Struct rustc_data_structures::bit_set::BitMatrix

pub struct BitMatrix<R: Idx, C: Idx> { /* fields omitted */ }

A fixed-size 2D bit matrix type with a dense representation.

R and C are index types used to identify rows and columns respectively; typically newtyped usize wrappers, but they can also just be usize.

All operations that involve a row and/or column index will panic if the index exceeds the relevant bound.

Methods

impl<R: Idx, C: Idx> BitMatrix<R, C>

pub fn new(num_rows: usize, num_columns: usize) -> BitMatrix<R, C>

Creates a new rows x columns matrix, initially empty.

pub fn from_row_n(row: &BitSet<C>, num_rows: usize) -> BitMatrix<R, C>

Creates a new matrix, with row used as the value for every row.

pub fn rows(&self) -> impl Iterator<Item = R>

pub fn insert(&mut self, row: R, column: C) -> bool

Sets the cell at (row, column) to true. Put another way, insert column to the bitset for row.

Returns true if this changed the matrix.

pub fn contains(&self, row: R, column: C) -> bool

Do the bits from row contain column? Put another way, is the matrix cell at (row, column) true? Put yet another way, if the matrix represents (transitive) reachability, can row reach column?

pub fn intersect_rows(&self, row1: R, row2: R) -> Vec<C>

Returns those indices that are true in rows a and b. This is an O(n) operation where n is the number of elements (somewhat independent from the actual size of the intersection, in particular).

pub fn union_rows(&mut self, read: R, write: R) -> bool

Adds the bits from row read to the bits from row write, and returns true if anything changed.

This is used when computing transitive reachability because if you have an edge write -> read, because in that case write can reach everything that read can (and potentially more).

pub fn union_row_with(&mut self, with: &BitSet<C>, write: R) -> bool

Adds the bits from with to the bits from row write, and returns true if anything changed.

pub fn insert_all_into_row(&mut self, row: R)

Sets every cell in row to true.

Important traits for &'_ [u8]

impl<'_> Read for &'_ [u8]impl<'_> Write for &'_ mut [u8]

pub fn words(&self) -> &[Word]

Gets a slice of the underlying words.

Important traits for BitIter<'a, T>

impl<'a, T: Idx> Iterator for BitIter<'a, T> type Item = T;

pub fn iter(&self, row: R) -> BitIter<C>

Iterates through all the columns set to true in a given row of the matrix.

pub fn count(&self, row: R) -> usize

Returns the number of elements in row.

Trait Implementations

impl<R: Idx, C: Idx, CTX> HashStable<CTX> for BitMatrix<R, C>

fn hash_stable<W: StableHasherResult>(
    &self,
    ctx: &mut CTX,
    hasher: &mut StableHasher<W>
)

impl<R: PartialEq + Idx, C: PartialEq + Idx> PartialEq<BitMatrix<R, C>> for BitMatrix<R, C>

fn eq(&self, other: &BitMatrix<R, C>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &BitMatrix<R, C>) -> bool

This method tests for !=.

impl<R: Clone + Idx, C: Clone + Idx> Clone for BitMatrix<R, C>

fn clone(&self) -> BitMatrix<R, C>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<R: Eq + Idx, C: Eq + Idx> Eq for BitMatrix<R, C>

impl<R: Debug + Idx, C: Debug + Idx> Debug for BitMatrix<R, C>

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

Formats the value using the given formatter.

impl<R: Encodable + Idx, C: Encodable + Idx> Encodable for BitMatrix<R, C>

fn encode<__SRC: Encoder>(&self, s: &mut __SRC) -> Result<(), __SRC::Error>

impl<R: Decodable + Idx, C: Decodable + Idx> Decodable for BitMatrix<R, C>

fn decode<__DRC: Decoder>(
    d: &mut __DRC
) -> Result<BitMatrix<R, C>, __DRC::Error>