acorn.js

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 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 to report issues.

This file defines the main parser interface. The library also comes with a error-tolerant parser and an abstract syntax tree walker, defined in other files.

 
(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 = "0.3.2";

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, with the caveat that the SpiderMonkey-specific syntax (let, yield, inline XML, etc) is not recognized.

 
  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.

 
    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 property holding a [start, end] array with the same numbers, set the ranges option to true.

 
    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 location is on, you can pass this to record the source file in every node's loc object.

 
    sourceFile: 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) {
      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}, _plusmin = {binop: 9, prefix: true, beforeExpr: true};
  var _incdec = {postfix: true, prefix: true, isUpdate: true}, _prefix = {prefix: true, beforeExpr: true};
  var _bin1 = {binop: 1, beforeExpr: true}, _bin2 = {binop: 2, beforeExpr: true};
  var _bin3 = {binop: 3, beforeExpr: true}, _bin4 = {binop: 4, beforeExpr: true};
  var _bin5 = {binop: 5, beforeExpr: true}, _bin6 = {binop: 6, beforeExpr: true};
  var _bin7 = {binop: 7, beforeExpr: true}, _bin8 = {binop: 8, beforeExpr: true};
  var _bin10 = {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\u2028\u2029\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 !== 8329) {
      ++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) {
        ++tokPos;
        ++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(_bin10, 1);
  }

  function readToken_pipe_amp(code) { // '|&'
    var next = input.charCodeAt(tokPos + 1);
    if (next === code) return finishOp(code === 124 ? _bin1 : _bin2, 2);
    if (next === 61) return finishOp(_assign, 2);
    return finishOp(code === 124 ? _bin3 : _bin5, 1);
  }

  function readToken_caret() { // '^'
    var next = input.charCodeAt(tokPos + 1);
    if (next === 61) return finishOp(_assign, 2);
    return finishOp(_bin4, 1);
  }

  function readToken_plus_min(code) { // '+-'
    var next = input.charCodeAt(tokPos + 1);
    if (next === code) {
      if (next == 45 && input.charCodeAt(tokPos + 2) == 62 && lastEnd < tokLineStart) {
             		           
                               
                            
                                
               
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(_bin8, size);
    }
    if (next == 33 && code == 60 && input.charCodeAt(tokPos + 2) == 45 && input.charCodeAt(tokPos + 3) == 45) {
             		           
                               
                            
                                
               
'