Struct Env 

pub struct Env { /* private fields */ }

Lexical scope environment using a stack of frames.

Each frame is a Vec of bindings, scanned linearly. For typical scope sizes (<20 variables), linear scan with Symbol (u32) comparison is faster than HashMap due to cache locality.

Implementations

impl Env

pub fn new() -> Self

pub fn pool(&self) -> &StringPool

Get a reference to the string pool.

pub fn pool_mut(&mut self) -> &mut StringPool

Get a mutable reference to the string pool.

pub fn intern(&mut self, s: &str) -> Symbol

Intern a string and return its symbol.

pub fn resolve(&self, sym: Symbol) -> &str

Resolve a symbol to its string.

pub fn push_scope(&mut self)

Push a new scope frame.

pub fn pop_scope(&mut self)

Pop the current scope frame.

pub fn define(&mut self, name: String, value: Value, mutable: bool)

Define a new variable in the current scope.

pub fn define_sym(&mut self, sym: Symbol, value: Value, mutable: bool)

Define a variable by symbol in the current scope.

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

Get a variable’s value by name, searching from innermost scope outward.

pub fn get_sym(&self, sym: Symbol) -> Option<&Value>

Get a variable’s value by symbol.

pub fn set(&mut self, name: &str, value: Value) -> Result<(), String>

Set an existing variable’s value. Returns error if not found or not mutable.

pub fn set_sym(&mut self, sym: Symbol, value: Value) -> Result<(), String>

Set a variable by symbol.

pub fn top_level(&self) -> HashMap<String, Value>

Get all top-level bindings (for engine.get_all()).

pub fn capture(&self) -> HashMap<String, Value>

Snapshot current environment for closure capture.

Trait Implementations

impl Clone for Env

fn clone(&self) -> Env

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Env

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

Formats the value using the given formatter.

impl Default for Env

fn default() -> Self

Returns the “default value” for a type.