct BoundedScope

pub struct BoundedScope<'a, 'b: 'a> { /* private fields */ }

Implementations

impl<'a> BoundedScope<'a, 'a>

pub fn new(f: impl FnOnce(Scope<'a>) + 'a) -> ScopeDisposer<'a>

Creates a new scope.

This function returns a ScopeDisposer that must be used to dispose of the scope. If the disposer is not used, the scope will leak memory.

pub fn immediate(f: impl FnOnce(Scope<'a>) + 'a)

Creates a new scope and immediately disposes it.

pub fn child( self, f: impl for<'b> FnOnce(BoundedScope<'b, 'a>), ) -> ScopeDisposer<'a>

Creates a new child scope.

pub fn alloc<T: Sendable + 'static>(&self, item: T) -> &'a T

Allocates an item in the scope.

pub unsafe fn alloc_unsafe<T: Sendable + 'a>(self, item: T) -> &'a T

Allocates an item in the scope.

Safety

• item must never reference any other item in the arena in it’s Drop implementation.

pub fn alloc_mut<T: Sendable + 'static>(&self, item: T) -> &'a mut T

Allocates an item in the scope.

pub unsafe fn alloc_mut_unsafe<T: Sendable + 'a>(self, item: T) -> &'a mut T

Allocates an item in the scope.

Safety

• item must never reference any other item in the arena in it’s Drop implementation.

pub fn signal<T: SendSync + 'static>(self, value: T) -> &'a Signal<T>

Creates a signal in the scope.

pub fn untrack<T>(self, f: impl FnOnce() -> T) -> T

Runs a scope without tracking any dependencies.

pub fn effect(self, f: impl FnMut() + Sendable + 'a)

Creates an effect.

Effects are callbacks that are run whenever a dependency changes (eg. a signal is updated).

Examples

let signal = cx.signal(0);

cx.effect(|| {
    println!("signal is {}", signal.get()); // prints "signal is 0"
});

signal.set(1); // prints "signal is 1"

pub fn effect_scoped( self, f: impl for<'b> FnMut(BoundedScope<'b, 'a>) + Sendable + 'a, )

Creates an effect in a child scope. See Scope::effect.

pub fn memo<T: SendSync + 'static>( self, f: impl FnMut() -> T + Sendable + 'a, ) -> &'a ReadSignal<T>

Creates a signal that is recomputed every time a dependency is updated.

Examples

let signal = cx.signal(0);

let memo = cx.memo(|| *signal.get() * 2);

assert_eq!(*memo, 0);

signal.set(2);
assert_eq!(*memo, 4);

pub fn bind<T: Clone + PartialEq + SendSync + 'static>( self, signal_a: &'a Signal<T>, signal_b: &'a Signal<T>, )

This will create an effect that binds two signals together. Whenever one of the signals is updated, the other will be updated to the same value. This is useful for creating two-way bindings (eg. a checkbox).

When initializing the binding, the value of signal_b will be used.

pub fn dynamic<T: SendSync + 'static>( self, f: impl FnMut(BoundedScope<'_, 'a>) -> T + Sendable + 'a, ) -> SharedSignal<T>

Creates a shared signal that is recomputed every time a dependency is updated.

Trait Implementations

impl<'a, 'b: 'a> Clone for BoundedScope<'a, 'b>

fn clone(&self) -> BoundedScope<'a, 'b>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a, 'b: 'a> Debug for BoundedScope<'a, 'b>

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

Formats the value using the given formatter.

impl<'a, 'b: 'a> Copy for BoundedScope<'a, 'b>

impl<'a, 'b> Send for BoundedScope<'a, 'b>

impl<'a, 'b> Sync for BoundedScope<'a, 'b>