Struct Env 

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

A Sema environment: a chain of scopes with bindings.

Fields

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

parent: Option<Rc<Env>>

version: Rc<Cell<u64>>

Monotonic mutation counter the VM’s inline global cache is keyed on. Held behind an Rc so it travels with bindings: every Env handle cloned from this one shares this same cell. A mutation through any handle (a set! on a loaded unit’s per-form-VM clone, a different frame’s home-globals handle) is therefore observed by a cache entry keyed on any other handle to the same bindings — a fresh cell per clone would let a recursive reader keep serving a value its own handle’s set! never bumped (issue #82). A distinct bindings map (new/with_parent) still gets its own cell, since it is a genuinely independent scope.

Implementations

impl Env

pub fn new() -> Self

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

pub fn bump_version(&self)

Bump the version counter shared by every handle to this scope’s bindings. The VM’s inline global cache is keyed on it, so bumping after any mutation makes every VM observing this scope (through any clone) re-read instead of serving a stale cached value.

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!).

pub fn all_names(&self) -> Vec<Spur>

Collect all bound variable names across all scopes (for suggestions).

pub fn iter_bindings(&self, f: impl FnMut(Spur, &Value))

Iterate over bindings in the current scope only (not parent scopes).

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

Get a binding from the current scope only (not parent scopes).

pub fn replace_bindings( &self, new_bindings: impl IntoIterator<Item = (Spur, Value)>, )

Replace all bindings in the current scope with the given iterator. Used for bulk restore (e.g., undo/rollback).

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.