Enum icu_collections::codepointtrie::TrieType

pub enum TrieType {
    Fast = 0,
    Small = 1,
}

The type of trie represents whether the trie has an optimization that would make it smaller or faster.

Regarding performance, a trie being a small or fast type affects the number of array lookups needed for code points in the range [0x1000, 0x10000). In this range, Small tries use 4 array lookups, while Fast tries use 2 array lookups. Code points before the interval (in [0, 0x1000)) will always use 2 array lookups. Code points after the interval (in [0x10000, 0x10FFFF]) will always use 4 array lookups.

Regarding size, Fast type tries are larger than Small type tries because the minimum size of the index array is larger. The minimum size is the “fast max” limit, which is the limit of the range of code points with 2 array lookups.

See the document Unicode Properties and Code Point Tries in ICU4X.

Also see UCPTrieType in ICU4C.

Variants

Fast = 0

Represents the “fast” type code point tries for the TrieType trait. The “fast max” limit is set to 0xffff.

Small = 1

Represents the “small” type code point tries for the TrieType trait. The “fast max” limit is set to 0x0fff.

Trait Implementations

impl Clone for TrieType

fn clone(&self) -> TrieType

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for TrieType

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

Formats the value using the given formatter.

impl PartialEq for TrieType

fn eq(&self, other: &TrieType) -> 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 TryFrom<u8> for TrieType

type Error = Error

The type returned in the event of a conversion error.

fn try_from(trie_type_int: u8) -> Result<TrieType, Error>

Performs the conversion.

impl Copy for TrieType

impl Eq for TrieType

impl StructuralPartialEq for TrieType