[nobug] initial work on integrating Acorn with Orion
diff --git a/bundles/org.eclipse.orion.client.javascript/web/acorn/LICENSE b/bundles/org.eclipse.orion.client.javascript/web/acorn/LICENSE
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+Copyright (C) 2012-2014 by various contributors (see AUTHORS)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/bundles/org.eclipse.orion.client.javascript/web/acorn/README.md b/bundles/org.eclipse.orion.client.javascript/web/acorn/README.md
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+# Acorn
+
+[![Build Status](https://travis-ci.org/marijnh/acorn.svg?branch=master)](https://travis-ci.org/marijnh/acorn)
+
+A tiny, fast JavaScript parser, written completely in JavaScript.
+
+## Installation
+
+The easiest way to install acorn is with [`npm`][npm].
+
+[npm]: http://npmjs.org
+
+```sh
+npm install acorn
+```
+
+Alternately, download the source.
+
+```sh
+git clone https://github.com/marijnh/acorn.git
+```
+
+## Components
+
+When run in a CommonJS (node.js) or AMD environment, exported values
+appear in the interfaces exposed by the individual files, as usual.
+When loaded in the browser (Acorn works in any JS-enabled browser more
+recent than IE5) without any kind of module management, a single
+global object `acorn` will be defined, and all the exported properties
+will be added to that.
+
+### acorn.js
+
+This file contains the actual parser (and is what you get when you
+`require("acorn")` in node.js).
+
+**parse**`(input, options)` is used to parse a JavaScript program.
+The `input` parameter is a string, `options` can be undefined or an
+object setting some of the options listed below. The return value will
+be an abstract syntax tree object as specified by the
+[Mozilla Parser API][mozapi].
+
+When  encountering   a  syntax   error,  the   parser  will   raise  a
+`SyntaxError` object with a meaningful  message. The error object will
+have a `pos` property that indicates the character offset at which the
+error occurred,  and a `loc`  object that contains a  `{line, column}`
+object referring to that same position.
+
+[mozapi]: https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API
+
+- **ecmaVersion**: Indicates the ECMAScript version to parse. Must be
+  either 3, 5, or 6. This influences support for strict mode, the set
+  of reserved words, and support for new syntax features. Default is 5.
+
+- **strictSemicolons**: If `true`, prevents the parser from doing
+  automatic semicolon insertion, and statements that do not end with
+  a semicolon will generate an error. Defaults to `false`.
+
+- **allowTrailingCommas**: If `false`, the parser will not allow
+  trailing commas in array and object literals. Default is `true`.
+
+- **forbidReserved**: If `true`, using a reserved word will generate
+  an error. Defaults to `false`. When given the value `"everywhere"`,
+  reserved words and keywords can also not be used as property names
+  (as in Internet Explorer's old parser).
+  
+- **allowReturnOutsideFunction**: By default, a return statement at
+  the top level raises an error. Set this to `true` to accept such
+  code.
+
+- **locations**: When `true`, each node has a `loc` object attached
+  with `start` and `end` subobjects, each of which contains the
+  one-based line and zero-based column numbers in `{line, column}`
+  form. Default is `false`.
+
+- **onToken**: If a function is passed for this option, each found
+  token will be passed in same format as `tokenize()` returns.
+
+  If array is passed, each found token is pushed to it.
+
+  Note that you are not allowed to call the parser from the
+  callback—that will corrupt its internal state.
+
+- **onComment**: If a function is passed for this option, whenever a
+  comment is encountered the function will be called with the
+  following parameters:
+
+  - `block`: `true` if the comment is a block comment, false if it
+    is a line comment.
+  - `text`: The content of the comment.
+  - `start`: Character offset of the start of the comment.
+  - `end`: Character offset of the end of the comment.
+
+  When the `locations` options is on, the `{line, column}` locations
+  of the comment’s start and end are passed as two additional
+  parameters.
+
+  If array is passed for this option, each found comment is pushed
+  to it as object in Esprima format:
+  
+  ```javascript
+  {
+    "type": "Line" | "Block",
+    "value": "comment text",
+    "range": ...,
+    "loc": ...
+  }
+  ```
+
+  Note that you are not allowed to call the parser from the
+  callback—that will corrupt its internal state.
+
+- **ranges**: 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`.
+
+- **program**: It is possible to parse multiple files into a single
+  AST by passing the tree produced by parsing the first file as the
+  `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.
+
+- **sourceFile**: When the `locations` option is `true`, you can pass
+  this option to add a `source` attribute in every node’s `loc`
+  object. Note that the contents of this option are not examined or
+  processed in any way; you are free to use whatever format you
+  choose.
+
+- **directSourceFile**: Like `sourceFile`, but a `sourceFile` property
+  will be added directly to the nodes, rather than the `loc` object.
