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- 'use strict';
- Object.defineProperty(exports, '__esModule', {
- value: true,
- });
- exports.Lexer = void 0;
- exports.isPunctuatorTokenKind = isPunctuatorTokenKind;
- var _syntaxError = require('../error/syntaxError.js');
- var _ast = require('./ast.js');
- var _blockString = require('./blockString.js');
- var _characterClasses = require('./characterClasses.js');
- var _tokenKind = require('./tokenKind.js');
- /**
- * Given a Source object, creates a Lexer for that source.
- * A Lexer is a stateful stream generator in that every time
- * it is advanced, it returns the next token in the Source. Assuming the
- * source lexes, the final Token emitted by the lexer will be of kind
- * EOF, after which the lexer will repeatedly return the same EOF token
- * whenever called.
- */
- class Lexer {
- /**
- * The previously focused non-ignored token.
- */
- /**
- * The currently focused non-ignored token.
- */
- /**
- * The (1-indexed) line containing the current token.
- */
- /**
- * The character offset at which the current line begins.
- */
- constructor(source) {
- const startOfFileToken = new _ast.Token(
- _tokenKind.TokenKind.SOF,
- 0,
- 0,
- 0,
- 0,
- );
- this.source = source;
- this.lastToken = startOfFileToken;
- this.token = startOfFileToken;
- this.line = 1;
- this.lineStart = 0;
- }
- get [Symbol.toStringTag]() {
- return 'Lexer';
- }
- /**
- * Advances the token stream to the next non-ignored token.
- */
- advance() {
- this.lastToken = this.token;
- const token = (this.token = this.lookahead());
- return token;
- }
- /**
- * Looks ahead and returns the next non-ignored token, but does not change
- * the state of Lexer.
- */
- lookahead() {
- let token = this.token;
- if (token.kind !== _tokenKind.TokenKind.EOF) {
- do {
- if (token.next) {
- token = token.next;
- } else {
- // Read the next token and form a link in the token linked-list.
- const nextToken = readNextToken(this, token.end); // @ts-expect-error next is only mutable during parsing.
- token.next = nextToken; // @ts-expect-error prev is only mutable during parsing.
- nextToken.prev = token;
- token = nextToken;
- }
- } while (token.kind === _tokenKind.TokenKind.COMMENT);
- }
- return token;
- }
- }
- /**
- * @internal
- */
- exports.Lexer = Lexer;
- function isPunctuatorTokenKind(kind) {
- return (
- kind === _tokenKind.TokenKind.BANG ||
- kind === _tokenKind.TokenKind.DOLLAR ||
- kind === _tokenKind.TokenKind.AMP ||
- kind === _tokenKind.TokenKind.PAREN_L ||
- kind === _tokenKind.TokenKind.PAREN_R ||
- kind === _tokenKind.TokenKind.SPREAD ||
- kind === _tokenKind.TokenKind.COLON ||
- kind === _tokenKind.TokenKind.EQUALS ||
- kind === _tokenKind.TokenKind.AT ||
- kind === _tokenKind.TokenKind.BRACKET_L ||
- kind === _tokenKind.TokenKind.BRACKET_R ||
- kind === _tokenKind.TokenKind.BRACE_L ||
- kind === _tokenKind.TokenKind.PIPE ||
- kind === _tokenKind.TokenKind.BRACE_R
- );
- }
- /**
- * A Unicode scalar value is any Unicode code point except surrogate code
- * points. In other words, the inclusive ranges of values 0x0000 to 0xD7FF and
- * 0xE000 to 0x10FFFF.
- *
- * SourceCharacter ::
- * - "Any Unicode scalar value"
- */
- function isUnicodeScalarValue(code) {
- return (
- (code >= 0x0000 && code <= 0xd7ff) || (code >= 0xe000 && code <= 0x10ffff)
- );
- }
- /**
- * The GraphQL specification defines source text as a sequence of unicode scalar
- * values (which Unicode defines to exclude surrogate code points). However
- * JavaScript defines strings as a sequence of UTF-16 code units which may
- * include surrogates. A surrogate pair is a valid source character as it
- * encodes a supplementary code point (above U+FFFF), but unpaired surrogate
- * code points are not valid source characters.
