Struct ddo::core::utils::LexBitSet

pub struct LexBitSet<'a>(pub &'a BitSet);

A totally ordered Bitset wrapper. Useful to implement tie break mechanisms. This wrapper orders the bitsets according to the lexical order of their underlying bits.

Note:

This implementation uses the underlying words representation of the bitsets to perform several comparisons at once. Hence, using a LexBitSet should be more efficient than trying to establish the total ordering yourself with a loop on the 1-bits of the two sets.

Example

let mut a = BitSet::new(5);
let mut b = BitSet::new(5);

a.set(2, true);  // bits 0..2 match for a and b
b.set(2, true);

a.set(3, false); // a and b diverge on bit 3
b.set(3, true);  // and a has a 0 bit in that pos

a.set(4, true);  // anything that remains after
b.set(4, false); // the firs lexicographical difference is ignored

assert!(LexBitSet(&a) < LexBitSet(&b));

Trait Implementations

impl<'a> Debug for LexBitSet<'a>

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

Formats the value using the given formatter.

impl<'_> Eq for LexBitSet<'_>

Because LexBitSet defines a total order, it makes sense to consider that it also defines an equivalence relation. As such, it implements the standard Eq and PartialEq traits.

impl<'_> Ord for LexBitSet<'_>

The LexBitSet implements a total order on bitsets. As such, it must implement the standard trait Ord.

Note:

This implementation uses the underlying words representation of the bitsets to perform several comparisons at once. Hence, using a LexBitSet should be more efficient than trying to establish the total ordering yourself with a loop on the 1-bits of the two sets.

fn cmp(&self, other: &Self) -> Ordering

This method returns an [Ordering] between self and other.

#[must_use]fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl<'_> PartialEq<LexBitSet<'_>> for LexBitSet<'_>

Having LexBitSet to implement PartialEq means that it at least defines a partial equivalence relation.

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

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

#[must_use]fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'_> PartialOrd<LexBitSet<'_>> for LexBitSet<'_>

Because it is a total order, LexBitSet must also be a partial order. Hence, it must implement the standard trait PartialOrd.

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.