Struct v8::Promise

#[repr(C)]
pub struct Promise(/* private fields */);

An instance of the built-in Promise constructor (ES6 draft).

Implementations

impl Promise

pub fn state(&self) -> PromiseState

Returns the value of the [PromiseState] field.

pub fn has_handler(&self) -> bool

Returns true if the promise has at least one derived promise, and therefore resolve/reject handlers (including default handler).

pub fn result<'s>(&self, scope: &mut HandleScope<'s>) -> Local<'s, Value>

Returns the content of the [[PromiseResult]] field. The Promise must not be pending.

pub fn catch<'s>( &self, scope: &mut HandleScope<'s>, handler: Local<'_, Function>, ) -> Option<Local<'s, Promise>>

Register a rejection handler with a promise.

See Self::then2.

pub fn then<'s>( &self, scope: &mut HandleScope<'s>, handler: Local<'_, Function>, ) -> Option<Local<'s, Promise>>

Register a resolution handler with a promise.

See Self::then2.

pub fn then2<'s>( &self, scope: &mut HandleScope<'s>, on_fulfilled: Local<'_, Function>, on_rejected: Local<'_, Function>, ) -> Option<Local<'s, Promise>>

Register a resolution/rejection handler with a promise. The handler is given the respective resolution/rejection value as an argument. If the promise is already resolved/rejected, the handler is invoked at the end of turn.

Methods from Deref<Target = Object>

pub fn set( &self, scope: &mut HandleScope<'_>, key: Local<'_, Value>, value: Local<'_, Value>, ) -> Option<bool>

Set only return Just(true) or Empty(), so if it should never fail, use result.Check().

pub fn set_with_receiver( &self, scope: &mut HandleScope<'_>, key: Local<'_, Value>, value: Local<'_, Value>, receiver: Local<'_, Object>, ) -> Option<bool>

SetWithReceiver only return Just(true) or Empty(), so if it should never fail, use result.Check().

pub fn set_index( &self, scope: &mut HandleScope<'_>, index: u32, value: Local<'_, Value>, ) -> Option<bool>

Set only return Just(true) or Empty(), so if it should never fail, use result.Check().

pub fn set_prototype( &self, scope: &mut HandleScope<'_>, prototype: Local<'_, Value>, ) -> Option<bool>

Set the prototype object. This does not skip objects marked to be skipped by proto and it does not consult the security handler.

pub fn get_constructor_name(&self) -> Local<'_, String>

Returns the name of the function invoked as a constructor for this object.

pub fn create_data_property( &self, scope: &mut HandleScope<'_>, key: Local<'_, Name>, value: Local<'_, Value>, ) -> Option<bool>

Implements CreateDataProperty (ECMA-262, 7.3.4).

Defines a configurable, writable, enumerable property with the given value on the object unless the property already exists and is not configurable or the object is not extensible.

Returns true on success.

pub fn define_own_property( &self, scope: &mut HandleScope<'_>, key: Local<'_, Name>, value: Local<'_, Value>, attr: PropertyAttribute, ) -> Option<bool>

Implements DefineOwnProperty.

In general, CreateDataProperty will be faster, however, does not allow for specifying attributes.

Returns true on success.

pub fn define_property( &self, scope: &mut HandleScope<'_>, key: Local<'_, Name>, descriptor: &PropertyDescriptor, ) -> Option<bool>

pub fn get<'s>( &self, scope: &mut HandleScope<'s>, key: Local<'_, Value>, ) -> Option<Local<'s, Value>>

pub fn get_with_receiver<'s>( &self, scope: &mut HandleScope<'s>, key: Local<'_, Value>, receiver: Local<'_, Object>, ) -> Option<Local<'s, Value>>

pub fn get_index<'s>( &self, scope: &mut HandleScope<'s>, index: u32, ) -> Option<Local<'s, Value>>

pub fn get_prototype<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, Value>>

Get the prototype object. This does not skip objects marked to be skipped by proto and it does not consult the security handler.

pub fn set_accessor( &self, scope: &mut HandleScope<'_>, name: Local<'_, Name>, getter: impl for<'s> MapFnTo<AccessorNameGetterCallback<'s>>, ) -> Option<bool>