- */
- function isSupplementaryCodePoint(body, location) {
- return (
- isLeadingSurrogate(body.charCodeAt(location)) &&
- isTrailingSurrogate(body.charCodeAt(location + 1))
- );
- }
- function isLeadingSurrogate(code) {
- return code >= 0xd800 && code <= 0xdbff;
- }
- function isTrailingSurrogate(code) {
- return code >= 0xdc00 && code <= 0xdfff;
- }
- /**
- * Prints the code point (or end of file reference) at a given location in a
- * source for use in error messages.
- *
- * Printable ASCII is printed quoted, while other points are printed in Unicode
- * code point form (ie. U+1234).
- */
- function printCodePointAt(lexer, location) {
- const code = lexer.source.body.codePointAt(location);
- if (code === undefined) {
- return _tokenKind.TokenKind.EOF;
- } else if (code >= 0x0020 && code <= 0x007e) {
- // Printable ASCII
- const char = String.fromCodePoint(code);
- return char === '"' ? "'\"'" : `"${char}"`;
- } // Unicode code point
- return 'U+' + code.toString(16).toUpperCase().padStart(4, '0');
- }
- /**
- * Create a token with line and column location information.
- */
- function createToken(lexer, kind, start, end, value) {
- const line = lexer.line;
- const col = 1 + start - lexer.lineStart;
- return new _ast.Token(kind, start, end, line, col, value);
- }
- /**
- * Gets the next token from the source starting at the given position.
- *
- * This skips over whitespace until it finds the next lexable token, then lexes
- * punctuators immediately or calls the appropriate helper function for more
- * complicated tokens.
- */
- function readNextToken(lexer, start) {
- const body = lexer.source.body;
- const bodyLength = body.length;
- let position = start;
- while (position < bodyLength) {
- const code = body.charCodeAt(position); // SourceCharacter
- switch (code) {
- // Ignored ::
- // - UnicodeBOM
- // - WhiteSpace
- // - LineTerminator
- // - Comment
- // - Comma
- //
- // UnicodeBOM :: "Byte Order Mark (U+FEFF)"
- //
- // WhiteSpace ::
- // - "Horizontal Tab (U+0009)"
- // - "Space (U+0020)"
- //
- // Comma :: ,
- case 0xfeff: // <BOM>
- case 0x0009: // \t
- case 0x0020: // <space>
- case 0x002c:
- // ,
- ++position;
- continue;
- // LineTerminator ::
- // - "New Line (U+000A)"
- // - "Carriage Return (U+000D)" [lookahead != "New Line (U+000A)"]
- // - "Carriage Return (U+000D)" "New Line (U+000A)"
- case 0x000a:
- // \n
- ++position;
- ++lexer.line;
- lexer.lineStart = position;
- continue;
- case 0x000d:
- // \r
- if (body.charCodeAt(position + 1) === 0x000a) {
- position += 2;
- } else {
- ++position;
- }
- ++lexer.line;
- lexer.lineStart = position;
- continue;
- // Comment
- case 0x0023:
- // #
- return readComment(lexer, position);
- // Token ::
- // - Punctuator
- // - Name
- // - IntValue
- // - FloatValue
- // - StringValue
- //
- // Punctuator :: one of ! $ & ( ) ... : = @ [ ] { | }
- case 0x0021:
- // !
- return createToken(
- lexer,
- _tokenKind.TokenKind.BANG,
- position,
- position + 1,
- );
- case 0x0024:
- // $
- return createToken(
- lexer,
- _tokenKind.TokenKind.DOLLAR,
- position,
- position + 1,
- );
- case 0x0026:
- // &
- return createToken(
- lexer,
- _tokenKind.TokenKind.AMP,
- position,
- position + 1,
- );
- case 0x0028:
- // (
- return createToken(
- lexer,
- _tokenKind.TokenKind.PAREN_L,
- position,
- position + 1,
- );
- case 0x0029:
- // )
- return createToken(
- lexer,
- _tokenKind.TokenKind.PAREN_R,
- position,
- position + 1,
- );
- case 0x002e:
- // .
