Struct VariableStore 

pub struct VariableStore { /* private fields */ }

Type-erased variable store

Stores variables with type erasure using Box<dyn Any + 'static>. Variables are owned by the store and cannot reference each other (which aligns with Lisp’s immutable data structure semantics).

Thread Safety

The store is protected by a Mutex and can be accessed from multiple threads safely. In practice, it’s accessed via a global static in the subprocess binary.

Constraints (ODD-0038 Decision 7)

• Box<dyn Any + 'static> requires owned data
• No inter-variable references possible
• Aligns with Lisp semantics (immutable data structures)

Examples

use oxur_repl::subprocess::VariableStore;

let mut store = VariableStore::new();

// Store a value
store.set("x".to_string(), 42i32);

// Retrieve with correct type
let x: Option<&i32> = store.get("x");
assert_eq!(x, Some(&42));

// Wrong type returns None
let x: Option<&String> = store.get("x");
assert_eq!(x, None);

Implementations

impl VariableStore

pub fn new() -> Self

Create a new empty variable store

pub fn set<T: 'static + Send>(&mut self, name: String, value: T)

Store a variable with type erasure

Arguments

• name - Variable name
• value - Value to store (must be 'static and Send)

Type Parameters

• T - Type of value (must be 'static and Send)

pub fn get<T: 'static>(&self, name: &str) -> Option<&T>

Get a variable with type checking

Returns Some(&T) if the variable exists and has the correct type, None otherwise.

Arguments

• name - Variable name

Type Parameters

• T - Expected type of variable

pub fn get_mut<T: 'static>(&mut self, name: &str) -> Option<&mut T>

Get a mutable reference to a variable

Returns Some(&mut T) if the variable exists and has the correct type, None otherwise.

Arguments

• name - Variable name

Type Parameters

• T - Expected type of variable

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

Check if a variable exists

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

Remove a variable

Returns true if the variable existed and was removed

pub fn len(&self) -> usize

Get number of stored variables

pub fn is_empty(&self) -> bool

Check if store is empty

pub fn clear(&mut self)

Clear all variables

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

List all variable names

Trait Implementations

impl Debug for VariableStore

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

Formats the value using the given formatter.

impl Default for VariableStore

fn default() -> VariableStore

Returns the “default value” for a type.