Struct BitmaskV 

pub struct BitmaskV {
    pub bitmask: Arc<Bitmask>,
    pub offset: usize,
    /* private fields */
}

BitmaskView

Zero-copy, bounds-checked window over a Bitmask.

Fields

• bitmask: backing Bitmask (shared via Arc).
• offset: start bit position in the parent mask.
• len: number of bits in the view.

Behaviour

• All indexing is relative to the view’s start.
• All accesses are in-bounds (panics if violated).
• No allocation or buffer copying occurs when creating or slicing views.

Example

use minarrow::Bitmask;
use minarrow::BitmaskV;

let mask = Bitmask::from_bools(&[true, false, true, true, false]);
let view = BitmaskV::new(mask, 1, 3); // window: false, true, true

assert_eq!(view.len(), 3);
assert!(!view.get(0));
assert!(view.get(1));
assert!(view.get(2));

Fields

bitmask: Arc<Bitmask>

The outer bitmask that this view is derived from - we retain a reference to it. Importantly, this is the full bitmask - not the view, and thus should not be accessed as though it were the view subset.

offset: usize

The index offset from 0 that for where this view starts from the outer bitmask

Implementations

impl BitmaskV

pub fn new(bitmask: Bitmask, offset: usize, len: usize) -> BitmaskV

Construct a view over bitmask[offset..offset+len).

pub fn len(&self) -> usize

Returns the length (number of bits) in the view.

pub fn is_empty(&self) -> bool

Returns true if the view is empty.

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

Returns the value at logical index i within the view.

pub fn as_bytes_window(&self) -> (&[u8], usize, usize)

Returns a slice of the bitmask’s bytes Due to the booleans being bitpacked in a u8, the slice retains:
Pos 0: Buffer: The bitpacked u8 buffer.
Pos 1: Offset: Bit offset indicating where it starts in that byte.
Pos 2: Length: Logical length in bits of the slice

pub fn to_bitmask(&self) -> Bitmask

Returns a Bitmask copy of the view.

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

Returns an iterator over all set bits (indices relative to the window).

pub fn iter_cleared(&self) -> impl Iterator<Item = usize>

Returns an iterator over all cleared bits (indices relative to the window).

pub fn count_ones(&self) -> usize

Counts number of set bits in the view.

pub fn count_zeros(&self) -> usize

Counts number of cleared bits in the view.

pub fn all_set(&self) -> bool

Returns true if all bits in the view are set.

pub fn all_unset(&self) -> bool

Returns true if all bits in the view are cleared.

pub fn has_cleared(&self) -> bool

Returns true if any bit in the view is cleared.

pub fn any_set(&self) -> bool

Returns true if any bit in the view is set.

pub fn slice(&self, offset: usize, len: usize) -> BitmaskV

Slices the view further by logical offset and len (relative to this window).

pub fn end(&self) -> usize

Returns the exclusive end row index of the window (relative to bitmask).

pub fn as_tuple(&self) -> (&Bitmask, usize, usize)

Returns the underlying window as a tuple: (&Bitmask, offset, len).

Trait Implementations

impl Clone for BitmaskV

fn clone(&self) -> BitmaskV

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Concatenate for BitmaskV

fn concat(self, other: BitmaskV) -> Result<BitmaskV, MinarrowError>

Concatenates two bitmask views by materialising both to owned bitmasks, concatenating them, and wrapping the result back in a view.

Notes

• This operation copies data from both views to create owned bitmasks.
• The resulting view has offset=0 and length equal to the combined length.

impl Debug for BitmaskV

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

Formats the value using the given formatter.

impl Display for BitmaskV

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

Formats the value using the given formatter.

impl Index<usize> for BitmaskV

fn index(&self, index: usize) -> &<BitmaskV as Index<usize>>::Output

Returns a reference to a constant true or false value depending on the bit at index.

Note: This does not return a reference into the underlying bitmask storage. The reference points to a compiler-promoted static constant, so its address is unrelated to the internal buffer. Use Self::get if you need the value directly.

type Output = bool

The returned type after indexing.

impl PartialEq for BitmaskV

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

Equality operator ==.

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

Inequality operator !=.

impl Shape for BitmaskV

fn shape(&self) -> ShapeDim

Returns arbitrary Shape dimension for any data shape

fn shape_1d(&self) -> usize

Returns the first dimension shape

fn shape_2d(&self) -> (usize, usize)

Returns the first and second dimension shapes

fn shape_3d(&self) -> (usize, usize, usize)

Returns the first, second and third dimension shapes

fn shape_4d(&self) -> (usize, usize, usize, usize)

Returns the first, second, third and fourth dimension shapes

impl StructuralPartialEq for BitmaskV