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JavaScript

/* eslint max-len: 0 */
import {input, isFlowEnabled, state} from "../traverser/base";
import {unexpected} from "../traverser/util";
import {charCodes} from "../util/charcodes";
import {IS_IDENTIFIER_CHAR, IS_IDENTIFIER_START} from "../util/identifier";
import {IS_WHITESPACE, skipWhiteSpace} from "../util/whitespace";
import {ContextualKeyword} from "./keywords";
import readWord from "./readWord";
import { TokenType as tt} from "./types";
export var IdentifierRole; (function (IdentifierRole) {
const Access = 0; IdentifierRole[IdentifierRole["Access"] = Access] = "Access";
const ExportAccess = Access + 1; IdentifierRole[IdentifierRole["ExportAccess"] = ExportAccess] = "ExportAccess";
const TopLevelDeclaration = ExportAccess + 1; IdentifierRole[IdentifierRole["TopLevelDeclaration"] = TopLevelDeclaration] = "TopLevelDeclaration";
const FunctionScopedDeclaration = TopLevelDeclaration + 1; IdentifierRole[IdentifierRole["FunctionScopedDeclaration"] = FunctionScopedDeclaration] = "FunctionScopedDeclaration";
const BlockScopedDeclaration = FunctionScopedDeclaration + 1; IdentifierRole[IdentifierRole["BlockScopedDeclaration"] = BlockScopedDeclaration] = "BlockScopedDeclaration";
const ObjectShorthandTopLevelDeclaration = BlockScopedDeclaration + 1; IdentifierRole[IdentifierRole["ObjectShorthandTopLevelDeclaration"] = ObjectShorthandTopLevelDeclaration] = "ObjectShorthandTopLevelDeclaration";
const ObjectShorthandFunctionScopedDeclaration = ObjectShorthandTopLevelDeclaration + 1; IdentifierRole[IdentifierRole["ObjectShorthandFunctionScopedDeclaration"] = ObjectShorthandFunctionScopedDeclaration] = "ObjectShorthandFunctionScopedDeclaration";
const ObjectShorthandBlockScopedDeclaration = ObjectShorthandFunctionScopedDeclaration + 1; IdentifierRole[IdentifierRole["ObjectShorthandBlockScopedDeclaration"] = ObjectShorthandBlockScopedDeclaration] = "ObjectShorthandBlockScopedDeclaration";
const ObjectShorthand = ObjectShorthandBlockScopedDeclaration + 1; IdentifierRole[IdentifierRole["ObjectShorthand"] = ObjectShorthand] = "ObjectShorthand";
// Any identifier bound in an import statement, e.g. both A and b from
// `import A, * as b from 'A';`
const ImportDeclaration = ObjectShorthand + 1; IdentifierRole[IdentifierRole["ImportDeclaration"] = ImportDeclaration] = "ImportDeclaration";
const ObjectKey = ImportDeclaration + 1; IdentifierRole[IdentifierRole["ObjectKey"] = ObjectKey] = "ObjectKey";
// The `foo` in `import {foo as bar} from "./abc";`.
const ImportAccess = ObjectKey + 1; IdentifierRole[IdentifierRole["ImportAccess"] = ImportAccess] = "ImportAccess";
})(IdentifierRole || (IdentifierRole = {}));
/**
* Extra information on jsxTagStart tokens, used to determine which of the three
* jsx functions are called in the automatic transform.
*/
export var JSXRole; (function (JSXRole) {
// The element is self-closing or has a body that resolves to empty. We
// shouldn't emit children at all in this case.
const NoChildren = 0; JSXRole[JSXRole["NoChildren"] = NoChildren] = "NoChildren";
// The element has a single explicit child, which might still be an arbitrary
// expression like an array. We should emit that expression as the children.
const OneChild = NoChildren + 1; JSXRole[JSXRole["OneChild"] = OneChild] = "OneChild";
// The element has at least two explicitly-specified children or has spread
// children, so child positions are assumed to be "static". We should wrap
// these children in an array.
const StaticChildren = OneChild + 1; JSXRole[JSXRole["StaticChildren"] = StaticChildren] = "StaticChildren";
// The element has a prop named "key" after a prop spread, so we should fall
// back to the createElement function.
