Struct Value 

pub struct Value<'a> { /* private fields */ }

Value with lifetime

Methods from Deref<Target = JSValue>

pub fn to_atom(&self, ctx: &ContextImpl) -> Result<Atom, i32>

convert value to atom. if value is not string or symbol, corece value to string then convert to atom.

Note: returned atom is cloned, caller should free it after use.

pub fn arith_cmp( &self, ctx: &ContextImpl, other: JSValue, ) -> Result<Option<Ordering>, i32>

arithmatic compare of two values. returns None only if value converted to NaN

pub fn arith_eq(&self, ctx: &ContextImpl, other: Self) -> Result<bool, i32>

test arithmatical equality (no-strict-eq): self == other?

pub fn strict_eq(&self, other: Self) -> bool

test strict equality (strict-eq): self === other?

pub fn is_same(&self, other: Self) -> bool

test if two values are strictly same. (-0, 0) not same

pub fn is_same0(&self, other: Self) -> bool

test if two values are strictly same. (-0, 0) is same

pub fn sort_cmp(&self, ctx: &ContextImpl, other: Self) -> Result<Ordering, i32>

get order of self and other.

pub fn opaque(&self) -> Option<NonNull<c_void>>

if the value is a user class instance, returns the opaque pointer if available

pub fn opaque_ref<T>(&self) -> Option<&T>

pub fn as_object_AsyncFunction(&self) -> Option<&AsyncFunction>

pub fn as_object_AsyncFunction_mut(&mut self) -> Option<&mut AsyncFunction>

pub fn call_async( &self, ctx: &mut ContextImpl, this_obj: JSValue, args: &[JSValue], flags: i32, ) -> Result<Promise, i32>

if value is a bytecode function, call it in async manner

pub fn as_object_BCFunction(&self) -> Option<&BCFunction>

pub fn as_object_BCFunction_mut(&mut self) -> Option<&mut BCFunction>

pub fn ensure_function(&self, ctx: &ContextImpl) -> Result<&Self, i32>

check if value self is a function or a callable object. raise exception if not.

pub fn as_object_BytecodeFunction(&self) -> Option<&BytecodeFunction>

pub fn as_object_BytecodeFunction_mut( &mut self, ) -> Option<&mut BytecodeFunction>

pub fn as_object_BoundFunction(&self) -> Option<&BoundFunction>

pub fn as_object_BoundFunction_mut(&mut self) -> Option<&mut BoundFunction>

pub fn call( &self, ctx: &ContextImpl, this_obj: JSValue, args: &[JSValue], ) -> JSResult

call self value. if value is not callable, returns ‘not function error’.

pub fn invoke( &self, ctx: &ContextImpl, method: Atom, args: &[JSValue], ) -> JSResult

call function self.method

pub fn invoke_defined( &self, ctx: &ContextImpl, method: Atom, args: &[JSValue], ) -> Result<Option<JSResult>, i32>

call self.method function if property method is neither null nor undefined. otherwise, returns None.

pub fn invoke_callable( &self, ctx: &ContextImpl, method: Atom, args: &[JSValue], ) -> Result<Option<JSResult>, i32>

call self.method if property method is callable. otherwise, returns None

method is not consumed

pub fn as_object_NativeFunctionWithData( &self, ) -> Option<&NativeFunctionWithData>

pub fn as_object_NativeFunctionWithData_mut( &mut self, ) -> Option<&mut NativeFunctionWithData>

pub fn match_native_callback(&self, callback: Callback, magic: i32) -> bool

Checks if a JSValue is native function of specific type. Matches both the callback pointer and magic.

pub fn install_fields( &mut self, ctx: &ContextImpl, entries: &'static [FieldDef], ) -> Result<(), i32>

pub fn is_integral(&self, ctx: &ContextImpl) -> Result<bool, i32>

test if the value is an intergral number. returns Err if test has exception.

pub fn to_number(&self, ctx: &ContextImpl) -> Result<JSValue, i32>

Convert value to number Int or Float64 (could be NaN).

