Struct FunctionalDependency

pub struct FunctionalDependency {
    from: FixedBitSet,
    to: FixedBitSet,
}

FunctionalDependency represent a dependency of from –> to.

For columns ABCD, the FD AC –> B is represented as {0, 2} –> {1} using FixedBitset.

Fields

from: FixedBitSet

to: FixedBitSet

Implementations

impl FunctionalDependency

pub fn new(from: FixedBitSet, to: FixedBitSet) -> Self

Create a FunctionalDependency with bitset. This indicate a from –> to dependency.

pub fn from(&self) -> &FixedBitSet

pub fn to(&self) -> &FixedBitSet

pub fn grow(&mut self, columns: usize)

Grow the capacity of FunctionalDependency to columns, all new columns initialized to zero.

pub fn set_from(&mut self, column_index: usize, enabled: bool)

pub fn set_to(&mut self, column_index: usize, enabled: bool)

pub fn with_indices(column_cnt: usize, from: &[usize], to: &[usize]) -> Self

Create a FunctionalDependency with column indices. The order of the indices doesn’t matter. It is treated as a combination of columns.

fn with_key(column_cnt: usize, key_indices: &[usize]) -> Self

Create a FunctionalDependency with a key. The combination of these columns can determine all other columns.

pub fn with_constant(column_cnt: usize, constant_indices: &[usize]) -> Self

Create a FunctionalDependency for constant columns. These columns can be determined by any column.

pub fn into_parts(self) -> (FixedBitSet, FixedBitSet)

Trait Implementations

impl Clone for FunctionalDependency

fn clone(&self) -> FunctionalDependency

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for FunctionalDependency

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

Formats the value using the given formatter.

impl Default for FunctionalDependency

fn default() -> FunctionalDependency

Returns the “default value” for a type.

impl Display for FunctionalDependency

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

Formats the value using the given formatter.

impl Hash for FunctionalDependency

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for FunctionalDependency

fn eq(&self, other: &FunctionalDependency) -> 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 Eq for FunctionalDependency

impl StructuralPartialEq for FunctionalDependency