Note: SideEffectType affects the getter only, not the setter.

pub fn set_accessor_with_setter( &self, scope: &mut HandleScope<'_>, name: Local<'_, Name>, getter: impl for<'s> MapFnTo<AccessorNameGetterCallback<'s>>, setter: impl for<'s> MapFnTo<AccessorNameSetterCallback<'s>>, ) -> Option<bool>

pub fn set_accessor_with_configuration( &self, scope: &mut HandleScope<'_>, name: Local<'_, Name>, configuration: AccessorConfiguration<'_>, ) -> Option<bool>

pub fn get_identity_hash(&self) -> NonZeroI32

Returns the V8 hash value for this value. The current implementation uses a hidden property to store the identity hash.

The return value will never be 0. Also, it is not guaranteed to be unique.

pub fn get_creation_context<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, Context>>

Returns the context in which the object was created.

pub fn get_own_property_names<'s>( &self, scope: &mut HandleScope<'s>, args: GetPropertyNamesArgs, ) -> Option<Local<'s, Array>>

This function has the same functionality as GetPropertyNames but the returned array doesn’t contain the names of properties from prototype objects.

pub fn get_property_names<'s>( &self, scope: &mut HandleScope<'s>, args: GetPropertyNamesArgs, ) -> Option<Local<'s, Array>>

Returns an array containing the names of the filtered properties of this object, including properties from prototype objects. The array returned by this method contains the same values as would be enumerated by a for-in statement over this object.

pub fn has( &self, scope: &mut HandleScope<'_>, key: Local<'_, Value>, ) -> Option<bool>

pub fn has_index(&self, scope: &mut HandleScope<'_>, index: u32) -> Option<bool>

pub fn has_own_property( &self, scope: &mut HandleScope<'_>, key: Local<'_, Name>, ) -> Option<bool>

HasOwnProperty() is like JavaScript’s Object.prototype.hasOwnProperty().

pub fn delete( &self, scope: &mut HandleScope<'_>, key: Local<'_, Value>, ) -> Option<bool>

pub fn delete_index( &self, scope: &mut HandleScope<'_>, index: u32, ) -> Option<bool>

pub fn internal_field_count(&self) -> usize

Gets the number of internal fields for this Object.

pub fn get_internal_field<'s>( &self, scope: &mut HandleScope<'s>, index: usize, ) -> Option<Local<'s, Data>>

Gets the data from an internal field.

pub unsafe fn get_aligned_pointer_from_internal_field( &self, index: i32, ) -> *const c_void

Gets a 2-byte-aligned native pointer from an internal field.

Safety

This field must have been set by SetAlignedPointerInInternalField, everything else leads to undefined behavior.

pub fn set_aligned_pointer_in_internal_field( &self, index: i32, value: *const c_void, )

Sets a 2-byte-aligned native pointer in an internal field. To retrieve such a field, GetAlignedPointerFromInternalField must be used.

pub fn is_api_wrapper(&self) -> bool

Returns true if this object can be generally used to wrap object objects. This means that the object either follows the convention of using embedder fields to denote type/instance pointers or is using the Wrap()/Unwrap() APIs for the same purpose. Returns false otherwise.

Note that there may be other objects that use embedder fields but are not used as API wrapper objects. E.g., v8::Promise may in certain configuration use embedder fields but promises are not generally supported as API wrappers. The method will return false in those cases.

pub fn set_integrity_level( &self, scope: &mut HandleScope<'_>, level: IntegrityLevel, ) -> Option<bool>

Sets the integrity level of the object.

pub fn set_internal_field(&self, index: usize, data: Local<'_, Data>) -> bool

Sets the data in an internal field. Returns false when the index is out of bounds, true otherwise.

pub fn get_private<'s>( &self, scope: &mut HandleScope<'s>, key: Local<'_, Private>, ) -> Option<Local<'s, Value>>

Functionality for private properties. This is an experimental feature, use at your own risk. Note: Private properties are not inherited. Do not rely on this, since it may change.

pub fn set_private( &self, scope: &mut HandleScope<'_>, key: Local<'_, Private>, value: Local<'_, Value>, ) -> Option<bool>

