Struct LocalEnv 

pub struct LocalEnv<'a, V> { /* private fields */ }

A layered lexical environment for HIR locals.

Each binder (for-comp, scan, unfold, match arm) layers a child frame holding its few bindings over the enclosing environment instead of cloning the full local map; lookup walks the parent chain. LocalIds are unique within one lowered body, so frames never shadow one another — the chain is purely an ownership layering, and nested binders cost O(own bindings) instead of O(visible locals).

Implementations

impl<'a, V> LocalEnv<'a, V>

pub const fn root() -> Self

Create an empty root environment.

pub const fn from_bindings(bindings: Vec<(LocalId, V)>) -> Self

Create a root environment holding the given bindings.

pub const fn child<'b>(&'b self, bindings: Vec<(LocalId, V)>) -> LocalEnv<'b, V>

where 'a: 'b,

Layer a child frame holding bindings over this environment.

pub fn get(&self, id: LocalId) -> Option<&V>

Look up a local by its lexical identity, innermost frame first.

pub fn bind(&mut self, id: LocalId, value: V)

Bind or update a local in this frame.

Iterating binders (for-comp elements, scan/unfold steps) rebind the same LocalId once per iteration without growing the frame.

Trait Implementations

impl<'a, V: Debug> Debug for LocalEnv<'a, V>

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

Formats the value using the given formatter.

impl<V> Default for LocalEnv<'_, V>

fn default() -> Self

Returns the “default value” for a type.