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esprima.js
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esprima.js
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/*
Copyright (C) 2012 Ariya Hidayat <[email protected]>
Copyright (C) 2012 Mathias Bynens <[email protected]>
Copyright (C) 2012 Joost-Wim Boekesteijn <[email protected]>
Copyright (C) 2012 Kris Kowal <[email protected]>
Copyright (C) 2012 Yusuke Suzuki <[email protected]>
Copyright (C) 2012 Arpad Borsos <[email protected]>
Copyright (C) 2011 Ariya Hidayat <[email protected]>
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*jslint bitwise:true plusplus:true */
/*global esprima:true, define:true, exports:true, window: true,
throwError: true, generateStatement: true, peek: true,
parseAssignmentExpression: true, parseBlock: true, parseExpression: true,
parseFunctionDeclaration: true, parseFunctionExpression: true,
parseFunctionSourceElements: true, parseVariableIdentifier: true,
parseLeftHandSideExpression: true,
parseStatement: true, parseSourceElement: true */
(function (root, factory) {
'use strict';
// Universal Module Definition (UMD) to support AMD, CommonJS/Node.js,
// Rhino, and plain browser loading.
if (typeof define === 'function' && define.amd) {
define(['exports'], factory);
} else if (typeof exports !== 'undefined') {
factory(exports);
} else {
factory((root.esprima = {}));
}
}(this, function (exports) {
'use strict';
var Token,
TokenName,
Syntax,
PropertyKind,
Messages,
Regex,
SyntaxTreeDelegate,
source,
strict,
index,
lineNumber,
lineStart,
length,
delegate,
lookahead,
state,
extra;
Token = {
BooleanLiteral: 1,
EOF: 2,
Identifier: 3,
Keyword: 4,
NullLiteral: 5,
NumericLiteral: 6,
Punctuator: 7,
StringLiteral: 8
};
TokenName = {};
TokenName[Token.BooleanLiteral] = 'Boolean';
TokenName[Token.EOF] = '<end>';
TokenName[Token.Identifier] = 'Identifier';
TokenName[Token.Keyword] = 'Keyword';
TokenName[Token.NullLiteral] = 'Null';
TokenName[Token.NumericLiteral] = 'Numeric';
TokenName[Token.Punctuator] = 'Punctuator';
TokenName[Token.StringLiteral] = 'String';
Syntax = {
AssignmentExpression: 'AssignmentExpression',
ArrayExpression: 'ArrayExpression',
BlockStatement: 'BlockStatement',
BinaryExpression: 'BinaryExpression',
BreakStatement: 'BreakStatement',
CallExpression: 'CallExpression',
CatchClause: 'CatchClause',
ConditionalExpression: 'ConditionalExpression',
ContinueStatement: 'ContinueStatement',
DoWhileStatement: 'DoWhileStatement',
DebuggerStatement: 'DebuggerStatement',
EmptyStatement: 'EmptyStatement',
ExpressionStatement: 'ExpressionStatement',
ForStatement: 'ForStatement',
ForInStatement: 'ForInStatement',
FunctionDeclaration: 'FunctionDeclaration',
FunctionExpression: 'FunctionExpression',
Identifier: 'Identifier',
IfStatement: 'IfStatement',
Literal: 'Literal',
LabeledStatement: 'LabeledStatement',
LogicalExpression: 'LogicalExpression',
MemberExpression: 'MemberExpression',
NewExpression: 'NewExpression',
ObjectExpression: 'ObjectExpression',
Program: 'Program',
Property: 'Property',
ReturnStatement: 'ReturnStatement',
SequenceExpression: 'SequenceExpression',
SwitchStatement: 'SwitchStatement',
SwitchCase: 'SwitchCase',
ThisExpression: 'ThisExpression',
ThrowStatement: 'ThrowStatement',
TryStatement: 'TryStatement',
UnaryExpression: 'UnaryExpression',
UpdateExpression: 'UpdateExpression',
VariableDeclaration: 'VariableDeclaration',
VariableDeclarator: 'VariableDeclarator',
WhileStatement: 'WhileStatement',
WithStatement: 'WithStatement'
};
PropertyKind = {
Data: 1,
Get: 2,
Set: 4
};
// Error messages should be identical to V8.
