Struct ScannerState 

pub struct ScannerState {
    pub interner: Interner,
    /* private fields */
}

The scanner state that holds the current position and token information.

ZERO-COPY OPTIMIZATION: Source is stored as UTF-8 text directly (no Vec). For ASCII-only files (99% of TypeScript), byte position == character position. Positions are byte-based internally for performance, converted when needed.

Fields

interner: Interner

String interner for identifier deduplication

Implementations

impl ScannerState

pub fn new(text: String, skip_trivia: bool) -> ScannerState

Exported scanner accessors are JS bindings and cannot be made const because #[wasm_bindgen] methods in this crate are non-const. Create a new scanner state with the given text. ZERO-COPY: No Vec allocation, works directly with UTF-8 bytes.

pub fn get_pos(&self) -> usize

Get the current position (end position of current token).

pub fn set_pos(&mut self, pos: usize)

Set the current position (used for rescanning compound tokens). This allows consuming partial tokens like splitting >> into > + >.

pub fn get_token_full_start(&self) -> usize

Get the full start position (including leading trivia).

pub fn get_token_start(&self) -> usize

Get the start position of the current token (excluding trivia).

pub fn get_token_end(&self) -> usize

Get the end position of the current token.

pub fn get_token(&self) -> SyntaxKind

Get the current token kind.

pub fn get_token_value(&self) -> String

Get the current token’s string value. Note: Prefer get_token_value_ref() to avoid allocation when possible.

pub fn get_token_text(&self) -> String

Get the current token’s text from the source.

pub fn get_token_flags(&self) -> u32

Get the token flags.

pub fn has_preceding_line_break(&self) -> bool

Check if there was a preceding line break.

pub fn is_unterminated(&self) -> bool

Check if the token is unterminated.

pub fn is_identifier(&self) -> bool

Check if the current token is an identifier.

pub fn is_reserved_word(&self) -> bool

Check if the current token is a reserved word.

pub fn set_text( &mut self, text: String, start: Option<usize>, length: Option<usize>, )

Set the text to scan. ZERO-COPY: Works directly with UTF-8 bytes.

pub fn reset_token_state(&mut self, new_pos: usize)

Reset the token state to a specific position.

pub fn get_text(&self) -> String

Get the source text.

pub fn scan(&mut self) -> SyntaxKind

Scan the next token.

pub fn re_scan_greater_token(&mut self) -> SyntaxKind

Re-scan the current > token to see if it should be >=, >>, >>>, >>=, or >>>=. This is used by the parser for type arguments and bitwise operators.

pub fn re_scan_slash_token(&mut self) -> SyntaxKind

Re-scan the current / or /= token as a regex literal. This is used by the parser when it determines the context requires a regex.

pub fn re_scan_asterisk_equals_token(&mut self) -> SyntaxKind

Re-scan the current *= token as * followed by =. Used when parsing computed property names.

pub fn re_scan_template_token( &mut self, _is_tagged_template: bool, ) -> SyntaxKind

Re-scan the current } token as the continuation of a template literal. Called by the parser when it determines that a } is closing a template expression.

Arguments

• is_tagged_template - If true, invalid escape sequences should not report errors (tagged templates can have invalid escapes that get passed to the tag function as raw). For now, we don’t report errors anyway, so this parameter affects nothing.

pub fn re_scan_template_head_or_no_substitution_template( &mut self, ) -> SyntaxKind

Re-scan template head or no-substitution template. Used when the parser needs to rescan the start of a template.

pub fn scan_jsx_identifier(&mut self) -> SyntaxKind

Scan a JSX identifier. In JSX, identifiers can contain hyphens (like data-testid).

pub fn re_scan_jsx_token( &mut self, allow_multiline_jsx_text: bool, ) -> SyntaxKind

Re-scan the current token as a JSX token. Used when the parser enters JSX context and needs to rescan. Must reset to full_start_pos (before trivia), not token_start (after trivia), so that JSX text nodes include leading whitespace/newlines. Matches tsc: pos = tokenStart = fullStartPos;

pub fn scan_jsx_attribute_value(&mut self) -> SyntaxKind

Scan a JSX attribute value (string literal or expression).

pub fn re_scan_jsx_attribute_value(&mut self) -> SyntaxKind

Re-scan a JSX attribute value from the current token position.

pub fn re_scan_less_than_token(&mut self) -> SyntaxKind

Re-scan a < token in JSX context. Returns LessThanSlashToken if followed by /, otherwise LessThanToken.

pub fn re_scan_hash_token(&mut self) -> SyntaxKind

Re-scan the current # token as a hash token or private identifier.

pub fn re_scan_question_token(&mut self) -> SyntaxKind

Re-scan the current ? token for optional chaining.

pub fn scan_jsdoc_token(&mut self) -> SyntaxKind

Scan a JSDoc token. Used when parsing JSDoc comments.

pub fn scan_jsdoc_comment_text_token( &mut self, in_backticks: bool, ) -> SyntaxKind

Scan JSDoc comment text token. Used for scanning the text content within JSDoc comments.

pub fn scan_shebang_trivia(&mut self) -> usize

Scan a shebang (#!) at the start of the file. Returns the length of the shebang line (including newline), or 0 if no shebang.

