Struct Environment 

pub struct Environment { /* private fields */ }

Environment for storing variables

Implementations

impl Environment

pub fn new() -> Self

Create a new global environment (with pre-allocated capacity)

pub fn with_parent(parent: Rc<RefCell<Environment>>) -> Self

Create a new environment with a parent

pub fn set(&mut self, name: String, value: Value)

Set a variable in the current scope

pub fn get(&self, name: &str) -> Option<Value>

Get a variable from this scope or parent scopes (优化路径)

pub fn has(&self, name: &str) -> bool

Check if a variable exists in this scope or parent scopes

pub fn update(&mut self, name: &str, value: Value) -> bool

Update a variable in the scope where it was defined Returns true if the variable was found and updated

pub fn keys(&self) -> Vec<String>

Get all variable names in this scope

pub fn clear(&mut self)

Clear all variables in this scope (not parent scopes)

Trait Implementations

impl Clone for Environment

fn clone(&self) -> Environment

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Environment

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

Formats the value using the given formatter.

impl Default for Environment

fn default() -> Self

Returns the “default value” for a type.