Messages = {
UnexpectedToken: 'Unexpected token %0',
UnexpectedNumber: 'Unexpected number',
UnexpectedString: 'Unexpected string',
UnexpectedIdentifier: 'Unexpected identifier',
UnexpectedReserved: 'Unexpected reserved word',
UnexpectedEOS: 'Unexpected end of input',
NewlineAfterThrow: 'Illegal newline after throw',
InvalidRegExp: 'Invalid regular expression',
UnterminatedRegExp: 'Invalid regular expression: missing /',
InvalidLHSInAssignment: 'Invalid left-hand side in assignment',
InvalidLHSInForIn: 'Invalid left-hand side in for-in',
MultipleDefaultsInSwitch: 'More than one default clause in switch statement',
NoCatchOrFinally: 'Missing catch or finally after try',
UnknownLabel: 'Undefined label \'%0\'',
Redeclaration: '%0 \'%1\' has already been declared',
IllegalContinue: 'Illegal continue statement',
IllegalBreak: 'Illegal break statement',
IllegalReturn: 'Illegal return statement',
StrictModeWith: 'Strict mode code may not include a with statement',
StrictCatchVariable: 'Catch variable may not be eval or arguments in strict mode',
StrictVarName: 'Variable name may not be eval or arguments in strict mode',
StrictParamName: 'Parameter name eval or arguments is not allowed in strict mode',
StrictParamDupe: 'Strict mode function may not have duplicate parameter names',
StrictFunctionName: 'Function name may not be eval or arguments in strict mode',
StrictOctalLiteral: 'Octal literals are not allowed in strict mode.',
StrictDelete: 'Delete of an unqualified identifier in strict mode.',
StrictDuplicateProperty: 'Duplicate data property in object literal not allowed in strict mode',
AccessorDataProperty: 'Object literal may not have data and accessor property with the same name',
AccessorGetSet: 'Object literal may not have multiple get/set accessors with the same name',
StrictLHSAssignment: 'Assignment to eval or arguments is not allowed in strict mode',
StrictLHSPostfix: 'Postfix increment/decrement may not have eval or arguments operand in strict mode',
StrictLHSPrefix: 'Prefix increment/decrement may not have eval or arguments operand in strict mode',
StrictReservedWord: 'Use of future reserved word in strict mode'
};
// See also tools/generate-unicode-regex.py.
Regex = {
