Struct HashSetData 

pub struct HashSetData {
    pub keys: Arc<Vec<Arc<String>>>,
    pub index: HashMap<u64, Vec<u32>>,
}

HashSet storage — one keyspace, no values. Mirror of HashMapData with the values buffer dropped.

ADR-006 §2.7.15 / Q16 amendment (mirror of §2.7.9 FilterExpr / §2.7.13 Reference precedent for the cardinality-amendment shape, but Set is a HashMap sibling — full HeapValue::HashSet arm rather than pure-discriminator). Reuses the Stage C P1(b) Phase 2d Array shape (TypedBuffer<Arc<String>>) for the keys buffer verbatim. Insertion order is the canonical storage; the index is a sidecar acceleration structure for O(1) set.has(key).

String-only keyspace at landing (per the W9-set-methods owner audit’s Path A scope and the §2.7.15 Q16 ruling). Heterogeneous- element keysets (int-keyed, TypedObject-keyed) are explicitly out-of-scope; the Path B (TypedSet<T> per element kind) rebuild is a future Phase-2c amendment with measurement.

Fields

keys: Arc<Vec<Arc<String>>>

Insertion-ordered keys (string-typed buffer).

Storage shape: Arc<Vec<Arc<String>>> post-V3-S5 ckpt-5-prime²a (Migration shape (a) per supervisor 2026-05-15 ratification — TypedBuffer<T> wrapper layer retired wholesale at ckpt-4; Arc<Vec<T>> is the smallest delta preserving Arc::make_mut clone-on-write semantics).

index: HashMap<u64, Vec<u32>>

Eager bucket-index: hash → list of indices into keys array. Enables O(1) lookup at set.has(key). Hash is FNV-1a over the key string bytes — same as HashMapData::index.

Implementations

impl HashSetData

pub fn new() -> Self

Build an empty HashSetData with no entries.

pub fn from_keys(keys: Vec<Arc<String>>) -> Self

Build from a Vec<Arc<String>> of keys, computing the bucket index eagerly. Duplicate keys in the input are collapsed (insertion-order preserved, first occurrence wins).

pub fn len(&self) -> usize

Number of entries.

pub fn is_empty(&self) -> bool

Whether the set is empty.

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

Whether the set contains the given key. O(1) via the bucket index plus a short bucket scan for collision disambiguation.

pub fn insert(&mut self, key: Arc<String>) -> bool

Insert a key. Returns true if the key was newly added, false if it was already present (no-op in the latter case).

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

Remove the entry under key. Returns true if the key was present (and removed), false if no entry existed. The bucket index is updated to reflect the buffer’s post-removal indices: every entry after the removed slot shifts down by one position (mirror of HashMapData::remove).

Trait Implementations

impl Clone for HashSetData

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HashSetData

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

Formats the value using the given formatter.

impl Default for HashSetData

fn default() -> Self

Returns the “default value” for a type.