Struct Interner 

pub struct Interner { /* private fields */ }

An append-only set of strings, each mapped to a Symbol.

Strings are never removed, which is what makes a Symbol valid for the lifetime of the compilation and what lets the storage be a plain growing buffer.

Implementations

impl Interner

pub fn new() -> Self

An interner holding the reserved names and nothing else.

pub fn with_capacity(cap: usize) -> Self

An interner with room for cap strings, to avoid regrowing on a large header set.

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

Interns s, returning the existing symbol if it has been seen.

Panics

Panics if more than Idx::MAX distinct strings are interned.

pub fn intern_bytes(&mut self, bytes: &[u8]) -> Symbol

Interns a spelling that may not be text, returning the existing symbol if it has been seen.

A spelling that is UTF-8 is interned as itself, so nothing changes for the common case and a byte spelling equal to a name is the same symbol as that name. One that is not gets a symbol of its own whose text is the lossy reading, which is what Interner::resolve hands back, and whose bytes are kept beside it for Interner::resolve_bytes.

Panics

Panics if more than Idx::MAX distinct spellings are interned.

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

The text behind a symbol.

Panics

Panics if the symbol came from a different interner. There is one interner per compilation, so this is a bug rather than a condition to handle.

pub fn resolve_bytes(&self, sym: Symbol) -> &[u8]

The bytes behind a symbol, which is the spelling exactly as it was written.

The same as resolve(sym).as_bytes() for every symbol that came from text, which is all of them but the ones Interner::intern_bytes made from bytes that are not UTF-8.

Panics

Panics if the symbol came from a different interner, as Interner::resolve does.

pub fn len(&self) -> usize

How many distinct strings have been interned, the reserved names included.

pub fn is_empty(&self) -> bool

Whether anything but the reserved names has been interned.

pub fn bytes(&self) -> usize

Total bytes of interned text, which is the number worth watching on a large build.

Trait Implementations

impl Debug for Interner

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

Formats the value using the given formatter.

impl Default for Interner

fn default() -> Self

Returns the “default value” for a type.