pub fn to_numeric(&self, ctx: &ContextImpl) -> Result<JSValue, i32>

Convert value to Int, Float64 (could be NaN) value, or Err. Because BigInt is not supported, this method is same as coerce_to_number()

pub fn coerce_to_u8_clamp(&self, ctx: &ContextImpl) -> Result<u8, i32>

pub fn to_i32(&self, ctx: &ContextImpl) -> Result<i32, i32>

coerce value to i32.

pub fn to_i32_saturating(&self, ctx: &ContextImpl) -> Result<i32, i32>

pub fn to_i32_clamp( &self, ctx: &ContextImpl, min: i32, max: i32, min_offset: i32, ) -> Result<i32, i32>

pub fn to_u32(&self, ctx: &ContextImpl) -> Result<u32, i32>

pub fn to_i64_saturating(&self, ctx: &ContextImpl) -> Result<i64, i32>

pub fn to_i64_clamp( &self, ctx: &ContextImpl, min: i64, max: i64, neg_offset: i64, ) -> Result<i64, i32>

[min, max] is inclusive range.

pub fn to_f64(&self, ctx: &ContextImpl) -> Result<f64, i32>

coerce value to f64.

pub fn to_length(&self, ctx: &ContextImpl) -> Result<i64, i32>

convert value to length between [0, MAX_SAFE_INTEGER].

pub fn as_object(&self) -> Option<&Object>

pub fn as_object_mut(&mut self) -> Option<&mut Object>

pub unsafe fn as_object_unchecked(&self) -> &Object

pub unsafe fn as_object_mut_unchecked(&mut self) -> &mut Object

pub fn objectify(&self, ctx: &ContextImpl) -> Result<Object, i32>

Migrage value to object. Handles primitive wrapping according to ES6 ToObject conversion rules.

For example:

• object => object (as-is)
• 10 => [object 10]
• true => [object true]
• “abc” => [object “abc”]
• Symbol() => [object Symbol()]
• null, undefined => Error

pub fn is_constructor(&self) -> bool

pub fn prevent_extensions(&mut self, ctx: &ContextImpl) -> Result<bool, i32>

pub fn seal(&mut self, ctx: &ContextImpl, freeze: bool) -> Result<(), i32>

Seal self if it is an object.

pub fn is_sealed( &mut self, ctx: &ContextImpl, is_frozen: bool, ) -> Result<bool, i32>

check if value is sealed. Object value will check property, Non-object value is always treated as sealed.

pub fn retrive_object_payload( &self, ctx: &ContextImpl, class_id: ClassID, ) -> Result<&ObjectPayload, i32>

get object value’s payload borrow ref. if the value is not an object, or optionally is not the required class_id, throws type error.

pub fn retrive_object_payload_mut( &mut self, ctx: &ContextImpl, class_id: ClassID, ) -> Result<&mut ObjectPayload, i32>

get object value’s payload borrow ref. if the value is not an object, or optionally is not the required class_id, throws type error.

pub fn check_brand(&self, ctx: &ContextImpl, func: JSValue) -> Result<bool, i32>

check if self has own property suggested by func.<home_object>.<brand>.

pub fn add_brand( &mut self, ctx: &ContextImpl, home_obj: JSValue, ) -> Result<(), i32>

assign ‘home_obj’ a symbol as its ident, store that symbol in home_obj. field. if self is an object, then defined a property with the home_obj’s symbol as key.

pub fn set_private_field( &mut self, ctx: &ContextImpl, name: JSValue, val: JSValue, ) -> Result<(), i32>

pub fn get_private_field(&self, ctx: &ContextImpl, name: JSValue) -> JSResult

pub fn define_private_field( &mut self, ctx: &ContextImpl, name: JSValue, val: JSValue, ) -> Result<(), i32>

Private fields can be added even on non extensible objects or Proxies

pub fn define_property_value( &mut self, ctx: &ContextImpl, prop: Atom, value: JSValue, flags: u32, ) -> Result<bool, i32>

add or update a property with value. Note: prop is not consumed.

