The Tor Browser: toolkit/devtools/acorn/acorn.js@b8a032363ba2 (annotated)

toolkit/devtools/acorn/acorn.js@b8a032363ba2 (annotated)

toolkit/devtools/acorn/acorn.js

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 // Acorn is a tiny, fast JavaScript parser written in JavaScript.
 //
 // Acorn was written by Marijn Haverbeke and released under an MIT
 // license. The Unicode regexps (for identifiers and whitespace) were
 // taken from [Esprima](http://esprima.org) by Ariya Hidayat.
 //
 // Git repositories for Acorn are available at
 //
 //     http://marijnhaverbeke.nl/git/acorn
 //     https://github.com/marijnh/acorn.git
 //
 // Please use the [github bug tracker][ghbt] to report issues.
 //
 // [ghbt]: https://github.com/marijnh/acorn/issues
 //
 // This file defines the main parser interface. The library also comes
 // with a [error-tolerant parser][dammit] and an
 // [abstract syntax tree walker][walk], defined in other files.
 //
 // [dammit]: acorn_loose.js
 // [walk]: util/walk.js
 (function(root, mod) {
   if (typeof exports == "object" && typeof module == "object") return mod(exports); // CommonJS
   if (typeof define == "function" && define.amd) return define(["exports"], mod); // AMD
   mod(root.acorn || (root.acorn = {})); // Plain browser env
 })(this, function(exports) {
   "use strict";
   exports.version = "0.4.1";
   // The main exported interface (under `self.acorn` when in the
   // browser) is a `parse` function that takes a code string and
   // returns an abstract syntax tree as specified by [Mozilla parser
   // API][api], with the caveat that the SpiderMonkey-specific syntax
   // (`let`, `yield`, inline XML, etc) is not recognized.
   //
   // [api]: https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API
   var options, input, inputLen, sourceFile;
   exports.parse = function(inpt, opts) {
     input = String(inpt); inputLen = input.length;
     setOptions(opts);
     initTokenState();
     return parseTopLevel(options.program);
   };
   // A second optional argument can be given to further configure
   // the parser process. These options are recognized:
   var defaultOptions = exports.defaultOptions = {
     // `ecmaVersion` indicates the ECMAScript version to parse. Must
     // be either 3 or 5. This
     // influences support for strict mode, the set of reserved words, and
     // support for getters and setter.
     ecmaVersion: 5,
     // Turn on `strictSemicolons` to prevent the parser from doing
     // automatic semicolon insertion.
     strictSemicolons: false,
     // When `allowTrailingCommas` is false, the parser will not allow
     // trailing commas in array and object literals.
     allowTrailingCommas: true,
     // By default, reserved words are not enforced. Enable
     // `forbidReserved` to enforce them.
     forbidReserved: false,
     // When `locations` is on, `loc` properties holding objects with
     // `start` and `end` properties in `{line, column}` form (with
     // line being 1-based and column 0-based) will be attached to the
     // nodes.
     locations: false,
     // A function can be passed as `onComment` option, which will
     // cause Acorn to call that function with `(block, text, start,
     // end)` parameters whenever a comment is skipped. `block` is a
     // boolean indicating whether this is a block (`/* */`) comment,
     // `text` is the content of the comment, and `start` and `end` are
     // character offsets that denote the start and end of the comment.
     // When the `locations` option is on, two more parameters are
     // passed, the full `{line, column}` locations of the start and
     // end of the comments. Note that you are not allowed to call the
     // parser from the callback—that will corrupt its internal state.
     onComment: null,
     // Nodes have their start and end characters offsets recorded in
     // `start` and `end` properties (directly on the node, rather than
     // the `loc` object, which holds line/column data. To also add a
     // [semi-standardized][range] `range` property holding a `[start,
     // end]` array with the same numbers, set the `ranges` option to
     // `true`.
     //
     // [range]: https://bugzilla.mozilla.org/show_bug.cgi?id=745678
     ranges: false,
     // It is possible to parse multiple files into a single AST by
     // passing the tree produced by parsing the first file as
     // `program` option in subsequent parses. This will add the
     // toplevel forms of the parsed file to the `Program` (top) node
     // of an existing parse tree.
     program: null,
     // When `locations` is on, you can pass this to record the source
     // file in every node's `loc` object.
     sourceFile: null,
     // This value, if given, is stored in every node, whether
     // `locations` is on or off.
     directSourceFile: null
   };
   function setOptions(opts) {
     options = opts || {};
     for (var opt in defaultOptions) if (!Object.prototype.hasOwnProperty.call(options, opt))
       options[opt] = defaultOptions[opt];
     sourceFile = options.sourceFile || null;
   }
   // The `getLineInfo` function is mostly useful when the
   // `locations` option is off (for performance reasons) and you
   // want to find the line/column position for a given character
   // offset. `input` should be the code string that the offset refers
   // into.
   var getLineInfo = exports.getLineInfo = function(input, offset) {
     for (var line = 1, cur = 0;;) {
       lineBreak.lastIndex = cur;
       var match = lineBreak.exec(input);
       if (match && match.index < offset) {
         ++line;
         cur = match.index + match[0].length;
       } else break;
     }
     return {line: line, column: offset - cur};
   };
   // Acorn is organized as a tokenizer and a recursive-descent parser.
   // The `tokenize` export provides an interface to the tokenizer.
   // Because the tokenizer is optimized for being efficiently used by
   // the Acorn parser itself, this interface is somewhat crude and not
   // very modular. Performing another parse or call to `tokenize` will
   // reset the internal state, and invalidate existing tokenizers.
   exports.tokenize = function(inpt, opts) {
     input = String(inpt); inputLen = input.length;
     setOptions(opts);
     initTokenState();
     var t = {};
     function getToken(forceRegexp) {
       lastEnd = tokEnd;
       readToken(forceRegexp);
       t.start = tokStart; t.end = tokEnd;
       t.startLoc = tokStartLoc; t.endLoc = tokEndLoc;
       t.type = tokType; t.value = tokVal;
       return t;
     }
     getToken.jumpTo = function(pos, reAllowed) {
       tokPos = pos;
       if (options.locations) {
         tokCurLine = 1;
         tokLineStart = lineBreak.lastIndex = 0;
         var match;
         while ((match = lineBreak.exec(input)) && match.index < pos) {
           ++tokCurLine;
           tokLineStart = match.index + match[0].length;
         }
       }
       tokRegexpAllowed = reAllowed;
       skipSpace();
     };
     return getToken;
   };
   // State is kept in (closure-)global variables. We already saw the
   // `options`, `input`, and `inputLen` variables above.
   // The current position of the tokenizer in the input.
   var tokPos;
   // The start and end offsets of the current token.
   var tokStart, tokEnd;
   // When `options.locations` is true, these hold objects
   // containing the tokens start and end line/column pairs.
   var tokStartLoc, tokEndLoc;
   // The type and value of the current token. Token types are objects,
   // named by variables against which they can be compared, and
   // holding properties that describe them (indicating, for example,
   // the precedence of an infix operator, and the original name of a
   // keyword token). The kind of value that's held in `tokVal` depends
   // on the type of the token. For literals, it is the literal value,
   // for operators, the operator name, and so on.
   var tokType, tokVal;
   // Interal state for the tokenizer. To distinguish between division
   // operators and regular expressions, it remembers whether the last
   // token was one that is allowed to be followed by an expression.
   // (If it is, a slash is probably a regexp, if it isn't it's a
   // division operator. See the `parseStatement` function for a
   // caveat.)
   var tokRegexpAllowed;
   // When `options.locations` is true, these are used to keep
   // track of the current line, and know when a new line has been
   // entered.
   var tokCurLine, tokLineStart;
   // These store the position of the previous token, which is useful
   // when finishing a node and assigning its `end` position.
   var lastStart, lastEnd, lastEndLoc;
   // This is the parser's state. `inFunction` is used to reject
   // `return` statements outside of functions, `labels` to verify that
   // `break` and `continue` have somewhere to jump to, and `strict`
   // indicates whether strict mode is on.
   var inFunction, labels, strict;
   // This function is used to raise exceptions on parse errors. It
   // takes an offset integer (into the current `input`) to indicate
   // the location of the error, attaches the position to the end
   // of the error message, and then raises a `SyntaxError` with that
   // message.
   function raise(pos, message) {
     var loc = getLineInfo(input, pos);
     message += " (" + loc.line + ":" + loc.column + ")";
     var err = new SyntaxError(message);
     err.pos = pos; err.loc = loc; err.raisedAt = tokPos;
     throw err;
   }
   // Reused empty array added for node fields that are always empty.
   var empty = [];
   // ## Token types
   // The assignment of fine-grained, information-carrying type objects
   // allows the tokenizer to store the information it has about a
   // token in a way that is very cheap for the parser to look up.
