Struct ThunkData

pub struct ThunkData { /* private fields */ }

The mutable data stored inside a thunk.

Implementations

impl ThunkData

pub fn new(closure: Closure) -> Self

Create new standard thunk data.

pub fn new_rev(orig: Closure, deps: FieldDeps) -> Self

Create new revertible thunk data.

pub fn init_cached(&mut self, rec_env: &[(Ident, Thunk)])

Initialize the cached value of a revertible thunk, given the recursive environment of the corresponding record. This function is a no-op on a standard thunk.

Invariant

This function must be called exactly once on a revertible thunk, after the initial construction. It’s part of its initialization. Calling it on a revertible thunks a second time, with a cached value which is not set to None, will panic.

Non-revertible thunks are not concerned: this function has no effect on them, even if called repeatedly.

This function is similar in spirit to setting the cached value to be the explicit function application given as built by saturate, but applied to arguments taken from rec_env. The major difference is that init_cached avoids the creation of the intermediate redex (fun id1 .. id n => orig) <closure@1> .. <closure@n> as well as the intermediate thunks and terms, because we can compute the application right away, in-place.

pub fn closure(&self) -> &Closure

Return a reference to the closure currently cached.

pub fn closure_mut(&mut self) -> &mut Closure

Return a mutable reference to the closure currently cached.

pub fn into_closure(self) -> Closure

Consume the data and return the cached closure.

pub fn update(&mut self, new: Closure)

Update the cached closure.

pub fn revert(thunk: &Rc<RefCell<ThunkData>>) -> Rc<RefCell<ThunkData>>

Create a freshly unevaluated thunk (minus ident_type) from a thunk, reverted to its original state before the first update.

For standard thunk data, the content is unchanged and shared with the original thunk: in this case, revert() is the same as cloning the original thunk.

For revertible thunk data, the result is independent from the original one: any update to one of the thunks doesn’t affect the other.

The new thunk is unlocked, whatever the locking status of the original thunk.

pub fn map<F>(&self, f: F) -> Self

where F: FnMut(&Closure) -> Closure,

Map a function over the content of the thunk to create a new independent thunk. If the thunk is revertible, the mapping function is applied on both the original expression and the cached expression.

The new thunk is unlocked, whatever the locking status of the original thunk.

pub fn deps(&self) -> FieldDeps

Return the potential field dependencies stored in a revertible thunk. See crate::transform::free_vars

Trait Implementations

impl Clone for ThunkData

fn clone(&self) -> ThunkData

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ThunkData

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

Formats the value using the given formatter.

impl PartialEq for ThunkData

fn eq(&self, other: &ThunkData) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ThunkData