NonAsciiIdentifierStart: new RegExp('[\xaa\xb5\xba\xc0-\xd6\xd8-\xf6\xf8-\u02c1\u02c6-\u02d1\u02e0-\u02e4\u02ec\u02ee\u0370-\u0374\u0376\u0377\u037a-\u037d\u0386\u0388-\u038a\u038c\u038e-\u03a1\u03a3-\u03f5\u03f7-\u0481\u048a-\u0527\u0531-\u0556\u0559\u0561-\u0587\u05d0-\u05ea\u05f0-\u05f2\u0620-\u064a\u066e\u066f\u0671-\u06d3\u06d5\u06e5\u06e6\u06ee\u06ef\u06fa-\u06fc\u06ff\u0710\u0712-\u072f\u074d-\u07a5\u07b1\u07ca-\u07ea\u07f4\u07f5\u07fa\u0800-\u0815\u081a\u0824\u0828\u0840-\u0858\u08a0\u08a2-\u08ac\u0904-\u0939\u093d\u0950\u0958-\u0961\u0971-\u0977\u0979-\u097f\u0985-\u098c\u098f\u0990\u0993-\u09a8\u09aa-\u09b0\u09b2\u09b6-\u09b9\u09bd\u09ce\u09dc\u09dd\u09df-\u09e1\u09f0\u09f1\u0a05-\u0a0a\u0a0f\u0a10\u0a13-\u0a28\u0a2a-\u0a30\u0a32\u0a33\u0a35\u0a36\u0a38\u0a39\u0a59-\u0a5c\u0a5e\u0a72-\u0a74\u0a85-\u0a8d\u0a8f-\u0a91\u0a93-\u0aa8\u0aaa-\u0ab0\u0ab2\u0ab3\u0ab5-\u0ab9\u0abd\u0ad0\u0ae0\u0ae1\u0b05-\u0b0c\u0b0f\u0b10\u0b13-\u0b28\u0b2a-\u0b30\u0b32\u0b33\u0b35-\u0b39\u0b3d\u0b5c\u0b5d\u0b5f-\u0b61\u0b71\u0b83\u0b85-\u0b8a\u0b8e-\u0b90\u0b92-\u0b95\u0b99\u0b9a\u0b9c\u0b9e\u0b9f\u0ba3\u0ba4\u0ba8-\u0baa\u0bae-\u0bb9\u0bd0\u0c05-\u0c0c\u0c0e-\u0c10\u0c12-\u0c28\u0c2a-\u0c33\u0c35-\u0c39\u0c3d\u0c58\u0c59\u0c60\u0c61\u0c85-\u0c8c\u0c8e-\u0c90\u0c92-\u0ca8\u0caa-\u0cb3\u0cb5-\u0cb9\u0cbd\u0cde\u0ce0\u0ce1\u0cf1\u0cf2\u0d05-\u0d0c\u0d0e-\u0d10\u0d12-\u0d3a\u0d3d\u0d4e\u0d60\u0d61\u0d7a-\u0d7f\u0d85-\u0d96\u0d9a-\u0db1\u0db3-\u0dbb\u0dbd\u0dc0-\u0dc6\u0e01-\u0e30\u0e32\u0e33\u0e40-\u0e46\u0e81\u0e82\u0e84\u0e87\u0e88\u0e8a\u0e8d\u0e94-\u0e97\u0e99-\u0e9f\u0ea1-\u0ea3\u0ea5\u0ea7\u0eaa\u0eab\u0ead-\u0eb0\u0eb2\u0eb3\u0ebd\u0ec0-\u0ec4\u0ec6\u0edc-\u0edf\u0f00\u0f40-\u0f47\u0f49-\u0f6c\u0f88-\u0f8c\u1000-\u102a\u103f\u1050-\u1055\u105a-\u105d\u1061\u1065\u1066\u106e-\u1070\u1075-\u1081\u108e\u10a0-\u10c5\u10c7\u10cd\u10d0-\u10fa\u10fc-\u1248\u124a-\u124d\u1250-\u1256\u1258\u125a-\u125d\u1260-\u1288\u128a-\u128d\u1290-\u12b0\u12b2-\u12b5\u12b8-\u12be\u12c0\u12c2-\u12c5\u12c8-\u12d6\u12d8-\u1310\u1312-\u1315\u1318-\u135a\u1380-\u138f\u13a0-\u13f4\u1401-\u166c\u166f-\u167f\u1681-\u169a\u16a0-\u16ea\u16ee-\u16f0\u1700-\u170c\u170e-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176c\u176e-\u1770\u1780-\u17b3\u17d7\u17dc\u1820-\u1877\u1880-\u18a8\u18aa\u18b0-\u18f5\u1900-\u191c\u1950-\u