- if (
- body.charCodeAt(position + 1) === 0x002e &&
- body.charCodeAt(position + 2) === 0x002e
- ) {
- return createToken(
- lexer,
- _tokenKind.TokenKind.SPREAD,
- position,
- position + 3,
- );
- }
- break;
- case 0x003a:
- // :
- return createToken(
- lexer,
- _tokenKind.TokenKind.COLON,
- position,
- position + 1,
- );
- case 0x003d:
- // =
- return createToken(
- lexer,
- _tokenKind.TokenKind.EQUALS,
- position,
- position + 1,
- );
- case 0x0040:
- // @
- return createToken(
- lexer,
- _tokenKind.TokenKind.AT,
- position,
- position + 1,
- );
- case 0x005b:
- // [
- return createToken(
- lexer,
- _tokenKind.TokenKind.BRACKET_L,
- position,
- position + 1,
- );
- case 0x005d:
- // ]
- return createToken(
- lexer,
- _tokenKind.TokenKind.BRACKET_R,
- position,
- position + 1,
- );
- case 0x007b:
- // {
- return createToken(
- lexer,
- _tokenKind.TokenKind.BRACE_L,
- position,
- position + 1,
- );
- case 0x007c:
- // |
- return createToken(
- lexer,
- _tokenKind.TokenKind.PIPE,
- position,
- position + 1,
- );
- case 0x007d:
- // }
- return createToken(
- lexer,
- _tokenKind.TokenKind.BRACE_R,
- position,
- position + 1,
- );
- // StringValue
- case 0x0022:
- // "
- if (
- body.charCodeAt(position + 1) === 0x0022 &&
- body.charCodeAt(position + 2) === 0x0022
- ) {
- return readBlockString(lexer, position);
- }
- return readString(lexer, position);
- } // IntValue | FloatValue (Digit | -)
- if ((0, _characterClasses.isDigit)(code) || code === 0x002d) {
- return readNumber(lexer, position, code);
- } // Name
- if ((0, _characterClasses.isNameStart)(code)) {
- return readName(lexer, position);
- }
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- code === 0x0027
- ? 'Unexpected single quote character (\'), did you mean to use a double quote (")?'
- : isUnicodeScalarValue(code) || isSupplementaryCodePoint(body, position)
- ? `Unexpected character: ${printCodePointAt(lexer, position)}.`
- : `Invalid character: ${printCodePointAt(lexer, position)}.`,
- );
- }
- return createToken(lexer, _tokenKind.TokenKind.EOF, bodyLength, bodyLength);
- }
- /**
- * Reads a comment token from the source file.
- *
- * ```
- * Comment :: # CommentChar* [lookahead != CommentChar]
- *
- * CommentChar :: SourceCharacter but not LineTerminator
- * ```
- */
- function readComment(lexer, start) {
- const body = lexer.source.body;
- const bodyLength = body.length;
- let position = start + 1;
- while (position < bodyLength) {
- const code = body.charCodeAt(position); // LineTerminator (\n | \r)
- if (code === 0x000a || code === 0x000d) {
- break;
- } // SourceCharacter
- if (isUnicodeScalarValue(code)) {
- ++position;
- } else if (isSupplementaryCodePoint(body, position)) {
- position += 2;
- } else {
- break;
- }
- }
- return createToken(
- lexer,
- _tokenKind.TokenKind.COMMENT,
- start,
- position,
- body.slice(start + 1, position),
- );
- }
- /**
- * Reads a number token from the source file, either a FloatValue or an IntValue
- * depending on whether a FractionalPart or ExponentPart is encountered.
- *
- * ```
- * IntValue :: IntegerPart [lookahead != {Digit, `.`, NameStart}]
- *
- * IntegerPart ::
- * - NegativeSign? 0
- * - NegativeSign? NonZeroDigit Digit*
- *
- * NegativeSign :: -
- *
- * NonZeroDigit :: Digit but not `0`
- *
- * FloatValue ::
- * - IntegerPart FractionalPart ExponentPart [lookahead != {Digit, `.`, NameStart}]
- * - IntegerPart FractionalPart [lookahead != {Digit, `.`, NameStart}]
- * - IntegerPart ExponentPart [lookahead != {Digit, `.`, NameStart}]
- *
- * FractionalPart :: . Digit+
- *
- * ExponentPart :: ExponentIndicator Sign? Digit+
- *
- * ExponentIndicator :: one of `e` `E`
- *
- * Sign :: one of + -
- * ```
- */
- function readNumber(lexer, start, firstCode) {
- const body = lexer.source.body;
- let position = start;
- let code = firstCode;
- let isFloat = false; // NegativeSign (-)
- if (code === 0x002d) {
- code = body.charCodeAt(++position);
- } // Zero (0)
- if (code === 0x0030) {
- code = body.charCodeAt(++position);
- if ((0, _characterClasses.isDigit)(code)) {
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- `Invalid number, unexpected digit after 0: ${printCodePointAt(
- lexer,
- position,
- )}.`,
- );
- }
- } else {
- position = readDigits(lexer, position, code);
- code = body.charCodeAt(position);
- } // Full stop (.)
