Enum mongodb::options::CollationStrength

#[non_exhaustive]
pub enum CollationStrength {
    Primary,
    Secondary,
    Tertiary,
    Quaternary,
    Identical,
}

The level of comparison to perform. Corresponds to ICU Comparison Levels.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Primary

Typically, this is used to denote differences between base characters (for example, “a” < “b”).

This is also called the level-1 strength.

Secondary

Accents in the characters are considered secondary differences (for example, “as” < “às” < “at”).

This is also called the level-2 strength.

Tertiary

Upper and lower case differences in characters are distinguished at the tertiary level (for example, “ao” < “Ao” < “aò”).

This is also called the level-3 strength.

Quaternary

When punctuation is ignored at level 1-3, an additional level can be used to distinguish words with and without punctuation (for example, “ab” < “a-b” < “aB”).

This is also called the level-4 strength.

Identical

When all other levels are equal, the identical level is used as a tiebreaker. The Unicode code point values of the NFD form of each string are compared at this level, just in case there is no difference at levels 1-4.

This is also called the level-5 strength.

Trait Implementations

impl Clone for CollationStrength

fn clone(&self) -> CollationStrength

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for CollationStrength

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CollationStrength

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for CollationStrength

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

Formats the value using the given formatter.

impl From<CollationStrength> for u32

fn from(strength: CollationStrength) -> Self

Converts to this type from the input type.

impl Serialize for CollationStrength

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>where S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFrom<u32> for CollationStrength

type Error = Error

The type returned in the event of a conversion error.

fn try_from(level: u32) -> Result<Self, Self::Error>

Performs the conversion.

impl Copy for CollationStrength