Enum Value 

pub enum Value {
    Undefined,
    Null,
    Bool(bool),
    Number(f64),
    String(String),
    Array(Rc<Vec<Value>>),
    Object(Rc<Map>),
}

A JSON-like value.

Scalars are owned. Array and Object share their contents through Rc so an unchanged subtree can be returned by pointer.

Variants

Undefined

JavaScript undefined. Absent root, removal sentinel, or a read-back sparse hole.

Null

JavaScript null. A real value, treated as a map for type coercion.

Bool(bool)

A boolean.

Number(f64)

A number. Carries the raw f64 so -0.0 and NaN survive.

String(String)

A string.

Array(Rc<Vec<Value>>)

An array. Sparse holes are stored as Undefined, since a JavaScript hole reads back as undefined.

Object(Rc<Map>)

A map of string keys to values.

Implementations

impl Value

pub fn is_undefined(&self) -> bool

Whether this is Undefined.

pub fn as_array(&self) -> Option<&[Value]>

Borrow the array contents, if this is an array.

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

Borrow the map contents, if this is an object.

pub fn array(items: Vec<Value>) -> Value

Build an array value from items.

pub fn object(map: Map) -> Value

Build a map value from a Map.

pub fn from_pairs<K, I>(pairs: I) -> Value

where K: Into<String>, I: IntoIterator<Item = (K, Value)>,

Build a map value from key and value pairs, in order.

Convenience for tests and call sites that hold literal data.

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

Pointer equality for shared containers.

Returns true when both values are the same array or the same map by Rc pointer. This is the structural-sharing check: an untouched subtree returns its original pointer, so callers can detect “no change” cheaply. Scalars never share, so this returns false for them.

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

SameValue equality, the Object.is algorithm.

Numbers follow SameValue: every NaN equals every NaN regardless of bit pattern, and +0.0 does not equal -0.0. Containers compare by pointer, which is what the engine’s no-op check needs. This is not deep equality. Two distinct arrays with equal contents are not SameValue equal.

Trait Implementations

impl Clone for Value

fn clone(&self) -> Value

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Value

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

Formats the value using the given formatter.

impl From<&str> for Value

fn from(s: &str) -> Value

Converts to this type from the input type.

impl From<Map> for Value

fn from(map: Map) -> Value

Converts to this type from the input type.

impl From<String> for Value

fn from(s: String) -> Value

Converts to this type from the input type.

impl From<Vec<Value>> for Value

fn from(items: Vec<Value>) -> Value

Converts to this type from the input type.

impl From<bool> for Value

fn from(b: bool) -> Value

Converts to this type from the input type.

impl From<f32> for Value

fn from(n: f32) -> Value

Converts to this type from the input type.

impl From<f64> for Value

fn from(n: f64) -> Value

Converts to this type from the input type.

impl From<i32> for Value

fn from(n: i32) -> Value

Converts to this type from the input type.

impl From<u32> for Value

fn from(n: u32) -> Value

Converts to this type from the input type.

impl PartialEq for Value

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

Deep value equality.

Numbers follow SameValue, so NaN == NaN holds for any two NaN and tests can assert on it. This matches same_value on scalars and is deliberate. Do not switch the Number arm to plain ==, or NaN assertions break. Arrays and maps compare element by element, which is where this differs from same_value: two distinct arrays with equal contents are equal here but not under same_value. This is the equality assert_eq! uses in tests, not the engine’s no-op check.

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

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