Struct PersistentVec 

pub struct PersistentVec<T: Clone> { /* private fields */ }

Persistent vector with structural sharing, backed by an RRB-tree.

All “mutating” operations return a new version while the original is left unchanged. Structural sharing (via Arc) ensures that only O(log N) nodes are newly allocated per operation.

use scirs2_core::data_structures::PersistentVec;

let v0: PersistentVec<u32> = PersistentVec::new();
let v1 = v0.push_back(1);
let v2 = v1.push_back(2);

assert_eq!(v2.len(), 2);
assert_eq!(v2.get(0), Some(&1));
// v1 is still valid and unchanged:
assert_eq!(v1.len(), 1);

Implementations

impl<T: Clone> PersistentVec<T>

pub fn new() -> Self

Creates an empty persistent vector.

pub fn len(&self) -> usize

Returns the number of elements.

pub fn is_empty(&self) -> bool

Returns true when the vector contains no elements.

pub fn get(&self, index: usize) -> Option<&T>

Returns a reference to the element at index, or None if out of bounds.

O(log N) time, no allocation.

pub fn push_back(&self, value: T) -> Self

Returns a new vector with value appended to the end.

Amortised O(log N) — O(1) when the tail has room.

pub fn update(&self, index: usize, value: T) -> Option<Self>

Returns a new vector with the element at index replaced by value.

Returns None if index >= self.len(). O(log N) node allocations.

pub fn pop_back(&self) -> Option<(Self, T)>

Removes and returns the last element, returning (new_vec, value).

Returns None if the vector is empty. O(log N) in the worst case, O(1) common case.

pub fn iter(&self) -> PersistentVecIter<T>

Returns an iterator over references to elements in order.

Trait Implementations

impl<T: Clone + Clone> Clone for PersistentVec<T>

fn clone(&self) -> PersistentVec<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Clone> Default for PersistentVec<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Clone> FromIterator<T> for PersistentVec<T>

fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self

Creates a value from an iterator.