const KeyAfterPropSpread = StaticChildren + 1; JSXRole[JSXRole["KeyAfterPropSpread"] = KeyAfterPropSpread] = "KeyAfterPropSpread";
})(JSXRole || (JSXRole = {}));
export function isDeclaration(token) {
const role = token.identifierRole;
return (
role === IdentifierRole.TopLevelDeclaration ||
role === IdentifierRole.FunctionScopedDeclaration ||
role === IdentifierRole.BlockScopedDeclaration ||
role === IdentifierRole.ObjectShorthandTopLevelDeclaration ||
role === IdentifierRole.ObjectShorthandFunctionScopedDeclaration ||
role === IdentifierRole.ObjectShorthandBlockScopedDeclaration
);
}
export function isNonTopLevelDeclaration(token) {
const role = token.identifierRole;
return (
role === IdentifierRole.FunctionScopedDeclaration ||
role === IdentifierRole.BlockScopedDeclaration ||
role === IdentifierRole.ObjectShorthandFunctionScopedDeclaration ||
role === IdentifierRole.ObjectShorthandBlockScopedDeclaration
);
}
export function isTopLevelDeclaration(token) {
const role = token.identifierRole;
return (
role === IdentifierRole.TopLevelDeclaration ||
role === IdentifierRole.ObjectShorthandTopLevelDeclaration ||
role === IdentifierRole.ImportDeclaration
);
}
export function isBlockScopedDeclaration(token) {
const role = token.identifierRole;
// Treat top-level declarations as block scope since the distinction doesn't matter here.
return (
role === IdentifierRole.TopLevelDeclaration ||
role === IdentifierRole.BlockScopedDeclaration ||
role === IdentifierRole.ObjectShorthandTopLevelDeclaration ||
role === IdentifierRole.ObjectShorthandBlockScopedDeclaration
);
}
export function isFunctionScopedDeclaration(token) {
const role = token.identifierRole;
return (
role === IdentifierRole.FunctionScopedDeclaration ||
role === IdentifierRole.ObjectShorthandFunctionScopedDeclaration
);
}
export function isObjectShorthandDeclaration(token) {
return (
token.identifierRole === IdentifierRole.ObjectShorthandTopLevelDeclaration ||
token.identifierRole === IdentifierRole.ObjectShorthandBlockScopedDeclaration ||
token.identifierRole === IdentifierRole.ObjectShorthandFunctionScopedDeclaration
);
}
// Object type used to represent tokens. Note that normally, tokens
// simply exist as properties on the parser object. This is only
// used for the onToken callback and the external tokenizer.
export class Token {
constructor() {
this.type = state.type;
this.contextualKeyword = state.contextualKeyword;
this.start = state.start;
this.end = state.end;
this.scopeDepth = state.scopeDepth;
this.isType = state.isType;
this.identifierRole = null;
this.jsxRole = null;
this.shadowsGlobal = false;
this.isAsyncOperation = false;
this.contextId = null;
this.rhsEndIndex = null;
this.isExpression = false;
this.numNullishCoalesceStarts = 0;
this.numNullishCoalesceEnds = 0;
this.isOptionalChainStart = false;
this.isOptionalChainEnd = false;
this.subscriptStartIndex = null;
this.nullishStartIndex = null;
}
// Initially false for all tokens, then may be computed in a follow-up step that does scope
// analysis.
// Initially false for all tokens, but may be set during transform to mark it as containing an
// await operation.
// For assignments, the index of the RHS. For export tokens, the end of the export.
// For class tokens, records if the class is a class expression or a class statement.
// Number of times to insert a `nullishCoalesce(` snippet before this token.
// Number of times to insert a `)` snippet after this token.
// If true, insert an `optionalChain([` snippet before this token.
// If true, insert a `])` snippet after this token.
// Tag for `.`, `?.`, `[`, `?.[`, `(`, and `?.(` to denote the "root" token for this
// subscript chain. This can be used to determine if this chain is an optional chain.
// Tag for `??` operators to denote the root token for this nullish coalescing call.