   // All token type variables start with an underscore, to make them
   // easy to recognize.
   // These are the general types. The `type` property is only used to
   // make them recognizeable when debugging.
   var _num = {type: "num"}, _regexp = {type: "regexp"}, _string = {type: "string"};
   var _name = {type: "name"}, _eof = {type: "eof"};
   // Keyword tokens. The `keyword` property (also used in keyword-like
   // operators) indicates that the token originated from an
   // identifier-like word, which is used when parsing property names.
   //
   // The `beforeExpr` property is used to disambiguate between regular
   // expressions and divisions. It is set on all token types that can
   // be followed by an expression (thus, a slash after them would be a
   // regular expression).
   //
   // `isLoop` marks a keyword as starting a loop, which is important
   // to know when parsing a label, in order to allow or disallow
   // continue jumps to that label.
   var _break = {keyword: "break"}, _case = {keyword: "case", beforeExpr: true}, _catch = {keyword: "catch"};
   var _continue = {keyword: "continue"}, _debugger = {keyword: "debugger"}, _default = {keyword: "default"};
   var _do = {keyword: "do", isLoop: true}, _else = {keyword: "else", beforeExpr: true};
   var _finally = {keyword: "finally"}, _for = {keyword: "for", isLoop: true}, _function = {keyword: "function"};
   var _if = {keyword: "if"}, _return = {keyword: "return", beforeExpr: true}, _switch = {keyword: "switch"};
   var _throw = {keyword: "throw", beforeExpr: true}, _try = {keyword: "try"}, _var = {keyword: "var"};
   var _while = {keyword: "while", isLoop: true}, _with = {keyword: "with"}, _new = {keyword: "new", beforeExpr: true};
   var _this = {keyword: "this"};
   // The keywords that denote values.
   var _null = {keyword: "null", atomValue: null}, _true = {keyword: "true", atomValue: true};
   var _false = {keyword: "false", atomValue: false};
   // Some keywords are treated as regular operators. `in` sometimes
   // (when parsing `for`) needs to be tested against specifically, so
   // we assign a variable name to it for quick comparing.
   var _in = {keyword: "in", binop: 7, beforeExpr: true};
   // Map keyword names to token types.
   var keywordTypes = {"break": _break, "case": _case, "catch": _catch,
                       "continue": _continue, "debugger": _debugger, "default": _default,
                       "do": _do, "else": _else, "finally": _finally, "for": _for,
                       "function": _function, "if": _if, "return": _return, "switch": _switch,
                       "throw": _throw, "try": _try, "var": _var, "while": _while, "with": _with,
                       "null": _null, "true": _true, "false": _false, "new": _new, "in": _in,
                       "instanceof": {keyword: "instanceof", binop: 7, beforeExpr: true}, "this": _this,
                       "typeof": {keyword: "typeof", prefix: true, beforeExpr: true},
                       "void": {keyword: "void", prefix: true, beforeExpr: true},
                       "delete": {keyword: "delete", prefix: true, beforeExpr: true}};
   // Punctuation token types. Again, the `type` property is purely for debugging.
   var _bracketL = {type: "[", beforeExpr: true}, _bracketR = {type: "]"}, _braceL = {type: "{", beforeExpr: true};
   var _braceR = {type: "}"}, _parenL = {type: "(", beforeExpr: true}, _parenR = {type: ")"};
   var _comma = {type: ",", beforeExpr: true}, _semi = {type: ";", beforeExpr: true};
   var _colon = {type: ":", beforeExpr: true}, _dot = {type: "."}, _question = {type: "?", beforeExpr: true};
   // Operators. These carry several kinds of properties to help the
   // parser use them properly (the presence of these properties is
   // what categorizes them as operators).
   //
   // `binop`, when present, specifies that this operator is a binary
   // operator, and will refer to its precedence.
   //
   // `prefix` and `postfix` mark the operator as a prefix or postfix
   // unary operator. `isUpdate` specifies that the node produced by
   // the operator should be of type UpdateExpression rather than
   // simply UnaryExpression (`++` and `--`).
   //
   // `isAssign` marks all of `=`, `+=`, `-=` etcetera, which act as
   // binary operators with a very low precedence, that should result
   // in AssignmentExpression nodes.
   var _slash = {binop: 10, beforeExpr: true}, _eq = {isAssign: true, beforeExpr: true};
   var _assign = {isAssign: true, beforeExpr: true};
   var _incDec = {postfix: true, prefix: true, isUpdate: true}, _prefix = {prefix: true, beforeExpr: true};
   var _logicalOR = {binop: 1, beforeExpr: true};
   var _logicalAND = {binop: 2, beforeExpr: true};
   var _bitwiseOR = {binop: 3, beforeExpr: true};
   var _bitwiseXOR = {binop: 4, beforeExpr: true};
   var _bitwiseAND = {binop: 5, beforeExpr: true};
   var _equality = {binop: 6, beforeExpr: true};
   var _relational = {binop: 7, beforeExpr: true};
   var _bitShift = {binop: 8, beforeExpr: true};
   var _plusMin = {binop: 9, prefix: true, beforeExpr: true};
   var _multiplyModulo = {binop: 10, beforeExpr: true};
   // Provide access to the token types for external users of the
   // tokenizer.
   exports.tokTypes = {bracketL: _bracketL, bracketR: _bracketR, braceL: _braceL, braceR: _braceR,
                       parenL: _parenL, parenR: _parenR, comma: _comma, semi: _semi, colon: _colon,
                       dot: _dot, question: _question, slash: _slash, eq: _eq, name: _name, eof: _eof,
                       num: _num, regexp: _regexp, string: _string};
   for (var kw in keywordTypes) exports.tokTypes["_" + kw] = keywordTypes[kw];
   // This is a trick taken from Esprima. It turns out that, on
   // non-Chrome browsers, to check whether a string is in a set, a
   // predicate containing a big ugly `switch` statement is faster than
   // a regular expression, and on Chrome the two are about on par.
   // This function uses `eval` (non-lexical) to produce such a
   // predicate from a space-separated string of words.
   //
   // It starts by sorting the words by length.
   function makePredicate(words) {
     words = words.split(" ");
     var f = "", cats = [];
     out: for (var i = 0; i < words.length; ++i) {
       for (var j = 0; j < cats.length; ++j)
         if (cats[j][0].length == words[i].length) {
           cats[j].push(words[i]);
           continue out;
         }
       cats.push([words[i]]);
     }
     function compareTo(arr) {
       if (arr.length == 1) return f += "return str === " + JSON.stringify(arr[0]) + ";";
       f += "switch(str){";
       for (var i = 0; i < arr.length; ++i) f += "case " + JSON.stringify(arr[i]) + ":";
       f += "return true}return false;";
     }
     // When there are more than three length categories, an outer
     // switch first dispatches on the lengths, to save on comparisons.
     if (cats.length > 3) {
       cats.sort(function(a, b) {return b.length - a.length;});
       f += "switch(str.length){";
       for (var i = 0; i < cats.length; ++i) {
         var cat = cats[i];
         f += "case " + cat[0].length + ":";
         compareTo(cat);
       }
       f += "}";
     // Otherwise, simply generate a flat `switch` statement.