Functionality for private properties. This is an experimental feature, use at your own risk. Note: Private properties are not inherited. Do not rely on this, since it may change.

pub fn delete_private( &self, scope: &mut HandleScope<'_>, key: Local<'_, Private>, ) -> Option<bool>

Functionality for private properties. This is an experimental feature, use at your own risk. Note: Private properties are not inherited. Do not rely on this, since it may change.

pub fn has_private( &self, scope: &mut HandleScope<'_>, key: Local<'_, Private>, ) -> Option<bool>

Functionality for private properties. This is an experimental feature, use at your own risk. Note: Private properties are not inherited. Do not rely on this, since it may change.

pub fn get_property_attributes( &self, scope: &mut HandleScope<'_>, key: Local<'_, Value>, ) -> Option<PropertyAttribute>

Gets the property attributes of a property which can be PropertyAttribute::NONE or any combination of PropertyAttribute::READ_ONLY, PropertyAttribute::DONT_ENUM and PropertyAttribute::DONT_DELETE. Returns PropertyAttribute::NONE when the property doesn’t exist.

pub fn get_own_property_descriptor<'s>( &self, scope: &mut HandleScope<'s>, key: Local<'_, Name>, ) -> Option<Local<'s, Value>>

Implements Object.getOwnPropertyDescriptor(O, P), see https://tc39.es/ecma262/#sec-object.getownpropertydescriptor.

pub fn preview_entries<'s>( &self, scope: &mut HandleScope<'s>, ) -> (Option<Local<'s, Array>>, bool)

If this object is a Set, Map, WeakSet or WeakMap, this returns a representation of the elements of this object as an array. If this object is a SetIterator or MapIterator, this returns all elements of the underlying collection, starting at the iterator’s current position.

Also returns a boolean, indicating whether the returned array contains key & values (for example when the value is Set.entries()).

pub fn get_real_named_property<'s>( &self, scope: &mut HandleScope<'s>, key: Local<'_, Name>, ) -> Option<Local<'s, Value>>

If result.IsEmpty() no real property was located on the object or in the prototype chain. This means interceptors in the prototype chain are not called.

pub fn has_real_named_property( &self, scope: &mut HandleScope<'_>, key: Local<'_, Name>, ) -> Option<bool>

pub fn get_real_named_property_attributes( &self, scope: &mut HandleScope<'_>, key: Local<'_, Name>, ) -> Option<PropertyAttribute>

Gets the property attributes of a real property which can be None or any combination of ReadOnly, DontEnum and DontDelete. Interceptors in the prototype chain are not called.

Methods from Deref<Target = Value>

pub fn is_undefined(&self) -> bool

Returns true if this value is the undefined value. See ECMA-262 4.3.10.

pub fn is_null(&self) -> bool

Returns true if this value is the null value. See ECMA-262 4.3.11.

pub fn is_null_or_undefined(&self) -> bool

Returns true if this value is either the null or the undefined value. See ECMA-262 4.3.11. and 4.3.12

pub fn is_true(&self) -> bool

Returns true if this value is true. This is not the same as BooleanValue(). The latter performs a conversion to boolean, i.e. the result of Boolean(value) in JS, whereas this checks value === true.

pub fn is_false(&self) -> bool

Returns true if this value is false. This is not the same as !BooleanValue(). The latter performs a conversion to boolean, i.e. the result of !Boolean(value) in JS, whereas this checks value === false.

pub fn is_name(&self) -> bool

Returns true if this value is a symbol or a string. This is equivalent to typeof value === 'string' || typeof value === 'symbol' in JS.

pub fn is_string(&self) -> bool

Returns true if this value is an instance of the String type. See ECMA-262 8.4.

pub fn is_symbol(&self) -> bool

Returns true if this value is a symbol. This is equivalent to typeof value === 'symbol' in JS.

pub fn is_function(&self) -> bool

Returns true if this value is a function.

pub fn is_array(&self) -> bool

Returns true if this value is an array. Note that it will return false for an Proxy for an array.

pub fn is_object(&self) -> bool

Returns true if this value is an object.

pub fn is_big_int(&self) -> bool

Returns true if this value is a bigint. This is equivalent to typeof value === 'bigint' in JS.