}
// ## Tokenizer
// Move to the next token
export function next() {
state.tokens.push(new Token());
nextToken();
}
// Call instead of next when inside a template, since that needs to be handled differently.
export function nextTemplateToken() {
state.tokens.push(new Token());
state.start = state.pos;
readTmplToken();
}
// The tokenizer never parses regexes by default. Instead, the parser is responsible for
// instructing it to parse a regex when we see a slash at the start of an expression.
export function retokenizeSlashAsRegex() {
if (state.type === tt.assign) {
--state.pos;
}
readRegexp();
}
export function pushTypeContext(existingTokensInType) {
for (let i = state.tokens.length - existingTokensInType; i < state.tokens.length; i++) {
state.tokens[i].isType = true;
}
const oldIsType = state.isType;
state.isType = true;
return oldIsType;
}
export function popTypeContext(oldIsType) {
state.isType = oldIsType;
}
export function eat(type) {
if (match(type)) {
next();
return true;
} else {
return false;
}
}
export function eatTypeToken(tokenType) {
const oldIsType = state.isType;
state.isType = true;
eat(tokenType);
state.isType = oldIsType;
}
export function match(type) {
return state.type === type;
}
export function lookaheadType() {
const snapshot = state.snapshot();
next();
const type = state.type;
state.restoreFromSnapshot(snapshot);
return type;
}
export class TypeAndKeyword {
constructor(type, contextualKeyword) {
this.type = type;
this.contextualKeyword = contextualKeyword;
}
}
export function lookaheadTypeAndKeyword() {
const snapshot = state.snapshot();
next();
const type = state.type;
const contextualKeyword = state.contextualKeyword;
state.restoreFromSnapshot(snapshot);
return new TypeAndKeyword(type, contextualKeyword);
}
export function nextTokenStart() {
return nextTokenStartSince(state.pos);
}
export function nextTokenStartSince(pos) {
skipWhiteSpace.lastIndex = pos;
const skip = skipWhiteSpace.exec(input);
return pos + skip[0].length;
}
export function lookaheadCharCode() {
return input.charCodeAt(nextTokenStart());
}
// Read a single token, updating the parser object's token-related
// properties.
export function nextToken() {
skipSpace();
state.start = state.pos;
if (state.pos >= input.length) {
const tokens = state.tokens;
// We normally run past the end a bit, but if we're way past the end, avoid an infinite loop.
// Also check the token positions rather than the types since sometimes we rewrite the token
// type to something else.
if (
tokens.length >= 2 &&
tokens[tokens.length - 1].start >= input.length &&
tokens[tokens.length - 2].start >= input.length
) {
unexpected("Unexpectedly reached the end of input.");
}
finishToken(tt.eof);
return;
}
readToken(input.charCodeAt(state.pos));
}
function readToken(code) {
// Identifier or keyword. '\uXXXX' sequences are allowed in
// identifiers, so '\' also dispatches to that.
if (
IS_IDENTIFIER_START[code] ||
code === charCodes.backslash ||
(code === charCodes.atSign && input.charCodeAt(state.pos + 1) === charCodes.atSign)
) {
readWord();
} else {
getTokenFromCode(code);
}
}
function skipBlockComment() {
while (
input.charCodeAt(state.pos) !== charCodes.asterisk ||
input.charCodeAt(state.pos + 1) !== charCodes.slash
) {
state.pos++;
if (state.pos > input.length) {
unexpected("Unterminated comment", state.pos - 2);
return;
}
}
state.pos += 2;
}
export function skipLineComment(startSkip) {
let ch = input.charCodeAt((state.pos += startSkip));
if (state.pos < input.length) {
while (
ch !== charCodes.lineFeed &&
ch !== charCodes.carriageReturn &&
ch !== charCodes.lineSeparator &&
ch !== charCodes.paragraphSeparator &&
++state.pos < input.length
) {
ch = input.charCodeAt(state.pos);
}
}
}
// Called at the start of the parse and after every token. Skips
// whitespace and comments.
