Struct Ctx 

pub struct Ctx { /* private fields */ }

The long-lived state of an evaluation, the equivalent of a JS realm: the unique-id source for closure identities, the builtin module cache, the environment free list, and the module loader — a resolver plus the cache of modules loaded through it (load).

A host creates one per program run, per Python realm object or per playground session, and passes &Ctx to every call. Imports are still resolved before evaluation, and loaded modules are Rc-held values. See docs/done/2026-10-02_elly-host.md.

Implementations

impl Ctx

pub fn new() -> Self

A context with a fresh id source and no module resolver, so every import fails. Used by crate::eval::eval and crate::eval::apply.

pub fn with_resolver(resolver: Box<dyn ModuleResolver>) -> Self

A context whose imports are served by resolver.

pub fn with_ids(ids: u64) -> Self

A context resuming an id source at ids so identities continue from an earlier context. Needed only when values outlive the Ctx that made them and a fresh one runs them: without it, a module’s reserved id block and later closure ids could alias, and __eq would call them equal.

Hosts keep one long-lived Ctx instead. The module bench is the remaining user: it wants a fresh context per timed pass, as run_eval gets one.

pub fn ids_used(&self) -> u64

Returns the current id source value to seed a successor context (see with_ids).

impl Ctx

pub fn load(&self, spec: &str) -> Result<Value, LoadError>

Loads a module and its import graph through this context’s resolver, returning the instance for spec. A module already in the cache is reused, so two loads that reach one module share its instance.

Without a resolver, every spec is LoadError::NotFound.

Loading is not re-entrant: nothing evaluates while a graph is instantiated, so no host callback can run a nested load.

pub fn load_source(&self, name: &str, src: &str) -> Result<Value, LoadError>

Loads a module from src under name, resolving its imports through this context’s resolver. The caller supplied the text, so it replaces whatever name held in the cache — the explicit reload.

pub fn instances(&self) -> Ref<'_, Instances>

The modules loaded so far, by canonical name.

Trait Implementations

impl Default for Ctx

fn default() -> Self

Returns the “default value” for a type.

impl Drop for Ctx

Frees the cells iteratively: dropping the list whole would recurse once per cell.

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.