Constant

waterui_core::constant

Struct Constant

pub struct Constant<T>(/* private fields */);

Expand description

A reactive constant value that never changes.

Constant<T> is a simple implementation of the Signal trait that always returns the same value when computed. It serves as a way to introduce static values into a reactive computation graph.

§Type Parameters

T: The value type, which must be Clone + 'static.

§Examples

use nami::{Signal, constant};

let c = constant(42);
assert_eq!(c.get(), 42);

Trait Implementations§

impl<T> Clone for Constant<T>
where T: Clone,

fn clone(&self) -> Constant<T>

Returns a duplicate of the value. Read more

1.0.0 · Source§

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

Performs copy-assignment from source. Read more

impl<T> Debug for Constant<T>
where T: Debug,

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

Formats the value using the given formatter. Read more

impl<T> From<T> for Constant<T>

fn from(value: T) -> Constant<T>

Creates a new Constant from a value.

§Parameters

value: The value to be wrapped in a Constant.

§Returns

A new Constant instance containing the provided value.

impl<T> Signal for Constant<T>
where T: Clone + 'static,

fn get(&self) -> <Constant<T> as Signal>::Output

Computes the constant value.

This simply returns a clone of the contained value.

§Returns

A clone of the constant value.

fn watch(&self, _watcher: impl Fn(Context<<Constant<T> as Signal>::Output>))

Adds a watcher to this constant.

Since a constant never changes, this function returns a WatcherGuard with an empty cleanup function. The provided watcher will never be notified of any changes.

§Parameters

_watcher: A watcher that would be notified of changes (unused).

§Returns

A WatcherGuard with an empty cleanup function.

type Output = T

The type of value produced by this computation.

type Guard = ()

The guard type returned by the watch method that manages watcher lifecycle.

Auto Trait Implementations§

impl<T> Freeze for Constant<T>
where T: Freeze,

impl<T> RefUnwindSafe for Constant<T>
where T: RefUnwindSafe,

impl<T> Send for Constant<T>
where T: Send,

impl<T> Sync for Constant<T>
where T: Sync,

impl<T> Unpin for Constant<T>
where T: Unpin,

impl<T> UnwindSafe for Constant<T>
where T: UnwindSafe,

Blanket Implementations§

impl<S> AnimationExt for S
where S: SignalExt,

fn animated(self) -> WithMetadata<Self, Animation>
where Self: Sized,

Apply default animation to this reactive value Read more

fn with_animation(self, animation: Animation) -> WithMetadata<Self, Animation>
where Self: Sized,

Apply a specific animation to this reactive value Read more

impl<T> Any for T
where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T
where T: ?Sized,

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T
where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

impl<T> CloneToUninit for T
where T: Clone,

unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)

Performs copy-assignment from self to dest. Read more

impl<C, F, T1, T2, Output> FlattenMap<F, (T1, T2), Output> for C
where C: Signal<Output = (T1, T2)> + 'static, F: 'static + Clone + Fn(T1, T2) -> Output, T1: 'static, T2: 'static, Output: 'static,

fn flatten_map(self, f: F) -> Map<C, impl Clone + Fn((T1, T2)), Output>

Maps a function over the flattened elements of a nested tuple. Read more

impl<C, F, T1, T2, T3, Output> FlattenMap<F, (T1, T2, T3), Output> for C
where C: Signal<Output = ((T1, T2), T3)> + 'static, F: 'static + Clone + Fn(T1, T2, T3) -> Output, Output: 'static,

fn flatten_map(self, f: F) -> Map<C, impl Clone + Fn(((T1, T2), T3)), Output>

Maps a function over the flattened elements of a nested tuple. Read more

impl<T> From<!> for T

fn from(t: !) -> T

Converts to this type from the input type.

impl<T> From<T> for T

fn from(t: T) -> T

Returns the argument unchanged.

impl<T> IdentifiableExt for T

fn use_id<F, Id>(self, f: F) -> UseId<Self, F>
where F: Fn(&Self) -> Id, Id: Ord + Hash,

Wraps the value in a UseId with the provided identification function.

fn self_id(self) -> SelfId<Self>

Wraps the value in a SelfId, making the value serve as its own identifier.

impl<T, U> Into<U> for T
where U: From<T>,

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

impl<C> SignalExt for C
where C: Signal,

fn map<F, Output>(self, f: F) -> Map<Self, F, Output>
where F: 'static + Clone + Fn(Self::Output) -> Output, Output: 'static, Self: 'static,

Transforms the output of this signal using the provided function.

fn zip<B>(self, b: B) -> Zip<Self, B>
where B: Signal, Self::Output: Clone, <B as Signal>::Output: Clone,

Combines this signal with another signal into a tuple.

fn cached(self) -> Cached<Self>
where Self::Output: Clone,

Wraps this signal with caching to avoid redundant computations.

fn computed(self) -> Computed<Self::Output>
where Self: 'static,

Converts this signal into a type-erased Computed container.

fn with<T>(self, metadata: T) -> WithMetadata<Self, T>

Attaches metadata to this signal’s watcher notifications.

fn debounce(self, duration: Duration) -> Debounce<Self, DefaultExecutor>
where Self::Output: Clone,

Creates a debounced version of this signal. Read more

fn throttle(self, duration: Duration) -> Throttle<Self, DefaultExecutor>
where Self::Output: Clone,

Creates a throttled version of this signal. Read more

impl<T> ToOwned for T
where T: Clone,

type Owned = T

The resulting type after obtaining ownership.

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more

impl<T, U> TryFrom<U> for T
where U: Into<T>,

type Error = Infallible

The type returned in the event of a conversion error.

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.