export function skipSpace() {
while (state.pos < input.length) {
const ch = input.charCodeAt(state.pos);
switch (ch) {
case charCodes.carriageReturn:
if (input.charCodeAt(state.pos + 1) === charCodes.lineFeed) {
++state.pos;
}
case charCodes.lineFeed:
case charCodes.lineSeparator:
case charCodes.paragraphSeparator:
++state.pos;
break;
case charCodes.slash:
switch (input.charCodeAt(state.pos + 1)) {
case charCodes.asterisk:
state.pos += 2;
skipBlockComment();
break;
case charCodes.slash:
skipLineComment(2);
break;
default:
return;
}
break;
default:
if (IS_WHITESPACE[ch]) {
++state.pos;
} else {
return;
}
}
}
}
// Called at the end of every token. Sets various fields, and skips the space after the token, so
// that the next one's `start` will point at the right position.
export function finishToken(
type,
contextualKeyword = ContextualKeyword.NONE,
) {
state.end = state.pos;
state.type = type;
state.contextualKeyword = contextualKeyword;
}
// ### Token reading
// This is the function that is called to fetch the next token. It
// is somewhat obscure, because it works in character codes rather
// than characters, and because operator parsing has been inlined
// into it.
//
// All in the name of speed.
function readToken_dot() {
const nextChar = input.charCodeAt(state.pos + 1);
if (nextChar >= charCodes.digit0 && nextChar <= charCodes.digit9) {
readNumber(true);
return;
}
if (nextChar === charCodes.dot && input.charCodeAt(state.pos + 2) === charCodes.dot) {
state.pos += 3;
finishToken(tt.ellipsis);
} else {
++state.pos;
finishToken(tt.dot);
}
}
function readToken_slash() {
const nextChar = input.charCodeAt(state.pos + 1);
if (nextChar === charCodes.equalsTo) {
finishOp(tt.assign, 2);
} else {
finishOp(tt.slash, 1);
}
}
function readToken_mult_modulo(code) {
// '%*'
let tokenType = code === charCodes.asterisk ? tt.star : tt.modulo;
let width = 1;
let nextChar = input.charCodeAt(state.pos + 1);
// Exponentiation operator **
if (code === charCodes.asterisk && nextChar === charCodes.asterisk) {
width++;
nextChar = input.charCodeAt(state.pos + 2);
tokenType = tt.exponent;
}
// Match *= or %=, disallowing *=> which can be valid in flow.
if (
nextChar === charCodes.equalsTo &&
input.charCodeAt(state.pos + 2) !== charCodes.greaterThan
) {
width++;
tokenType = tt.assign;
}
finishOp(tokenType, width);
}
function readToken_pipe_amp(code) {
// '|&'
const nextChar = input.charCodeAt(state.pos + 1);
if (nextChar === code) {
if (input.charCodeAt(state.pos + 2) === charCodes.equalsTo) {
// ||= or &&=
finishOp(tt.assign, 3);
} else {
// || or &&
finishOp(code === charCodes.verticalBar ? tt.logicalOR : tt.logicalAND, 2);
}
return;
}
if (code === charCodes.verticalBar) {
// '|>'
if (nextChar === charCodes.greaterThan) {
finishOp(tt.pipeline, 2);
return;
} else if (nextChar === charCodes.rightCurlyBrace && isFlowEnabled) {
// '|}'
finishOp(tt.braceBarR, 2);
return;
}
}
if (nextChar === charCodes.equalsTo) {
finishOp(tt.assign, 2);
return;
}
finishOp(code === charCodes.verticalBar ? tt.bitwiseOR : tt.bitwiseAND, 1);
}
function readToken_caret() {
// '^'
const nextChar = input.charCodeAt(state.pos + 1);
if (nextChar === charCodes.equalsTo) {
finishOp(tt.assign, 2);
} else {
finishOp(tt.bitwiseXOR, 1);
}
}
function readToken_plus_min(code) {
// '+-'
const nextChar = input.charCodeAt(state.pos + 1);
if (nextChar === code) {
// Tentatively call this a prefix operator, but it might be changed to postfix later.
finishOp(tt.preIncDec, 2);
return;
}
if (nextChar === charCodes.equalsTo) {
finishOp(tt.assign, 2);
} else if (code === charCodes.plusSign) {
finishOp(tt.plus, 1);
} else {
finishOp(tt.minus, 1);
}
}
function readToken_lt() {
const nextChar = input.charCodeAt(state.pos + 1);
if (nextChar === charCodes.lessThan) {
if (input.charCodeAt(state.pos + 2) === charCodes.equalsTo) {
finishOp(tt.assign, 3);
return;
}
// We see <<, but need to be really careful about whether to treat it as a
// true left-shift or as two < tokens.