- if (code === 0x002e) {
- isFloat = true;
- code = body.charCodeAt(++position);
- position = readDigits(lexer, position, code);
- code = body.charCodeAt(position);
- } // E e
- if (code === 0x0045 || code === 0x0065) {
- isFloat = true;
- code = body.charCodeAt(++position); // + -
- if (code === 0x002b || code === 0x002d) {
- code = body.charCodeAt(++position);
- }
- position = readDigits(lexer, position, code);
- code = body.charCodeAt(position);
- } // Numbers cannot be followed by . or NameStart
- if (code === 0x002e || (0, _characterClasses.isNameStart)(code)) {
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- `Invalid number, expected digit but got: ${printCodePointAt(
- lexer,
- position,
- )}.`,
- );
- }
- return createToken(
- lexer,
- isFloat ? _tokenKind.TokenKind.FLOAT : _tokenKind.TokenKind.INT,
- start,
- position,
- body.slice(start, position),
- );
- }
- /**
- * Returns the new position in the source after reading one or more digits.
- */
- function readDigits(lexer, start, firstCode) {
- if (!(0, _characterClasses.isDigit)(firstCode)) {
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- start,
- `Invalid number, expected digit but got: ${printCodePointAt(
- lexer,
- start,
- )}.`,
- );
- }
- const body = lexer.source.body;
- let position = start + 1; // +1 to skip first firstCode
- while ((0, _characterClasses.isDigit)(body.charCodeAt(position))) {
- ++position;
- }
- return position;
- }
- /**
- * Reads a single-quote string token from the source file.
- *
- * ```
- * StringValue ::
- * - `""` [lookahead != `"`]
- * - `"` StringCharacter+ `"`
- *
- * StringCharacter ::
- * - SourceCharacter but not `"` or `\` or LineTerminator
- * - `\u` EscapedUnicode
- * - `\` EscapedCharacter
- *
- * EscapedUnicode ::
- * - `{` HexDigit+ `}`
- * - HexDigit HexDigit HexDigit HexDigit
- *
- * EscapedCharacter :: one of `"` `\` `/` `b` `f` `n` `r` `t`
- * ```
- */
- function readString(lexer, start) {
- const body = lexer.source.body;
- const bodyLength = body.length;
- let position = start + 1;
- let chunkStart = position;
- let value = '';
- while (position < bodyLength) {
- const code = body.charCodeAt(position); // Closing Quote (")
- if (code === 0x0022) {
- value += body.slice(chunkStart, position);
- return createToken(
- lexer,
- _tokenKind.TokenKind.STRING,
- start,
- position + 1,
- value,
- );
- } // Escape Sequence (\)
- if (code === 0x005c) {
- value += body.slice(chunkStart, position);
- const escape =
- body.charCodeAt(position + 1) === 0x0075 // u
- ? body.charCodeAt(position + 2) === 0x007b // {
- ? readEscapedUnicodeVariableWidth(lexer, position)
- : readEscapedUnicodeFixedWidth(lexer, position)
- : readEscapedCharacter(lexer, position);
- value += escape.value;
- position += escape.size;
- chunkStart = position;
- continue;
- } // LineTerminator (\n | \r)
- if (code === 0x000a || code === 0x000d) {
- break;
- } // SourceCharacter
- if (isUnicodeScalarValue(code)) {
- ++position;
- } else if (isSupplementaryCodePoint(body, position)) {
- position += 2;
- } else {
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- `Invalid character within String: ${printCodePointAt(
- lexer,
- position,
- )}.`,
- );
- }
- }
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- 'Unterminated string.',
- );
- } // The string value and lexed size of an escape sequence.
