Enum JsValue

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pub enum JsValue {
    Undefined,
    Null,
    Boolean(bool),
    Number(f64),
    String(JsString),
    Symbol(Box<JsSymbol>),
    Object(JsObjectRef),
}

Expand description

A JavaScript value.

This is the primary type for representing all JavaScript values in the interpreter. Size-optimized to 16 bytes by boxing the rare Symbol variant.

§Conversions

use tsrun::JsValue;

// Numbers
let n: JsValue = 42.into();
let f: JsValue = 3.14.into();

// Strings
let s: JsValue = "hello".into();
let owned: JsValue = String::from("world").into();

// Booleans
let t: JsValue = true.into();

// Unit converts to undefined
let u: JsValue = ().into();
assert!(u.is_undefined());

§Type Coercion

Use to_boolean(), to_number(), to_string_value() for JS coercion:

use tsrun::JsValue;

// Falsy values
assert!(!JsValue::from(0).to_boolean());
assert!(!JsValue::from("").to_boolean());
assert!(!JsValue::Null.to_boolean());
assert!(!JsValue::Undefined.to_boolean());
assert!(!JsValue::from(f64::NAN).to_boolean());

// Truthy values
assert!(JsValue::from(1).to_boolean());
assert!(JsValue::from("x").to_boolean());

Variants§

§

Object(JsObjectRef)

Implementations§

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impl JsValue

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pub fn is_null_or_undefined(&self) -> bool

Check if this value is null or undefined

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pub fn is_callable(&self) -> bool

Check if this value is callable (a function)

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pub fn is_string(&self) -> bool

Check if this is a string value

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pub fn is_undefined(&self) -> bool

Check if this is undefined

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pub fn is_null(&self) -> bool

Check if this is null

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pub fn is_nullish(&self) -> bool

Check if this is null or undefined (alias for is_null_or_undefined)

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pub fn is_boolean(&self) -> bool

Check if this is a boolean

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pub fn is_number(&self) -> bool

Check if this is a number

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pub fn is_object(&self) -> bool

Check if this is an object

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pub fn is_symbol(&self) -> bool

Check if this is a symbol

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pub fn as_bool(&self) -> Option<bool>

Returns the boolean value if this is a Boolean, otherwise None

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

Returns the numeric value if this is a Number, otherwise None

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pub fn as_str(&self) -> Option<&str>

Returns the string slice if this is a String, otherwise None

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pub fn as_js_string(&self) -> Option<&JsString>

Returns a reference to the JsString if this is a String, otherwise None

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pub fn as_object(&self) -> Option<&Gc<JsObject>>

Returns a reference to the object if this is an Object, otherwise None

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pub fn as_symbol(&self) -> Option<&JsSymbol>

Returns a reference to the symbol if this is a Symbol, otherwise None

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pub fn guard_by(&self, guard: &Guard<JsObject>)

If this value is an object, add it to the guard. This keeps the object alive as long as the guard exists.

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pub fn to_boolean(&self) -> bool

Convert to boolean (ToBoolean)

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pub fn to_number(&self) -> f64

Convert to number (ToNumber)

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pub fn to_js_string(&self) -> JsString

Convert to string (ToString) Note: Prefer using Interpreter::to_js_string() which uses interned strings. This method is kept for internal use in value.rs, Debug impl, and tests.

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