+
+[range]: https://bugzilla.mozilla.org/show_bug.cgi?id=745678
+
+**parseExpressionAt**`(input, offset, options)` will parse a single
+expression in a string, and return its AST. It will not complain if
+there is more of the string left after the expression.
+
+**getLineInfo**`(input, offset)` can be used to get a `{line,
+column}` object for a given program string and character offset.
+
+**tokenize**`(input, options)` exports a primitive interface to
+Acorn's tokenizer. The function takes an input string and options
+similar to `parse` (though only some options are meaningful here), and
+returns a function that can be called repeatedly to read a single
+token, and returns a `{start, end, type, value}` object (with added
+`loc` property when the `locations` option is enabled and `range`
+property when the `ranges` option is enabled).
+
+**tokTypes** holds an object mapping names to the token type objects
+that end up in the `type` properties of tokens.
+
+#### Note on using with [Escodegen][escodegen]
+
+Escodegen supports generating comments from AST, attached in
+Esprima-specific format. In order to simulate same format in
+Acorn, consider following example:
+
+```javascript
+var comments = [], tokens = [];
+
+var ast = acorn.parse('var x = 42; // answer', {
+	// collect ranges for each node
+	ranges: true,
+	// collect comments in Esprima's format
+	onComment: comments,
+	// collect token ranges
+	onToken: tokens
+});
+
+// attach comments using collected information
+escodegen.attachComments(ast, comments, tokens);
+
+// generate code
+console.log(escodegen.generate(ast, {comment: true}));
+// > 'var x = 42;    // answer'
+```
+
+[escodegen]: https://github.com/Constellation/escodegen
+
+#### Using Acorn in an environment with a Content Security Policy
+
+Some contexts, such as Chrome Web Apps, disallow run-time code evaluation.
+Acorn uses `new Function` to generate fast functions that test whether
+a word is in a given set, and will trigger a security error when used
+in a context with such a
+[Content Security Policy](http://www.html5rocks.com/en/tutorials/security/content-security-policy/#eval-too)
+(see [#90](https://github.com/marijnh/acorn/issues/90) and
+[#123](https://github.com/marijnh/acorn/issues/123)).
+
+The `bin/without_eval` script can be used to generate a version of
+`acorn.js` that has the generated code inlined, and can thus run
+without evaluating anything. In versions of this library downloaded
+from NPM, this script will be available as `acorn_csp.js`.
+
+### acorn_loose.js ###
+
+This file implements an error-tolerant parser. It exposes a single
+function.
+
+**parse_dammit**`(input, options)` takes the same arguments and
+returns the same syntax tree as the `parse` function in `acorn.js`,
+but never raises an error, and will do its best to parse syntactically
+invalid code in as meaningful a way as it can. It'll insert identifier
+nodes with name `"✖"` as placeholders in places where it can't make
+sense of the input. Depends on `acorn.js`, because it uses the same
+tokenizer.
+
+### util/walk.js ###
+
+Implements an abstract syntax tree walker. Will store its interface in
+`acorn.walk` when used without a module system.
+
+**simple**`(node, visitors, base, state)` does a 'simple' walk over
+a tree. `node` should be the AST node to walk, and `visitors` an
+object with properties whose names correspond to node types in the
+[Mozilla Parser API][mozapi]. The properties should contain functions
+that will be called with the node object and, if applicable the state
+at that point. The last two arguments are optional. `base` is a walker
+algorithm, and `state` is a start state. The default walker will
+simply visit all statements and expressions and not produce a
+meaningful state. (An example of a use of state it to track scope at
+each point in the tree.)
+
+**ancestor**`(node, visitors, base, state)` does a 'simple' walk over
+a tree, building up an array of ancestor nodes (including the current node)
+and passing the array to callbacks in the `state` parameter.
+
+**recursive**`(node, state, functions, base)` does a 'recursive'
+walk, where the walker functions are responsible for continuing the
+walk on the child nodes of their target node. `state` is the start
+state, and `functions` should contain an object that maps node types
+to walker functions. Such functions are called with `(node, state, c)`
+arguments, and can cause the walk to continue on a sub-node by calling
+the `c` argument on it with `(node, state)` arguments. The optional
+`base` argument provides the fallback walker functions for node types
+that aren't handled in the `functions` object. If not given, the
+default walkers will be used.
+
+**make**`(functions, base)` builds a new walker object by using the
+walker functions in `functions` and filling in the missing ones by
+taking defaults from `base`.
+
+**findNodeAt**`(node, start, end, test, base, state)` tries to
+locate a node in a tree at the given start and/or end offsets, which
+satisfies the predicate `test`. `start` end `end` can be either `null`
+(as wildcard) or a number. `test` may be a string (indicating a node
+type) or a function that takes `(nodeType, node)` arguments and
+returns a boolean indicating whether this node is interesting. `base`
+and `state` are optional, and can be used to specify a custom walker.