     } else {
       compareTo(words);
     }
     return new Function("str", f);
   }
   // The ECMAScript 3 reserved word list.
   var isReservedWord3 = makePredicate("abstract boolean byte char class double enum export extends final float goto implements import int interface long native package private protected public short static super synchronized throws transient volatile");
   // ECMAScript 5 reserved words.
   var isReservedWord5 = makePredicate("class enum extends super const export import");
   // The additional reserved words in strict mode.
   var isStrictReservedWord = makePredicate("implements interface let package private protected public static yield");
   // The forbidden variable names in strict mode.
   var isStrictBadIdWord = makePredicate("eval arguments");
   // And the keywords.
   var isKeyword = makePredicate("break case catch continue debugger default do else finally for function if return switch throw try var while with null true false instanceof typeof void delete new in this");
   // ## Character categories
   // Big ugly regular expressions that match characters in the
   // whitespace, identifier, and identifier-start categories. These
   // are only applied when a character is found to actually have a
   // code point above 128.
   var nonASCIIwhitespace = /[\u1680\u180e\u2000-\u200a\u202f\u205f\u3000\ufeff]/;
   var nonASCIIidentifierStartChars = "\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";
   var nonASCIIidentifierChars = "\u0300-\u036f\u0483-\u0487\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u0620-\u0649\u0672-\u06d3\u06e7-\u06e8\u06fb-\u06fc\u0730-\u074a\u0800-\u0814\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0840-\u0857\u08e4-\u08fe\u0900-\u0903\u093a-\u093c\u093e-\u094f\u0951-\u0957\u0962-\u0963\u0966-\u096f\u0981-\u0983\u09bc\u09be-\u09c4\u09c7\u09c8\u09d7\u09df-\u09e0\u0a01-\u0a03\u0a3c\u0a3e-\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a66-\u0a71\u0a75\u0a81-\u0a83\u0abc\u0abe-\u0ac5\u0ac7-\u0ac9\u0acb-\u0acd\u0ae2-\u0ae3\u0ae6-\u0aef\u0b01-\u0b03\u0b3c\u0b3e-\u0b44\u0b47\u0b48\u0b4b-\u0b4d\u0b56\u0b57\u0b5f-\u0b60\u0b66-\u0b6f\u0b82\u0bbe-\u0bc2\u0bc6-\u0bc8\u0bca-\u0bcd\u0bd7\u0be6-\u0bef\u0c01-\u0c03\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62-\u0c63\u0c66-\u0c6f\u0c82\u0c83\u0cbc\u0cbe-\u0cc4\u0cc6-\u0cc8\u0cca-\u0ccd\u0cd5\u0cd6\u0ce2-\u0ce3\u0ce6-\u0cef\u0d02\u0d03\u0d46-\u0d48\u0d57\u0d62-\u0d63\u0d66-\u0d6f\u0d82\u0d83\u0dca\u0dcf-\u0dd4\u0dd6\u0dd8-\u0ddf\u0df2\u0df3\u0e34-\u0e3a\u0e40-\u0e45\u0e50-\u0e59\u0eb4-\u0eb9\u0ec8-\u0ecd\u0ed0-\u0ed9\u0f18\u0f19\u0f20-\u0f29\u0f35\u0f37\u0f39\u0f41-\u0f47\u0f71-\u0f84\u0f86-\u0f87\u0f8d-\u0f97\u0f99-\u0fbc\u0fc6\u1000-\u1029\u1040-\u1049\u1067-\u106d\u1071-\u1074\u1082-\u108d\u108f-\u109d\u135d-\u135f\u170e-\u1710\u1720-\u1730\u1740-\u1750\u1772\u1773\u1780-\u17b2\u17dd\u17e0-\u17e9\u180b-\u180d\u1810-\u1819\u1920-\u192b\u1930-\u193b\u1951-\u196d\u19b0-\u19c0\u19c8-\u19c9\u19d0-\u19d9\u1a00-\u1a15\u1a20-\u1a53\u1a60-\u1a7c\u1a7f-\u1a89\u1a90-\u1a99\u1b46-\u1b4b\u1b50-\u1b59\u1b6b-\u1b73\u1bb0-\u1bb9\u1be6-\u1bf3\u1c00-\u1c22\u1c40-\u1c49\u1c5b-\u1c7d\u1cd0-\u1cd2\u1d00-\u1dbe\u1e01-\u1f15\u200c\u200d\u203f\u2040\u2054\u20d0-\u20dc\u20e1\u20e5-\u20f0\u2d81-\u2d96\u2de0-\u2dff\u3021-\u3028\u3099\u309a\ua640-\ua66d\ua674-\ua67d\ua69f\ua6f0-\ua6f1\ua7f8-\ua800\ua806\ua80b\ua823-\ua827\ua880-\ua881\ua8b4-\ua8c4\ua8d0-\ua8d9\ua8f3-\ua8f7\ua900-\ua909\ua926-\ua92d\ua930-\ua945\ua980-\ua983\ua9b3-\ua9c0\uaa00-\uaa27\uaa40-\uaa41\uaa4c-\uaa4d\uaa50-\uaa59\uaa7b\uaae0-\uaae9\uaaf2-\uaaf3\uabc0-\uabe1\uabec\uabed\uabf0-\uabf9\ufb20-\ufb28\ufe00-\ufe0f\ufe20-\ufe26\ufe33\ufe34\ufe4d-\ufe4f\uff10-\uff19\uff3f";
   var nonASCIIidentifierStart = new RegExp("[" + nonASCIIidentifierStartChars + "]");
   var nonASCIIidentifier = new RegExp("[" + nonASCIIidentifierStartChars + nonASCIIidentifierChars + "]");
   // Whether a single character denotes a newline.
   var newline = /[\n\r\u2028\u2029]/;
   // Matches a whole line break (where CRLF is considered a single
   // line break). Used to count lines.
   var lineBreak = /\r\n|[\n\r\u2028\u2029]/g;
   // Test whether a given character code starts an identifier.
   var isIdentifierStart = exports.isIdentifierStart = function(code) {
     if (code < 65) return code === 36;
     if (code < 91) return true;
     if (code < 97) return code === 95;
     if (code < 123)return true;
     return code >= 0xaa && nonASCIIidentifierStart.test(String.fromCharCode(code));
   };
   // Test whether a given character is part of an identifier.
   var isIdentifierChar = exports.isIdentifierChar = function(code) {
     if (code < 48) return code === 36;
     if (code < 58) return true;
     if (code < 65) return false;
     if (code < 91) return true;
     if (code < 97) return code === 95;
     if (code < 123)return true;
     return code >= 0xaa && nonASCIIidentifier.test(String.fromCharCode(code));
   };
   // ## Tokenizer
   // These are used when `options.locations` is on, for the
   // `tokStartLoc` and `tokEndLoc` properties.
   function line_loc_t() {
     this.line = tokCurLine;
     this.column = tokPos - tokLineStart;
   }
   // Reset the token state. Used at the start of a parse.
   function initTokenState() {
     tokCurLine = 1;
     tokPos = tokLineStart = 0;
     tokRegexpAllowed = true;
     skipSpace();
   }
   // Called at the end of every token. Sets `tokEnd`, `tokVal`, and
   // `tokRegexpAllowed`, and skips the space after the token, so that
   // the next one's `tokStart` will point at the right position.
   function finishToken(type, val) {
     tokEnd = tokPos;
     if (options.locations) tokEndLoc = new line_loc_t;
     tokType = type;
     skipSpace();
     tokVal = val;
     tokRegexpAllowed = type.beforeExpr;
   }
   function skipBlockComment() {
     var startLoc = options.onComment && options.locations && new line_loc_t;
     var start = tokPos, end = input.indexOf("*/", tokPos += 2);
     if (end === -1) raise(tokPos - 2, "Unterminated comment");
     tokPos = end + 2;
     if (options.locations) {
       lineBreak.lastIndex = start;
       var match;
       while ((match = lineBreak.exec(input)) && match.index < tokPos) {
         ++tokCurLine;
         tokLineStart = match.index + match[0].length;
       }
     }
     if (options.onComment)
       options.onComment(true, input.slice(start + 2, end), start, tokPos,
                         startLoc, options.locations && new line_loc_t);
   }
   function skipLineComment() {
     var start = tokPos;
     var startLoc = options.onComment && options.locations && new line_loc_t;
     var ch = input.charCodeAt(tokPos+=2);
     while (tokPos < inputLen && ch !== 10 && ch !== 13 && ch !== 8232 && ch !== 8233) {
       ++tokPos;
       ch = input.charCodeAt(tokPos);
     }
     if (options.onComment)
       options.onComment(false, input.slice(start + 2, tokPos), start, tokPos,
                         startLoc, options.locations && new line_loc_t);
   }
   // Called at the start of the parse and after every token. Skips
   // whitespace and comments, and.
