Struct js_sys::Symbol

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

Implementations

impl Symbol

pub fn has_instance() -> Symbol

The Symbol.hasInstance well-known symbol is used to determine if a constructor object recognizes an object as its instance. The instanceof operator’s behavior can be customized by this symbol.

MDN documentation

impl Symbol

pub fn is_concat_spreadable() -> Symbol

The Symbol.isConcatSpreadable well-known symbol is used to configure if an object should be flattened to its array elements when using the Array.prototype.concat() method.

MDN documentation

impl Symbol

pub fn async_iterator() -> Symbol

The Symbol.asyncIterator well-known symbol specifies the default AsyncIterator for an object. If this property is set on an object, it is an async iterable and can be used in a for await...of loop.

MDN documentation

impl Symbol

pub fn iterator() -> Symbol

The Symbol.iterator well-known symbol specifies the default iterator for an object. Used by for...of.

MDN documentation

impl Symbol

pub fn match_() -> Symbol

The Symbol.match well-known symbol specifies the matching of a regular expression against a string. This function is called by the String.prototype.match() method.

MDN documentation

impl Symbol

pub fn replace() -> Symbol

The Symbol.replace well-known symbol specifies the method that replaces matched substrings of a string. This function is called by the String.prototype.replace() method.

For more information, see RegExp.prototype[@@replace]() and String.prototype.replace().

MDN documentation

impl Symbol

pub fn search() -> Symbol

The Symbol.search well-known symbol specifies the method that returns the index within a string that matches the regular expression. This function is called by the String.prototype.search() method.

For more information, see RegExp.prototype[@@search]() and String.prototype.search().

MDN documentation

impl Symbol

pub fn species() -> Symbol

The well-known symbol Symbol.species specifies a function-valued property that the constructor function uses to create derived objects.

MDN documentation

impl Symbol

pub fn split() -> Symbol

The Symbol.split well-known symbol specifies the method that splits a string at the indices that match a regular expression. This function is called by the String.prototype.split() method.

For more information, see RegExp.prototype[@@split]() and String.prototype.split(). MDN documentation

impl Symbol

pub fn to_primitive() -> Symbol

The Symbol.toPrimitive is a symbol that specifies a function valued property that is called to convert an object to a corresponding primitive value.

MDN documentation

impl Symbol

pub fn to_string_tag() -> Symbol

The Symbol.toStringTag well-known symbol is a string valued property that is used in the creation of the default string description of an object. It is accessed internally by the Object.prototype.toString() method.

MDN documentation

impl Symbol

pub fn for_(key: &str) -> Symbol

The Symbol.for(key) method searches for existing symbols in a runtime-wide symbol registry with the given key and returns it if found. Otherwise a new symbol gets created in the global symbol registry with this key.

MDN documentation

impl Symbol

pub fn key_for(sym: &Symbol) -> JsValue

The Symbol.keyFor(sym) method retrieves a shared symbol key from the global symbol registry for the given symbol.

MDN documentation

impl Symbol

pub fn to_string(&self) -> JsString

The toString() method returns a string representing the specified Symbol object.

MDN documentation

impl Symbol

pub fn unscopables() -> Symbol

The Symbol.unscopables well-known symbol is used to specify an object value of whose own and inherited property names are excluded from the with environment bindings of the associated object.

MDN documentation

impl Symbol

pub fn value_of(&self) -> Symbol

The valueOf() method returns the primitive value of a Symbol object.

MDN documentation

Methods from Deref<Target = JsValue>

pub const NULL: JsValue

pub const UNDEFINED: JsValue

pub const TRUE: JsValue

pub const FALSE: JsValue

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

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

Tests whether this JS value is a JS string.

pub fn as_string(&self) -> Option<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.

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>

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

Tests whether this JS value is null

pub fn is_undefined(&self) -> bool

Tests whether this JS value is undefined

pub fn is_symbol(&self) -> bool

Tests whether the type of this JS value is symbol

pub fn is_object(&self) -> bool

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

pub fn is_function(&self) -> bool

Tests whether the type of this JS value is function.

pub fn is_truthy(&self) -> bool

Tests whether the value is “truthy”.

pub fn is_falsy(&self) -> bool

Tests whether the value is “falsy”.

Trait Implementations

impl AsRef<JsValue> for Symbol

fn as_ref(&self) -> &JsValue

Performs the conversion.

impl AsRef<Symbol> for Symbol

fn as_ref(&self) -> &Symbol

Performs the conversion.

impl Clone for Symbol

fn clone(&self) -> Symbol

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Symbol

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

Formats the value using the given formatter.

impl Deref for Symbol

type Target = JsValue

The resulting type after dereferencing.

fn deref(&self) -> &JsValue

Dereferences the value.

impl From<JsValue> for Symbol

fn from(obj: JsValue) -> Symbol

Performs the conversion.

impl From<Symbol> for JsValue

fn from(obj: Symbol) -> JsValue

Performs the conversion.

impl FromWasmAbi for Symbol

type Abi = <JsValue as FromWasmAbi>::Abi

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

unsafe fn from_abi(js: Self::Abi) -> Self

Recover a Self from Self::Abi.

impl IntoWasmAbi for Symbol

type Abi = <JsValue as IntoWasmAbi>::Abi

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

fn into_abi(self) -> Self::Abi

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl<'a> IntoWasmAbi for &'a Symbol

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

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

fn into_abi(self) -> Self::Abi

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl JsCast for Symbol

fn instanceof(val: &JsValue) -> bool

Performs a dynamic instanceof check to see whether the JsValue provided is an instance of this type.

fn is_type_of(val: &JsValue) -> bool

Performs a dynamic check to see whether the JsValue provided is a value of this type.

fn unchecked_from_js(val: JsValue) -> Self

Performs a zero-cost unchecked conversion from a JsValue into an instance of Self

fn unchecked_from_js_ref(val: &JsValue) -> &Self

Performs a zero-cost unchecked conversion from a &JsValue into an instance of &Self.

pub fn has_type<T>(&self) -> bool where
    T: JsCast, 

Test whether this JS value has a type T.

pub fn dyn_into<T>(self) -> Result<T, Self> where
    T: JsCast, 

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

pub fn dyn_ref<T>(&self) -> Option<&T> where
    T: JsCast, 

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

pub fn unchecked_into<T>(self) -> T where
    T: JsCast, 

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

pub fn unchecked_ref<T>(&self) -> &T where
    T: JsCast, 

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

pub fn is_instance_of<T>(&self) -> bool where
    T: JsCast, 

Test whether this JS value is an instance of the type T.

impl OptionFromWasmAbi for Symbol

fn is_none(abi: &Self::Abi) -> bool

Tests whether the argument is a “none” instance. If so it will be deserialized as None, and otherwise it will be passed to FromWasmAbi.

impl OptionIntoWasmAbi for Symbol

fn none() -> Self::Abi

Returns an ABI instance indicating “none”, which JS will interpret as the None branch of this option.

impl<'a> OptionIntoWasmAbi for &'a Symbol

fn none() -> Self::Abi

Returns an ABI instance indicating “none”, which JS will interpret as the None branch of this option.

impl RefFromWasmAbi for Symbol

type Abi = <JsValue as RefFromWasmAbi>::Abi

The wasm ABI type references to Self are recovered from.

type Anchor = ManuallyDrop<Symbol>

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.

unsafe fn ref_from_abi(js: Self::Abi) -> Self::Anchor

Recover a Self::Anchor from Self::Abi.

impl WasmDescribe for Symbol

fn describe()