+Nodes are tested from inner to outer, so if two nodes match the
+boundaries, the inner one will be preferred.
+
+**findNodeAround**`(node, pos, test, base, state)` is a lot like
+`findNodeAt`, but will match any node that exists 'around' (spanning)
+the given position.
+
+**findNodeAfter**`(node, pos, test, base, state)` is similar to
+`findNodeAround`, but will match all nodes *after* the given position
+(testing outer nodes before inner nodes).
+
+## Command line interface
+
+The `bin/acorn` utility can be used to parse a file from the command
+line. It accepts as arguments its input file and the following
+options:
+
+- `--ecma3|--ecma5|--ecma6`: Sets the ECMAScript version to parse. Default is
+  version 5.
+
+- `--strictSemicolons`: Prevents the parser from doing automatic
+  semicolon insertion. Statements that do not end in semicolons will
+  generate an error.
+
+- `--locations`: Attaches a "loc" object to each node with "start" and
+  "end" subobjects, each of which contains the one-based line and
+  zero-based column numbers in `{line, column}` form.
+
+- `--compact`: No whitespace is used in the AST output.
+
+- `--silent`: Do not output the AST, just return the exit status.
+
+- `--help`: Print the usage information and quit.
+
+The utility spits out the syntax tree as JSON data.
diff --git a/bundles/org.eclipse.orion.client.javascript/web/acorn/acorn.js b/bundles/org.eclipse.orion.client.javascript/web/acorn/acorn.js
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+// 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.current = function() { return new Token(); };
+    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;
+  }
+
+  // Parses lvalue (assignable) atom.
+
+  function parseAssignableAtom() {
+    if (options.ecmaVersion < 6) return parseIdent();
+    switch (tokType) {
+      case _name:
+        return parseIdent();
+
+      case _bracketL:
+        var node = startNode();
+        next();
+        var elts = node.elements = [], first = true;
+        while (!eat(_bracketR)) {
+          first ? first = false : expect(_comma);
+          if (tokType === _ellipsis) {
+            var spread = startNode();
+            next();
+            spread.argument = parseAssignableAtom();
+            checkSpreadAssign(spread.argument);
+            elts.push(finishNode(spread, "SpreadElement"));
+            expect(_bracketR);
+            break;
+          }
+          elts.push(tokType === _comma ? null : parseMaybeDefault());
+        }
+        return finishNode(node, "ArrayPattern");
+
+      case _braceL:
+        return parseObj(true);
+
+      default:
+        unexpected();
+    }
+  }
+
+  // Parses assignment pattern around given atom if possible.
+
+  function parseMaybeDefault(startPos, left) {
+    left = left || parseAssignableAtom();
+    if (!eat(_eq)) return left;
+    var node = startPos ? startNodeAt(startPos) : startNode();
+    node.operator = "=";
+    node.left = left;
+    node.right = parseMaybeAssign();
+    return finishNode(node, "AssignmentPattern");
+  }
+
+  // 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 = parseAssignableAtom();
+      checkLVal(clause.param, true);
+      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 = parseAssignableAtom();
+      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(isPattern) {
+    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, start;
+      if (options.ecmaVersion >= 6) {
+        prop.method = false;
+        prop.shorthand = false;
+        if (isPattern) {
+          start = storeCurrentPos();
+        } else {
+          isGenerator = eat(_star);
+        }
+      }
+      parsePropertyName(prop);
+      if (eat(_colon)) {
+        prop.value = isPattern ? parseMaybeDefault(start) : parseMaybeAssign();
+        prop.kind = "init";
+      } else if (options.ecmaVersion >= 6 && tokType === _parenL) {
+        if (isPattern) unexpected();
+        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 || isPattern) 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 = isPattern ? parseMaybeDefault(start, prop.key) : prop.key;
+        prop.shorthand = true;
+      } else unexpected();
+
+      checkPropClash(prop, propHash);
+      node.properties.push(finishNode(prop, "Property"));
+    }
+    return finishNode(node, isPattern ? "ObjectPattern" : "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 = parseAssignableAtom();
+        checkSpreadAssign(node.rest);
+        expect(_parenR);
+        defaults.push(null);
+        break;
+      } else {
+        node.params.push(parseAssignableAtom());
+        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();
+      var isGenerator = eat(_star);
+      parsePropertyName(method);
+      if (tokType !== _parenL && !method.computed && method.key.type === "Identifier" &&
+          method.key.name === "static") {
+        if (isGenerator) unexpected();
+        method['static'] = true;
+        isGenerator = eat(_star);
+        parsePropertyName(method);
+      } else {
+        method['static'] = false;
+      }
+      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 = parseAssignableAtom();
+      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");
+  }
+});
diff --git a/bundles/org.eclipse.orion.client.javascript/web/acorn/acorn_loose.js b/bundles/org.eclipse.orion.client.javascript/web/acorn/acorn_loose.js
new file mode 100644
index 0000000..62626fe
--- /dev/null
+++ b/bundles/org.eclipse.orion.client.javascript/web/acorn/acorn_loose.js
@@ -0,0 +1,1186 @@
+// Acorn: Loose parser
+//
+// This module provides an alternative parser (`parse_dammit`) that
+// exposes that same interface as `parse`, but will try to parse
+// anything as JavaScript, repairing syntax error the best it can.