   function skipSpace() {
     while (tokPos < inputLen) {
       var ch = input.charCodeAt(tokPos);
       if (ch === 32) { // ' '
         ++tokPos;
       } else if (ch === 13) {
         ++tokPos;
         var next = input.charCodeAt(tokPos);
         if (next === 10) {
           ++tokPos;
         }
         if (options.locations) {
           ++tokCurLine;
           tokLineStart = tokPos;
         }
       } else if (ch === 10 || ch === 8232 || ch === 8233) {
         ++tokPos;
         if (options.locations) {
           ++tokCurLine;
           tokLineStart = tokPos;
         }
       } else if (ch > 8 && ch < 14) {
         ++tokPos;
       } else if (ch === 47) { // '/'
         var next = input.charCodeAt(tokPos + 1);
         if (next === 42) { // '*'
           skipBlockComment();
         } else if (next === 47) { // '/'
           skipLineComment();
         } else break;
       } else if (ch === 160) { // '\xa0'
         ++tokPos;
       } else if (ch >= 5760 && nonASCIIwhitespace.test(String.fromCharCode(ch))) {
         ++tokPos;
       } else {
         break;
       }
     }
   }
   // ### 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.
   //
   // The `forceRegexp` parameter is used in the one case where the
   // `tokRegexpAllowed` trick does not work. See `parseStatement`.
   function readToken_dot() {
     var next = input.charCodeAt(tokPos + 1);
     if (next >= 48 && next <= 57) return readNumber(true);
     ++tokPos;
     return finishToken(_dot);
   }
   function readToken_slash() { // '/'
     var next = input.charCodeAt(tokPos + 1);
     if (tokRegexpAllowed) {++tokPos; return readRegexp();}
     if (next === 61) return finishOp(_assign, 2);
     return finishOp(_slash, 1);
   }
   function readToken_mult_modulo() { // '%*'
     var next = input.charCodeAt(tokPos + 1);
     if (next === 61) return finishOp(_assign, 2);
     return finishOp(_multiplyModulo, 1);
   }
   function readToken_pipe_amp(code) { // '|&'
     var next = input.charCodeAt(tokPos + 1);
     if (next === code) return finishOp(code === 124 ? _logicalOR : _logicalAND, 2);
     if (next === 61) return finishOp(_assign, 2);
     return finishOp(code === 124 ? _bitwiseOR : _bitwiseAND, 1);
   }
   function readToken_caret() { // '^'
     var next = input.charCodeAt(tokPos + 1);
     if (next === 61) return finishOp(_assign, 2);
     return finishOp(_bitwiseXOR, 1);
   }
   function readToken_plus_min(code) { // '+-'
     var next = input.charCodeAt(tokPos + 1);
     if (next === code) {
       if (next == 45 && input.charCodeAt(tokPos + 2) == 62 &&
           newline.test(input.slice(lastEnd, tokPos))) {
         // A `-->` line comment
         tokPos += 3;
         skipLineComment();
         skipSpace();
         return readToken();
       }
       return finishOp(_incDec, 2);
     }
     if (next === 61) return finishOp(_assign, 2);
     return finishOp(_plusMin, 1);
   }
   function readToken_lt_gt(code) { // '<>'
     var next = input.charCodeAt(tokPos + 1);
     var size = 1;
     if (next === code) {
       size = code === 62 && input.charCodeAt(tokPos + 2) === 62 ? 3 : 2;
       if (input.charCodeAt(tokPos + size) === 61) return finishOp(_assign, size + 1);
       return finishOp(_bitShift, size);
     }
     if (next == 33 && code == 60 && input.charCodeAt(tokPos + 2) == 45 &&
         input.charCodeAt(tokPos + 3) == 45) {
       // `<!--`, an XML-style comment that should be interpreted as a line comment
       tokPos += 4;
       skipLineComment();
       skipSpace();
       return readToken();
     }
     if (next === 61)
       size = input.charCodeAt(tokPos + 2) === 61 ? 3 : 2;
     return finishOp(_relational, size);
   }
   function readToken_eq_excl(code) { // '=!'
     var next = input.charCodeAt(tokPos + 1);
     if (next === 61) return finishOp(_equality, input.charCodeAt(tokPos + 2) === 61 ? 3 : 2);
     return finishOp(code === 61 ? _eq : _prefix, 1);
   }
   function getTokenFromCode(code) {
     switch(code) {
       // The interpretation of a dot depends on whether it is followed
       // by a digit.
     case 46: // '.'
       return readToken_dot();
       // Punctuation tokens.
     case 40: ++tokPos; return finishToken(_parenL);
     case 41: ++tokPos; return finishToken(_parenR);
     case 59: ++tokPos; return finishToken(_semi);
     case 44: ++tokPos; return finishToken(_comma);
     case 91: ++tokPos; return finishToken(_bracketL);
     case 93: ++tokPos; return finishToken(_bracketR);
     case 123: ++tokPos; return finishToken(_braceL);
     case 125: ++tokPos; return finishToken(_braceR);
     case 58: ++tokPos; return finishToken(_colon);
     case 63: ++tokPos; return finishToken(_question);
       // '0x' is a hexadecimal number.
     case 48: // '0'
       var next = input.charCodeAt(tokPos + 1);
       if (next === 120 || next === 88) return readHexNumber();
       // Anything else beginning with a digit is an integer, octal
       // number, or float.
     case 49: case 50: case 51: case 52: case 53: case 54: case 55: case 56: case 57: // 1-9
       return readNumber(false);
       // Quotes produce strings.
     case 34: case 39: // '"', "'"
       return readString(code);
     // Operators are parsed inline in tiny state machines. '=' (61) 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 47: // '/'
       return readToken_slash(code);
     case 37: case 42: // '%*'
       return readToken_mult_modulo();
     case 124: case 38: // '|&'
       return readToken_pipe_amp(code);
     case 94: // '^'
       return readToken_caret();
     case 43: case 45: // '+-'
       return readToken_plus_min(code);
     case 60: case 62: // '<>'
       return readToken_lt_gt(code);
     case 61: case 33: // '=!'
       return readToken_eq_excl(code);
     case 126: // '~'
       return finishOp(_prefix, 1);
     }
     return false;
   }
   function readToken(forceRegexp) {
     if (!forceRegexp) tokStart = tokPos;
     else tokPos = tokStart + 1;
     if (options.locations) tokStartLoc = new line_loc_t;
     if (forceRegexp) return readRegexp();
     if (tokPos >= inputLen) return finishToken(_eof);
     var code = input.charCodeAt(tokPos);
     // Identifier or keyword. '\uXXXX' sequences are allowed in
     // identifiers, so '\' also dispatches to that.
     if (isIdentifierStart(code) || code === 92 /* '\' */) return readWord();
     var tok = getTokenFromCode(code);
     if (tok === false) {
       // If we are here, we either found a non-ASCII identifier
       // character, or something that's entirely disallowed.
       var ch = String.fromCharCode(code);
       if (ch === "\\" || nonASCIIidentifierStart.test(ch)) return readWord();
       raise(tokPos, "Unexpected character '" + ch + "'");
     }
     return tok;
   }
   function finishOp(type, size) {
     var str = input.slice(tokPos, tokPos + size);
     tokPos += size;
     finishToken(type, str);
   }
   // Parse a regular expression. Some context-awareness is necessary,
   // since a '/' inside a '[]' set does not end the expression.