pub fn is_boolean(&self) -> bool

Returns true if this value is boolean. This is equivalent to typeof value === 'boolean' in JS.

pub fn is_number(&self) -> bool

Returns true if this value is a number.

pub fn is_external(&self) -> bool

Returns true if this value is an External object.

pub fn is_int32(&self) -> bool

Returns true if this value is a 32-bit signed integer.

pub fn is_uint32(&self) -> bool

Returns true if this value is a 32-bit unsigned integer.

pub fn is_date(&self) -> bool

Returns true if this value is a Date.

pub fn is_arguments_object(&self) -> bool

Returns true if this value is an Arguments object.

pub fn is_big_int_object(&self) -> bool

Returns true if this value is a BigInt object.

pub fn is_boolean_object(&self) -> bool

Returns true if this value is a Boolean object.

pub fn is_number_object(&self) -> bool

Returns true if this value is a Number object.

pub fn is_string_object(&self) -> bool

Returns true if this value is a String object.

pub fn is_symbol_object(&self) -> bool

Returns true if this value is a Symbol object.

pub fn is_native_error(&self) -> bool

Returns true if this value is a NativeError.

pub fn is_reg_exp(&self) -> bool

Returns true if this value is a RegExp.

pub fn is_async_function(&self) -> bool

Returns true if this value is an async function.

pub fn is_generator_function(&self) -> bool

Returns true if this value is a Generator function.

pub fn is_promise(&self) -> bool

Returns true if this value is a Promise.

pub fn is_map(&self) -> bool

Returns true if this value is a Map.

pub fn is_set(&self) -> bool

Returns true if this value is a Set.

pub fn is_map_iterator(&self) -> bool

Returns true if this value is a Map Iterator.

pub fn is_set_iterator(&self) -> bool

Returns true if this value is a Set Iterator.

pub fn is_generator_object(&self) -> bool

Returns true if this value is a Generator Object.

pub fn is_weak_map(&self) -> bool

Returns true if this value is a WeakMap.

pub fn is_weak_set(&self) -> bool

Returns true if this value is a WeakSet.

pub fn is_array_buffer(&self) -> bool

Returns true if this value is an ArrayBuffer.

pub fn is_array_buffer_view(&self) -> bool

Returns true if this value is an ArrayBufferView.

pub fn is_typed_array(&self) -> bool

Returns true if this value is one of TypedArrays.

pub fn is_uint8_array(&self) -> bool

Returns true if this value is an Uint8Array.

pub fn is_uint8_clamped_array(&self) -> bool

Returns true if this value is an Uint8ClampedArray.

pub fn is_int8_array(&self) -> bool

Returns true if this value is an Int8Array.

pub fn is_uint16_array(&self) -> bool

Returns true if this value is an Uint16Array.

pub fn is_int16_array(&self) -> bool

Returns true if this value is an Int16Array.

pub fn is_uint32_array(&self) -> bool

Returns true if this value is an Uint32Array.

pub fn is_int32_array(&self) -> bool

Returns true if this value is an Int32Array.

pub fn is_float32_array(&self) -> bool

Returns true if this value is a Float32Array.

pub fn is_float64_array(&self) -> bool

Returns true if this value is a Float64Array.

pub fn is_big_int64_array(&self) -> bool

Returns true if this value is a BigInt64Array.

pub fn is_big_uint64_array(&self) -> bool

Returns true if this value is a BigUint64Array.

pub fn is_data_view(&self) -> bool

Returns true if this value is a DataView.

pub fn is_shared_array_buffer(&self) -> bool

Returns true if this value is a SharedArrayBuffer. This is an experimental feature.

pub fn is_proxy(&self) -> bool

Returns true if this value is a JavaScript Proxy.

pub fn is_wasm_memory_object(&self) -> bool

Returns true if this value is a WasmMemoryObject.

pub fn is_wasm_module_object(&self) -> bool

Returns true if this value is a WasmModuleObject.

pub fn is_module_namespace_object(&self) -> bool

Returns true if the value is a Module Namespace Object.

pub fn strict_equals(&self, that: Local<'_, Value>) -> bool

pub fn same_value(&self, that: Local<'_, Value>) -> bool

pub fn same_value_zero(&self, that: Local<'_, Value>) -> bool

Implements the the abstract operation SameValueZero, which is defined in ECMA-262 6th edition § 7.2.10 (http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero).