pub fn define_property_value_str( &mut self, ctx: &ContextImpl, prop: &str, val: JSValue, flags: u32, ) -> Result<bool, i32>

pub fn define_property_value_u32( &mut self, ctx: &ContextImpl, idx: u32, val: JSValue, flags: u32, ) -> Result<bool, i32>

pub fn define_property_value_i64( &mut self, ctx: &ContextImpl, idx: i64, val: JSValue, flags: u32, ) -> Result<bool, i32>

pub fn define_property_getset( &mut self, ctx: &ContextImpl, prop: Atom, getter: JSValue, setter: JSValue, flags: u32, ) -> Result<bool, i32>

pub fn create_data_property_u32( &mut self, ctx: &ContextImpl, idx: i64, val: JSValue, flags: u32, ) -> Result<bool, i32>

👎Deprecated: use JSValue::define_property_value_i64() or JSValue::define_property_value_u32()

pub fn delete_property( &mut self, ctx: &ContextImpl, prop: Atom, flags: u32, ) -> Result<bool, i32>

如果属性不可配置或无效对象则返回 false, 出现异常时返回 Err. flags 可以是 0、JS_PROP_THROW 或 JS_PROP_THROW_STRICT

pub fn delete_property_i64( &mut self, ctx: &ContextImpl, idx: i64, flags: u32, ) -> Result<bool, i32>

pub fn get_property(&self, ctx: &ContextImpl, prop: Atom) -> JSResult

get property by prop atom

pub fn get_property_value(&self, ctx: &ContextImpl, prop: JSValue) -> JSResult

get property by prop value

pub fn get_property_str(&self, ctx: &ContextImpl, prop: &str) -> JSResult

get property by str prop

pub fn get_property_u32(&self, ctx: &ContextImpl, idx: u32) -> JSResult

get property by u32 prop

pub fn get_property_i64(&self, ctx: &ContextImpl, idx: i64) -> JSResult

pub fn try_get_property_i64( &self, ctx: &ContextImpl, idx: i64, ) -> Result<Option<JSValue>, i32>

Check if self has a generalized numeric property idx. If yes, get property value of the prop idx. Returns Err for exception, Ok(Some(_)) if property exists, Ok(None) if proprty does not exist.

pub fn get_own_property_kvs( &self, ctx: &ContextImpl, flags: i32, kind: JSIteratorKindEnum, ) -> Result<Box<[(JSValue, JSValue)]>, i32>

Gets object’s own properties [key, value] pairs.

Returns list of [key, value] pairs, sorted according to js specification.

##Arguments##

• ctx - JavaScript context
• flags - Property filter flags
• kind - Iteration mode (keys, values, or entries)

Similar to JavaScript’s Object.keys(), Object.values(), Object.entries()

pub fn has_own_property( &self, ctx: &ContextImpl, prop: Atom, ) -> Result<bool, i32>

test if own property prop exists.

pub fn has_own_property_str( &self, ctx: &ContextImpl, prop: &str, ) -> Result<bool, i32>

pub fn get_own_property( &mut self, ctx: &ContextImpl, prop: Atom, ) -> Result<Option<JSPropertyDescriptor>, i32>

get description of own property.

pub fn is_extensible(&self, ctx: &ContextImpl) -> Result<bool, i32>

return Err() if exception (Proxy object only) or TRUE/FALSE

pub fn has_property(&self, ctx: &ContextImpl, prop: Atom) -> Result<bool, i32>

pub fn copy_data_properties_from( &mut self, ctx: &ContextImpl, source: &Self, excluded: &Self, setprop: bool, ) -> Result<(), i32>

copy and assign enumerable properties from source value to self. equivelent to js Object::assign(self, source)

pub fn get_length_prop(&self, ctx: &ContextImpl) -> Result<i64, i32>

Read length property defined on self. if length property is null or undefined, returns 0.