196d\u1970-\u1974\u1980-\u19ab\u19c1-\u19c7\u1a00-\u1a16\u1a20-\u1a54\u1aa7\u1b05-\u1b33\u1b45-\u1b4b\u1b83-\u1ba0\u1bae\u1baf\u1bba-\u1be5\u1c00-\u1c23\u1c4d-\u1c4f\u1c5a-\u1c7d\u1ce9-\u1cec\u1cee-\u1cf1\u1cf5\u1cf6\u1d00-\u1dbf\u1e00-\u1f15\u1f18-\u1f1d\u1f20-\u1f45\u1f48-\u1f4d\u1f50-\u1f57\u1f59\u1f5b\u1f5d\u1f5f-\u1f7d\u1f80-\u1fb4\u1fb6-\u1fbc\u1fbe\u1fc2-\u1fc4\u1fc6-\u1fcc\u1fd0-\u1fd3\u1fd6-\u1fdb\u1fe0-\u1fec\u1ff2-\u1ff4\u1ff6-\u1ffc\u2071\u207f\u2090-\u209c\u2102\u2107\u210a-\u2113\u2115\u2119-\u211d\u2124\u2126\u2128\u212a-\u212d\u212f-\u2139\u213c-\u213f\u2145-\u2149\u214e\u2160-\u2188\u2c00-\u2c2e\u2c30-\u2c5e\u2c60-\u2ce4\u2ceb-\u2cee\u2cf2\u2cf3\u2d00-\u2d25\u2d27\u2d2d\u2d30-\u2d67\u2d6f\u2d80-\u2d96\u2da0-\u2da6\u2da8-\u2dae\u2db0-\u2db6\u2db8-\u2dbe\u2dc0-\u2dc6\u2dc8-\u2dce\u2dd0-\u2dd6\u2dd8-\u2dde\u2e2f\u3005-\u3007\u3021-\u3029\u3031-\u3035\u3038-\u303c\u3041-\u3096\u309d-\u309f\u30a1-\u30fa\u30fc-\u30ff\u3105-\u312d\u3131-\u318e\u31a0-\u31ba\u31f0-\u31ff\u3400-\u4db5\u4e00-\u9fcc\ua000-\ua48c\ua4d0-\ua4fd\ua500-\ua60c\ua610-\ua61f\ua62a\ua62b\ua640-\ua66e\ua67f-\ua697\ua6a0-\ua6ef\ua717-\ua71f\ua722-\ua788\ua78b-\ua78e\ua790-\ua793\ua7a0-\ua7aa\ua7f8-\ua801\ua803-\ua805\ua807-\ua80a\ua80c-\ua822\ua840-\ua873\ua882-\ua8b3\ua8f2-\ua8f7\ua8fb\ua90a-\ua925\ua930-\ua946\ua960-\ua97c\ua984-\ua9b2\ua9cf\uaa00-\uaa28\uaa40-\uaa42\uaa44-\uaa4b\uaa60-\uaa76\uaa7a\uaa80-\uaaaf\uaab1\uaab5\uaab6\uaab9-\uaabd\uaac0\uaac2\uaadb-\uaadd\uaae0-\uaaea\uaaf2-\uaaf4\uab01-\uab06\uab09-\uab0e\uab11-\uab16\uab20-\uab26\uab28-\uab2e\uabc0-\uabe2\uac00-\ud7a3\ud7b0-\ud7c6\ud7cb-\ud7fb\uf900-\ufa6d\ufa70-\ufad9\ufb00-\ufb06\ufb13-\ufb17\ufb1d\ufb1f-\ufb28\ufb2a-\ufb36\ufb38-\ufb3c\ufb3e\ufb40\ufb41\ufb43\ufb44\ufb46-\ufbb1\ufbd3-\ufd3d\ufd50-\ufd8f\ufd92-\ufdc7\ufdf0-\ufdfb\ufe70-\ufe74\ufe76-\ufefc\uff21-\uff3a\uff41-\uff5a\uff66-\uffbe\uffc2-\uffc7\uffca-\uffcf\uffd2-\uffd7\uffda-\uffdc]'),
NonAsciiIdentifierPart: new 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\uffc7\uffca-\uffcf\uffd2-\uffd7\uffda-\uffdc]')
};
// Ensure the condition is true, otherwise throw an error.
// This is only to have a better contract semantic, i.e. another safety net
// to catch a logic error. The condition shall be fulfilled in normal case.