+// There are circumstances in which it will raise an error and give
+// up, but they are very rare. The resulting AST will be a mostly
+// valid JavaScript AST (as per the [Mozilla parser API][api], except
+// that:
+//
+// - Return outside functions is allowed
+//
+// - Label consistency (no conflicts, break only to existing labels)
+//   is not enforced.
+//
+// - Bogus Identifier nodes with a name of `"✖"` are inserted whenever
+//   the parser got too confused to return anything meaningful.
+//
+// [api]: https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API
+//
+// The expected use for this is to *first* try `acorn.parse`, and only
+// if that fails switch to `parse_dammit`. The loose parser might
+// parse badly indented code incorrectly, so **don't** use it as
+// your default parser.
+//
+// Quite a lot of acorn.js is duplicated here. The alternative was to
+// add a *lot* of extra cruft to that file, making it less readable
+// and slower. Copying and editing the code allowed me to make
+// invasive changes and simplifications without creating a complicated
+// tangle.
+
+(function(root, mod) {
+  if (typeof exports == "object" && typeof module == "object") return mod(exports, require("./acorn")); // CommonJS
+  if (typeof define == "function" && define.amd) return define(["exports", "./acorn"], mod); // AMD
+  mod(root.acorn || (root.acorn = {}), root.acorn); // Plain browser env
+})(this, function(exports, acorn) {
+  "use strict";
+
+  var tt = acorn.tokTypes;
+
+  var options, input, fetchToken, context;
+
+  acorn.defaultOptions.tabSize = 4;
+
+  exports.parse_dammit = function(inpt, opts) {
+    if (!opts) opts = {};
+    input = String(inpt);
+    fetchToken = acorn.tokenize(input, opts);
+    options = fetchToken.options;
+    sourceFile = options.sourceFile || null;
+    context = [];
+    nextLineStart = 0;
+    ahead.length = 0;
+    next();
+    return parseTopLevel();
+  };
+
+  var lastEnd, token = {start: 0, end: 0}, ahead = [];
+  var curLineStart, nextLineStart, curIndent, lastEndLoc, sourceFile;
+
+  function next(forceRegexp) {
+    lastEnd = token.end;
+    if (options.locations)
+      lastEndLoc = token.endLoc;
+    if (forceRegexp)
+      ahead.length = 0;
+
+    token = ahead.shift() || readToken(forceRegexp);
+    if (options.onToken)
+      options.onToken(token);
+
+    if (token.start >= nextLineStart) {
+      while (token.start >= nextLineStart) {
+        curLineStart = nextLineStart;
+        nextLineStart = lineEnd(curLineStart) + 1;
+      }
+      curIndent = indentationAfter(curLineStart);
+    }
+  }
+
+  function readToken(forceRegexp) {
+    for (;;) {
+      try {
+        var tok = fetchToken(forceRegexp);
+        if (tok.type === tt.dot && input.substr(tok.end, 1) === '.') {
+          tok = fetchToken();
+          tok.start--;
+          tok.type = tt.ellipsis;
+        }
+        return tok;
+      } catch(e) {
+        if (!(e instanceof SyntaxError)) throw e;
+
+        // Try to skip some text, based on the error message, and then continue
+        var msg = e.message, pos = e.raisedAt, replace = true;
+        if (/unterminated/i.test(msg)) {
+          pos = lineEnd(e.pos + 1);
+          if (/string/.test(msg)) {
+            replace = {start: e.pos, end: pos, type: tt.string, value: input.slice(e.pos + 1, pos)};
+          } else if (/regular expr/i.test(msg)) {
+            var re = input.slice(e.pos, pos);
+            try { re = new RegExp(re); } catch(e) {}
+            replace = {start: e.pos, end: pos, type: tt.regexp, value: re};
+          } else if (/template/.test(msg)) {
+            replace = {start: e.pos, end: pos,
+                       type: input.charAt(e.pos) == "`" ? tt.template : tt.templateContinued,
+                       value: input.slice(e.pos + 1, pos)};
+          } else if (/comment/.test(msg)) {
+            replace = fetchToken.current();
+          } else {
+            replace = false;
+          }
+        } else if (/invalid (unicode|regexp|number)|expecting unicode|octal literal|is reserved|directly after number/i.test(msg)) {
+          while (pos < input.length && !isSpace(input.charCodeAt(pos))) ++pos;
+        } else if (/character escape|expected hexadecimal/i.test(msg)) {
+          while (pos < input.length) {
+            var ch = input.charCodeAt(pos++);
+            if (ch === 34 || ch === 39 || isNewline(ch)) break;
+          }
+        } else if (/unexpected character/i.test(msg)) {
+          pos++;
+          replace = false;