Returned length is in range [0, MAX_SAFE_INTEGER]

pub fn set_property( &self, ctx: &ContextImpl, prop: Atom, val: Self, ) -> Result<bool, i32>

pub fn set_property_value( &mut self, ctx: &ContextImpl, prop: Self, val: Self, flags: u32, ) -> Result<bool, i32>

pub fn set_property_u32( &mut self, ctx: &ContextImpl, idx: u32, val: Self, ) -> Result<bool, i32>

pub fn set_property_i64( &mut self, ctx: &ContextImpl, idx: i64, val: Self, ) -> Result<bool, i32>

pub fn set_property_str( &mut self, ctx: &ContextImpl, prop: &str, val: Self, ) -> Result<bool, i32>

pub fn prototype(&self, ctx: &ContextImpl) -> JSResult

Get prototype of value. Returns an object value if it has prototype, NULL for no prototype. Returns Err in case of Proxy object.

pub unsafe fn string_unchecked(&self) -> &StringRef

get a reference to value’s string description. won’t change value’s ref_count. will panic if value is not string type.

pub fn to_string_or_symbol(&self, ctx: &ContextImpl) -> Result<Self, i32>

Convert self to string or symbol value. (string is preferred)

pub fn to_propkey(&self, ctx: &ContextImpl) -> Result<JSValue, i32>

An alias for JSValue::to_string_or_symbol.

pub fn to_string(&self, ctx: &ContextImpl) -> Result<StringRef, i32>

Coerce value self to string. if self is symbol, will return Err.

pub fn to_string_non_undefined_or_null( &self, ctx: &ContextImpl, ) -> Result<StringRef, i32>

Coerce value val to string, but null or undefined are forbidden.

pub fn to_locale_string(&self, ctx: &ContextImpl) -> Result<JSValue, i32>

Invoking toLocaleString() method.

pub fn type_of(&self) -> Atom

get typeof value, equivalent to js typeof val

Note: returned atom is not cloned, if caller want keep reference, should clone it.

pub fn instance_of(&self, ctx: &ContextImpl, ctor: JSValue) -> Result<bool, i32>

Test if value self is instance of ctor. Equivalent to self instanceof ctor

pub fn to_primitive(&self, ctx: &ContextImpl, hint: i32) -> Result<JSValue, i32>

Coerce value to primitive (non-object) value

pub fn to_bool(&self) -> Result<bool, i32>

coerce value to bool

pub fn inspect(&self, ctx: &ContextImpl) -> Result<String, i32>

Get inspect representation string of self value. inspect() string is only used for interactive prompting, use to_string() for other cases.

pub fn is_exception(&self) -> bool

pub fn is_null(&self) -> bool

pub fn is_undefined(&self) -> bool

pub fn is_undefined_or_null(&self) -> bool

pub fn is_object(&self) -> bool

pub fn is_string(&self) -> bool

pub fn is_symbol(&self) -> bool

pub fn is_bool(&self) -> bool

pub fn is_int(&self) -> bool

pub fn is_float64(&self) -> bool

pub fn is_number(&self) -> bool

pub fn is_module(&self) -> bool

pub fn is_uninitialized(&self) -> bool

pub fn is_htmldda(&self) -> bool

pub fn is_function(&self) -> bool

Test if value self can be called, that means value is a:

• Compiled bytecode functions
• Proxy objects that wrapping a function
• Objects of native class which has call handler

pub fn is_error(&self) -> bool

pub fn as_object_Array(&self) -> Option<&Array>

pub fn as_object_Array_mut(&mut self) -> Option<&mut Array>

pub fn is_array(&self, ctx: &ContextImpl) -> Result<bool, i32>

check if self is an Array object return Err if exception (proxy case) or TRUE/FALSE

pub fn is_fast_array(&self) -> bool

test if value is fast array (could be one of Array, Argument, TypedArray fast array).

pub fn with_fast_array_values<R>( &self, f: impl FnOnce(&[JSValue]) -> R, ) -> Option<R>

if value is Array or Argument class, and is fast array, returns values slice.

pub fn with_fast_array_values_mut<R>( &mut self, f: impl FnOnce(&mut Vec<JSValue>) -> R, ) -> Option<R>

if value is Array or Argument class, and is a fast array, run closure with values slice, otherwise returns None.

