Struct rustc_ap_rustc_span::symbol::Symbol

pub struct Symbol(_);

An interned string.

Internally, a Symbol is implemented as an index, and all operations (including hashing, equality, and ordering) operate on that index. The use of rustc_index::newtype_index! means that Option<Symbol> only takes up 4 bytes, because rustc_index::newtype_index! reserves the last 256 values for tagging purposes.

Note that Symbol cannot directly be a rustc_index::newtype_index! because it implements fmt::Debug, Encodable, and Decodable in special ways.

Implementations

impl Symbol

pub fn intern(string: &str) -> Self

Maps a string to its interned representation.

pub fn as_str(self) -> SymbolStr

Convert to a SymbolStr. This is a slowish operation because it requires locking the symbol interner.

pub fn as_u32(self) -> u32

pub fn is_empty(self) -> bool

pub fn to_ident_string(self) -> String

This method is supposed to be used in error messages, so it’s expected to be identical to printing the original identifier token written in source code (token_to_string, Ident::to_string), except that symbols don’t keep the rawness flag or edition, so we have to guess the rawness using the global edition.

impl Symbol

pub fn is_reserved(self, edition: impl Copy + FnOnce() -> Edition) -> bool

pub fn is_path_segment_keyword(self) -> bool

A keyword or reserved identifier that can be used as a path segment.

pub fn is_bool_lit(self) -> bool

Returns true if the symbol is true or false.

pub fn can_be_raw(self) -> bool

Returns true if this symbol can be a raw identifier.

Trait Implementations

impl Clone for Symbol

fn clone(&self) -> Symbol

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Symbol

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

Formats the value using the given formatter.

impl<D: Decoder> Decodable<D> for Symbol

fn decode(d: &mut D) -> Result<Symbol, D::Error>

impl Display for Symbol

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

Formats the value using the given formatter.

impl<S: Encoder> Encodable<S> for Symbol

fn encode(&self, s: &mut S) -> Result<(), S::Error>

impl Hash for Symbol

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<CTX> HashStable<CTX> for Symbol

fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher)

impl Ord for Symbol

fn cmp(&self, other: &Symbol) -> Ordering

This method returns an Ordering between self and other.

#[must_use]

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Symbol> for Symbol

fn eq(&self, other: &Symbol) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Symbol) -> bool

This method tests for !=.

impl PartialOrd<Symbol> for Symbol

fn partial_cmp(&self, other: &Symbol) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<CTX> ToStableHashKey<CTX> for Symbol

type KeyType = SymbolStr

fn to_stable_hash_key(&self, _: &CTX) -> SymbolStr

impl Copy for Symbol

impl Eq for Symbol

impl StructuralEq for Symbol

impl StructuralPartialEq for Symbol