   function readRegexp() {
     var content = "", escaped, inClass, start = tokPos;
     for (;;) {
       if (tokPos >= inputLen) raise(start, "Unterminated regular expression");
       var ch = input.charAt(tokPos);
       if (newline.test(ch)) raise(start, "Unterminated regular expression");
       if (!escaped) {
         if (ch === "[") inClass = true;
         else if (ch === "]" && inClass) inClass = false;
         else if (ch === "/" && !inClass) break;
         escaped = ch === "\\";
       } else escaped = false;
       ++tokPos;
     }
     var content = input.slice(start, tokPos);
     ++tokPos;
     // Need to use `readWord1` because '\uXXXX' sequences are allowed
     // here (don't ask).
     var mods = readWord1();
     if (mods && !/^[gmsiy]*$/.test(mods)) raise(start, "Invalid regexp flag");
     try {
       var value = new RegExp(content, mods);
     } catch (e) {
       if (e instanceof SyntaxError) raise(start, e.message);
       raise(e);
     }
     return finishToken(_regexp, value);
   }
   // Read an integer in the given radix. Return null if zero digits
   // were read, the integer value otherwise. When `len` is given, this
   // will return `null` unless the integer has exactly `len` digits.
   function readInt(radix, len) {
     var start = tokPos, total = 0;
     for (var i = 0, e = len == null ? Infinity : len; i < e; ++i) {
       var code = input.charCodeAt(tokPos), val;
       if (code >= 97) val = code - 97 + 10; // a
       else if (code >= 65) val = code - 65 + 10; // A
       else if (code >= 48 && code <= 57) val = code - 48; // 0-9
       else val = Infinity;
       if (val >= radix) break;
       ++tokPos;
       total = total * radix + val;
     }
     if (tokPos === start || len != null && tokPos - start !== len) return null;
     return total;
   }
   function readHexNumber() {
     tokPos += 2; // 0x
     var val = readInt(16);
     if (val == null) raise(tokStart + 2, "Expected hexadecimal number");
     if (isIdentifierStart(input.charCodeAt(tokPos))) raise(tokPos, "Identifier directly after number");
     return finishToken(_num, val);
   }
   // Read an integer, octal integer, or floating-point number.
   function readNumber(startsWithDot) {
     var start = tokPos, isFloat = false, octal = input.charCodeAt(tokPos) === 48;
     if (!startsWithDot && readInt(10) === null) raise(start, "Invalid number");
     if (input.charCodeAt(tokPos) === 46) {
       ++tokPos;
       readInt(10);
       isFloat = true;
     }
     var next = input.charCodeAt(tokPos);
     if (next === 69 || next === 101) { // 'eE'
       next = input.charCodeAt(++tokPos);
       if (next === 43 || next === 45) ++tokPos; // '+-'
       if (readInt(10) === null) raise(start, "Invalid number");
       isFloat = true;
     }
     if (isIdentifierStart(input.charCodeAt(tokPos))) raise(tokPos, "Identifier directly after number");
     var str = input.slice(start, tokPos), val;
     if (isFloat) val = parseFloat(str);
     else if (!octal || str.length === 1) val = parseInt(str, 10);
     else if (/[89]/.test(str) || strict) raise(start, "Invalid number");
     else val = parseInt(str, 8);
     return finishToken(_num, val);
   }
   // Read a string value, interpreting backslash-escapes.
   function readString(quote) {
     tokPos++;
     var out = "";
     for (;;) {
       if (tokPos >= inputLen) raise(tokStart, "Unterminated string constant");
       var ch = input.charCodeAt(tokPos);
       if (ch === quote) {
         ++tokPos;
         return finishToken(_string, out);
       }
       if (ch === 92) { // '\'
         ch = input.charCodeAt(++tokPos);
         var octal = /^[0-7]+/.exec(input.slice(tokPos, tokPos + 3));
         if (octal) octal = octal[0];
         while (octal && parseInt(octal, 8) > 255) octal = octal.slice(0, -1);
         if (octal === "0") octal = null;
         ++tokPos;
         if (octal) {
           if (strict) raise(tokPos - 2, "Octal literal in strict mode");
           out += String.fromCharCode(parseInt(octal, 8));
           tokPos += octal.length - 1;
         } else {
           switch (ch) {
           case 110: out += "\n"; break; // 'n' -> '\n'
           case 114: out += "\r"; break; // 'r' -> '\r'
           case 120: out += String.fromCharCode(readHexChar(2)); break; // 'x'
           case 117: out += String.fromCharCode(readHexChar(4)); break; // 'u'
           case 85: out += String.fromCharCode(readHexChar(8)); break; // 'U'
           case 116: out += "\t"; break; // 't' -> '\t'
           case 98: out += "\b"; break; // 'b' -> '\b'
           case 118: out += "\u000b"; break; // 'v' -> '\u000b'
           case 102: out += "\f"; break; // 'f' -> '\f'
           case 48: out += "\0"; break; // 0 -> '\0'
           case 13: if (input.charCodeAt(tokPos) === 10) ++tokPos; // '\r\n'
           case 10: // ' \n'
             if (options.locations) { tokLineStart = tokPos; ++tokCurLine; }
             break;
           default: out += String.fromCharCode(ch); break;
           }
         }
       } else {
         if (ch === 13 || ch === 10 || ch === 8232 || ch === 8233) raise(tokStart, "Unterminated string constant");
         out += String.fromCharCode(ch); // '\'
         ++tokPos;
       }
     }
   }
   // Used to read character escape sequences ('\x', '\u', '\U').
   function readHexChar(len) {
     var n = readInt(16, len);
     if (n === null) raise(tokStart, "Bad character escape sequence");
     return n;
   }
   // Used to signal to callers of `readWord1` whether the word
   // contained any escape sequences. This is needed because words with
   // escape sequences must not be interpreted as keywords.
   var containsEsc;
   // Read an identifier, and return it as a string. Sets `containsEsc`
   // to whether the word contained a '\u' escape.
   //
   // Only builds up the word character-by-character when it actually
   // containeds an escape, as a micro-optimization.
   function readWord1() {
     containsEsc = false;
     var word, first = true, start = tokPos;
     for (;;) {
       var ch = input.charCodeAt(tokPos);
       if (isIdentifierChar(ch)) {
         if (containsEsc) word += input.charAt(tokPos);
         ++tokPos;
       } else if (ch === 92) { // "\"
         if (!containsEsc) word = input.slice(start, tokPos);
         containsEsc = true;
         if (input.charCodeAt(++tokPos) != 117) // "u"
           raise(tokPos, "Expecting Unicode escape sequence \\uXXXX");
         ++tokPos;
         var esc = readHexChar(4);
         var escStr = String.fromCharCode(esc);
         if (!escStr) raise(tokPos - 1, "Invalid Unicode escape");
         if (!(first ? isIdentifierStart(esc) : isIdentifierChar(esc)))
           raise(tokPos - 4, "Invalid Unicode escape");
         word += escStr;
       } else {
         break;
       }
       first = false;
     }
     return containsEsc ? word : input.slice(start, tokPos);
   }
   // Read an identifier or keyword token. Will check for reserved
   // words when necessary.
   function readWord() {
     var word = readWord1();
     var type = _name;
     if (!containsEsc) {
       if (isKeyword(word)) type = keywordTypes[word];
       else if (options.forbidReserved &&
                (options.ecmaVersion === 3 ? isReservedWord3 : isReservedWord5)(word) ||
                strict && isStrictReservedWord(word))
         raise(tokStart, "The keyword '" + word + "' is reserved");
     }
     return finishToken(type, word);
   }
   // ## Parser
   // A recursive descent parser operates by defining functions for all
   // syntactic elements, and recursively calling those, each function
   // advancing the input stream and returning an AST node. Precedence
   // of constructs (for example, the fact that `!x[1]` means `!(x[1])`
   // instead of `(!x)[1]` is handled by the fact that the parser
   // function that parses unary prefix operators is called first, and
   // in turn calls the function that parses `[]` subscripts — that
   // way, it'll receive the node for `x[1]` already parsed, and wraps
   // *that* in the unary operator node.
   //
   // Acorn uses an [operator precedence parser][opp] to handle binary
   // operator precedence, because it is much more compact than using
   // the technique outlined above, which uses different, nesting
   // functions to specify precedence, for all of the ten binary
   // precedence levels that JavaScript defines.
