Struct BitMask 

pub struct BitMask { /* private fields */ }

Packed bitmask over N rows. One bit per row, stored in 64-bit words.

Iteration uses trailing_zeros() for O(popcount) scanning — entirely-zero words are skipped in O(1).

Implementations

impl BitMask

pub fn all_true(nrows: usize) -> Self

All rows set (all-true mask).

pub fn all_false(nrows: usize) -> Self

No rows set (all-false mask).

pub fn from_bools(bools: &[bool]) -> Self

Construct from a bool slice, one entry per row.

pub fn get(&self, i: usize) -> bool

Get bit at row i.

pub fn set(&mut self, i: usize)

Set bit at row i.

pub fn clear(&mut self, i: usize)

Clear bit at row i.

pub fn count_ones(&self) -> usize

Number of set bits (visible rows).

pub fn and(&self, other: &BitMask) -> BitMask

AND two masks together (chained filter semantics).

Panics if nrows differs — this is a programming error (same base data).

pub fn or(&self, other: &BitMask) -> BitMask

OR two masks together.

pub fn iter_set(&self) -> impl Iterator<Item = usize> + '_

Iterate over set row indices in ascending order (deterministic).

Uses word-level bit scanning with trailing_zeros() for O(popcount) iteration. Entirely-zero words are skipped in O(1).

pub fn nrows(&self) -> usize

Total rows this mask covers.

pub fn nwords(&self) -> usize

Number of backing u64 words.

pub fn size_bytes(&self) -> usize

Memory size in bytes.

Trait Implementations

impl Clone for BitMask

fn clone(&self) -> BitMask

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BitMask

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

Formats the value using the given formatter.