+        } else if (/regular expression/i.test(msg)) {
+          replace = true;
+        } else {
+          throw e;
+        }
+        resetTo(pos);
+        if (replace === true) replace = {start: pos, end: pos, type: tt.name, value: "✖"};
+        if (replace) {
+          if (options.locations) {
+            replace.startLoc = acorn.getLineInfo(input, replace.start);
+            replace.endLoc = acorn.getLineInfo(input, replace.end);
+          }
+          return replace;
+        }
+      }
+    }
+  }
+
+  function resetTo(pos) {
+    for (;;) {
+      try {
+        var ch = input.charAt(pos - 1);
+        var reAllowed = !ch || /[\[\{\(,;:?\/*=+\-~!|&%^<>]/.test(ch) ||
+          /[enwfd]/.test(ch) && /\b(keywords|case|else|return|throw|new|in|(instance|type)of|delete|void)$/.test(input.slice(pos - 10, pos));
+        return fetchToken.jumpTo(pos, reAllowed);
+      } catch(e) {
+        if (!(e instanceof SyntaxError && /unterminated comment/i.test(e.message))) throw e;
+        pos = lineEnd(e.pos + 1);
+        if (pos >= input.length) return;
+      }
+    }
+  }
+
+  function lookAhead(n) {
+    while (n > ahead.length)
+      ahead.push(readToken());
+    return ahead[n-1];
+  }
+
+  var newline = /[\n\r\u2028\u2029]/;
+
+  function isNewline(ch) {
+    return ch === 10 || ch === 13 || ch === 8232 || ch === 8329;
+  }
+  function isSpace(ch) {
+    return (ch < 14 && ch > 8) || ch === 32 || ch === 160 || isNewline(ch);
+  }
+
+  function pushCx() {
+    context.push(curIndent);
+  }
+  function popCx() {
+    curIndent = context.pop();
+  }
+
+  function lineEnd(pos) {
+    while (pos < input.length && !isNewline(input.charCodeAt(pos))) ++pos;
+    return pos;
+  }
+  function indentationAfter(pos) {
+    for (var count = 0;; ++pos) {
+      var ch = input.charCodeAt(pos);
+      if (ch === 32) ++count;
+      else if (ch === 9) count += options.tabSize;
+      else return count;
+    }
+  }
+
+  function closes(closeTok, indent, line, blockHeuristic) {
+    if (token.type === closeTok || token.type === tt.eof) return true;
+    if (line != curLineStart && curIndent < indent && tokenStartsLine() &&
+        (!blockHeuristic || nextLineStart >= input.length ||
+         indentationAfter(nextLineStart) < indent)) return true;
+    return false;
+  }
+
+  function tokenStartsLine() {
+    for (var p = token.start - 1; p >= curLineStart; --p) {
+      var ch = input.charCodeAt(p);
+      if (ch !== 9 && ch !== 32) return false;
+    }
+    return true;
+  }
+
+  function Node(start) {
+    this.type = null;
+    this.start = start;
+    this.end = null;
+  }
+  Node.prototype = acorn.Node.prototype;
+
+  function SourceLocation(start) {
+    this.start = start || token.startLoc || {line: 1, column: 0};
+    this.end = null;
+    if (sourceFile !== null) this.source = sourceFile;
+  }
+
+  function startNode() {
+    var node = new Node(token.start);
+    if (options.locations)
+      node.loc = new SourceLocation();
+    if (options.directSourceFile)
+      node.sourceFile = options.directSourceFile;
+    if (options.ranges)
+      node.range = [token.start, 0];
+    return node;
+  }
+
+  function storeCurrentPos() {
+    return options.locations ? [token.start, token.startLoc] : token.start;
+  }
+
+  function startNodeAt(pos) {
+    var node;
+    if (options.locations) {
+      node = new Node(pos[0]);
+      node.loc = new SourceLocation(pos[1]);
+    } else {
+      node = new Node(pos);
+    }
+    if (options.directSourceFile)
+      node.sourceFile = options.directSourceFile;
+    if (options.ranges)
+      node.range = [pos[0], 0];
+    return node;
+  }
+
+  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;
+  }
+
+  function dummyIdent() {
+    var dummy = startNode();
+    dummy.name = "✖";
+    return finishNode(dummy, "Identifier");
+  }
+  function isDummy(node) { return node.name == "✖"; }
+
+  function eat(type) {
+    if (token.type === type) {
+      next();
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+  function canInsertSemicolon() {
+    return (token.type === tt.eof || token.type === tt.braceR || newline.test(input.slice(lastEnd, token.start)));
+  }
+  function semicolon() {
+    return eat(tt.semi);
+  }
+
+  function expect(type) {
+    if (eat(type)) return true;
+    if (lookAhead(1).type == type) {
+      next(); next();
+      return true;
+    }
+    if (lookAhead(2).type == type) {
+      next(); next(); next();
+      return true;
+    }
+  }
+
+  function checkLVal(expr) {
+    if (!expr) return expr;
+    switch (expr.type) {