   //
   // [opp]: http://en.wikipedia.org/wiki/Operator-precedence_parser
   // ### Parser utilities
   // Continue to the next token.
   function next() {
     lastStart = tokStart;
     lastEnd = tokEnd;
     lastEndLoc = tokEndLoc;
     readToken();
   }
   // Enter strict mode. Re-reads the next token to please pedantic
   // tests ("use strict"; 010; -- should fail).
   function setStrict(strct) {
     strict = strct;
     tokPos = tokStart;
     if (options.locations) {
       while (tokPos < tokLineStart) {
         tokLineStart = input.lastIndexOf("\n", tokLineStart - 2) + 1;
         --tokCurLine;
       }
     }
     skipSpace();
     readToken();
   }
   // Start an AST node, attaching a start offset.
   function node_t() {
     this.type = null;
     this.start = tokStart;
     this.end = null;
   }
   function node_loc_t() {
     this.start = tokStartLoc;
     this.end = null;
     if (sourceFile !== null) this.source = sourceFile;
   }
   function startNode() {
     var node = new node_t();
     if (options.locations)
       node.loc = new node_loc_t();
     if (options.directSourceFile)
       node.sourceFile = options.directSourceFile;
     if (options.ranges)
       node.range = [tokStart, 0];
     return node;
   }
   // Start a node whose start offset information should be based on
   // the start of another node. For example, a binary operator node is
   // only started after its left-hand side has already been parsed.
   function startNodeFrom(other) {
     var node = new node_t();
     node.start = other.start;
     if (options.locations) {
       node.loc = new node_loc_t();
       node.loc.start = other.loc.start;
     }
     if (options.ranges)
       node.range = [other.range[0], 0];
     return node;
   }
   // Finish an AST node, adding `type` and `end` properties.
   function finishNode(node, type) {
     node.type = type;
     node.end = lastEnd;
     if (options.locations)
       node.loc.end = lastEndLoc;
     if (options.ranges)
       node.range[1] = lastEnd;
     return node;
   }
   // Test whether a statement node is the string literal `"use strict"`.
   function isUseStrict(stmt) {
     return options.ecmaVersion >= 5 && stmt.type === "ExpressionStatement" &&
       stmt.expression.type === "Literal" && stmt.expression.value === "use strict";
   }
   // Predicate that tests whether the next token is of the given
   // type, and if yes, consumes it as a side effect.
   function eat(type) {
     if (tokType === type) {
       next();
       return true;
     }
   }
   // Test whether a semicolon can be inserted at the current position.
   function canInsertSemicolon() {
     return !options.strictSemicolons &&
       (tokType === _eof || tokType === _braceR || newline.test(input.slice(lastEnd, tokStart)));
   }
   // Consume a semicolon, or, failing that, see if we are allowed to
   // pretend that there is a semicolon at this position.
   function semicolon() {
     if (!eat(_semi) && !canInsertSemicolon()) unexpected();
   }
   // Expect a token of a given type. If found, consume it, otherwise,
   // raise an unexpected token error.
   function expect(type) {
     if (tokType === type) next();
     else unexpected();
   }
   // Raise an unexpected token error.
   function unexpected() {
     raise(tokStart, "Unexpected token");
   }
   // Verify that a node is an lval — something that can be assigned
   // to.
   function checkLVal(expr) {
     if (expr.type !== "Identifier" && expr.type !== "MemberExpression")
       raise(expr.start, "Assigning to rvalue");
     if (strict && expr.type === "Identifier" && isStrictBadIdWord(expr.name))
       raise(expr.start, "Assigning to " + expr.name + " in strict mode");
   }
   // ### Statement parsing
   // Parse a program. Initializes the parser, reads any number of
   // statements, and wraps them in a Program node.  Optionally takes a
   // `program` argument.  If present, the statements will be appended
   // to its body instead of creating a new node.
   function parseTopLevel(program) {
     lastStart = lastEnd = tokPos;
     if (options.locations) lastEndLoc = new line_loc_t;
     inFunction = strict = null;
     labels = [];
     readToken();
     var node = program || startNode(), first = true;
     if (!program) node.body = [];
     while (tokType !== _eof) {
       var stmt = parseStatement();
       node.body.push(stmt);
       if (first && isUseStrict(stmt)) setStrict(true);
       first = false;
     }
     return finishNode(node, "Program");
   }
   var loopLabel = {kind: "loop"}, switchLabel = {kind: "switch"};
   // Parse a single statement.
   //
   // If expecting a statement and finding a slash operator, parse a
   // regular expression literal. This is to handle cases like
   // `if (foo) /blah/.exec(foo);`, where looking at the previous token
   // does not help.
   function parseStatement() {
     if (tokType === _slash || tokType === _assign && tokVal == "/=")
       readToken(true);
     var starttype = tokType, node = startNode();
     // Most types of statements are recognized by the keyword they
     // start with. Many are trivial to parse, some require a bit of
     // complexity.
     switch (starttype) {
     case _break: case _continue:
       next();
       var isBreak = starttype === _break;
       if (eat(_semi) || canInsertSemicolon()) node.label = null;
       else if (tokType !== _name) unexpected();
       else {
         node.label = parseIdent();
         semicolon();
       }
       // Verify that there is an actual destination to break or
       // continue to.
       for (var i = 0; i < labels.length; ++i) {
         var lab = labels[i];
         if (node.label == null || lab.name === node.label.name) {
           if (lab.kind != null && (isBreak || lab.kind === "loop")) break;
           if (node.label && isBreak) break;
         }
       }
       if (i === labels.length) raise(node.start, "Unsyntactic " + starttype.keyword);
       return finishNode(node, isBreak ? "BreakStatement" : "ContinueStatement");
     case _debugger:
       next();
       semicolon();
       return finishNode(node, "DebuggerStatement");
     case _do:
       next();
       labels.push(loopLabel);
       node.body = parseStatement();
       labels.pop();
       expect(_while);
       node.test = parseParenExpression();
       semicolon();
       return finishNode(node, "DoWhileStatement");
       // Disambiguating between a `for` and a `for`/`in` loop is
       // non-trivial. Basically, we have to parse the init `var`
       // statement or expression, disallowing the `in` operator (see
       // the second parameter to `parseExpression`), and then check
       // whether the next token is `in`. When there is no init part
       // (semicolon immediately after the opening parenthesis), it is
       // a regular `for` loop.
     case _for:
       next();
       labels.push(loopLabel);
       expect(_parenL);
       if (tokType === _semi) return parseFor(node, null);
       if (tokType === _var) {
         var init = startNode();
         next();
         parseVar(init, true);
         finishNode(init, "VariableDeclaration");
         if (init.declarations.length === 1 && eat(_in))
           return parseForIn(node, init);
         return parseFor(node, init);
       }
       var init = parseExpression(false, true);
       if (eat(_in)) {checkLVal(init); return parseForIn(node, init);}
       return parseFor(node, init);
     case _function:
       next();
       return parseFunction(node, true);
     case _if:
       next();
       node.test = parseParenExpression();
       node.consequent = parseStatement();
       node.alternate = eat(_else) ? parseStatement() : null;
       return finishNode(node, "IfStatement");
     case _return:
       if (!inFunction) raise(tokStart, "'return' outside of function");
       next();
       // In `return` (and `break`/`continue`), the keywords with
       // optional arguments, we eagerly look for a semicolon or the
       // possibility to insert one.
       if (eat(_semi) || canInsertSemicolon()) node.argument = null;
       else { node.argument = parseExpression(); semicolon(); }
       return finishNode(node, "ReturnStatement");
     case _switch:
       next();
       node.discriminant = parseParenExpression();
       node.cases = [];
       expect(_braceL);
       labels.push(switchLabel);
       // Statements under must be grouped (by label) in SwitchCase
       // nodes. `cur` is used to keep the node that we are currently
       // adding statements to.
