gecko/devtools/shared/acorn/acorn.js
J. Ryan Stinnett 4b3635c0bb Bug 912121 - Migrate major DevTools directories. rs=devtools
Move major DevTools files to new directories using the following steps:

hg mv browser/devtools devtools/client
hg mv toolkit/devtools/server devtools/server
hg mv toolkit/devtools devtools/shared

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2015-09-21 12:02:24 -05:00

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JavaScript

// Acorn is a tiny, fast JavaScript parser written in JavaScript.
//
// Acorn was written by Marijn Haverbeke and various contributors 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 = "0.11.1";
// 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 inline XML 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();
var startPos = options.locations ? [tokPos, curPosition()] : tokPos;
initParserState();
return parseTopLevel(options.program || startNodeAt(startPos));
};
// 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, or 6. This influences support for strict
// mode, the set of reserved words, support for getters and
// setters and other features.
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. When this option has the
// value "everywhere", reserved words and keywords can also not be
// used as property names.
forbidReserved: false,
// When enabled, a return at the top level is not considered an
// error.
allowReturnOutsideFunction: false,
// When enabled, import/export statements are not constrained to
// appearing at the top of the program.
allowImportExportEverywhere: false,
// When enabled, hashbang directive in the beginning of file
// is allowed and treated as a line comment.
allowHashBang: 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 `onToken` option, which will
// cause Acorn to call that function with object in the same
// format as tokenize() returns. Note that you are not
// allowed to call the parser from the callback—that will
// corrupt its internal state.
onToken: null,
// 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,
// When enabled, parenthesized expressions are represented by
// (non-standard) ParenthesizedExpression nodes
preserveParens: false
};
// This function tries to parse a single expression at a given
// offset in a string. Useful for parsing mixed-language formats
// that embed JavaScript expressions.
exports.parseExpressionAt = function(inpt, pos, opts) {
input = String(inpt); inputLen = input.length;
setOptions(opts);
initTokenState(pos);
initParserState();
return parseExpression();
};
var isArray = function (obj) {
return Object.prototype.toString.call(obj) === "[object Array]";
};
function setOptions(opts) {
options = {};
for (var opt in defaultOptions)
options[opt] = opts && has(opts, opt) ? opts[opt] : defaultOptions[opt];
sourceFile = options.sourceFile || null;
if (isArray(options.onToken)) {
var tokens = options.onToken;
options.onToken = function (token) {
tokens.push(token);
};
}
if (isArray(options.onComment)) {
var comments = options.onComment;
options.onComment = function (block, text, start, end, startLoc, endLoc) {
var comment = {
type: block ? 'Block' : 'Line',
value: text,
start: start,
end: end
};
if (options.locations) {
comment.loc = new SourceLocation();
comment.loc.start = startLoc;
comment.loc.end = endLoc;
}
if (options.ranges)
comment.range = [start, end];
comments.push(comment);
};
}
isKeyword = options.ecmaVersion >= 6 ? isEcma6Keyword : isEcma5AndLessKeyword;
}
// 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};
};
function Token() {
this.type = tokType;
this.value = tokVal;
this.start = tokStart;
this.end = tokEnd;
if (options.locations) {
this.loc = new SourceLocation();
this.loc.end = tokEndLoc;
// TODO: remove in next major release
this.startLoc = tokStartLoc;
this.endLoc = tokEndLoc;
}
if (options.ranges)
this.range = [tokStart, tokEnd];
}
exports.Token = Token;
// 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();
skipSpace();
function getToken() {
lastEnd = tokEnd;
readToken();
return new Token();
}
getToken.jumpTo = function(pos, exprAllowed) {
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;
}
}
tokExprAllowed = !!exprAllowed;
skipSpace();
};
getToken.options = options;
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;
// Internal 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. In
// some cases, notably after ')' or '}' tokens, the situation
// depends on the context before the matching opening bracket, so
// tokContext keeps a stack of information about current bracketed
// forms.
var tokContext, tokExprAllowed;
// 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, `inGenerator` to
// reject `yield`s outside of generators, `labels` to verify
// that `break` and `continue` have somewhere to jump to, and
// `strict` indicates whether strict mode is on.
var inFunction, inGenerator, labels, strict;
// This counter is used for checking that arrow expressions did
// not contain nested parentheses in argument list.
var metParenL;
// This is used by the tokenizer to track the template strings it is
// inside, and count the amount of open braces seen inside them, to
// be able to switch back to a template token when the } to match ${
// is encountered. It will hold an array of integers.
var templates;
function initParserState() {
lastStart = lastEnd = tokPos;
if (options.locations) lastEndLoc = curPosition();
inFunction = inGenerator = strict = false;
labels = [];
skipSpace();
readToken();
}
// 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 _let = {keyword: "let"}, _const = {keyword: "const"};
var _while = {keyword: "while", isLoop: true}, _with = {keyword: "with"}, _new = {keyword: "new", beforeExpr: true};
var _this = {keyword: "this"};
var _class = {keyword: "class"}, _extends = {keyword: "extends", beforeExpr: true};
var _export = {keyword: "export"}, _import = {keyword: "import"};
var _yield = {keyword: "yield", beforeExpr: true};
// 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, "let": _let, "const": _const,
"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},
"class": _class, "extends": _extends,
"export": _export, "import": _import, "yield": _yield};
// 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};
var _arrow = {type: "=>", beforeExpr: true}, _template = {type: "template"}, _templateContinued = {type: "templateContinued"};
var _ellipsis = {type: "...", prefix: true, 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 _modulo = {binop: 10, beforeExpr: true};
// '*' may be multiply or have special meaning in ES6
var _star = {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, ellipsis: _ellipsis, question: _question, slash: _slash, eq: _eq,
name: _name, eof: _eof, num: _num, regexp: _regexp, string: _string,
arrow: _arrow, template: _template, templateContinued: _templateContinued, star: _star,
assign: _assign};
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 ecma5AndLessKeywords = "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";
var isEcma5AndLessKeyword = makePredicate(ecma5AndLessKeywords);
var isEcma6Keyword = makePredicate(ecma5AndLessKeywords + " let const class extends export import yield");
var isKeyword = isEcma5AndLessKeyword;
// ## 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.
// Generated by `tools/generate-identifier-regex.js`.