+      case "Identifier":
+      case "MemberExpression":
+      case "ObjectPattern":
+      case "ArrayPattern":
+      case "SpreadElement":
+      case "AssignmentPattern":
+        return expr;
+
+      default:
+        return dummyIdent();
+    }
+  }
+
+  function parseTopLevel() {
+    var node = startNodeAt(options.locations ? [0, acorn.getLineInfo(input, 0)] : 0);
+    node.body = [];
+    while (token.type !== tt.eof) node.body.push(parseStatement());
+    lastEnd = token.end;
+    lastEndLoc = token.endLoc;
+    return finishNode(node, "Program");
+  }
+
+  function parseStatement() {
+    if (token.type === tt.slash || token.type === tt.assign && token.value === "/=")
+      next(true);
+
+    var starttype = token.type, node = startNode();
+
+    switch (starttype) {
+    case tt._break: case tt._continue:
+      next();
+      var isBreak = starttype === tt._break;
+      if (semicolon() || canInsertSemicolon()) {
+        node.label = null;
+      } else {
+        node.label = token.type === tt.name ? parseIdent() : null;
+        semicolon();
+      }
+      return finishNode(node, isBreak ? "BreakStatement" : "ContinueStatement");
+
+    case tt._debugger:
+      next();
+      semicolon();
+      return finishNode(node, "DebuggerStatement");
+
+    case tt._do:
+      next();
+      node.body = parseStatement();
+      node.test = eat(tt._while) ? parseParenExpression() : dummyIdent();
+      semicolon();
+      return finishNode(node, "DoWhileStatement");
+
+    case tt._for:
+      next();
+      pushCx();
+      expect(tt.parenL);
+      if (token.type === tt.semi) return parseFor(node, null);
+      if (token.type === tt._var || token.type === tt._let) {
+        var init = parseVar(true);
+        if (init.declarations.length === 1 && (token.type === tt._in || token.type === tt.name && token.value === "of")) {
+          return parseForIn(node, init);
+        }
+        return parseFor(node, init);
+      }
+      var init = parseExpression(false, true);
+      if (token.type === tt._in || token.type === tt.name && token.value === "of") {
+        return parseForIn(node, checkLVal(init));
+      }
+      return parseFor(node, init);
+
+    case tt._function:
+      next();
+      return parseFunction(node, true);
+
+    case tt._if:
+      next();
+      node.test = parseParenExpression();
+      node.consequent = parseStatement();
+      node.alternate = eat(tt._else) ? parseStatement() : null;
+      return finishNode(node, "IfStatement");
+
+    case tt._return:
+      next();
+      if (eat(tt.semi) || canInsertSemicolon()) node.argument = null;
+      else { node.argument = parseExpression(); semicolon(); }
+      return finishNode(node, "ReturnStatement");
+
+    case tt._switch:
+      var blockIndent = curIndent, line = curLineStart;
+      next();
+      node.discriminant = parseParenExpression();
+      node.cases = [];
+      pushCx();
+      expect(tt.braceL);
+
+      for (var cur; !closes(tt.braceR, blockIndent, line, true);) {
+        if (token.type === tt._case || token.type === tt._default) {
+          var isCase = token.type === tt._case;
+          if (cur) finishNode(cur, "SwitchCase");
+          node.cases.push(cur = startNode());
+          cur.consequent = [];
+          next();
+          if (isCase) cur.test = parseExpression();
+          else cur.test = null;
+          expect(tt.colon);
+        } else {
+          if (!cur) {
+            node.cases.push(cur = startNode());
+            cur.consequent = [];
+            cur.test = null;
+          }
+          cur.consequent.push(parseStatement());
+        }
+      }
+      if (cur) finishNode(cur, "SwitchCase");
+      popCx();
+      eat(tt.braceR);
+      return finishNode(node, "SwitchStatement");
+
+    case tt._throw:
+      next();
+      node.argument = parseExpression();
+      semicolon();
+      return finishNode(node, "ThrowStatement");
+
+    case tt._try:
+      next();
+      node.block = parseBlock();
+      node.handler = null;
+      if (token.type === tt._catch) {
+        var clause = startNode();
+        next();
+        expect(tt.parenL);
+        clause.param = parseIdent();
+        expect(tt.parenR);
+        clause.guard = null;
+        clause.body = parseBlock();
+        node.handler = finishNode(clause, "CatchClause");
+      }
+      node.finalizer = eat(tt._finally) ? parseBlock() : null;
+      if (!node.handler && !node.finalizer) return node.block;
+      return finishNode(node, "TryStatement");
+
+    case tt._var:
+    case tt._let:
