[][src]Struct wasm_bindgen::JsValue

pub struct JsValue { /* fields omitted */ }

Representation of an object owned by JS.

A JsValue doesn't actually live in Rust right now but actually in a table owned by the wasm-bindgen generated JS glue code. Eventually the ownership will transfer into wasm directly and this will likely become more efficient, but for now it may be slightly slow.

Methods

impl JsValue
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The null JS value constant.

The undefined JS value constant.

The true JS value constant.

The false JS value constant.

Creates a new JS value which is a string.

The utf-8 string provided is copied to the JS heap and the string will be owned by the JS garbage collector.

Creates a new JS value which is a number.

This function creates a JS value representing a number (a heap allocated number) and returns a handle to the JS version of it.

Creates a new JS value which is a boolean.

This function creates a JS object representing a boolean (a heap allocated boolean) and returns a handle to the JS version of it.

Creates a new JS value representing undefined.

Creates a new JS value representing null.

Creates a new JS symbol with the optional description specified.

This function will invoke the Symbol constructor in JS and return the JS object corresponding to the symbol created.

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.

Tests whether this JS value is a JS string.

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.

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.

Tests whether this JS value is null

Tests whether this JS value is undefined

Tests whether the type of this JS value is symbol

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

Tests whether the type of this JS value is function.

Trait Implementations

impl IntoWasmAbi for JsValue
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The wasm ABI type that this converts into when crossing the ABI boundary. Read more

impl<'a> IntoWasmAbi for &'a JsValue
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The wasm ABI type that this converts into when crossing the ABI boundary. Read more

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

impl RefFromWasmAbi for JsValue
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The wasm ABI type references to Self are recovered from.

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 JsCast for JsValue
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Test whether this JS value is an instance of the type T. Read more

Performs a dynamic cast (checked at runtime) of this value into the target type T. Read more

Performs a dynamic cast (checked at runtime) of this value into the target type T. Read more

Performs a zero-cost unchecked cast into the specified type. Read more

Performs a zero-cost unchecked cast into a reference to the specified type. Read more

impl Debug for JsValue
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impl PartialEq<JsValue> for JsValue
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This method tests for !=.

impl PartialEq<bool> for JsValue
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This method tests for !=.

impl PartialEq<str> for JsValue
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This method tests for !=.

impl<'a> PartialEq<&'a str> for JsValue
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This method tests for !=.

impl PartialEq<String> for JsValue
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This method tests for !=.

impl<'a> PartialEq<&'a String> for JsValue
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This method tests for !=.

impl PartialEq<i8> for JsValue
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This method tests for !=.

impl PartialEq<u8> for JsValue
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This method tests for !=.

impl PartialEq<i16> for JsValue
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This method tests for !=.

impl PartialEq<u16> for JsValue
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This method tests for !=.

impl PartialEq<i32> for JsValue
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This method tests for !=.

impl PartialEq<u32> for JsValue
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This method tests for !=.

impl PartialEq<f32> for JsValue
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This method tests for !=.

impl PartialEq<f64> for JsValue
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This method tests for !=.

impl Drop for JsValue
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impl<'a> From<&'a str> for JsValue
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impl<'a> From<&'a String> for JsValue
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impl From<String> for JsValue
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impl From<bool> for JsValue
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impl<'a, T> From<&'a T> for JsValue where
    T: JsCast
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impl<T> From<Option<T>> for JsValue where
    JsValue: From<T>, 
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impl From<i8> for JsValue
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impl From<u8> for JsValue
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impl From<i16> for JsValue
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impl From<u16> for JsValue
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impl From<i32> for JsValue
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impl From<u32> for JsValue
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impl From<f32> for JsValue
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impl From<f64> for JsValue
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impl Clone for JsValue
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Performs copy-assignment from source. Read more

impl<T: ?Sized> AsRef<JsValue> for Closure<T>
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impl AsRef<JsValue> for JsValue
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Auto Trait Implementations

impl !Send for JsValue

impl !Sync for JsValue

Blanket Implementations

impl<T, U> TryFrom for T where
    T: From<U>, 
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🔬 This is a nightly-only experimental API. (try_from)

The type returned in the event of a conversion error.

impl<T> From for T
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impl<T, U> TryInto for T where
    U: TryFrom<T>, 
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🔬 This is a nightly-only experimental API. (try_from)

The type returned in the event of a conversion error.

impl<T, U> Into for T where
    U: From<T>, 
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impl<T> Borrow for T where
    T: ?Sized
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impl<T> BorrowMut for T where
    T: ?Sized
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impl<T> Any for T where
    T: 'static + ?Sized
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impl<T> ToOwned for T where
    T: Clone
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