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\u037F\u0386\u0388-\u038A\u038C\u038E-\u03A1\u03A3-\u03F5\u03F7-\u0481\u048A-\u052F\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-\u08B2\u0904-\u0939\u093D\u0950\u0958-\u0961\u0971-\u0980\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-\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-\u16F8\u1700-\u170C\u170E-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176C\u176E-\u1770\u1780-\u17B3\u17D7\u17DC\u1820-\u1877\u1880-\u18A8\u18AA\u18B0-\u18F5\u1900-\u191E\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-\uA69D\uA6A0-\uA6EF\uA717-\uA71F\uA722-\uA788\uA78B-\uA78E\uA790-\uA7AD\uA7B0\uA7B1\uA7F7-\uA801\uA803-\uA805\uA807-\uA80A\uA80C-\uA822\uA840-\uA873\uA882-\uA8B3\uA8F2-\uA8F7\uA8FB\uA90A-\uA925\uA930-\uA946\uA960-\uA97C\uA984-\uA9B2\uA9CF\uA9E0-\uA9E4\uA9E6-\uA9EF\uA9FA-\uA9FE\uAA00-\uAA28\uAA40-\uAA42\uAA44-\uAA4B\uAA60-\uAA76\uAA7A\uAA7E-\uAAAF\uAAB1\uAAB5\uAAB6\uAAB9-\uAABD\uAAC0\uAAC2\uAADB-\uAADD\uAAE0-\uAAEA\uAAF2-\uAAF4\uAB01-\uAB06\uAB09-\uAB0E\uAB11-\uAB16\uAB20-\uAB26\uAB28-\uAB2E\uAB30-\uAB5A\uAB5C-\uAB5F\uAB64\uAB65\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\u064B-\u0669\u0670\u06D6-\u06DC\u06DF-\u06E4\u06E7\u06E8\u06EA-\u06ED\u06F0-\u06F9\u0711\u0730-\u074A\u07A6-\u07B0\u07C0-\u07C9\u07EB-\u07F3\u0816-\u0819\u081B-\u0823\u0825-\u0827\u0829-\u082D\u0859-\u085B\u08E4-\u0903\u093A-\u093C\u093E-\u094F\u0951-\u0957\u0962\u0963\u0966-\u096F\u0981-\u0983\u09BC\u09BE-\u09C4\u09C7\u09C8\u09CB-\u09CD\u09D7\u09E2\u09E3\u09E6-\u09EF\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\u0B62\u0B63\u0B66-\u0B6F\u0B82\u0BBE-\u0BC2\u0BC6-\u0BC8\u0BCA-\u0BCD\u0BD7\u0BE6-\u0BEF\u0C00-\u0C03\u0C3E-\u0C44\u0C46-\u0C48\u0C4A-\u0C4D\u0C55\u0C56\u0C62\u0C63\u0C66-\u0C6F\u0C81-\u0C83\u0CBC\u0CBE-\u0CC4\u0CC6-\u0CC8\u0CCA-\u0CCD\u0CD5\u0CD6\u0CE2\u0CE3\u0CE6-\u0CEF\u0D01-\u0D03\u0D3E-\u0D44\u0D46-\u0D48\u0D4A-\u0D4D\u0D57\u0D62\u0D63\u0D66-\u0D6F\u0D82\u0D83\u0DCA\u0DCF-\u0DD4\u0DD6\u0DD8-\u0DDF\u0DE6-\u0DEF\u0DF2\u0DF3\u0E31\u0E34-\u0E3A\u0E47-\u0E4E\u0E50-\u0E59\u0EB1\u0EB4-\u0EB9\u0EBB\u0EBC\u0EC8-\u0ECD\u0ED0-\u0ED9\u0F18\u0F19\u0F20-\u0F29\u0F35\u0F37\u0F39\u0F3E\u0F3F\u0F71-\u0F84\u0F86\u0F87\u0F8D-\u0F97\u0F99-\u0FBC\u0FC6\u102B-\u103E\u1040-\u1049\u1056-\u1059\u105E-\u1060\u1062-\u1064\u1067-\u106D\u1071-\u1074\u1082-\u108D\u108F-\u109D\u135D-\u135F\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17B4-\u17D3\u17DD\u17E0-\u17E9\u180B-\u180D\u1810-\u1819\u18A9\u1920-\u192B\u1930-\u193B\u1946-\u194F\u19B0-\u19C0\u19C8\u19C9\u19D0-\u19D9\u1A17-\u1A1B\u1A55-\u1A5E\u1A60-\u1A7C\u1A7F-\u1A89\u1A90-\u1A99\u1AB0-\u1ABD\u1B00-\u1B04\u1B34-\u1B44\u1B50-\u1B59\u1B6B-\u1B73\u1B80-\u1B82\u1BA1-\u1BAD\u1BB0-\u1BB9\u1BE6-\u1BF3\u1C24-\u1C37\u1C40-\u1C49\u1C50-\u1C59\u1CD0-\u1CD2\u1CD4-\u1CE8\u1CED\u1CF2-\u1CF4\u1CF8\u1CF9\u1DC0-\u1DF5\u1DFC-\u1DFF\u200C\u200D\u203F\u2040\u2054\u20D0-\u20DC\u20E1\u20E5-\u20F0\u2CEF-\u2CF1\u2D7F\u2DE0-\u2DFF\u302A-\u302F\u3099\u309A\uA620-\uA629\uA66F\uA674-\uA67D\uA69F\uA6F0\uA6F1\uA802\uA806\uA80B\uA823-\uA827\uA880\uA881\uA8B4-\uA8C4\uA8D0-\uA8D9\uA8E0-\uA8F1\uA900-\uA909\uA926-\uA92D\uA947-\uA953\uA980-\uA983\uA9B3-\uA9C0\uA9D0-\uA9D9\uA9E5\uA9F0-\uA9F9\uAA29-\uAA36\uAA43\uAA4C\uAA4D\uAA50-\uAA59\uAA7B-\uAA7D\uAAB0\uAAB2-\uAAB4\uAAB7\uAAB8\uAABE\uAABF\uAAC1\uAAEB-\uAAEF\uAAF5\uAAF6\uABE3-\uABEA\uABEC\uABED\uABF0-\uABF9\uFB1E\uFE00-\uFE0F\uFE20-\uFE2D\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]/;
function isNewLine(code) {
return code === 10 || code === 13 || code === 0x2028 || code == 0x2029;
}
// 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 Position(line, col) {
this.line = line;
this.column = col;
}
Position.prototype.offset = function(n) {
return new Position(this.line, this.column + n);
};
function curPosition() {
return new Position(tokCurLine, tokPos - tokLineStart);
}
// Reset the token state. Used at the start of a parse.
function initTokenState(pos) {
if (pos) {
tokPos = pos;
tokLineStart = Math.max(0, input.lastIndexOf("\n", pos));
tokCurLine = input.slice(0, tokLineStart).split(newline).length;
} else {
tokCurLine = 1;
tokPos = tokLineStart = 0;
}
tokType = _eof;
tokContext = [];
tokExprAllowed = true;
metParenL = 0;
templates = [];
if (tokPos === 0 && options.allowHashBang && input.slice(0, 2) === '#!') {
skipLineComment(2);
}
}
// The algorithm used to determine whether a regexp can appear at a
// given point in the program is loosely based on sweet.js' approach.