+    case tt._const:
+      return parseVar();
+
+    case tt._while:
+      next();
+      node.test = parseParenExpression();
+      node.body = parseStatement();
+      return finishNode(node, "WhileStatement");
+
+    case tt._with:
+      next();
+      node.object = parseParenExpression();
+      node.body = parseStatement();
+      return finishNode(node, "WithStatement");
+
+    case tt.braceL:
+      return parseBlock();
+
+    case tt.semi:
+      next();
+      return finishNode(node, "EmptyStatement");
+
+    case tt._class:
+      return parseObj(true, true);
+
+    case tt._import:
+      return parseImport();
+
+    case tt._export:
+      return parseExport();
+
+    default:
+      var expr = parseExpression();
+      if (isDummy(expr)) {
+        next();
+        if (token.type === tt.eof) return finishNode(node, "EmptyStatement");
+        return parseStatement();
+      } else if (starttype === tt.name && expr.type === "Identifier" && eat(tt.colon)) {
+        node.body = parseStatement();
+        node.label = expr;
+        return finishNode(node, "LabeledStatement");
+      } else {
+        node.expression = expr;
+        semicolon();
+        return finishNode(node, "ExpressionStatement");
+      }
+    }
+  }
+
+  function parseBlock() {
+    var node = startNode();
+    pushCx();
+    expect(tt.braceL);
+    var blockIndent = curIndent, line = curLineStart;
+    node.body = [];
+    while (!closes(tt.braceR, blockIndent, line, true))
+      node.body.push(parseStatement());
+    popCx();
+    eat(tt.braceR);
+    return finishNode(node, "BlockStatement");
+  }
+
+  function parseFor(node, init) {
+    node.init = init;
+    node.test = node.update = null;
+    if (eat(tt.semi) && token.type !== tt.semi) node.test = parseExpression();
+    if (eat(tt.semi) && token.type !== tt.parenR) node.update = parseExpression();
+    popCx();
+    expect(tt.parenR);
+    node.body = parseStatement();
+    return finishNode(node, "ForStatement");
+  }
+
+  function parseForIn(node, init) {
+    var type = token.type === tt._in ? "ForInStatement" : "ForOfStatement";
+    next();
+    node.left = init;
+    node.right = parseExpression();
+    popCx();
+    expect(tt.parenR);
+    node.body = parseStatement();
+    return finishNode(node, type);
+  }
+
+  function parseVar(noIn) {
+    var node = startNode();
+    node.kind = token.type.keyword;
+    next();
+    node.declarations = [];
+    do {
+      var decl = startNode();
+      decl.id = options.ecmaVersion >= 6 ? toAssignable(parseExprAtom()) : parseIdent();
+      decl.init = eat(tt.eq) ? parseExpression(true, noIn) : null;
+      node.declarations.push(finishNode(decl, "VariableDeclarator"));
+    } while (eat(tt.comma));
+    if (!node.declarations.length) {
+      var decl = startNode();
+      decl.id = dummyIdent();
+      node.declarations.push(finishNode(decl, "VariableDeclarator"));
+    }
+    if (!noIn) semicolon();
+    return finishNode(node, "VariableDeclaration");
+  }
+
+  function parseExpression(noComma, noIn) {
+    var start = storeCurrentPos();
+    var expr = parseMaybeAssign(noIn);
+    if (!noComma && token.type === tt.comma) {
+      var node = startNodeAt(start);
+      node.expressions = [expr];
+      while (eat(tt.comma)) node.expressions.push(parseMaybeAssign(noIn));
+      return finishNode(node, "SequenceExpression");
+    }
+    return expr;
+  }
+
+  function parseParenExpression() {
+    pushCx();
+    expect(tt.parenL);
+    var val = parseExpression();
+    popCx();
+    expect(tt.parenR);
+    return val;
+  }
+
+  function parseMaybeAssign(noIn) {
+    var start = storeCurrentPos();
+    var left = parseMaybeConditional(noIn);
+    if (token.type.isAssign) {
+      var node = startNodeAt(start);
+      node.operator = token.value;
+      node.left = token.type === tt.eq ? toAssignable(left) : checkLVal(left);
+      next();
+      node.right = parseMaybeAssign(noIn);
+      return finishNode(node, "AssignmentExpression");
+    }
+    return left;
+  }
+
+  function parseMaybeConditional(noIn) {
+    var start = storeCurrentPos();
+    var expr = parseExprOps(noIn);
+    if (eat(tt.question)) {
+      var node = startNodeAt(start);
+      node.test = expr;
+      node.consequent = parseExpression(true);
+      node.alternate = expect(tt.colon) ? parseExpression(true, noIn) : dummyIdent();
+      return finishNode(node, "ConditionalExpression");
+    }
+    return expr;
+  }
+
+  function parseExprOps(noIn) {
+    var start = storeCurrentPos();
