GetIteratorFromMethod ( obj, method )

More information:

• ECMA reference

GetIterator ( obj, kind )

More information:

• ECMA reference

Abstract operationOrdinaryHasInstance ( C, O )

More information:

• ECMAScript reference

Converts aserde_json::Value to aJsValue.

§Example

useboa_engine::{Context, JsValue};letdata =r#"    {        "name": "John Doe",        "age": 43,        "phones": [            "+44 1234567",            "+44 2345678"        ]     }"#;letjson: serde_json::Value = serde_json::from_str(data).unwrap();letmutcontext = Context::default();letvalue = JsValue::from_json(&json,&mutcontext).unwrap();

Converts theJsValue to aserde_json::Value.

If theJsValue isUndefined, this method will returnNone.Otherwise it will return the correspondingserde_json::Value.

§Example

useboa_engine::{Context, JsValue};letdata =r#"    {        "name": "John Doe",        "age": 43,        "phones": [            "+44 1234567",            "+44 2345678"        ]     }"#;letjson: serde_json::Value = serde_json::from_str(data).unwrap();letmutcontext = Context::default();letvalue = JsValue::from_json(&json,&mutcontext).unwrap();letback_to_json = value.to_json(&mutcontext).unwrap();

This function is the inverse ofTryFromJs. It tries to convert aJsValue to a givenRust type.

A helper function for specifically printing object values

Deep strict equality.

If the value is an object/array, also compare the key-values.It usesstrict_equals() for non-object values.

Strict equality comparison.

This method is executed when doing strict equality comparisons with the=== operator.For more information, checkhttps://tc39.es/ecma262/#sec-strict-equality-comparison.

Abstract equality comparison.

This method is executed when doing abstract equality comparisons with the== operator.For more information, checkhttps://tc39.es/ecma262/#sec-abstract-equality-comparison

The internal comparison abstract operation SameValue(x, y),where x and y are ECMAScript language values, produces true or false.

More information:

• ECMAScript

The internal comparison abstract operationSameValueZero(x, y),wherex andy are ECMAScript language values, producestrue orfalse.

SameValueZero differs fromSameValue only in its treatment of+0 and-0.

More information:

• ECMAScript

Perform the binary+ operator on the value and return the result.

Perform the binary- operator on the value and return the result.

Perform the binary* operator on the value and return the result.

Perform the binary/ operator on the value and return the result.

Perform the binary% operator on the value and return the result.

Perform the binary** operator on the value and return the result.

Perform the binary& operator on the value and return the result.

Perform the binary| operator on the value and return the result.

Perform the binary^ operator on the value and return the result.

Perform the binary<< operator on the value and return the result.

Perform the binary>> operator on the value and return the result.

Perform the binary>>> operator on the value and return the result.

Abstract operationInstanceofOperator ( V, target )

More information:

• ECMAScript reference

Returns the negated value.

Returns the negated boolean value.

Abstract relational comparison

The comparisonx < y, wherex andy are values, producestrue,false,orundefined (which indicates that at least one operand isNaN).

In addition tox andy the algorithm takes a Boolean flag namedLeftFirst as a parameter.The flag is used to control the order in which operations with potentially visible side-effectsare performed uponx andy. It is necessary because ECMAScript specifies left to right evaluationof expressions. The default value ofLeftFirst istrue and indicates that thex parametercorresponds to an expression that occurs to the left of they parameter’s corresponding expression.

IfLeftFirst isfalse, the reverse is the case and operations must be performed upony beforex.

More Information:

• ECMAScript reference

The less than operator (<) returnstrue if the left operand is less than the right operand,andfalse otherwise.

More Information:

• MDN documentation
• ECMAScript reference

The less than or equal operator (<=) returnstrue if the left operand is less thanor equal to the right operand, andfalse otherwise.

More Information:

• MDN documentation
• ECMAScript reference

The greater than operator (>) returnstrue if the left operand is greater thanthe right operand, andfalse otherwise.

More Information:

• MDN documentation
• ECMAScript reference

The greater than or equal operator (>=) returnstrue if the left operand is greater thanor equal to the right operand, andfalse otherwise.

More Information:

• MDN documentation
• ECMAScript reference

Get the type of a value

This is the abstract operation Type(v), as described inhttps://tc39.es/ecma262/multipage/ecmascript-data-types-and-values.html#sec-ecmascript-language-types.

CheckJsValue::type_of if you need to call thetypeof operator.

Create a newJsValue.

Return the variant of this value.

Creates a newundefined value.

Creates a newnull value.

Creates a new number withNaN value.

Creates a new number withInfinity value.

Creates a new number with-Infinity value.

Creates a new number from a float.

Returns true if the value is an object.

Returns the object if the value is object, otherwiseNone.

Consumes the value and return the inner object if it was an object.

It determines if the value is a callable function with a[[Call]] internal method.

More information:

• ECMAScript reference

Returns the callable value if the value is callable, otherwiseNone.

Returns aJsFunction if the value is callable, otherwiseNone.This is equivalent toJsFunction::from_object(value.as_callable()?).

Returns true if the value is a constructor object.

Returns the constructor if the value is a constructor, otherwiseNone.

Returns true if the value is a promise object.

Returns the value as a promise if the value is a promise, otherwiseNone.

Returns true if the value is a regular expression object.

Returns the value as a regular expression if the value is a regexp, otherwiseNone.