// See https://github.com/mozilla/sweet.js/wiki/design
var b_stat = {token: "{", isExpr: false}, b_expr = {token: "{", isExpr: true};
var p_stat = {token: "(", isExpr: false}, p_expr = {token: "(", isExpr: true};
function braceIsBlock(prevType) {
var parent;
if (prevType === _colon && (parent = tokContext[tokContext.length - 1]).token == "{")
return !parent.isExpr;
if (prevType === _return)
return newline.test(input.slice(lastEnd, tokStart));
if (prevType === _else || prevType === _semi || prevType === _eof)
return true;
if (prevType == _braceL)
return tokContext[tokContext.length - 1] === b_stat;
return !tokExprAllowed;
}
// Called at the end of every token. Sets `tokEnd`, `tokVal`, and
// maintains `tokContext` and `tokExprAllowed`, and skips the space
// after the token, so that the next one's `tokStart` will point at
// the right position.
function finishToken(type, val, shouldSkipSpace) {
tokEnd = tokPos;
if (options.locations) tokEndLoc = curPosition();
var prevType = tokType;
tokType = type;
if (shouldSkipSpace !== false) skipSpace();
tokVal = val;
// Update context info
if (type === _parenR || type === _braceR) {
var out = tokContext.pop();
tokExprAllowed = !(out && out.isExpr);
} else if (type === _braceL) {
tokContext.push(braceIsBlock(prevType) ? b_stat : b_expr);
tokExprAllowed = true;
} else if (type == _parenL) {
var statementParens = prevType === _if || prevType === _for || prevType === _with || prevType === _while;
tokContext.push(statementParens ? p_stat : p_expr);
tokExprAllowed = true;
} else if (type == _incDec) {
// tokExprAllowed stays unchanged
} else if (type.keyword && prevType == _dot) {
tokExprAllowed = false;
} else if (tokExprAllowed && type == _function) {
tokExprAllowed = null;
} else {
tokExprAllowed = type.beforeExpr;
}
}
function skipBlockComment() {
var startLoc = options.onComment && options.locations && curPosition();
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 && curPosition());
}
function skipLineComment(startSkip) {
var start = tokPos;
var startLoc = options.onComment && options.locations && curPosition();
var ch = input.charCodeAt(tokPos+=startSkip);
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 + startSkip, tokPos), start, tokPos,
startLoc, options.locations && curPosition());
}
// 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(2);
} 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.
//
function readToken_dot() {
var next = input.charCodeAt(tokPos + 1);
if (next >= 48 && next <= 57) return readNumber(true);
var next2 = input.charCodeAt(tokPos + 2);
if (options.ecmaVersion >= 6 && next === 46 && next2 === 46) { // 46 = dot '.'
tokPos += 3;
return finishToken(_ellipsis);
} else {
++tokPos;
return finishToken(_dot);
}
}
function readToken_slash() { // '/'
var next = input.charCodeAt(tokPos + 1);
if (tokExprAllowed) {++tokPos; return readRegexp();}
if (next === 61) return finishOp(_assign, 2);
return finishOp(_slash, 1);
}
function readToken_mult_modulo(code) { // '%*'
var next = input.charCodeAt(tokPos + 1);
if (next === 61) return finishOp(_assign, 2);
return finishOp(code === 42 ? _star : _modulo, 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
skipLineComment(3);
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
skipLineComment(4);
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);
if (code === 61 && next === 62 && options.ecmaVersion >= 6) { // '=>'
tokPos += 2;
return finishToken(_arrow);
}
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 or another two dots.
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;
if (templates.length) ++templates[templates.length - 1];
return finishToken(_braceL);
case 125:
++tokPos;
if (templates.length && --templates[templates.length - 1] === 0)
return readTemplateString(_templateContinued);
else
return finishToken(_braceR);
case 58: ++tokPos; return finishToken(_colon);
case 63: ++tokPos; return finishToken(_question);
case 96: // '`'
if (options.ecmaVersion >= 6) {
++tokPos;
return readTemplateString(_template);
}
case 48: // '0'
var next = input.charCodeAt(tokPos + 1);
if (next === 120 || next === 88) return readRadixNumber(16); // '0x', '0X' - hex number
if (options.ecmaVersion >= 6) {
if (next === 111 || next === 79) return readRadixNumber(8); // '0o', '0O' - octal number
if (next === 98 || next === 66) return readRadixNumber(2); // '0b', '0B' - binary number
}
// 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();
case 37: case 42: // '%*'
return readToken_mult_modulo(code);
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() {
tokStart = tokPos;
if (options.locations) tokStartLoc = curPosition();
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);
}
var regexpUnicodeSupport = false;
try { new RegExp("\uffff", "u"); regexpUnicodeSupport = true; }
catch(e) {}
// 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();
var tmp = content;
if (mods) {
var validFlags = /^[gmsiy]*$/;
if (options.ecmaVersion >= 6) validFlags = /^[gmsiyu]*$/;
if (!validFlags.test(mods)) raise(start, "Invalid regular expression flag");
if (mods.indexOf('u') >= 0 && !regexpUnicodeSupport) {
// Replace each astral symbol and every Unicode code point
// escape sequence that represents such a symbol with a single
// ASCII symbol to avoid throwing on regular expressions that
// are only valid in combination with the `/u` flag.
tmp = tmp
.replace(/\\u\{([0-9a-fA-F]{5,6})\}/g, "x")
.replace(/[\uD800-\uDBFF][\uDC00-\uDFFF]/g, "x");
}
}
// Detect invalid regular expressions.