// Do NOT use this to enforce a certain condition on any user input.
function assert(condition, message) {
if (!condition) {
throw new Error('ASSERT: ' + message);
}
}
function isDecimalDigit(ch) {
return (ch >= 48 && ch <= 57); // 0..9
}
function isHexDigit(ch) {
return '0123456789abcdefABCDEF'.indexOf(ch) >= 0;
}
function isOctalDigit(ch) {
return '01234567'.indexOf(ch) >= 0;
}
// 7.2 White Space
function isWhiteSpace(ch) {
return (ch === 32) || // space
(ch === 9) || // tab
(ch === 0xB) ||
(ch === 0xC) ||
(ch === 0xA0) ||
(ch >= 0x1680 && '\u1680\u180E\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u202F\u205F\u3000\uFEFF'.indexOf(String.fromCharCode(ch)) > 0);
}
// 7.3 Line Terminators
function isLineTerminator(ch) {
return (ch === 10) || (ch === 13) || (ch === 0x2028) || (ch === 0x2029);
}
// 7.6 Identifier Names and Identifiers
function isIdentifierStart(ch) {
return (ch === 36) || (ch === 95) || // $ (dollar) and _ (underscore)
(ch >= 65 && ch <= 90) || // A..Z
(ch >= 97 && ch <= 122) || // a..z
(ch === 92) || // \ (backslash)
((ch >= 0x80) && Regex.NonAsciiIdentifierStart.test(String.fromCharCode(ch)));
}
function isIdentifierPart(ch) {
return (ch === 36) || (ch === 95) || // $ (dollar) and _ (underscore)
(ch >= 65 && ch <= 90) || // A..Z
(ch >= 97 && ch <= 122) || // a..z
(ch >= 48 && ch <= 57) || // 0..9
(ch === 92) || // \ (backslash)
((ch >= 0x80) && Regex.NonAsciiIdentifierPart.test(String.fromCharCode(ch)));
}
// 7.6.1.2 Future Reserved Words
function isFutureReservedWord(id) {
switch (id) {
case 'class':
case 'enum':
case 'export':
case 'extends':
case 'import':
case 'super':
return true;
default:
return false;
}
}
function isStrictModeReservedWord(id) {
switch (id) {
case 'implements':
case 'interface':
case 'package':
case 'private':
case 'protected':
case 'public':
case 'static':
case 'yield':
case 'let':
return true;
default:
return false;
}
}
function isRestrictedWord(id) {
return id === 'eval' || id === 'arguments';
}
// 7.6.1.1 Keywords
function isKeyword(id) {
if (strict && isStrictModeReservedWord(id)) {
return true;
}
// 'const' is specialized as Keyword in V8.
// 'yield' and 'let' are for compatiblity with SpiderMonkey and ES.next.
// Some others are from future reserved words.
switch (id.length) {
case 2:
return (id === 'if') || (id === 'in') || (id === 'do');
case 3:
return (id === 'var') || (id === 'for') || (id === 'new') ||
(id === 'try') || (id === 'let');
case 4:
return (id === 'this') || (id === 'else') || (id === 'case') ||
(id === 'void') || (id === 'with') || (id === 'enum');
case 5:
return (id === 'while') || (id === 'break') || (id === 'catch') ||
(id === 'throw') || (id === 'const') || (id === 'yield') ||
(id === 'class') || (id === 'super');
case 6:
return (id === 'return') || (id === 'typeof') || (id === 'delete') ||
(id === 'switch') || (id === 'export') || (id === 'import');
case 7:
return (id === 'default') || (id === 'finally') || (id === 'extends');
case 8:
return (id === 'function') || (id === 'continue') || (id === 'debugger');
case 10:
return (id === 'instanceof');
default:
return false;
}
}
// 7.4 Comments
function skipComment() {
var ch, blockComment, lineComment;
blockComment = false;
lineComment = false;
while (index < length) {
ch = source.charCodeAt(index);
if (lineComment) {
++index;
if (isLineTerminator(ch)) {
lineComment = false;
if (ch === 13 && source.charCodeAt(index) === 10) {
++index;
}
++lineNumber;
lineStart = index;
}
} else if (blockComment) {
if (isLineTerminator(ch)) {
if (ch === 13 && source.charCodeAt(index + 1) === 10) {
++index;
}
++lineNumber;
++index;
lineStart = index;
if (index >= length) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
} else {
ch = source.charCodeAt(index++);
if (index >= length) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
// Block comment ends with '*/' (char #42, char #47).