pub fn re_scan_invalid_identifier(&mut self) -> SyntaxKind

Re-scan an invalid identifier to check if it’s valid in a specific context.

impl ScannerState

pub fn save_state(&self) -> ScannerSnapshot

Save the current scanner state for look-ahead.

pub fn restore_state(&mut self, snapshot: ScannerSnapshot)

Restore a saved scanner state.

pub const fn get_token_atom(&self) -> Atom

Get the interned atom for the current identifier token. Returns Atom::NONE if the current token is not an identifier. This enables O(1) string comparison for identifiers.

pub const fn get_invalid_separator_pos(&self) -> Option<usize>

pub const fn invalid_separator_is_consecutive(&self) -> bool

pub fn get_regex_flag_errors(&self) -> &[RegexFlagError]

Get the regex flag errors detected during scanning.

pub fn get_scanner_diagnostics(&self) -> &[ScannerDiagnostic]

Get general scanner diagnostics (e.g., conflict marker errors).

pub fn resolve_atom(&self, atom: Atom) -> &str

Resolve an atom back to its string value. Panics if the atom is invalid.

pub const fn interner(&self) -> &Interner

Get a reference to the interner for direct use by the parser.

pub const fn interner_mut(&mut self) -> &mut Interner

Get a mutable reference to the interner.

pub fn take_interner(&mut self) -> Interner

Take ownership of the interner, replacing it with a new empty one. Used to transfer the interner to NodeArena after parsing.

pub fn get_token_value_ref(&self) -> &str

ZERO-COPY: Get the current token value as a reference. For identifiers/keywords, returns the interned string. For other tokens, returns the token_value or raw source slice. This avoids allocation compared to get_token_value().

pub fn get_token_text_ref(&self) -> &str

ZERO-COPY: Get the raw token text directly from source. This is the unprocessed text from token_start to current pos.

pub fn source_slice(&self, start: usize, end: usize) -> &str

ZERO-COPY: Get a slice of the source text by positions.

pub fn source_text(&self) -> &str

Get the source text reference.

impl ScannerState

pub fn source_text_arc(&self) -> Arc<str>

Get a cloned handle to the shared source text.

Trait Implementations

impl From<ScannerState> for JsValue

fn from(value: ScannerState) -> JsValue

Converts to this type from the input type.

impl FromWasmAbi for ScannerState

type Abi = u32

The Wasm ABI type that this converts from when coming back out from the ABI boundary.

unsafe fn from_abi(js: u32) -> ScannerState

Recover a Self from Self::Abi.

impl IntoWasmAbi for ScannerState

type Abi = u32

The Wasm ABI type that this converts into when crossing the ABI boundary.

fn into_abi(self) -> u32

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl LongRefFromWasmAbi for ScannerState

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRef<ScannerState>

Same as RefFromWasmAbi::Anchor

unsafe fn long_ref_from_abi( js: <ScannerState as LongRefFromWasmAbi>::Abi, ) -> <ScannerState as LongRefFromWasmAbi>::Anchor

Same as RefFromWasmAbi::ref_from_abi

impl OptionFromWasmAbi for ScannerState

fn is_none(abi: &<ScannerState as FromWasmAbi>::Abi) -> bool

Tests whether the argument is a “none” instance. If so it will be deserialized as None, and otherwise it will be passed to FromWasmAbi.

impl OptionIntoWasmAbi for ScannerState

fn none() -> <ScannerState as IntoWasmAbi>::Abi

Returns an ABI instance indicating “none”, which JS will interpret as the None branch of this option.

impl RefFromWasmAbi for ScannerState

type Abi = u32

The Wasm ABI type references to Self are recovered from.

type Anchor = RcRef<ScannerState>

The type that holds the reference to Self for the duration of the invocation of the function that has an &Self parameter. This is required to ensure that the lifetimes don’t persist beyond one function call, and so that they remain anonymous.

unsafe fn ref_from_abi( js: <ScannerState as RefFromWasmAbi>::Abi, ) -> <ScannerState as RefFromWasmAbi>::Anchor

Recover a Self::Anchor from Self::Abi.

impl RefMutFromWasmAbi for ScannerState

type Abi = u32

Same as RefFromWasmAbi::Abi

type Anchor = RcRefMut<ScannerState>

Same as RefFromWasmAbi::Anchor

unsafe fn ref_mut_from_abi( js: <ScannerState as RefMutFromWasmAbi>::Abi, ) -> <ScannerState as RefMutFromWasmAbi>::Anchor

Same as RefFromWasmAbi::ref_from_abi

impl TryFromJsValue for ScannerState

fn try_from_js_value(value: JsValue) -> Result<ScannerState, JsValue>

Performs the conversion.

fn try_from_js_value_ref(value: &JsValue) -> Option<ScannerState>

Performs the conversion.

impl VectorFromWasmAbi for ScannerState

type Abi = <Box<[JsValue]> as FromWasmAbi>::Abi

unsafe fn vector_from_abi( js: <ScannerState as VectorFromWasmAbi>::Abi, ) -> Box<[ScannerState]>

impl VectorIntoWasmAbi for ScannerState

type Abi = <Box<[JsValue]> as IntoWasmAbi>::Abi

fn vector_into_abi( vector: Box<[ScannerState]>, ) -> <ScannerState as VectorIntoWasmAbi>::Abi