try {
new RegExp(tmp);
} catch (e) {
if (e instanceof SyntaxError) raise(start, "Error parsing regular expression: " + e.message);
raise(e);
}
// Get a regular expression object for this pattern-flag pair, or `null` in
// case the current environment doesn't support the flags it uses.
try {
var value = new RegExp(content, mods);
} catch (err) {
value = null;
}
return finishToken(_regexp, {pattern: content, flags: mods, value: 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 readRadixNumber(radix) {
tokPos += 2; // 0x
var val = readInt(radix);
if (val == null) raise(tokStart + 2, "Expected number in radix " + radix);
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 readCodePoint() {
var ch = input.charCodeAt(tokPos), code;
if (ch === 123) {
if (options.ecmaVersion < 6) unexpected();
++tokPos;
code = readHexChar(input.indexOf('}', tokPos) - tokPos);
++tokPos;
if (code > 0x10FFFF) unexpected();
} else {
code = readHexChar(4);
}
// UTF-16 Encoding
if (code <= 0xFFFF) {
return String.fromCharCode(code);
}
var cu1 = ((code - 0x10000) >> 10) + 0xD800;
var cu2 = ((code - 0x10000) & 1023) + 0xDC00;
return String.fromCharCode(cu1, cu2);
}
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) { // '\'
out += readEscapedChar();
} else {
++tokPos;
if (isNewLine(ch)) {
raise(tokStart, "Unterminated string constant");
}
out += String.fromCharCode(ch); // '\'
}
}
}
function readTemplateString(type) {
if (type == _templateContinued) templates.pop();
var out = "", start = tokPos;;
for (;;) {
if (tokPos >= inputLen) raise(tokStart, "Unterminated template");
var ch = input.charAt(tokPos);
if (ch === "`" || ch === "$" && input.charCodeAt(tokPos + 1) === 123) { // '`', '${'
var raw = input.slice(start, tokPos);
++tokPos;
if (ch == "$") { ++tokPos; templates.push(1); }
return finishToken(type, {cooked: out, raw: raw});
}
if (ch === "\\") { // '\'
out += readEscapedChar();
} else {
++tokPos;
if (newline.test(ch)) {
if (ch === "\r" && input.charCodeAt(tokPos) === 10) {
++tokPos;
ch = "\n";
}
if (options.locations) {
++tokCurLine;
tokLineStart = tokPos;
}
}
out += ch;
}
}
}
// Used to read escaped characters
function readEscapedChar() {
var 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");
tokPos += octal.length - 1;
return String.fromCharCode(parseInt(octal, 8));
} else {
switch (ch) {
case 110: return "\n"; // 'n' -> '\n'
case 114: return "\r"; // 'r' -> '\r'
case 120: return String.fromCharCode(readHexChar(2)); // 'x'
case 117: return readCodePoint(); // 'u'
case 116: return "\t"; // 't' -> '\t'
case 98: return "\b"; // 'b' -> '\b'
case 118: return "\u000b"; // 'v' -> '\u000b'
case 102: return "\f"; // 'f' -> '\f'
case 48: return "\0"; // 0 -> '\0'
case 13: if (input.charCodeAt(tokPos) === 10) ++tokPos; // '\r\n'
case 10: // ' \n'
if (options.locations) { tokLineStart = tokPos; ++tokCurLine; }
return "";
default: return String.fromCharCode(ch);
}
}
}
// 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 && isKeyword(word))
type = keywordTypes[word];
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() {
if (options.onToken)
options.onToken(new Token());
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() {
this.type = null;
this.start = tokStart;
this.end = null;
}
exports.Node = Node;
function SourceLocation() {
this.start = tokStartLoc;
this.end = null;
if (sourceFile !== null) this.source = sourceFile;
}
function startNode() {
var node = new Node();
if (options.locations)
node.loc = new SourceLocation();
if (options.directSourceFile)
node.sourceFile = options.directSourceFile;
if (options.ranges)
node.range = [tokStart, 0];
return node;
}
// Sometimes, a node is only started *after* the token stream passed
// its start position. The functions below help storing a position
// and creating a node from a previous position.
function storeCurrentPos() {
return options.locations ? [tokStart, tokStartLoc] : tokStart;
}
function startNodeAt(pos) {
var node = new Node(), start = pos;
if (options.locations) {
node.loc = new SourceLocation();
node.loc.start = start[1];
start = pos[0];
}
node.start = start;
if (options.directSourceFile)
node.sourceFile = options.directSourceFile;
if (options.ranges)
node.range = [start, 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;
}
function finishNodeAt(node, type, pos) {
if (options.locations) { node.loc.end = pos[1]; pos = pos[0]; }
node.type = type;
node.end = pos;
if (options.ranges)
node.range[1] = pos;
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;
} else {
return false;
}
}
// 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) {
eat(type) || unexpected();
}
// Raise an unexpected token error.
function unexpected(pos) {
raise(pos != null ? pos : tokStart, "Unexpected token");
}
// Checks if hash object has a property.
function has(obj, propName) {
return Object.prototype.hasOwnProperty.call(obj, propName);
}
// Convert existing expression atom to assignable pattern
// if possible.
function toAssignable(node, allowSpread, checkType) {
if (options.ecmaVersion >= 6 && node) {
switch (node.type) {
case "Identifier":
case "MemberExpression":
break;
case "ObjectExpression":
node.type = "ObjectPattern";
for (var i = 0; i < node.properties.length; i++) {
var prop = node.properties[i];
if (prop.kind !== "init") unexpected(prop.key.start);
toAssignable(prop.value, false, checkType);
}
break;
case "ArrayExpression":
node.type = "ArrayPattern";
for (var i = 0, lastI = node.elements.length - 1; i <= lastI; i++) {
toAssignable(node.elements[i], i === lastI, checkType);
}
break;
case "SpreadElement":
if (allowSpread) {
toAssignable(node.argument, false, checkType);
checkSpreadAssign(node.argument);
} else {
unexpected(node.start);
}
break;
case "AssignmentExpression":
if (node.operator === "=") {
node.type = "AssignmentPattern";
} else {
unexpected(node.left.end);
}
break;
default:
if (checkType) unexpected(node.start);
}
}
return node;
}
// Checks if node can be assignable spread argument.
function checkSpreadAssign(node) {
if (node.type !== "Identifier" && node.type !== "ArrayPattern")
unexpected(node.start);
}
// Verify that argument names are not repeated, and it does not
// try to bind the words `eval` or `arguments`.
function checkFunctionParam(param, nameHash) {
switch (param.type) {
case "Identifier":
if (isStrictReservedWord(param.name) || isStrictBadIdWord(param.name))
raise(param.start, "Defining '" + param.name + "' in strict mode");
if (has(nameHash, param.name))
raise(param.start, "Argument name clash in strict mode");
nameHash[param.name] = true;
break;
case "ObjectPattern":
for (var i = 0; i < param.properties.length; i++)
checkFunctionParam(param.properties[i].value, nameHash);
break;
case "ArrayPattern":
for (var i = 0; i < param.elements.length; i++) {
var elem = param.elements[i];
if (elem) checkFunctionParam(elem, nameHash);
}
break;
}
}
// Check if property name clashes with already added.