if (ch === 42) {
ch = source.charCodeAt(index);
if (ch === 47) {
++index;
blockComment = false;
}
}
}
} else if (ch === 47) {
ch = source.charCodeAt(index + 1);
// Line comment starts with '//' (char #47, char #47).
if (ch === 47) {
index += 2;
lineComment = true;
} else if (ch === 42) {
// Block comment starts with '/*' (char #47, char #42).
index += 2;
blockComment = true;
if (index >= length) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
} else {
break;
}
} else if (isWhiteSpace(ch)) {
++index;
} else if (isLineTerminator(ch)) {
++index;
if (ch === 13 && source.charCodeAt(index) === 10) {
++index;
}
++lineNumber;
lineStart = index;
} else {
break;
}
}
}
function scanHexEscape(prefix) {
var i, len, ch, code = 0;
len = (prefix === 'u') ? 4 : 2;
for (i = 0; i < len; ++i) {
if (index < length && isHexDigit(source[index])) {
ch = source[index++];
code = code * 16 + '0123456789abcdef'.indexOf(ch.toLowerCase());
} else {
return '';
}
}
return String.fromCharCode(code);
}
function getEscapedIdentifier() {
var ch, id;
ch = source.charCodeAt(index++);
id = String.fromCharCode(ch);
// '\u' (char #92, char #117) denotes an escaped character.
if (ch === 92) {
if (source.charCodeAt(index) !== 117) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
++index;
ch = scanHexEscape('u');
if (!ch || ch === '\\' || !isIdentifierStart(ch.charCodeAt(0))) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
id = ch;
}
while (index < length) {
ch = source.charCodeAt(index);
if (!isIdentifierPart(ch)) {
break;
}
++index;
id += String.fromCharCode(ch);
// '\u' (char #92, char #117) denotes an escaped character.
if (ch === 92) {
id = id.substr(0, id.length - 1);
if (source.charCodeAt(index) !== 117) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
++index;
ch = scanHexEscape('u');
if (!ch || ch === '\\' || !isIdentifierPart(ch.charCodeAt(0))) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
id += ch;
}
}
return id;
}
function getIdentifier() {
var start, ch;
start = index++;
while (index < length) {
ch = source.charCodeAt(index);
if (ch === 92) {
// Blackslash (char #92) marks Unicode escape sequence.
index = start;
return getEscapedIdentifier();
}
if (isIdentifierPart(ch)) {
++index;
} else {
break;
}
}
return source.slice(start, index);
}
function scanIdentifier() {
var start, id, type;
start = index;
// Backslash (char #92) starts an escaped character.
id = (source.charCodeAt(index) === 92) ? getEscapedIdentifier() : getIdentifier();
// There is no keyword or literal with only one character.
// Thus, it must be an identifier.
if (id.length === 1) {
type = Token.Identifier;
} else if (isKeyword(id)) {
type = Token.Keyword;
} else if (id === 'null') {
type = Token.NullLiteral;
} else if (id === 'true' || id === 'false') {
type = Token.BooleanLiteral;
} else {
type = Token.Identifier;
}
return {
type: type,
value: id,
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
// 7.7 Punctuators
function scanPunctuator() {
var start = index,
code = source.charCodeAt(index),
code2,
ch1 = source[index],
ch2,
ch3,
ch4;
switch (code) {
// Check for most common single-character punctuators.
case 46: // . dot
case 40: // ( open bracket
case 41: // ) close bracket
case 59: // ; semicolon
case 44: // , comma
case 123: // { open curly brace
case 125: // } close curly brace
case 91: // [
case 93: // ]
case 58: // :
case 63: // ?
case 126: // ~
++index;
return {
type: Token.Punctuator,
value: String.fromCharCode(code),
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
default:
code2 = source.charCodeAt(index + 1);
// '=' (char #61) marks an assignment or comparison operator.