This operation is used to compare values for the purpose of insertion into a Set, or determining whether Map keys are equivalent. Its semantics are almost the same as strict_equals() and same_value(), with the following important distinctions:

• It considers NaN equal to NaN (unlike strict_equals()).
• It considers -0 equal to 0 (unlike same_value()).

pub fn to_big_int<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, BigInt>>

pub fn to_number<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, Number>>

pub fn to_string<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, String>>

pub fn to_rust_string_lossy(&self, scope: &mut HandleScope<'_>) -> String

Convenience function not present in the original V8 API.

pub fn to_detail_string<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, String>>

pub fn to_object<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, Object>>

pub fn to_integer<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, Integer>>

pub fn to_uint32<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, Uint32>>

pub fn to_int32<'s>( &self, scope: &mut HandleScope<'s>, ) -> Option<Local<'s, Int32>>

pub fn to_boolean<'s>( &self, scope: &mut HandleScope<'s, ()>, ) -> Local<'s, Boolean>

Perform the equivalent of Boolean(value) in JS. This can never fail.

pub fn instance_of( &self, scope: &mut HandleScope<'_>, object: Local<'_, Object>, ) -> Option<bool>

pub fn number_value(&self, scope: &mut HandleScope<'_>) -> Option<f64>

pub fn integer_value(&self, scope: &mut HandleScope<'_>) -> Option<i64>

pub fn uint32_value(&self, scope: &mut HandleScope<'_>) -> Option<u32>

pub fn int32_value(&self, scope: &mut HandleScope<'_>) -> Option<i32>

pub fn boolean_value(&self, scope: &mut HandleScope<'_, ()>) -> bool

pub fn get_hash(&self) -> NonZeroI32

Returns the V8 hash value for this value. The current implementation uses a hidden property to store the identity hash on some object types.

The return value will never be 0. Also, it is not guaranteed to be unique.

pub fn type_of<'s>(&self, scope: &mut HandleScope<'s, ()>) -> Local<'s, String>

pub fn type_repr(&self) -> &'static str

Utility method that returns human readable representation of the underlying value.

Methods from Deref<Target = Data>

pub fn is_big_int(&self) -> bool

Returns true if this data is a BigInt.

pub fn is_boolean(&self) -> bool

Returns true if this data is a Boolean.

pub fn is_context(&self) -> bool

Returns true if this data is a Context.

pub fn is_fixed_array(&self) -> bool

Returns true if this data is a FixedArray.

pub fn is_function_template(&self) -> bool

Returns true if this data is a FunctionTemplate.

pub fn is_module(&self) -> bool

Returns true if this data is a Module.

pub fn is_module_request(&self) -> bool

Returns true if this data is a ModuleRequest.

pub fn is_name(&self) -> bool

Returns true if this data is a Name.

pub fn is_number(&self) -> bool

Returns true if this data is a Number.

pub fn is_object_template(&self) -> bool

Returns true if this data is a ObjectTemplate.

pub fn is_primitive(&self) -> bool

Returns true if this data is a Primitive.

pub fn is_private(&self) -> bool

Returns true if this data is a Private.

pub fn is_string(&self) -> bool

Returns true if this data is a String.

pub fn is_symbol(&self) -> bool

Returns true if this data is a Symbol.

pub fn is_value(&self) -> bool

Returns true if this data is a Value.

Trait Implementations

impl Debug for Promise

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

Formats the value using the given formatter.

impl Deref for Promise

type Target = Object

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for Promise

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'s> PartialEq<Data> for Promise

fn eq(&self, other: &Data) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'s> PartialEq<Object> for Promise

fn eq(&self, other: &Object) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'s> PartialEq<Promise> for Data

fn eq(&self, other: &Promise) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'s> PartialEq<Promise> for Object

fn eq(&self, other: &Promise) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'s> PartialEq<Promise> for Value

fn eq(&self, other: &Promise) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'s> PartialEq<Value> for Promise

fn eq(&self, other: &Value) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'s> PartialEq for Promise

fn eq(&self, other: &Promise) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Promise