- function readEscapedUnicodeVariableWidth(lexer, position) {
- const body = lexer.source.body;
- let point = 0;
- let size = 3; // Cannot be larger than 12 chars (\u{00000000}).
- while (size < 12) {
- const code = body.charCodeAt(position + size++); // Closing Brace (})
- if (code === 0x007d) {
- // Must be at least 5 chars (\u{0}) and encode a Unicode scalar value.
- if (size < 5 || !isUnicodeScalarValue(point)) {
- break;
- }
- return {
- value: String.fromCodePoint(point),
- size,
- };
- } // Append this hex digit to the code point.
- point = (point << 4) | readHexDigit(code);
- if (point < 0) {
- break;
- }
- }
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- `Invalid Unicode escape sequence: "${body.slice(
- position,
- position + size,
- )}".`,
- );
- }
- function readEscapedUnicodeFixedWidth(lexer, position) {
- const body = lexer.source.body;
- const code = read16BitHexCode(body, position + 2);
- if (isUnicodeScalarValue(code)) {
- return {
- value: String.fromCodePoint(code),
- size: 6,
- };
- } // GraphQL allows JSON-style surrogate pair escape sequences, but only when
- // a valid pair is formed.
- if (isLeadingSurrogate(code)) {
- // \u
- if (
- body.charCodeAt(position + 6) === 0x005c &&
- body.charCodeAt(position + 7) === 0x0075
- ) {
- const trailingCode = read16BitHexCode(body, position + 8);
- if (isTrailingSurrogate(trailingCode)) {
- // JavaScript defines strings as a sequence of UTF-16 code units and
- // encodes Unicode code points above U+FFFF using a surrogate pair of
- // code units. Since this is a surrogate pair escape sequence, just
- // include both codes into the JavaScript string value. Had JavaScript
- // not been internally based on UTF-16, then this surrogate pair would
- // be decoded to retrieve the supplementary code point.
- return {
- value: String.fromCodePoint(code, trailingCode),
- size: 12,
- };
- }
- }
- }
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- `Invalid Unicode escape sequence: "${body.slice(position, position + 6)}".`,
- );
- }
- /**
- * Reads four hexadecimal characters and returns the positive integer that 16bit
- * hexadecimal string represents. For example, "000f" will return 15, and "dead"
- * will return 57005.
- *
- * Returns a negative number if any char was not a valid hexadecimal digit.
- */
- function read16BitHexCode(body, position) {
- // readHexDigit() returns -1 on error. ORing a negative value with any other
- // value always produces a negative value.
- return (
- (readHexDigit(body.charCodeAt(position)) << 12) |
- (readHexDigit(body.charCodeAt(position + 1)) << 8) |
- (readHexDigit(body.charCodeAt(position + 2)) << 4) |
- readHexDigit(body.charCodeAt(position + 3))
- );
- }
- /**
- * Reads a hexadecimal character and returns its positive integer value (0-15).
- *
- * '0' becomes 0, '9' becomes 9
- * 'A' becomes 10, 'F' becomes 15
- * 'a' becomes 10, 'f' becomes 15
- *
- * Returns -1 if the provided character code was not a valid hexadecimal digit.
