Struct Segmentation 

pub struct Segmentation { /* private fields */ }

CSR-style segmentation: groups elements into segments via offset array.

offsets.len() == n_segments + 1; segment i spans offsets[i]..offsets[i+1].

Implementations

impl Segmentation

pub fn from_offsets(offsets: Vec<u32>) -> Self

Build from pre-computed offsets (e.g., [0, 5, 12, 20] for 3 segments).

Panics

Panics if offsets is empty (needs at least the sentinel [0]).

pub fn from_change_points<K: PartialEq>(keys: impl Iterator<Item = K>) -> Self

Build by detecting change-points in a key sequence.

Each run of equal consecutive keys becomes one segment.

Example

let seg = Segmentation::from_change_points(["A","A","A","B","B","C"].iter().copied());
assert_eq!(seg.count(), 3);

pub fn count(&self) -> usize

Number of segments.

pub fn segment(&self, seg: usize) -> Range<usize>

Element range for segment seg.

Panics

Panics if seg >= self.count().

pub fn segment_of(&self, elem: usize) -> usize

O(log n) binary-search lookup: which segment contains element elem?

Returns the segment index such that segment(idx) contains elem.

Panics

Panics if elem is out of range (>= total element count).

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

Iterate over all segment ranges in order.

Trait Implementations

impl Clone for Segmentation

fn clone(&self) -> Segmentation

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Segmentation

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

Formats the value using the given formatter.

impl PartialEq for Segmentation

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Segmentation