Enum Comparison 

pub enum Comparison {
    Equal,
    NotEqual,
    Less,
    LessOrEqual,
    Greater,
    GreaterOrEqual,
    DistinctFrom,
    NotDistinctFrom,
}

Which comparison.

Variants

Equal

=, null if either side is null.

NotEqual

<>, null if either side is null.

Less

<, null if either side is null.

LessOrEqual

<=, null if either side is null.

Greater

>, null if either side is null.

GreaterOrEqual

>=, null if either side is null.

DistinctFrom

IS DISTINCT FROM, which is total and never null.

NotDistinctFrom

IS NOT DISTINCT FROM, which is total and never null.

Implementations

impl Comparison

pub fn is_total(self) -> bool

Whether this comparison treats null as a value rather than as an absence.

pub fn swapped(self) -> Self

The comparison that means the same thing with the two sides exchanged.

This is what halves the number of specialized loops. A constant on the left against a column on the right is the column against the constant with the inequality turned around, and writing it that way means the column against constant loop is written once and tested once rather than twice with a chance of the second one being subtly wrong.

Trait Implementations

impl Clone for Comparison

fn clone(&self) -> Comparison

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Comparison

impl Debug for Comparison

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

Formats the value using the given formatter.

impl Eq for Comparison

impl Hash for Comparison

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 Comparison

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Comparison