Returns true if the value is a symbol.

Returns the symbol if the value is a symbol, otherwiseNone.

Returns true if the value is undefined.

Returns true if the value is null.

Returns true if the value is null or undefined.

Returns the number if the value is a finite integral Number value, otherwiseNone.

More information:

• ECMAScript reference

Returns true if the value is a number.

Returns the number if the value is a number, otherwiseNone.

Returns true if the value is a string.

Returns the string if the value is a string, otherwiseNone.

Returns true if the value is a boolean.

Returns the boolean if the value is a boolean, otherwiseNone.

Returns true if the value is a bigint.

Returns aBigInt if the value is aBigInt primitive.

Converts the value to abool type.

More information:

• ECMAScript

The abstract operationToPrimitive takes an input argument and an optional argumentPreferredType.

https://tc39.es/ecma262/#sec-toprimitive

7.1.13 ToBigInt ( argument )

More information:

• ECMAScript reference

Returns an object that implementsDisplay.

By default, the internals are not shown, but they can be toggledwithValueDisplay::internals method.

§Examples

useboa_engine::JsValue;letvalue = JsValue::new(3);println!("{}", value.display());

Converts the value to a string.

This function is equivalent toString(value) in JavaScript.

Converts the value to an Object.

This function is equivalent toObject(value) in JavaScript.

See:https://tc39.es/ecma262/#sec-toobject

Converts the value to aPropertyKey, that can be used as a key for properties.

Seehttps://tc39.es/ecma262/#sec-topropertykey

It returns value converted to a numeric value of typeNumber orBigInt.

See:https://tc39.es/ecma262/#sec-tonumeric

Converts a value to an integral 32-bit unsigned integer.

This function is equivalent tovalue | 0 in JavaScript

See:https://tc39.es/ecma262/#sec-touint32

Converts a value to an integral 32-bit signed integer.

See:https://tc39.es/ecma262/#sec-toint32

7.1.10 ToInt8 ( argument )

More information:

• ECMAScript reference

7.1.11 ToUint8 ( argument )

More information:

• ECMAScript reference

7.1.12 ToUint8Clamp ( argument )

More information:

• ECMAScript reference

7.1.8 ToInt16 ( argument )

More information:

• ECMAScript reference

7.1.9 ToUint16 ( argument )

More information:

• ECMAScript reference

7.1.15 ToBigInt64 ( argument )

More information:

• ECMAScript reference

7.1.16 ToBigUint64 ( argument )

More information:

• ECMAScript reference

Converts a value to a non-negative integer if it is a valid integer index value.

See:https://tc39.es/ecma262/#sec-toindex

Converts argument to an integer suitable for use as the length of an array-like object.

See:https://tc39.es/ecma262/#sec-tolength

Abstract operationToIntegerOrInfinity ( argument )

This method converts aValue to an integer representing itsNumber value withfractional part truncated, or to +∞ or -∞ when thatNumber value is infinite.

More information:

• ECMAScript reference

Converts a value to a double precision floating point.

This function is equivalent to the unary+ operator (+value) in JavaScript

See:https://tc39.es/ecma262/#sec-tonumber

Converts a value to a 16-bit floating point.

Converts a value to a 32 bit floating point.

This is a more specialized version ofto_numeric, includingBigInt.

This function is equivalent toNumber(value) in JavaScript

See:https://tc39.es/ecma262/#sec-tonumeric

Check if theValue can be converted to anObject

The abstract operationRequireObjectCoercible takes argument argument.It throws an error if argument is a value that cannot be converted to an Object usingToObject.It is defined byTable 15

More information:

• ECMAScript reference

The abstract operationToPropertyDescriptor.

More information:

• ECMAScript reference

typeof operator. Returns a string representing the type of thegiven ECMA Value.

More information:

• ECMAScript reference

Same asJsValue::type_of, but returning aJsString instead.

Maps aJsValue intoOption<T> where T is the result of anoperation on a defined value. If the value isJsValue::undefined,thenJsValue::map will return None.

§Example

useboa_engine::{Context, JsValue};letmutcontext = Context::default();letdefined_value = JsValue::from(5);letundefined = JsValue::undefined();letdefined_result = defined_value    .map(|v| v.add(&JsValue::from(5),&mutcontext))    .transpose()    .unwrap();letundefined_result = undefined    .map(|v| v.add(&JsValue::from(5),&mutcontext))    .transpose()    .unwrap();assert_eq!(defined_result,Some(JsValue::from(10u8)));assert_eq!(undefined_result,None);

Maps aJsValue intoT where T is the result of anoperation on a defined value. If the value isJsValue::undefined,thenJsValue::map will return the provided default value.

§Example

useboa_engine::{Context, JsValue};letmutcontext = Context::default();letdefined_value = JsValue::from(5);letundefined = JsValue::undefined();letdefined_result = defined_value    .map_or(Ok(JsValue::new(true)), |v| {        v.add(&JsValue::from(5),&mutcontext)    })    .unwrap();letundefined_result = undefined    .map_or(Ok(JsValue::new(true)), |v| {        v.add(&JsValue::from(5),&mutcontext)    })    .unwrap();assert_eq!(defined_result, JsValue::new(10));assert_eq!(undefined_result, JsValue::new(true));

Returns the argument unchanged.

CallsU::from(self).

That is, this conversion is whatever the implementation ofFrom<T> for U chooses to do.