if (code2 === 61) {
switch (code) {
case 37: // %
case 38: // &
case 42: // *:
case 43: // +
case 45: // -
case 47: // /
case 60: // <
case 62: // >
case 94: // ^
case 124: // |
index += 2;
return {
type: Token.Punctuator,
value: String.fromCharCode(code) + String.fromCharCode(code2),
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
case 33: // !
case 61: // =
index += 2;
// !== and ===
if (source.charCodeAt(index) === 61) {
++index;
}
return {
type: Token.Punctuator,
value: source.slice(start, index),
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
default:
break;
}
}
break;
}
// Peek more characters.
ch2 = source[index + 1];
ch3 = source[index + 2];
ch4 = source[index + 3];
// 4-character punctuator: >>>=
if (ch1 === '>' && ch2 === '>' && ch3 === '>') {
if (ch4 === '=') {
index += 4;
return {
type: Token.Punctuator,
value: '>>>=',
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
}
// 3-character punctuators: === !== >>> <<= >>=
if (ch1 === '>' && ch2 === '>' && ch3 === '>') {
index += 3;
return {
type: Token.Punctuator,
value: '>>>',
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
if (ch1 === '<' && ch2 === '<' && ch3 === '=') {
index += 3;
return {
type: Token.Punctuator,
value: '<<=',
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
if (ch1 === '>' && ch2 === '>' && ch3 === '=') {
index += 3;
return {
type: Token.Punctuator,
value: '>>=',
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
// Other 2-character punctuators: ++ -- << >> && ||
if (ch1 === ch2 && ('+-<>&|'.indexOf(ch1) >= 0)) {
index += 2;
return {
type: Token.Punctuator,
value: ch1 + ch2,
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
if ('<>=!+-*%&|^/'.indexOf(ch1) >= 0) {
++index;
return {
type: Token.Punctuator,
value: ch1,
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
// 7.8.3 Numeric Literals
function scanNumericLiteral() {
var number, start, ch;
ch = source[index];
assert(isDecimalDigit(ch.charCodeAt(0)) || (ch === '.'),
'Numeric literal must start with a decimal digit or a decimal point');
start = index;
number = '';
if (ch !== '.') {
number = source[index++];
ch = source[index];
// Hex number starts with '0x'.
// Octal number starts with '0'.
if (number === '0') {
if (ch === 'x' || ch === 'X') {
number += source[index++];
while (index < length) {
ch = source[index];
if (!isHexDigit(ch)) {
break;
}
number += source[index++];
}
if (number.length <= 2) {
// only 0x
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
if (index < length) {
ch = source[index];
if (isIdentifierStart(ch.charCodeAt(0))) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
}
return {
type: Token.NumericLiteral,
value: parseInt(number, 16),
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
if (isOctalDigit(ch)) {
number += source[index++];
while (index < length) {
ch = source[index];
if (!isOctalDigit(ch)) {
break;
}
number += source[index++];
}
if (index < length) {
ch = source.charCodeAt(index);
if (isIdentifierStart(ch) || isDecimalDigit(ch)) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
}
return {
type: Token.NumericLiteral,
value: parseInt(number, 8),
octal: true,
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
// decimal number starts with '0' such as '09' is illegal.