pub fn to_array_length( &self, ctx: &ContextImpl, is_array_ctor: bool, ) -> Result<u32, i32>

coerce value to array length, which is in range [0, 2^32-1].

pub fn to_index(&self, ctx: &ContextImpl) -> Result<i64, i32>

coerce value to array index, which is in range [0, MAX_SAFE_INTEGER].

pub fn as_object_ArrayBuffer(&self) -> Option<&ArrayBuffer>

pub fn as_object_ArrayBuffer_mut(&mut self) -> Option<&mut ArrayBuffer>

pub fn as_object_AsyncGeneratorFunction( &self, ) -> Option<&AsyncGeneratorFunction>

pub fn as_object_AsyncGeneratorFunction_mut( &mut self, ) -> Option<&mut AsyncGeneratorFunction>

pub fn as_object_AsyncFromSyncIterator(&self) -> Option<&AsyncFromSyncIterator>

pub fn as_object_AsyncFromSyncIterator_mut( &mut self, ) -> Option<&mut AsyncFromSyncIterator>

pub fn get_iterator( &self, ctx: &ContextImpl, is_async: bool, ) -> Result<Option<Object>, i32>

Get self’s iterator object by calling [Symbol.iterator] or [Symbol.asyncIterator] method.

• In case when is_async=true and method [Symbol.asyncIterator] is not defined, try wrapping [Symbol.iterator] iterator (if any) into AsyncFromSyncIterator object.

• If neither [Symbol.iterator] nor [Symbol.asyncIterator] are defined, returns None indicating that self is not iterable.

pub fn get_iterator_must( &self, ctx: &ContextImpl, is_async: bool, ) -> Result<Object, i32>

Same as [get_iterator()], but will raise ‘not iterable’ error if get_iterator() returns None.

pub fn iter<'a>(&self, ctx: &'a ContextImpl) -> Result<ObjectIter<'a>, i32>

Return an object that implements Iterator trait to iterate JSValue. The iterator uses next() method to retrive next value.

pub fn as_object_MapIterator(&self) -> Option<&MapIterator>

pub fn as_object_MapIterator_mut(&mut self) -> Option<&mut MapIterator>

pub fn as_object_MapSet(&self) -> Option<&MapSet>

pub fn as_object_MapSet_mut(&mut self) -> Option<&mut MapSet>

pub fn as_object_Promise(&self) -> Option<&Promise>

pub fn as_object_Promise_mut(&mut self) -> Option<&mut Promise>

pub fn as_object_PromiseResolveFunc(&self) -> Option<&PromiseResolveFunc>

pub fn as_object_PromiseResolveFunc_mut( &mut self, ) -> Option<&mut PromiseResolveFunc>

pub fn as_object_Proxy(&self) -> Option<&Proxy>

pub fn as_object_Proxy_mut(&mut self) -> Option<&mut Proxy>

pub fn as_object_RegExp(&self) -> Option<&RegExp>

pub fn as_object_RegExp_mut(&mut self) -> Option<&mut RegExp>

pub fn as_object_DataView(&self) -> Option<&DataView>

pub fn as_object_DataView_mut(&mut self) -> Option<&mut DataView>

pub fn as_object_TypedArray(&self) -> Option<&TypedArray>

pub fn as_object_TypedArray_mut(&mut self) -> Option<&mut TypedArray>

Trait Implementations

impl<'a> Clone for Value<'a>

fn clone(&self) -> Value<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for Value<'a>

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

Formats the value using the given formatter.

impl<'a> Deref for Value<'a>

type Target = JSValue

The resulting type after dereferencing.

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

Dereferences the value.

impl<'a> DerefMut for Value<'a>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<'a> From<JSValue> for Value<'a>

fn from(value: JSValue) -> Self

Converts to this type from the input type.

impl<'a> From<Value<'a>> for JSValue

fn from(value: Value<'a>) -> Self

Converts to this type from the input type.

impl<'a> Copy for Value<'a>