if (state.isType) {
// Within a type, << might come up in a snippet like `Array<<T>() => void>`,
// so treat it as two < tokens. Importantly, this should only override <<
// rather than other tokens like <= . If we treated <= as < in a type
// context, then the snippet `a as T <= 1` would incorrectly start parsing
// a type argument on T. We don't need to worry about `a as T << 1`
// because TypeScript disallows that syntax.
finishOp(tt.lessThan, 1);
} else {
// Outside a type, this might be a true left-shift operator, or it might
// still be two open-type-arg tokens, such as in `f<<T>() => void>()`. We
// look at the token while considering the `f`, so we don't yet know that
// we're in a type context. In this case, we initially tokenize as a
// left-shift and correct after-the-fact as necessary in
// tsParseTypeArgumentsWithPossibleBitshift .
finishOp(tt.bitShiftL, 2);
}
return;
}
if (nextChar === charCodes.equalsTo) {
// <=
finishOp(tt.relationalOrEqual, 2);
} else {
finishOp(tt.lessThan, 1);
}
}
function readToken_gt() {
if (state.isType) {
// Avoid right-shift for things like `Array<Array<string>>` and
// greater-than-or-equal for things like `const a: Array<number>=[];`.
finishOp(tt.greaterThan, 1);
return;
}
const nextChar = input.charCodeAt(state.pos + 1);
if (nextChar === charCodes.greaterThan) {
const size = input.charCodeAt(state.pos + 2) === charCodes.greaterThan ? 3 : 2;
if (input.charCodeAt(state.pos + size) === charCodes.equalsTo) {
finishOp(tt.assign, size + 1);
return;
}
finishOp(tt.bitShiftR, size);
return;
}
if (nextChar === charCodes.equalsTo) {
// >=
finishOp(tt.relationalOrEqual, 2);
} else {
finishOp(tt.greaterThan, 1);
}
}
/**
* Called after `as` expressions in TS; we're switching from a type to a
* non-type context, so a > token may actually be >= . This is needed because >=
* must be tokenized as a > in a type context because of code like
* `const x: Array<T>=[];`, but `a as T >= 1` is a code example where it must be
* treated as >=.
*
* Notably, this only applies to >, not <. In a code snippet like `a as T <= 1`,
* we must NOT tokenize as <, or else the type parser will start parsing a type
* argument and fail.
*/
export function rescan_gt() {
if (state.type === tt.greaterThan) {
state.pos -= 1;
readToken_gt();
}
}
function readToken_eq_excl(code) {
// '=!'
const nextChar = input.charCodeAt(state.pos + 1);
if (nextChar === charCodes.equalsTo) {
finishOp(tt.equality, input.charCodeAt(state.pos + 2) === charCodes.equalsTo ? 3 : 2);
return;
}
if (code === charCodes.equalsTo && nextChar === charCodes.greaterThan) {
// '=>'
state.pos += 2;
finishToken(tt.arrow);
return;
}
finishOp(code === charCodes.equalsTo ? tt.eq : tt.bang, 1);
}
function readToken_question() {
// '?'
const nextChar = input.charCodeAt(state.pos + 1);
const nextChar2 = input.charCodeAt(state.pos + 2);
if (
nextChar === charCodes.questionMark &&
// In Flow (but not TypeScript), ??string is a valid type that should be
// tokenized as two individual ? tokens.
!(isFlowEnabled && state.isType)
) {
if (nextChar2 === charCodes.equalsTo) {
// '??='
finishOp(tt.assign, 3);
} else {
// '??'
finishOp(tt.nullishCoalescing, 2);
}
} else if (
nextChar === charCodes.dot &&
!(nextChar2 >= charCodes.digit0 && nextChar2 <= charCodes.digit9)
) {
// '.' not followed by a number
state.pos += 2;
finishToken(tt.questionDot);
} else {
++state.pos;
finishToken(tt.question);
}
}
export function getTokenFromCode(code) {
switch (code) {
case charCodes.numberSign:
++state.pos;
finishToken(tt.hash);
return;
// The interpretation of a dot depends on whether it is followed
// by a digit or another two dots.
