Struct StringInterner

pub struct StringInterner<S, H = RandomState>
where
    S: Symbol,
    H: BuildHasher,
{ /* private fields */ }

Caches strings efficiently, with minimal memory footprint and associates them with unique symbols. These symbols allow constant time comparisons and look-ups to the underlying interned strings.

Implementations

impl<S> StringInterner<S>

where S: Symbol,

pub fn new() -> StringInterner<S, RandomState>

Creates a new empty StringInterner.

pub fn with_capacity(cap: usize) -> Self

Creates a new StringInterner with the given initial capacity.

pub fn capacity(&self) -> usize

Returns the number of elements the StringInterner can hold without reallocating.

pub fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more elements to be interned into self.

The collection may reserve more space to avoid frequent allocations. After calling reserve, capacity will be greater than or equal to self.len() + additional. Does nothing if capacity is already sufficient.

impl<S, H> StringInterner<S, H>

where S: Symbol, H: BuildHasher,

pub fn with_hasher(hash_builder: H) -> StringInterner<S, H>

Creates a new empty StringInterner with the given hasher.

pub fn with_capacity_and_hasher( cap: usize, hash_builder: H, ) -> StringInterner<S, H>

Creates a new empty StringInterner with the given initial capacity and the given hasher.

pub fn get_or_intern<T>(&mut self, val: T) -> S

where T: Into<String> + AsRef<str>,

Interns the given value.

Returns a symbol to access it within this interner.

This either copies the contents of the string (e.g. for str) or moves them into this interner (e.g. for String).

pub fn resolve(&self, symbol: S) -> Option<&Arc<str>>

Returns the string slice associated with the given symbol if available, otherwise returns None.

pub unsafe fn resolve_unchecked(&self, symbol: S) -> &Arc<str>

Returns the string associated with the given symbol.

Note

This does not check whether the given symbol has an associated string for the given string interner instance.

Safety

This will result in undefined behaviour if the given symbol had no associated string for this interner instance.

pub fn get<T>(&self, val: T) -> Option<S>

where T: AsRef<str>,

Returns the symbol associated with the given string for this interner if existent, otherwise returns None.

pub fn len(&self) -> usize

Returns the number of uniquely interned strings within this interner.

pub fn is_empty(&self) -> bool

Returns true if the string interner holds no elements.

pub fn iter(&self) -> Iter<'_, S>

Returns an iterator over the interned strings.

pub fn iter_values(&self) -> Values<'_, S>

Returns an iterator over all intern indices and their associated strings.

pub fn shrink_to_fit(&mut self)

Shrinks the capacity of the interner as much as possible.

Trait Implementations

impl<S, H> Clone for StringInterner<S, H>

where S: Symbol, H: Clone + BuildHasher,

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<S, H> Debug for StringInterner<S, H>

where S: Symbol + Debug, H: BuildHasher + Debug,

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

Formats the value using the given formatter.

impl Default for StringInterner<Sym, RandomState>

fn default() -> Self

Returns the “default value” for a type.

impl<'de, Sym, H> Deserialize<'de> for StringInterner<Sym, H>

where Sym: Symbol, H: BuildHasher + Default,

fn deserialize<D>(deserializer: D) -> Result<StringInterner<Sym, H>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T, S> Extend<T> for StringInterner<S>

where S: Symbol, T: Into<String> + AsRef<str>,

fn extend<I>(&mut self, iter: I)

where I: IntoIterator<Item = T>,

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

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

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

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

Reserves capacity in a collection for the given number of additional elements.

impl<T, S> FromIterator<T> for StringInterner<S>

where S: Symbol, T: Into<String> + AsRef<str>,

fn from_iter<I>(iter: I) -> Self

where I: IntoIterator<Item = T>,

Creates a value from an iterator.

impl<S, H> IntoIterator for StringInterner<S, H>

where S: Symbol, H: BuildHasher,

type Item = (S, Arc<str>)

The type of the elements being iterated over.

type IntoIter = IntoIter<S>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<S, H> PartialEq for StringInterner<S, H>

where S: Symbol, H: BuildHasher,

fn eq(&self, rhs: &Self) -> 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<Sym, H> Serialize for StringInterner<Sym, H>

where Sym: Symbol, H: BuildHasher,

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

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<S, H> Eq for StringInterner<S, H>

where S: Symbol + Eq, H: BuildHasher + Eq,

impl<S, H> Send for StringInterner<S, H>

where S: Symbol + Send, H: BuildHasher,

impl<S, H> Sync for StringInterner<S, H>

where S: Symbol + Sync, H: BuildHasher,