- *
- * HexDigit :: one of
- * - `0` `1` `2` `3` `4` `5` `6` `7` `8` `9`
- * - `A` `B` `C` `D` `E` `F`
- * - `a` `b` `c` `d` `e` `f`
- */
- function readHexDigit(code) {
- return code >= 0x0030 && code <= 0x0039 // 0-9
- ? code - 0x0030
- : code >= 0x0041 && code <= 0x0046 // A-F
- ? code - 0x0037
- : code >= 0x0061 && code <= 0x0066 // a-f
- ? code - 0x0057
- : -1;
- }
- /**
- * | Escaped Character | Code Point | Character Name |
- * | ----------------- | ---------- | ---------------------------- |
- * | `"` | U+0022 | double quote |
- * | `\` | U+005C | reverse solidus (back slash) |
- * | `/` | U+002F | solidus (forward slash) |
- * | `b` | U+0008 | backspace |
- * | `f` | U+000C | form feed |
- * | `n` | U+000A | line feed (new line) |
- * | `r` | U+000D | carriage return |
- * | `t` | U+0009 | horizontal tab |
- */
- function readEscapedCharacter(lexer, position) {
- const body = lexer.source.body;
- const code = body.charCodeAt(position + 1);
- switch (code) {
- case 0x0022:
- // "
- return {
- value: '\u0022',
- size: 2,
- };
- case 0x005c:
- // \
- return {
- value: '\u005c',
- size: 2,
- };
- case 0x002f:
- // /
- return {
- value: '\u002f',
- size: 2,
- };
- case 0x0062:
- // b
- return {
- value: '\u0008',
- size: 2,
- };
- case 0x0066:
- // f
- return {
- value: '\u000c',
- size: 2,
- };
- case 0x006e:
- // n
- return {
- value: '\u000a',
- size: 2,
- };
- case 0x0072:
- // r
- return {
- value: '\u000d',
- size: 2,
- };
- case 0x0074:
- // t
- return {
- value: '\u0009',
- size: 2,
- };
- }
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- `Invalid character escape sequence: "${body.slice(
- position,
- position + 2,
- )}".`,
- );
- }
- /**
- * Reads a block string token from the source file.
- *
- * ```
- * StringValue ::
- * - `"""` BlockStringCharacter* `"""`
- *
- * BlockStringCharacter ::
- * - SourceCharacter but not `"""` or `\"""`
- * - `\"""`
- * ```
- */
- function readBlockString(lexer, start) {
- const body = lexer.source.body;
- const bodyLength = body.length;
- let lineStart = lexer.lineStart;
- let position = start + 3;
- let chunkStart = position;
- let currentLine = '';
- const blockLines = [];
- while (position < bodyLength) {
- const code = body.charCodeAt(position); // Closing Triple-Quote (""")
- if (
- code === 0x0022 &&
- body.charCodeAt(position + 1) === 0x0022 &&
- body.charCodeAt(position + 2) === 0x0022
- ) {
- currentLine += body.slice(chunkStart, position);
- blockLines.push(currentLine);
- const token = createToken(
- lexer,
- _tokenKind.TokenKind.BLOCK_STRING,
- start,
- position + 3, // Return a string of the lines joined with U+000A.
- (0, _blockString.dedentBlockStringLines)(blockLines).join('\n'),
- );
- lexer.line += blockLines.length - 1;
- lexer.lineStart = lineStart;
- return token;
- } // Escaped Triple-Quote (\""")
- if (
- code === 0x005c &&
- body.charCodeAt(position + 1) === 0x0022 &&
- body.charCodeAt(position + 2) === 0x0022 &&
- body.charCodeAt(position + 3) === 0x0022
- ) {
- currentLine += body.slice(chunkStart, position);
- chunkStart = position + 1; // skip only slash
- position += 4;
- continue;
- } // LineTerminator
- if (code === 0x000a || code === 0x000d) {
- currentLine += body.slice(chunkStart, position);
- blockLines.push(currentLine);
- if (code === 0x000d && body.charCodeAt(position + 1) === 0x000a) {
- position += 2;
- } else {
- ++position;
- }
- currentLine = '';
- chunkStart = position;
- lineStart = position;
- continue;
- } // SourceCharacter
- if (isUnicodeScalarValue(code)) {
- ++position;
- } else if (isSupplementaryCodePoint(body, position)) {
- position += 2;
- } else {
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- `Invalid character within String: ${printCodePointAt(
- lexer,
- position,
- )}.`,
- );
- }
- }
- throw (0, _syntaxError.syntaxError)(
- lexer.source,
- position,
- 'Unterminated string.',
- );
- }
- /**
- * Reads an alphanumeric + underscore name from the source.
- *
- * ```
- * Name ::
- * - NameStart NameContinue* [lookahead != NameContinue]
- * ```
- */
- function readName(lexer, start) {
- const body = lexer.source.body;
- const bodyLength = body.length;
- let position = start + 1;
- while (position < bodyLength) {
- const code = body.charCodeAt(position);
- if ((0, _characterClasses.isNameContinue)(code)) {
- ++position;
- } else {
- break;
- }
- }
- return createToken(
- lexer,
- _tokenKind.TokenKind.NAME,
- start,
- position,
- body.slice(start, position),
- );
- }
|