case charCodes.dot:
readToken_dot();
return;
// Punctuation tokens.
case charCodes.leftParenthesis:
++state.pos;
finishToken(tt.parenL);
return;
case charCodes.rightParenthesis:
++state.pos;
finishToken(tt.parenR);
return;
case charCodes.semicolon:
++state.pos;
finishToken(tt.semi);
return;
case charCodes.comma:
++state.pos;
finishToken(tt.comma);
return;
case charCodes.leftSquareBracket:
++state.pos;
finishToken(tt.bracketL);
return;
case charCodes.rightSquareBracket:
++state.pos;
finishToken(tt.bracketR);
return;
case charCodes.leftCurlyBrace:
if (isFlowEnabled && input.charCodeAt(state.pos + 1) === charCodes.verticalBar) {
finishOp(tt.braceBarL, 2);
} else {
++state.pos;
finishToken(tt.braceL);
}
return;
case charCodes.rightCurlyBrace:
++state.pos;
finishToken(tt.braceR);
return;
case charCodes.colon:
if (input.charCodeAt(state.pos + 1) === charCodes.colon) {
finishOp(tt.doubleColon, 2);
} else {
++state.pos;
finishToken(tt.colon);
}
return;
case charCodes.questionMark:
readToken_question();
return;
case charCodes.atSign:
++state.pos;
finishToken(tt.at);
return;
case charCodes.graveAccent:
++state.pos;
finishToken(tt.backQuote);
return;
case charCodes.digit0: {
const nextChar = input.charCodeAt(state.pos + 1);
// '0x', '0X', '0o', '0O', '0b', '0B'
if (
nextChar === charCodes.lowercaseX ||
nextChar === charCodes.uppercaseX ||
nextChar === charCodes.lowercaseO ||
nextChar === charCodes.uppercaseO ||
nextChar === charCodes.lowercaseB ||
nextChar === charCodes.uppercaseB
) {
readRadixNumber();
return;
}
}
// Anything else beginning with a digit is an integer, octal
// number, or float.
case charCodes.digit1:
case charCodes.digit2:
case charCodes.digit3:
case charCodes.digit4:
case charCodes.digit5:
case charCodes.digit6:
case charCodes.digit7:
case charCodes.digit8:
case charCodes.digit9:
readNumber(false);
return;
// Quotes produce strings.
case charCodes.quotationMark:
case charCodes.apostrophe:
readString(code);
return;
// Operators are parsed inline in tiny state machines. '=' (charCodes.equalsTo) is
// often referred to. `finishOp` simply skips the amount of
// characters it is given as second argument, and returns a token
// of the type given by its first argument.
case charCodes.slash:
readToken_slash();
return;
case charCodes.percentSign:
case charCodes.asterisk:
readToken_mult_modulo(code);
return;
case charCodes.verticalBar:
case charCodes.ampersand:
readToken_pipe_amp(code);
return;
case charCodes.caret:
readToken_caret();
return;
case charCodes.plusSign:
case charCodes.dash:
readToken_plus_min(code);
return;
case charCodes.lessThan:
readToken_lt();
return;
case charCodes.greaterThan:
readToken_gt();
return;
case charCodes.equalsTo:
case charCodes.exclamationMark:
readToken_eq_excl(code);
return;
case charCodes.tilde:
finishOp(tt.tilde, 1);
return;
default:
break;
}
unexpected(`Unexpected character '${String.fromCharCode(code)}'`, state.pos);
}
function finishOp(type, size) {
state.pos += size;
finishToken(type);
}
function readRegexp() {
const start = state.pos;
let escaped = false;
let inClass = false;
for (;;) {
if (state.pos >= input.length) {
unexpected("Unterminated regular expression", start);
return;
}
const code = input.charCodeAt(state.pos);
if (escaped) {
escaped = false;
} else {
if (code === charCodes.leftSquareBracket) {
inClass = true;
} else if (code === charCodes.rightSquareBracket && inClass) {
inClass = false;
} else if (code === charCodes.slash && !inClass) {
break;
}
escaped = code === charCodes.backslash;
}
++state.pos;
}
++state.pos;
// Need to use `skipWord` because '\uXXXX' sequences are allowed here (don't ask).
skipWord();
finishToken(tt.regexp);
}
/**
* Read a decimal integer. Note that this can't be unified with the similar code
* in readRadixNumber (which also handles hex digits) because "e" needs to be
* the end of the integer so that we can properly handle scientific notation.