// Object/class 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.
function checkPropClash(prop, propHash) {
if (options.ecmaVersion >= 6) return;
var key = prop.key, name;
switch (key.type) {
case "Identifier": name = key.name; break;
case "Literal": name = String(key.value); break;
default: return;
}
var kind = prop.kind || "init", other;
if (has(propHash, name)) {
other = propHash[name];
var isGetSet = kind !== "init";
if ((strict || isGetSet) && other[kind] || !(isGetSet ^ other.init))
raise(key.start, "Redefinition of property");
} else {
other = propHash[name] = {
init: false,
get: false,
set: false
};
}
other[kind] = true;
}
// Verify that a node is an lval — something that can be assigned
// to.
function checkLVal(expr, isBinding) {
switch (expr.type) {
case "Identifier":
if (strict && (isStrictBadIdWord(expr.name) || isStrictReservedWord(expr.name)))
raise(expr.start, (isBinding ? "Binding " : "Assigning to ") + expr.name + " in strict mode");
break;
case "MemberExpression":
if (isBinding) raise(expr.start, "Binding to member expression");
break;
case "ObjectPattern":
for (var i = 0; i < expr.properties.length; i++)
checkLVal(expr.properties[i].value, isBinding);
break;
case "ArrayPattern":
for (var i = 0; i < expr.elements.length; i++) {
var elem = expr.elements[i];
if (elem) checkLVal(elem, isBinding);
}
break;
case "AssignmentPattern":
case "SpreadElement":
break;
default:
raise(expr.start, "Assigning to rvalue");
}
}
// ### 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(node) {
var first = true;
if (!node.body) node.body = [];
while (tokType !== _eof) {
var stmt = parseStatement(true);
node.body.push(stmt);
if (first && isUseStrict(stmt)) setStrict(true);
first = false;
}
next();
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(topLevel) {
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: return parseBreakContinueStatement(node, starttype.keyword);
case _debugger: return parseDebuggerStatement(node);
case _do: return parseDoStatement(node);
case _for: return parseForStatement(node);
case _function: return parseFunctionStatement(node);
case _class: return parseClass(node, true);
case _if: return parseIfStatement(node);
case _return: return parseReturnStatement(node);
case _switch: return parseSwitchStatement(node);
case _throw: return parseThrowStatement(node);
case _try: return parseTryStatement(node);
case _var: case _let: case _const: return parseVarStatement(node, starttype.keyword);
case _while: return parseWhileStatement(node);
case _with: return parseWithStatement(node);
case _braceL: return parseBlock(); // no point creating a function for this
case _semi: return parseEmptyStatement(node);
case _export:
case _import:
if (!topLevel && !options.allowImportExportEverywhere)
raise(tokStart, "'import' and 'export' may only appear at the top level");
return starttype === _import ? parseImport(node) : parseExport(node);
// 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))
return parseLabeledStatement(node, maybeName, expr);
else return parseExpressionStatement(node, expr);
}
}
function parseBreakContinueStatement(node, keyword) {
var isBreak = keyword == "break";
next();
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 " + keyword);
return finishNode(node, isBreak ? "BreakStatement" : "ContinueStatement");
}
function parseDebuggerStatement(node) {
next();
semicolon();
return finishNode(node, "DebuggerStatement");
}
function parseDoStatement(node) {
next();
labels.push(loopLabel);
node.body = parseStatement();
labels.pop();
expect(_while);
node.test = parseParenExpression();
if (options.ecmaVersion >= 6)
eat(_semi);
else
semicolon();
return finishNode(node, "DoWhileStatement");
}
// Disambiguating between a `for` and a `for`/`in` or `for`/`of`
// 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` or `of`. When there is no init
// part (semicolon immediately after the opening parenthesis), it
// is a regular `for` loop.
function parseForStatement(node) {
next();
labels.push(loopLabel);
expect(_parenL);
if (tokType === _semi) return parseFor(node, null);
if (tokType === _var || tokType === _let) {
var init = startNode(), varKind = tokType.keyword, isLet = tokType === _let;
next();
parseVar(init, true, varKind);
finishNode(init, "VariableDeclaration");
if ((tokType === _in || (options.ecmaVersion >= 6 && tokType === _name && tokVal === "of")) && init.declarations.length === 1 &&
!(isLet && init.declarations[0].init))
return parseForIn(node, init);
return parseFor(node, init);
}
var init = parseExpression(false, true);
if (tokType === _in || (options.ecmaVersion >= 6 && tokType === _name && tokVal === "of")) {
checkLVal(init);
return parseForIn(node, init);
}
return parseFor(node, init);
}
function parseFunctionStatement(node) {
next();
return parseFunction(node, true);
}
function parseIfStatement(node) {
next();
node.test = parseParenExpression();
node.consequent = parseStatement();
node.alternate = eat(_else) ? parseStatement() : null;
return finishNode(node, "IfStatement");
}
function parseReturnStatement(node) {
if (!inFunction && !options.allowReturnOutsideFunction)
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");
}
function parseSwitchStatement(node) {
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");
}
function parseThrowStatement(node) {
next();
if (newline.test(input.slice(lastEnd, tokStart)))
raise(lastEnd, "Illegal newline after throw");
node.argument = parseExpression();
semicolon();
return finishNode(node, "ThrowStatement");
}
function parseTryStatement(node) {
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");
}
function parseVarStatement(node, kind) {
next();
parseVar(node, false, kind);
semicolon();
return finishNode(node, "VariableDeclaration");
}
function parseWhileStatement(node) {
next();
node.test = parseParenExpression();
labels.push(loopLabel);
node.body = parseStatement();
labels.pop();
return finishNode(node, "WhileStatement");
}
function parseWithStatement(node) {
if (strict) raise(tokStart, "'with' in strict mode");
next();
node.object = parseParenExpression();
node.body = parseStatement();
return finishNode(node, "WithStatement");
}
function parseEmptyStatement(node) {
next();
return finishNode(node, "EmptyStatement");
}
function parseLabeledStatement(node, maybeName, expr) {
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");
}
function parseExpressionStatement(node, expr) {
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, 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 (oldStrict === false) 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` and `for`/`of` loop, which are almost
// same from parser's perspective.
