Struct Interner 

pub struct Interner { /* private fields */ }

A string interner that maps strings to Symbol handles.

Thread-local, single-owner. For a Nix evaluator this is sufficient because evaluation is single-threaded.

Implementations

impl Interner

pub fn new() -> Interner

Create a new, empty interner.

pub fn with_capacity(cap: usize) -> Interner

Create an interner with pre-allocated capacity. Use when you know the approximate identifier count upfront — avoids hashmap resizes during the hot path.

pub fn intern(&mut self, s: &str) -> Symbol

Intern a string, returning its symbol. If the string was already interned, returns the existing symbol (O(1) amortized).

pub fn resolve(&self, sym: Symbol) -> &str

Resolve a symbol back to its string content.

Panics

Panics if the symbol was not produced by this interner.

pub fn resolve_rc(&self, sym: Symbol) -> Rc<str>

Resolve a symbol to its shared Rc<str> handle. Cheap to clone and pass around; prefer this over resolve(...).to_string() in hot paths.

Panics

Panics if the symbol was not produced by this interner.

pub fn try_resolve(&self, sym: Symbol) -> Option<&str>

Try to resolve a symbol, returning None if invalid.

pub fn lookup(&self, s: &str) -> Option<Symbol>

Look up a symbol for a string without interning it.

pub fn len(&self) -> usize

Return the number of interned strings.

pub fn is_empty(&self) -> bool

Whether the interner is empty.

Trait Implementations

impl Clone for Interner

fn clone(&self) -> Interner

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Interner

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

Formats the value using the given formatter.

impl Default for Interner

fn default() -> Interner

Returns the “default value” for a type.