*/
function readInt() {
while (true) {
const code = input.charCodeAt(state.pos);
if ((code >= charCodes.digit0 && code <= charCodes.digit9) || code === charCodes.underscore) {
state.pos++;
} else {
break;
}
}
}
function readRadixNumber() {
state.pos += 2; // 0x
// Walk to the end of the number, allowing hex digits.
while (true) {
const code = input.charCodeAt(state.pos);
if (
(code >= charCodes.digit0 && code <= charCodes.digit9) ||
(code >= charCodes.lowercaseA && code <= charCodes.lowercaseF) ||
(code >= charCodes.uppercaseA && code <= charCodes.uppercaseF) ||
code === charCodes.underscore
) {
state.pos++;
} else {
break;
}
}
const nextChar = input.charCodeAt(state.pos);
if (nextChar === charCodes.lowercaseN) {
++state.pos;
finishToken(tt.bigint);
} else {
finishToken(tt.num);
}
}
// Read an integer, octal integer, or floating-point number.
function readNumber(startsWithDot) {
let isBigInt = false;
let isDecimal = false;
if (!startsWithDot) {
readInt();
}
let nextChar = input.charCodeAt(state.pos);
if (nextChar === charCodes.dot) {
++state.pos;
readInt();
nextChar = input.charCodeAt(state.pos);
}
if (nextChar === charCodes.uppercaseE || nextChar === charCodes.lowercaseE) {
nextChar = input.charCodeAt(++state.pos);
if (nextChar === charCodes.plusSign || nextChar === charCodes.dash) {
++state.pos;
}
readInt();
nextChar = input.charCodeAt(state.pos);
}
if (nextChar === charCodes.lowercaseN) {
++state.pos;
isBigInt = true;
} else if (nextChar === charCodes.lowercaseM) {
++state.pos;
isDecimal = true;
}
if (isBigInt) {
finishToken(tt.bigint);
return;
}
if (isDecimal) {
finishToken(tt.decimal);
return;
}
finishToken(tt.num);
}
function readString(quote) {
state.pos++;
for (;;) {
if (state.pos >= input.length) {
unexpected("Unterminated string constant");
return;
}
const ch = input.charCodeAt(state.pos);
if (ch === charCodes.backslash) {
state.pos++;
} else if (ch === quote) {
break;
}
state.pos++;
}
state.pos++;
finishToken(tt.string);
}
// Reads template string tokens.
function readTmplToken() {
for (;;) {
if (state.pos >= input.length) {
unexpected("Unterminated template");
return;
}
const ch = input.charCodeAt(state.pos);
if (
ch === charCodes.graveAccent ||
(ch === charCodes.dollarSign && input.charCodeAt(state.pos + 1) === charCodes.leftCurlyBrace)
) {
if (state.pos === state.start && match(tt.template)) {
if (ch === charCodes.dollarSign) {
state.pos += 2;
finishToken(tt.dollarBraceL);
return;
} else {
++state.pos;
finishToken(tt.backQuote);
return;
}
}
finishToken(tt.template);
return;
}
if (ch === charCodes.backslash) {
state.pos++;
}
state.pos++;
}
}
// Skip to the end of the current word. Note that this is the same as the snippet at the end of
// readWord, but calling skipWord from readWord seems to slightly hurt performance from some rough
// measurements.
export function skipWord() {
while (state.pos < input.length) {
const ch = input.charCodeAt(state.pos);
if (IS_IDENTIFIER_CHAR[ch]) {
state.pos++;
} else if (ch === charCodes.backslash) {
// \u
state.pos += 2;
if (input.charCodeAt(state.pos) === charCodes.leftCurlyBrace) {
while (
state.pos < input.length &&
input.charCodeAt(state.pos) !== charCodes.rightCurlyBrace
) {
state.pos++;
}
state.pos++;
}
} else {
break;
}
}
}