function parseForIn(node, init) {
var type = tokType === _in ? "ForInStatement" : "ForOfStatement";
next();
node.left = init;
node.right = parseExpression();
expect(_parenR);
node.body = parseStatement();
labels.pop();
return finishNode(node, type);
}
// Parse a list of variable declarations.
function parseVar(node, noIn, kind) {
node.declarations = [];
node.kind = kind;
for (;;) {
var decl = startNode();
decl.id = options.ecmaVersion >= 6 ? toAssignable(parseExprAtom()) : parseIdent();
checkLVal(decl.id, true);
decl.init = eat(_eq) ? parseExpression(true, noIn) : (kind === _const.keyword ? unexpected() : 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 start = storeCurrentPos();
var expr = parseMaybeAssign(noIn);
if (!noComma && tokType === _comma) {
var node = startNodeAt(start);
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 start = storeCurrentPos();
var left = parseMaybeConditional(noIn);
if (tokType.isAssign) {
var node = startNodeAt(start);
node.operator = tokVal;
node.left = tokType === _eq ? toAssignable(left) : left;
checkLVal(left);
next();
node.right = parseMaybeAssign(noIn);
return finishNode(node, "AssignmentExpression");
}
return left;
}
// Parse a ternary conditional (`?:`) operator.
function parseMaybeConditional(noIn) {
var start = storeCurrentPos();
var expr = parseExprOps(noIn);
if (eat(_question)) {
var node = startNodeAt(start);
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) {
var start = storeCurrentPos();
return parseExprOp(parseMaybeUnary(), start, -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, leftStart, minPrec, noIn) {
var prec = tokType.binop;
if (prec != null && (!noIn || tokType !== _in)) {
if (prec > minPrec) {
var node = startNodeAt(leftStart);
node.left = left;
node.operator = tokVal;
var op = tokType;
next();
var start = storeCurrentPos();
node.right = parseExprOp(parseMaybeUnary(), start, prec, noIn);
finishNode(node, (op === _logicalOR || op === _logicalAND) ? "LogicalExpression" : "BinaryExpression");
return parseExprOp(node, leftStart, minPrec, noIn);
}
}
return left;
}
// Parse unary operators, both prefix and postfix.
function parseMaybeUnary() {
if (tokType.prefix) {
var node = startNode(), update = tokType.isUpdate, nodeType;
if (tokType === _ellipsis) {
nodeType = "SpreadElement";
} else {
nodeType = update ? "UpdateExpression" : "UnaryExpression";
node.operator = tokVal;
node.prefix = 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, nodeType);
}
var start = storeCurrentPos();
var expr = parseExprSubscripts();
while (tokType.postfix && !canInsertSemicolon()) {
var node = startNodeAt(start);
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() {
var start = storeCurrentPos();
return parseSubscripts(parseExprAtom(), start);
}
function parseSubscripts(base, start, noCalls) {
if (eat(_dot)) {
var node = startNodeAt(start);
node.object = base;
node.property = parseIdent(true);
node.computed = false;
return parseSubscripts(finishNode(node, "MemberExpression"), start, noCalls);
} else if (eat(_bracketL)) {
var node = startNodeAt(start);
node.object = base;
node.property = parseExpression();
node.computed = true;
expect(_bracketR);
return parseSubscripts(finishNode(node, "MemberExpression"), start, noCalls);
} else if (!noCalls && eat(_parenL)) {
var node = startNodeAt(start);
node.callee = base;
node.arguments = parseExprList(_parenR, false);
return parseSubscripts(finishNode(node, "CallExpression"), start, noCalls);
} else if (tokType === _template) {
var node = startNodeAt(start);
node.tag = base;
node.quasi = parseTemplate();
return parseSubscripts(finishNode(node, "TaggedTemplateExpression"), start, noCalls);
} 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 _yield:
if (inGenerator) return parseYield();
case _name:
var start = storeCurrentPos();
var id = parseIdent(tokType !== _name);
if (eat(_arrow)) {
return parseArrowExpression(startNodeAt(start), [id]);
}
return id;
case _regexp:
var node = startNode();
node.regex = {pattern: tokVal.pattern, flags: tokVal.flags};
node.value = tokVal.value;
node.raw = input.slice(tokStart, tokEnd);
next();
return finishNode(node, "Literal");
case _num: case _string:
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 start = storeCurrentPos();
var val, exprList;
next();
// check whether this is generator comprehension or regular expression
if (options.ecmaVersion >= 7 && tokType === _for) {
val = parseComprehension(startNodeAt(start), true);
} else {
var oldParenL = ++metParenL;
if (tokType !== _parenR) {
val = parseExpression();
exprList = val.type === "SequenceExpression" ? val.expressions : [val];
} else {
exprList = [];
}
expect(_parenR);
// if '=>' follows '(...)', convert contents to arguments
if (metParenL === oldParenL && eat(_arrow)) {
val = parseArrowExpression(startNodeAt(start), exprList);
} else {
// forbid '()' before everything but '=>'
if (!val) unexpected(lastStart);
// forbid '...' in sequence expressions
if (options.ecmaVersion >= 6) {
for (var i = 0; i < exprList.length; i++) {
if (exprList[i].type === "SpreadElement") unexpected();
}
}
if (options.preserveParens) {
var par = startNodeAt(start);
par.expression = val;
val = finishNode(par, "ParenthesizedExpression");
}
}
}
return val;
case _bracketL:
var node = startNode();
next();
// check whether this is array comprehension or regular array
if (options.ecmaVersion >= 7 && tokType === _for) {
return parseComprehension(node, false);
}
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 _class:
return parseClass(startNode(), false);
case _new:
return parseNew();
case _template:
return parseTemplate();
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();
var start = storeCurrentPos();
node.callee = parseSubscripts(parseExprAtom(), start, true);
if (eat(_parenL)) node.arguments = parseExprList(_parenR, false);
else node.arguments = empty;
return finishNode(node, "NewExpression");
}
// Parse template expression.