       for (var cur, sawDefault; tokType != _braceR;) {
         if (tokType === _case || tokType === _default) {
           var isCase = tokType === _case;
           if (cur) finishNode(cur, "SwitchCase");
           node.cases.push(cur = startNode());
           cur.consequent = [];
           next();
           if (isCase) cur.test = parseExpression();
           else {
             if (sawDefault) raise(lastStart, "Multiple default clauses"); sawDefault = true;
             cur.test = null;
           }
           expect(_colon);
         } else {
           if (!cur) unexpected();
           cur.consequent.push(parseStatement());
         }
       }
       if (cur) finishNode(cur, "SwitchCase");
       next(); // Closing brace
       labels.pop();
       return finishNode(node, "SwitchStatement");
     case _throw:
       next();
       if (newline.test(input.slice(lastEnd, tokStart)))
         raise(lastEnd, "Illegal newline after throw");
       node.argument = parseExpression();
       semicolon();
       return finishNode(node, "ThrowStatement");
     case _try:
       next();
       node.block = parseBlock();
       node.handler = null;
       if (tokType === _catch) {
         var clause = startNode();
         next();
         expect(_parenL);
         clause.param = parseIdent();
         if (strict && isStrictBadIdWord(clause.param.name))
           raise(clause.param.start, "Binding " + clause.param.name + " in strict mode");
         expect(_parenR);
         clause.guard = null;
         clause.body = parseBlock();
         node.handler = finishNode(clause, "CatchClause");
       }
       node.guardedHandlers = empty;
       node.finalizer = eat(_finally) ? parseBlock() : null;
       if (!node.handler && !node.finalizer)
         raise(node.start, "Missing catch or finally clause");
       return finishNode(node, "TryStatement");
     case _var:
       next();
       parseVar(node);
       semicolon();
       return finishNode(node, "VariableDeclaration");
     case _while:
       next();
       node.test = parseParenExpression();
       labels.push(loopLabel);
       node.body = parseStatement();
       labels.pop();
       return finishNode(node, "WhileStatement");
     case _with:
       if (strict) raise(tokStart, "'with' in strict mode");
       next();
       node.object = parseParenExpression();
       node.body = parseStatement();
       return finishNode(node, "WithStatement");
     case _braceL:
       return parseBlock();
     case _semi:
       next();
       return finishNode(node, "EmptyStatement");
       // If the statement does not start with a statement keyword or a
       // brace, it's an ExpressionStatement or LabeledStatement. We
       // simply start parsing an expression, and afterwards, if the
       // next token is a colon and the expression was a simple
       // Identifier node, we switch to interpreting it as a label.
     default:
       var maybeName = tokVal, expr = parseExpression();
       if (starttype === _name && expr.type === "Identifier" && eat(_colon)) {
         for (var i = 0; i < labels.length; ++i)
           if (labels[i].name === maybeName) raise(expr.start, "Label '" + maybeName + "' is already declared");
         var kind = tokType.isLoop ? "loop" : tokType === _switch ? "switch" : null;
         labels.push({name: maybeName, kind: kind});
         node.body = parseStatement();
         labels.pop();
         node.label = expr;
         return finishNode(node, "LabeledStatement");
       } else {
         node.expression = expr;
         semicolon();
         return finishNode(node, "ExpressionStatement");
       }
     }
   }
   // Used for constructs like `switch` and `if` that insist on
   // parentheses around their expression.
   function parseParenExpression() {
     expect(_parenL);
     var val = parseExpression();
     expect(_parenR);
     return val;
   }
   // Parse a semicolon-enclosed block of statements, handling `"use
   // strict"` declarations when `allowStrict` is true (used for
   // function bodies).
   function parseBlock(allowStrict) {
     var node = startNode(), first = true, strict = false, oldStrict;
     node.body = [];
     expect(_braceL);
     while (!eat(_braceR)) {
       var stmt = parseStatement();
       node.body.push(stmt);
       if (first && allowStrict && isUseStrict(stmt)) {
         oldStrict = strict;
         setStrict(strict = true);
       }
       first = false;
     }
     if (strict && !oldStrict) setStrict(false);
     return finishNode(node, "BlockStatement");
   }
   // Parse a regular `for` loop. The disambiguation code in
   // `parseStatement` will already have parsed the init statement or
   // expression.
   function parseFor(node, init) {
     node.init = init;
     expect(_semi);
     node.test = tokType === _semi ? null : parseExpression();
     expect(_semi);
     node.update = tokType === _parenR ? null : parseExpression();
     expect(_parenR);
     node.body = parseStatement();
     labels.pop();
     return finishNode(node, "ForStatement");
   }
   // Parse a `for`/`in` loop.
   function parseForIn(node, init) {
     node.left = init;
     node.right = parseExpression();
     expect(_parenR);
     node.body = parseStatement();
     labels.pop();
     return finishNode(node, "ForInStatement");
   }
   // Parse a list of variable declarations.
   function parseVar(node, noIn) {
     node.declarations = [];
     node.kind = "var";
     for (;;) {
       var decl = startNode();
       decl.id = parseIdent();
       if (strict && isStrictBadIdWord(decl.id.name))
         raise(decl.id.start, "Binding " + decl.id.name + " in strict mode");
       decl.init = eat(_eq) ? parseExpression(true, noIn) : null;
       node.declarations.push(finishNode(decl, "VariableDeclarator"));
       if (!eat(_comma)) break;
     }
     return node;
   }
   // ### Expression parsing
   // These nest, from the most general expression type at the top to
   // 'atomic', nondivisible expression types at the bottom. Most of
   // the functions will simply let the function(s) below them parse,
   // and, *if* the syntactic construct they handle is present, wrap
   // the AST node that the inner parser gave them in another node.
   // Parse a full expression. The arguments are used to forbid comma
   // sequences (in argument lists, array literals, or object literals)
   // or the `in` operator (in for loops initalization expressions).
   function parseExpression(noComma, noIn) {
     var expr = parseMaybeAssign(noIn);
     if (!noComma && tokType === _comma) {
       var node = startNodeFrom(expr);
       node.expressions = [expr];
       while (eat(_comma)) node.expressions.push(parseMaybeAssign(noIn));
       return finishNode(node, "SequenceExpression");
     }
     return expr;
   }
   // Parse an assignment expression. This includes applications of
   // operators like `+=`.
   function parseMaybeAssign(noIn) {
     var left = parseMaybeConditional(noIn);
     if (tokType.isAssign) {
       var node = startNodeFrom(left);
       node.operator = tokVal;
       node.left = left;
       next();
       node.right = parseMaybeAssign(noIn);
       checkLVal(left);
       return finishNode(node, "AssignmentExpression");
     }
     return left;
   }
   // Parse a ternary conditional (`?:`) operator.
   function parseMaybeConditional(noIn) {
     var expr = parseExprOps(noIn);
     if (eat(_question)) {
       var node = startNodeFrom(expr);
       node.test = expr;
       node.consequent = parseExpression(true);
       expect(_colon);
       node.alternate = parseExpression(true, noIn);
       return finishNode(node, "ConditionalExpression");
     }
     return expr;
   }
   // Start the precedence parser.
   function parseExprOps(noIn) {
     return parseExprOp(parseMaybeUnary(), -1, noIn);
   }
   // Parse binary operators with the operator precedence parsing
   // algorithm. `left` is the left-hand side of the operator.