if (ch && isDecimalDigit(ch.charCodeAt(0))) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
}
while (index < length) {
if (!isDecimalDigit(source.charCodeAt(index))) {
ch = source[index];
break;
}
number += source[index++];
}
}
if (ch === '.') {
number += source[index++];
while (index < length) {
if (!isDecimalDigit(source.charCodeAt(index))) {
ch = source[index];
break;
}
number += source[index++];
}
}
if (ch === 'e' || ch === 'E') {
number += source[index++];
ch = source[index];
if (ch === '+' || ch === '-') {
number += source[index++];
}
ch = source[index];
if (ch && isDecimalDigit(ch.charCodeAt(0))) {
number += source[index++];
while (index < length) {
if (!isDecimalDigit(source.charCodeAt(index))) {
ch = source[index];
break;
}
number += source[index++];
}
} else {
ch = 'character ' + ch;
if (index >= length) {
ch = '<end>';
}
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
}
if (index < length) {
if (isIdentifierStart(source.charCodeAt(index))) {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
}
return {
type: Token.NumericLiteral,
value: parseFloat(number),
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
// 7.8.4 String Literals
function scanStringLiteral() {
var str = '', quote, start, ch, code, unescaped, restore, octal = false;
quote = source[index];
assert((quote === '\'' || quote === '"'),
'String literal must starts with a quote');
start = index;
++index;
while (index < length) {
ch = source[index++];
if (ch === quote) {
quote = '';
break;
} else if (ch === '\\') {
ch = source[index++];
if (!ch || !isLineTerminator(ch.charCodeAt(0))) {
switch (ch) {
case 'n':
str += '\n';
break;
case 'r':
str += '\r';
break;
case 't':
str += '\t';
break;
case 'u':
case 'x':
restore = index;
unescaped = scanHexEscape(ch);
if (unescaped) {
str += unescaped;
} else {
index = restore;
str += ch;
}
break;
case 'b':
str += '\b';
break;
case 'f':
str += '\f';
break;
case 'v':
str += '\v';
break;
default:
if (isOctalDigit(ch)) {
code = '01234567'.indexOf(ch);
// \0 is not octal escape sequence
if (code !== 0) {
octal = true;
}
if (index < length && isOctalDigit(source[index])) {
octal = true;
code = code * 8 + '01234567'.indexOf(source[index++]);
// 3 digits are only allowed when string starts
// with 0, 1, 2, 3
if ('0123'.indexOf(ch) >= 0 &&
index < length &&
isOctalDigit(source[index])) {
code = code * 8 + '01234567'.indexOf(source[index++]);
}
}
str += String.fromCharCode(code);
} else {
str += ch;
}
break;
}
} else {
++lineNumber;
if (ch === '\r' && source[index] === '\n') {
++index;
}
}
} else if (isLineTerminator(ch.charCodeAt(0))) {
break;
} else {
str += ch;
}
}
if (quote !== '') {
throwError({}, Messages.UnexpectedToken, 'ILLEGAL');
}
return {
type: Token.StringLiteral,
value: str,
octal: octal,
lineNumber: lineNumber,
lineStart: lineStart,
range: [start, index]
};
}
function scanRegExp() {
var str, ch, start, pattern, flags, value, classMarker = false, restore, terminated = false;
lookahead = null;
skipComment();
start = index;
ch = source[index];
assert(ch === '/', 'Regular expression literal must start with a slash');
str = source[index++];
while (index < length) {
ch = source[index++];
str += ch;
if (classMarker) {
if (ch === ']') {
classMarker = false;
}
} else {
if (ch === '\\') {
ch = source[index++];
// ECMA-262 7.8.5
if (isLineTerminator(ch.charCodeAt(0))) {
throwError({}, Messages.UnterminatedRegExp);
}
str += ch;
} else if (ch === '/') {
terminated = true;
break;
} else if (ch === '[') {
classMarker = true;
} else if (isLineTerminator(ch.charCodeAt(0))) {
throwError({}, Messages.UnterminatedRegExp);
}
}
}
if (!terminated) {
throwError({}, Messages.UnterminatedRegExp);
}
// Exclude leading and trailing slash.
pattern = str.substr(1, str.length - 2);
flags = '';
while (index < length) {
ch = source[index];
if (!isIdentifierPart(ch.charCodeAt(0))) {
break;
}
++index;
if (ch === '\\' && index < length) {
ch = source[index];
if (ch === 'u') {
++index;
restore = index;
ch = scanHexEscape('u');
if (ch) {
flags += ch;
for (str += '\\u'; restore < index; ++restore) {
str += source[restore];
}
} else {
index = restore;
flags += 'u';
str += '\\u';
}
} else {
str += '\\';
}
} else {
flags += ch;
str += ch;
}
}
try {