function parseTemplateElement() {
var elem = startNodeAt(options.locations ? [tokStart + 1, tokStartLoc.offset(1)] : tokStart + 1);
elem.value = tokVal;
elem.tail = input.charCodeAt(tokEnd - 1) !== 123; // '{'
next();
var endOff = elem.tail ? 1 : 2;
return finishNodeAt(elem, "TemplateElement", options.locations ? [lastEnd - endOff, lastEndLoc.offset(-endOff)] : lastEnd - endOff);
}
function parseTemplate() {
var node = startNode();
node.expressions = [];
var curElt = parseTemplateElement();
node.quasis = [curElt];
while (!curElt.tail) {
node.expressions.push(parseExpression());
if (tokType !== _templateContinued) unexpected();
node.quasis.push(curElt = parseTemplateElement());
}
return finishNode(node, "TemplateLiteral");
}
// Parse an object literal.
function parseObj() {
var node = startNode(), first = true, propHash = {};
node.properties = [];
next();
while (!eat(_braceR)) {
if (!first) {
expect(_comma);
if (options.allowTrailingCommas && eat(_braceR)) break;
} else first = false;
var prop = startNode(), isGenerator;
if (options.ecmaVersion >= 6) {
prop.method = false;
prop.shorthand = false;
isGenerator = eat(_star);
}
parsePropertyName(prop);
if (eat(_colon)) {
prop.value = parseExpression(true);
prop.kind = "init";
} else if (options.ecmaVersion >= 6 && tokType === _parenL) {
prop.kind = "init";
prop.method = true;
prop.value = parseMethod(isGenerator);
} else if (options.ecmaVersion >= 5 && !prop.computed && prop.key.type === "Identifier" &&
(prop.key.name === "get" || prop.key.name === "set") &&
(tokType != _comma && tokType != _braceR)) {
if (isGenerator) unexpected();
prop.kind = prop.key.name;
parsePropertyName(prop);
prop.value = parseMethod(false);
} else if (options.ecmaVersion >= 6 && !prop.computed && prop.key.type === "Identifier") {
prop.kind = "init";
prop.value = prop.key;
prop.shorthand = true;
} else unexpected();
checkPropClash(prop, propHash);
node.properties.push(finishNode(prop, "Property"));
}
return finishNode(node, "ObjectExpression");
}
function parsePropertyName(prop) {
if (options.ecmaVersion >= 6) {
if (eat(_bracketL)) {
prop.computed = true;
prop.key = parseExpression();
expect(_bracketR);
return;
} else {
prop.computed = false;
}
}
prop.key = (tokType === _num || tokType === _string) ? parseExprAtom() : parseIdent(true);
}
// Initialize empty function node.
function initFunction(node) {
node.id = null;
node.params = [];
if (options.ecmaVersion >= 6) {
node.defaults = [];
node.rest = null;
node.generator = false;
}
}
// Parse a function declaration or literal (depending on the
// `isStatement` parameter).
function parseFunction(node, isStatement, allowExpressionBody) {
initFunction(node);
if (options.ecmaVersion >= 6) {
node.generator = eat(_star);
}
if (isStatement || tokType === _name) {
node.id = parseIdent();
}
parseFunctionParams(node);
parseFunctionBody(node, allowExpressionBody);
return finishNode(node, isStatement ? "FunctionDeclaration" : "FunctionExpression");
}
// Parse object or class method.
function parseMethod(isGenerator) {
var node = startNode();
initFunction(node);
parseFunctionParams(node);
var allowExpressionBody;
if (options.ecmaVersion >= 6) {
node.generator = isGenerator;
allowExpressionBody = true;
} else {
allowExpressionBody = false;
}
parseFunctionBody(node, allowExpressionBody);
return finishNode(node, "FunctionExpression");
}
// Parse arrow function expression with given parameters.
function parseArrowExpression(node, params) {
initFunction(node);
var defaults = node.defaults, hasDefaults = false;
for (var i = 0, lastI = params.length - 1; i <= lastI; i++) {
var param = params[i];
if (param.type === "AssignmentExpression" && param.operator === "=") {
hasDefaults = true;
params[i] = param.left;
defaults.push(param.right);
} else {
toAssignable(param, i === lastI, true);
defaults.push(null);
if (param.type === "SpreadElement") {
params.length--;
node.rest = param.argument;
break;
}
}
}
node.params = params;
if (!hasDefaults) node.defaults = [];
parseFunctionBody(node, true);
return finishNode(node, "ArrowFunctionExpression");
}
// Parse function parameters.
function parseFunctionParams(node) {
var defaults = [], hasDefaults = false;
expect(_parenL);
for (;;) {
if (eat(_parenR)) {
break;
} else if (options.ecmaVersion >= 6 && eat(_ellipsis)) {
node.rest = toAssignable(parseExprAtom(), false, true);
checkSpreadAssign(node.rest);
expect(_parenR);
defaults.push(null);
break;
} else {
node.params.push(options.ecmaVersion >= 6 ? toAssignable(parseExprAtom(), false, true) : parseIdent());
if (options.ecmaVersion >= 6) {
if (eat(_eq)) {
hasDefaults = true;
defaults.push(parseExpression(true));
} else {
defaults.push(null);
}
}
if (!eat(_comma)) {
expect(_parenR);
break;
}
}
}
if (hasDefaults) node.defaults = defaults;
}
// Parse function body and check parameters.
function parseFunctionBody(node, allowExpression) {
var isExpression = allowExpression && tokType !== _braceL;
if (isExpression) {
node.body = parseExpression(true);
node.expression = true;
} else {
// Start a new scope with regard to labels and the `inFunction`
// flag (restore them to their old value afterwards).
var oldInFunc = inFunction, oldInGen = inGenerator, oldLabels = labels;
inFunction = true; inGenerator = node.generator; labels = [];
node.body = parseBlock(true);
node.expression = false;
inFunction = oldInFunc; inGenerator = oldInGen; 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 || !isExpression && node.body.body.length && isUseStrict(node.body.body[0])) {
var nameHash = {};
if (node.id)
checkFunctionParam(node.id, {});
for (var i = 0; i < node.params.length; i++)
checkFunctionParam(node.params[i], nameHash);
if (node.rest)
checkFunctionParam(node.rest, nameHash);
}
}
// Parse a class declaration or literal (depending on the
// `isStatement` parameter).
