Struct Env 

pub struct Env {
    pub bindings: Rc<RefCell<HashMap<Spur, Value>>>,
    pub parent: Option<Rc<Env>>,
    pub version: Cell<u64>,
}

A Sema environment: a chain of scopes with bindings.

Fields

bindings: Rc<RefCell<HashMap<Spur, Value>>>

parent: Option<Rc<Env>>

version: Cell<u64>

Implementations

impl Env

pub fn new() -> Env

pub fn with_parent(parent: Rc<Env>) -> Env

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

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

pub fn set(&self, name: Spur, val: Value)

pub fn set_str(&self, name: &str, val: Value)

pub fn update(&self, name: Spur, val: Value)

Update a binding that already exists in the current scope.

pub fn take(&self, name: Spur) -> Option<Value>

Remove and return a binding from the current scope only.

pub fn take_anywhere(&self, name: Spur) -> Option<Value>

Remove and return a binding from any scope in the parent chain.

pub fn set_existing(&self, name: Spur, val: Value) -> bool

Set a variable in the scope where it’s defined (for set!).

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<(), Error>

Formats the value using the given formatter.

impl Default for Env

fn default() -> Env

Returns the “default value” for a type.