   // `minPrec` provides context that allows the function to stop and
   // defer further parser to one of its callers when it encounters an
   // operator that has a lower precedence than the set it is parsing.
   function parseExprOp(left, minPrec, noIn) {
     var prec = tokType.binop;
     if (prec != null && (!noIn || tokType !== _in)) {
       if (prec > minPrec) {
         var node = startNodeFrom(left);
         node.left = left;
         node.operator = tokVal;
         var op = tokType;
         next();
         node.right = parseExprOp(parseMaybeUnary(), prec, noIn);
         var exprNode = finishNode(node, (op === _logicalOR || op === _logicalAND) ? "LogicalExpression" : "BinaryExpression");
         return parseExprOp(exprNode, minPrec, noIn);
       }
     }
     return left;
   }
   // Parse unary operators, both prefix and postfix.
   function parseMaybeUnary() {
     if (tokType.prefix) {
       var node = startNode(), update = tokType.isUpdate;
       node.operator = tokVal;
       node.prefix = true;
       tokRegexpAllowed = true;
       next();
       node.argument = parseMaybeUnary();
       if (update) checkLVal(node.argument);
       else if (strict && node.operator === "delete" &&
                node.argument.type === "Identifier")
         raise(node.start, "Deleting local variable in strict mode");
       return finishNode(node, update ? "UpdateExpression" : "UnaryExpression");
     }
     var expr = parseExprSubscripts();
     while (tokType.postfix && !canInsertSemicolon()) {
       var node = startNodeFrom(expr);
       node.operator = tokVal;
       node.prefix = false;
       node.argument = expr;
       checkLVal(expr);
       next();
       expr = finishNode(node, "UpdateExpression");
     }
     return expr;
   }
   // Parse call, dot, and `[]`-subscript expressions.
   function parseExprSubscripts() {
     return parseSubscripts(parseExprAtom());
   }
   function parseSubscripts(base, noCalls) {
     if (eat(_dot)) {
       var node = startNodeFrom(base);
       node.object = base;
       node.property = parseIdent(true);
       node.computed = false;
       return parseSubscripts(finishNode(node, "MemberExpression"), noCalls);
     } else if (eat(_bracketL)) {
       var node = startNodeFrom(base);
       node.object = base;
       node.property = parseExpression();
       node.computed = true;
       expect(_bracketR);
       return parseSubscripts(finishNode(node, "MemberExpression"), noCalls);
     } else if (!noCalls && eat(_parenL)) {
       var node = startNodeFrom(base);
       node.callee = base;
       node.arguments = parseExprList(_parenR, false);
       return parseSubscripts(finishNode(node, "CallExpression"), noCalls);
     } else return base;
   }
   // Parse an atomic expression — either a single token that is an
   // expression, an expression started by a keyword like `function` or
   // `new`, or an expression wrapped in punctuation like `()`, `[]`,
   // or `{}`.
   function parseExprAtom() {
     switch (tokType) {
     case _this:
       var node = startNode();
       next();
       return finishNode(node, "ThisExpression");
     case _name:
       return parseIdent();
     case _num: case _string: case _regexp:
       var node = startNode();
       node.value = tokVal;
       node.raw = input.slice(tokStart, tokEnd);
       next();
       return finishNode(node, "Literal");
     case _null: case _true: case _false:
       var node = startNode();
       node.value = tokType.atomValue;
       node.raw = tokType.keyword;
       next();
       return finishNode(node, "Literal");
     case _parenL:
       var tokStartLoc1 = tokStartLoc, tokStart1 = tokStart;
       next();
       var val = parseExpression();
       val.start = tokStart1;
       val.end = tokEnd;
       if (options.locations) {
         val.loc.start = tokStartLoc1;
         val.loc.end = tokEndLoc;
       }
       if (options.ranges)
         val.range = [tokStart1, tokEnd];
       expect(_parenR);
       return val;
     case _bracketL:
       var node = startNode();
       next();
       node.elements = parseExprList(_bracketR, true, true);
       return finishNode(node, "ArrayExpression");
     case _braceL:
       return parseObj();
     case _function:
       var node = startNode();
       next();
       return parseFunction(node, false);
     case _new:
       return parseNew();
     default:
       unexpected();
     }
   }
   // New's precedence is slightly tricky. It must allow its argument
   // to be a `[]` or dot subscript expression, but not a call — at
   // least, not without wrapping it in parentheses. Thus, it uses the
   function parseNew() {
     var node = startNode();
     next();
     node.callee = parseSubscripts(parseExprAtom(), true);
     if (eat(_parenL)) node.arguments = parseExprList(_parenR, false);
     else node.arguments = empty;
     return finishNode(node, "NewExpression");
   }
   // Parse an object literal.
   function parseObj() {
     var node = startNode(), first = true, sawGetSet = false;
     node.properties = [];
     next();
     while (!eat(_braceR)) {
       if (!first) {
         expect(_comma);
         if (options.allowTrailingCommas && eat(_braceR)) break;
       } else first = false;
       var prop = {key: parsePropertyName()}, isGetSet = false, kind;
       if (eat(_colon)) {
         prop.value = parseExpression(true);
         kind = prop.kind = "init";
       } else if (options.ecmaVersion >= 5 && prop.key.type === "Identifier" &&
                  (prop.key.name === "get" || prop.key.name === "set")) {
         isGetSet = sawGetSet = true;
         kind = prop.kind = prop.key.name;
         prop.key = parsePropertyName();
         if (tokType !== _parenL) unexpected();
         prop.value = parseFunction(startNode(), false);
       } else unexpected();
       // getters and setters are not allowed to clash — either with
       // each other or with an init property — and in strict mode,
       // init properties are also not allowed to be repeated.
       if (prop.key.type === "Identifier" && (strict || sawGetSet)) {
         for (var i = 0; i < node.properties.length; ++i) {
           var other = node.properties[i];
           if (other.key.name === prop.key.name) {
             var conflict = kind == other.kind || isGetSet && other.kind === "init" ||
               kind === "init" && (other.kind === "get" || other.kind === "set");
             if (conflict && !strict && kind === "init" && other.kind === "init") conflict = false;
             if (conflict) raise(prop.key.start, "Redefinition of property");
           }
         }
       }
       node.properties.push(prop);
     }
     return finishNode(node, "ObjectExpression");
   }
   function parsePropertyName() {
     if (tokType === _num || tokType === _string) return parseExprAtom();
     return parseIdent(true);
   }
   // Parse a function declaration or literal (depending on the
   // `isStatement` parameter).
   function parseFunction(node, isStatement) {
     if (tokType === _name) node.id = parseIdent();
     else if (isStatement) unexpected();
     else node.id = null;
     node.params = [];
     var first = true;
     expect(_parenL);
     while (!eat(_parenR)) {
       if (!first) expect(_comma); else first = false;
       node.params.push(parseIdent());
     }
     // Start a new scope with regard to labels and the `inFunction`
     // flag (restore them to their old value afterwards).
     var oldInFunc = inFunction, oldLabels = labels;
     inFunction = true; labels = [];
     node.body = parseBlock(true);
     inFunction = oldInFunc; labels = oldLabels;
     // If this is a strict mode function, verify that argument names
     // are not repeated, and it does not try to bind the words `eval`
     // or `arguments`.
     if (strict || node.body.body.length && isUseStrict(node.body.body[0])) {
       for (var i = node.id ? -1 : 0; i < node.params.length; ++i) {
         var id = i < 0 ? node.id : node.params[i];
         if (isStrictReservedWord(id.name) || isStrictBadIdWord(id.name))
           raise(id.start, "Defining '" + id.name + "' in strict mode");
         if (i >= 0) for (var j = 0; j < i; ++j) if (id.name === node.params[j].name)
           raise(id.start, "Argument name clash in strict mode");
       }
     }
     return finishNode(node, isStatement ? "FunctionDeclaration" : "FunctionExpression");
   }
   // Parses a comma-separated list of expressions, and returns them as
   // an array. `close` is the token type that ends the list, and
   // `allowEmpty` can be turned on to allow subsequent commas with
   // nothing in between them to be parsed as `null` (which is needed
   // for array literals).
   function parseExprList(close, allowTrailingComma, allowEmpty) {
     var elts = [], first = true;
     while (!eat(close)) {
       if (!first) {
         expect(_comma);
         if (allowTrailingComma && options.allowTrailingCommas && eat(close)) break;
       } else first = false;
       if (allowEmpty && tokType === _comma) elts.push(null);
       else elts.push(parseExpression(true));
     }
     return elts;
   }
   // Parse the next token as an identifier. If `liberal` is true (used
   // when parsing properties), it will also convert keywords into
   // identifiers.
   function parseIdent(liberal) {
     var node = startNode();
     node.name = tokType === _name ? tokVal : (liberal && !options.forbidReserved && tokType.keyword) || unexpected();
     tokRegexpAllowed = false;
     next();
     return finishNode(node, "Identifier");
   }
 });