function parseClass(node, isStatement) {
next();
node.id = tokType === _name ? parseIdent() : isStatement ? unexpected() : null;
node.superClass = eat(_extends) ? parseExprSubscripts() : null;
var classBody = startNode();
classBody.body = [];
expect(_braceL);
while (!eat(_braceR)) {
var method = startNode();
if (tokType === _name && tokVal === "static") {
next();
method['static'] = true;
} else {
method['static'] = false;
}
var isGenerator = eat(_star);
parsePropertyName(method);
if (tokType !== _parenL && !method.computed && method.key.type === "Identifier" &&
(method.key.name === "get" || method.key.name === "set")) {
if (isGenerator) unexpected();
method.kind = method.key.name;
parsePropertyName(method);
} else {
method.kind = "";
}
method.value = parseMethod(isGenerator);
classBody.body.push(finishNode(method, "MethodDefinition"));
eat(_semi);
}
node.body = finishNode(classBody, "ClassBody");
return finishNode(node, isStatement ? "ClassDeclaration" : "ClassExpression");
}
// 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();
if (liberal && options.forbidReserved == "everywhere") liberal = false;
if (tokType === _name) {
if (!liberal &&
(options.forbidReserved &&
(options.ecmaVersion === 3 ? isReservedWord3 : isReservedWord5)(tokVal) ||
strict && isStrictReservedWord(tokVal)) &&
input.slice(tokStart, tokEnd).indexOf("\\") == -1)
raise(tokStart, "The keyword '" + tokVal + "' is reserved");
node.name = tokVal;
} else if (liberal && tokType.keyword) {
node.name = tokType.keyword;
} else {
unexpected();
}
next();
return finishNode(node, "Identifier");
}
// Parses module export declaration.
function parseExport(node) {
next();
// export var|const|let|function|class ...;
if (tokType === _var || tokType === _const || tokType === _let || tokType === _function || tokType === _class) {
node.declaration = parseStatement();
node['default'] = false;
node.specifiers = null;
node.source = null;
} else
// export default ...;
if (eat(_default)) {
node.declaration = parseExpression(true);
node['default'] = true;
node.specifiers = null;
node.source = null;
semicolon();
} else {
// export * from '...';
// export { x, y as z } [from '...'];
var isBatch = tokType === _star;
node.declaration = null;
node['default'] = false;
node.specifiers = parseExportSpecifiers();
if (tokType === _name && tokVal === "from") {
next();
node.source = tokType === _string ? parseExprAtom() : unexpected();
} else {
if (isBatch) unexpected();
node.source = null;
}
semicolon();
}
return finishNode(node, "ExportDeclaration");
}
// Parses a comma-separated list of module exports.
function parseExportSpecifiers() {
var nodes = [], first = true;
if (tokType === _star) {
// export * from '...'
var node = startNode();
next();
nodes.push(finishNode(node, "ExportBatchSpecifier"));
} else {
// export { x, y as z } [from '...']
expect(_braceL);
while (!eat(_braceR)) {
if (!first) {
expect(_comma);
if (options.allowTrailingCommas && eat(_braceR)) break;
} else first = false;
var node = startNode();
node.id = parseIdent(tokType === _default);
if (tokType === _name && tokVal === "as") {
next();
node.name = parseIdent(true);
} else {
node.name = null;
}
nodes.push(finishNode(node, "ExportSpecifier"));
}
}
return nodes;
}
// Parses import declaration.
function parseImport(node) {
next();
// import '...';
if (tokType === _string) {
node.specifiers = [];
node.source = parseExprAtom();
node.kind = "";
} else {
node.specifiers = parseImportSpecifiers();
if (tokType !== _name || tokVal !== "from") unexpected();
next();
node.source = tokType === _string ? parseExprAtom() : unexpected();
}
semicolon();
return finishNode(node, "ImportDeclaration");
}
// Parses a comma-separated list of module imports.
function parseImportSpecifiers() {
var nodes = [], first = true;
if (tokType === _name) {
// import defaultObj, { x, y as z } from '...'
var node = startNode();
node.id = parseIdent();
checkLVal(node.id, true);
node.name = null;
node['default'] = true;
nodes.push(finishNode(node, "ImportSpecifier"));
if (!eat(_comma)) return nodes;
}
if (tokType === _star) {
var node = startNode();
next();
if (tokType !== _name || tokVal !== "as") unexpected();
next();
node.name = parseIdent();
checkLVal(node.name, true);
nodes.push(finishNode(node, "ImportBatchSpecifier"));
return nodes;
}
expect(_braceL);
while (!eat(_braceR)) {
if (!first) {
expect(_comma);
if (options.allowTrailingCommas && eat(_braceR)) break;
} else first = false;
var node = startNode();
node.id = parseIdent(true);
if (tokType === _name && tokVal === "as") {
next();
node.name = parseIdent();
} else {
node.name = null;
}
checkLVal(node.name || node.id, true);
node['default'] = false;
nodes.push(finishNode(node, "ImportSpecifier"));
}
return nodes;
}
// Parses yield expression inside generator.
function parseYield() {
var node = startNode();
next();
if (eat(_semi) || canInsertSemicolon()) {
node.delegate = false;
node.argument = null;
} else {
node.delegate = eat(_star);
node.argument = parseExpression(true);
}
return finishNode(node, "YieldExpression");
}
// Parses array and generator comprehensions.
function parseComprehension(node, isGenerator) {
node.blocks = [];
while (tokType === _for) {
var block = startNode();
next();
expect(_parenL);
block.left = toAssignable(parseExprAtom());
checkLVal(block.left, true);
if (tokType !== _name || tokVal !== "of") unexpected();
next();
// `of` property is here for compatibility with Esprima's AST
// which also supports deprecated [for (... in ...) expr]
block.of = true;
block.right = parseExpression();
expect(_parenR);
node.blocks.push(finishNode(block, "ComprehensionBlock"));
}
node.filter = eat(_if) ? parseParenExpression() : null;
node.body = parseExpression();
expect(isGenerator ? _parenR : _bracketR);
node.generator = isGenerator;
return finishNode(node, "ComprehensionExpression");
}
});