[][src]Struct js_sys::AsyncIterator

#[repr(transparent)]
pub struct AsyncIterator { /* fields omitted */ }

Any object that conforms to the JS async iterator protocol. For example, something returned by myObject[Symbol.asyncIterator]().

MDN documentation

Methods

impl AsyncIterator[src]

pub fn next(&self) -> Result<Promise, JsValue>[src]

The next() method always has to return a Promise which resolves to an object with appropriate properties including done and value. If a non-object value gets returned (such as false or undefined), a TypeError ("iterator.next() returned a non-object value") will be thrown.

Methods from Deref<Target = JsValue>

pub const NULL: JsValue[src]

pub const UNDEFINED: JsValue[src]

pub const TRUE: JsValue[src]

pub const FALSE: JsValue[src]

pub fn as_f64(&self) -> Option<f64>[src]

Returns the f64 value of this JS value if it's an instance of a number.

If this JS value is not an instance of a number then this returns None.

pub fn is_string(&self) -> bool[src]

Tests whether this JS value is a JS string.

pub fn as_string(&self) -> Option<String>[src]

If this JS value is a string value, this function copies the JS string value into wasm linear memory, encoded as UTF-8, and returns it as a Rust String.

To avoid the copying and re-encoding, consider the JsString::try_from() function from js-sys instead.

If this JS value is not an instance of a string or if it's not valid utf-8 then this returns None.

UTF-16 vs UTF-8

JavaScript strings in general are encoded as UTF-16, but Rust strings are encoded as UTF-8. This can cause the Rust string to look a bit different than the JS string sometimes. For more details see the documentation about the str type which contains a few caveats about the encodings.

pub fn as_bool(&self) -> Option<bool>[src]

Returns the bool value of this JS value if it's an instance of a boolean.

If this JS value is not an instance of a boolean then this returns None.

pub fn is_null(&self) -> bool[src]

Tests whether this JS value is null

pub fn is_undefined(&self) -> bool[src]

Tests whether this JS value is undefined

pub fn is_symbol(&self) -> bool[src]

Tests whether the type of this JS value is symbol

pub fn is_object(&self) -> bool[src]

Tests whether typeof self == "object" && self !== null.

pub fn is_function(&self) -> bool[src]

Tests whether the type of this JS value is function.

pub fn is_truthy(&self) -> bool[src]

Tests whether the value is "truthy".

pub fn is_falsy(&self) -> bool[src]

Tests whether the value is "falsy".

Trait Implementations

impl AsRef<AsyncIterator> for AsyncIterator[src]

impl AsRef<JsValue> for AsyncIterator[src]

impl Clone for AsyncIterator[src]

impl Debug for AsyncIterator[src]

impl Deref for AsyncIterator[src]

type Target = JsValue

The resulting type after dereferencing.

impl From<AsyncIterator> for JsValue[src]

impl From<JsValue> for AsyncIterator[src]

impl FromWasmAbi for AsyncIterator[src]

type Abi = <JsValue as FromWasmAbi>::Abi

The wasm ABI type that this converts from when coming back out from the ABI boundary. Read more

impl IntoWasmAbi for AsyncIterator[src]

type Abi = <JsValue as IntoWasmAbi>::Abi

The wasm ABI type that this converts into when crossing the ABI boundary. Read more

impl<'a> IntoWasmAbi for &'a AsyncIterator[src]

type Abi = <&'a JsValue as IntoWasmAbi>::Abi

The wasm ABI type that this converts into when crossing the ABI boundary. Read more

impl JsCast for AsyncIterator[src]

impl OptionFromWasmAbi for AsyncIterator[src]

impl OptionIntoWasmAbi for AsyncIterator[src]

impl<'a> OptionIntoWasmAbi for &'a AsyncIterator[src]

impl RefFromWasmAbi for AsyncIterator[src]

type Abi = <JsValue as RefFromWasmAbi>::Abi

The wasm ABI type references to Self are recovered from.

type Anchor = ManuallyDrop<AsyncIterator>

The type that holds the reference to Self for the duration of the invocation of the function that has an &Self parameter. This is required to ensure that the lifetimes don't persist beyond one function call, and so that they remain anonymous. Read more

impl WasmDescribe for AsyncIterator[src]

Auto Trait Implementations

impl RefUnwindSafe for AsyncIterator

impl !Send for AsyncIterator

impl !Sync for AsyncIterator

impl Unpin for AsyncIterator

impl UnwindSafe for AsyncIterator

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> ReturnWasmAbi for T where
    T: IntoWasmAbi
[src]

type Abi = <T as IntoWasmAbi>::Abi

Same as IntoWasmAbi::Abi

impl<T> ToOwned for T where
    T: Clone
[src]

type Owned = T

The resulting type after obtaining ownership.

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

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

The type returned in the event of a conversion error.