Struct ContentMemo 

pub struct ContentMemo<K, V>
where
    K: Eq + Hash,
{ /* private fields */ }

A single-threaded content-keyed memo. K is the content address; the value Rc<V> is a pure function of K (see the module invariant). A hit is a cheap Rc::clone.

Implementations

impl<K, V> ContentMemo<K, V>

where K: Eq + Hash + Clone,

pub fn new() -> ContentMemo<K, V>

A fresh empty memo.

pub fn get_or_compute(&self, key: K, compute: impl FnOnce() -> V) -> Rc<V>

Return the memoized value for key, computing + storing it via compute on a miss. A hit is a cheap Rc::clone and is byte-identical to a recompute by the module’s purity invariant (the caller’s responsibility — compute must be a pure function of key).

pub fn clear(&self)

Drop all entries. Call at a natural boundary (e.g. per top-level eval) so stale keys from a prior computation cannot persist and collide.

pub fn len(&self) -> usize

Number of memoized entries.

pub fn is_empty(&self) -> bool

Whether the memo is empty.

impl<T, V> ContentMemo<ContentKey<T>, V>

where T: Hash,

pub fn get_or_compute_keyed( &self, input: &T, compute: impl FnOnce(&T) -> V, ) -> Rc<V>

The keyed memo API — the M3 seal for the key↔content decoupling axis.

Derives the ContentKey from input internally (so the key is provably the content address of input, not some ambient value the caller passed alongside it) and hands the same &input to compute. A caller therefore cannot memoize under a key decoupled from the computed input — the decoupling has no constructor.

A hit is a cheap Rc::clone and is byte-identical to a recompute by the module’s purity invariant — compute must still be a pure function of its &T argument (the C1-ceiling purity axis this seal does NOT close; see ContentKey).

Trait Implementations

impl<K, V> Debug for ContentMemo<K, V>

where K: Debug + Eq + Hash, V: Debug,

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

Formats the value using the given formatter.

impl<K, V> Default for ContentMemo<K, V>

where K: Eq + Hash,

fn default() -> ContentMemo<K, V>

Returns the “default value” for a type.