Struct Ident

Source

pub struct Ident {
    pub span: Span,
    pub ctxt: SyntaxContext,
    pub sym: Atom,
    pub optional: bool,
}

Expand description

A complete identifier with span.

Identifier of swc consists of two parts. The first one is symbol, which is stored using an interned string, Atom . The second one is SyntaxContext, which can be used to distinguish identifier with same symbol.

Let me explain this with an example.

let a = 5
{
    let a = 3;
}

In the code above, there are two variables with the symbol a.

Other compilers typically uses type like Scope, and store them nested, but in rust, type like Scope requires [Arc<Mutex>] so swc uses different approach. Instead of passing scopes, swc annotates two variables with different tag, which is named SyntaxContext. The notation for the syntax context is #n where n is a number. e.g. foo#1

For the example above, after applying resolver pass, it becomes.

let a#1 = 5
{
    let a#2 = 3;
}

Thanks to the tag we attached, we can now distinguish them.

(Atom, SyntaxContext)

See Id, which is a type alias for this.

This can be used to store all variables in a module to single hash map.

§Comparison

While comparing two identifiers, you can use .to_id().

§HashMap

There’s a type named Id which only contains minimal information to distinguish identifiers.

Fields§

§span: Span§ctxt: SyntaxContext§sym: Atom§optional: bool

TypeScript only. Used in case of an optional parameter.

Struct Ident Copy item path

§Comparison

§HashMap

Fields§

Implementations§

impl Ident

pub fn within_ignored_ctxt<F, Ret>(op: F) -> Retwhere F: FnOnce() -> Ret,

pub fn without_loc(self) -> Ident

pub fn to_id(&self) -> Id

pub fn is_valid_ascii_start(c: u8) -> bool

pub fn is_valid_non_ascii_start(c: char) -> bool

pub fn is_valid_start(c: char) -> bool

pub fn is_valid_non_ascii_continue(c: char) -> bool

pub fn is_valid_ascii_continue(c: u8) -> bool

pub fn is_valid_continue(c: char) -> bool

pub fn verify_symbol(s: &str) -> Result<(), String>

pub fn with_prefix(&self, prefix: &str) -> Ident

pub fn into_private(self) -> Ident

pub fn is_dummy(&self) -> bool

pub fn with_pos(self, lo: BytePos, hi: BytePos) -> Ident

impl Ident

pub const fn new(sym: Atom, span: Span, ctxt: SyntaxContext) -> Self

pub fn new_private(sym: Atom, span: Span) -> Self

pub const fn new_no_ctxt(sym: Atom, span: Span) -> Self

Trait Implementations§

impl AsRef<str> for Ident

fn as_ref(&self) -> &str

impl AstNode for Ident

const TYPE: &'static str = "Identifier"

impl Clone for Ident

fn clone(&self) -> Ident

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

impl Debug for Ident

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

impl Default for Ident

fn default() -> Ident

impl Display for Ident

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

impl EqIgnoreSpan for Ident

fn eq_ignore_span(&self, other: &Self) -> bool

impl EsReserved for Ident

fn is_reserved(&self) -> bool

fn is_reserved_in_strict_mode(&self, is_module: bool) -> bool

fn is_reserved_in_strict_bind(&self) -> bool

fn is_reserved_in_es3(&self) -> bool

fn is_reserved_in_any(&self) -> bool

impl From<&BindingIdent> for Ident

fn from(bi: &BindingIdent) -> Self

impl From<&str> for Ident

fn from(src: &str) -> Ident

impl From<(Atom, Span)> for Ident

fn from((sym, span): (Atom, Span)) -> Self

impl From<(Atom, SyntaxContext)> for Ident

fn from(id: Id) -> Self

impl From<Atom> for Ident

fn from(bi: Atom) -> Self

impl From<BindingIdent> for Ident

fn from(bi: BindingIdent) -> Self

impl From<Cow<'_, str>> for Ident

fn from(src: Cow<'_, str>) -> Ident

impl From<Ident> for Id

fn from(i: Ident) -> Self

impl From<Ident> for AssignTarget

fn from(src: Ident) -> AssignTarget

impl From<Ident> for BindingIdent

fn from(id: Ident) -> Self

impl From<Ident> for Box<Expr>

fn from(src: Ident) -> Box<Expr>

impl From<Ident> for Box<Pat>

fn from(src: Ident) -> Box<Pat>

impl From<Ident> for Expr

fn from(v: Ident) -> Self

impl From<Ident> for IdentName

fn from(i: Ident) -> Self

impl From<Ident> for JSXElementName

fn from(v: Ident) -> Self

impl From<Ident> for JSXObject

fn from(v: Ident) -> Self

impl From<Ident> for Key

fn from(src: Ident) -> Key

Struct Ident

pub fn within_ignored_ctxt<F, Ret>(op: F) -> Ret
where F: FnOnce() -> Ret,

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

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

fn map_with_mut<F>(&mut self, op: F)
where F: FnOnce(Self) -> Self,

impl<T> Any for T
where T: 'static + ?Sized,

impl<T> Borrow<T> for T
where T: ?Sized,

impl<T> BorrowMut<T> for T
where T: ?Sized,

impl<T> CloneToUninit for T
where T: Clone,

fn conv<T>(self) -> T
where Self: Into<T>,

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,