+    var indent = curIndent, line = curLineStart;
+    return parseExprOp(parseMaybeUnary(noIn), start, -1, noIn, indent, line);
+  }
+
+  function parseExprOp(left, start, minPrec, noIn, indent, line) {
+    if (curLineStart != line && curIndent < indent && tokenStartsLine()) return left;
+    var prec = token.type.binop;
+    if (prec != null && (!noIn || token.type !== tt._in)) {
+      if (prec > minPrec) {
+        var node = startNodeAt(start);
+        node.left = left;
+        node.operator = token.value;
+        next();
+        if (curLineStart != line && curIndent < indent && tokenStartsLine()) {
+          node.right = dummyIdent();
+        } else {
+          var rightStart = storeCurrentPos();
+          node.right = parseExprOp(parseMaybeUnary(noIn), rightStart, prec, noIn, indent, line);
+        }
+        finishNode(node, /&&|\|\|/.test(node.operator) ? "LogicalExpression" : "BinaryExpression");
+        return parseExprOp(node, start, minPrec, noIn, indent, line);
+      }
+    }
+    return left;
+  }
+
+  function parseMaybeUnary(noIn) {
+    if (token.type.prefix) {
+      var node = startNode(), update = token.type.isUpdate, nodeType;
+      if (token.type === tt.ellipsis) {
+        nodeType = "SpreadElement";
+      } else {
+        nodeType = update ? "UpdateExpression" : "UnaryExpression";
+        node.operator = token.value;
+        node.prefix = true;
+      }
+      node.operator = token.value;
+      node.prefix = true;
+      next();
+      node.argument = parseMaybeUnary(noIn);
+      if (update) node.argument = checkLVal(node.argument);
+      return finishNode(node, nodeType);
+    }
+    var start = storeCurrentPos();
+    var expr = parseExprSubscripts();
+    while (token.type.postfix && !canInsertSemicolon()) {
+      var node = startNodeAt(start);
+      node.operator = token.value;
+      node.prefix = false;
+      node.argument = checkLVal(expr);
+      next();
+      expr = finishNode(node, "UpdateExpression");
+    }
+    return expr;
+  }
+
+  function parseExprSubscripts() {
+    var start = storeCurrentPos();
+    return parseSubscripts(parseExprAtom(), start, false, curIndent, curLineStart);
+  }
+
+  function parseSubscripts(base, start, noCalls, startIndent, line) {
+    for (;;) {
+      if (curLineStart != line && curIndent <= startIndent && tokenStartsLine()) {
+        if (token.type == tt.dot && curIndent == startIndent)
+          --startIndent;
+        else
+          return base;
+      }
+
+      if (eat(tt.dot)) {
+        var node = startNodeAt(start);
+        node.object = base;
+        if (curLineStart != line && curIndent <= startIndent && tokenStartsLine())
+          node.property = dummyIdent();
+        else
+          node.property = parsePropertyAccessor() || dummyIdent();
+        node.computed = false;
+        base = finishNode(node, "MemberExpression");
+      } else if (token.type == tt.bracketL) {
+        pushCx();
+        next();
+        var node = startNodeAt(start);
+        node.object = base;
+        node.property = parseExpression();
+        node.computed = true;
+        popCx();
+        expect(tt.bracketR);
+        base = finishNode(node, "MemberExpression");
+      } else if (!noCalls && token.type == tt.parenL) {
+        pushCx();
+        var node = startNodeAt(start);
+        node.callee = base;
+        node.arguments = parseExprList(tt.parenR);
+        base = finishNode(node, "CallExpression");
+      } else if (token.type == tt.template) {
+        var node = startNodeAt(start);
+        node.tag = base;
+        node.quasi = parseTemplate();
+        base = finishNode(node, "TaggedTemplateExpression");
+      } else {
+        return base;
+      }
+    }
+  }
+
+  function parseExprAtom() {
+    switch (token.type) {
+    case tt._this:
+      var node = startNode();
+      next();
+      return finishNode(node, "ThisExpression");
+
+    case tt.name:
+      var start = storeCurrentPos();
+      var id = parseIdent();
+      return eat(tt.arrow) ? parseArrowExpression(startNodeAt(start), [id]) : id;
+
+    case tt.regexp:
+      var node = startNode();
+      var val = token.value;
+      node.regex = {pattern: val.pattern, flags: val.flags};
+      node.value = val.value;
+      node.raw = input.slice(token.start, token.end);
+      next();
+      return finishNode(node, "Literal");
+
+    case tt.num: case tt.string:
+      var node = startNode();
+      node.value = token.value;
+      node.raw = input.slice(token.start, token.end);
+      next();
+      return finishNode(node, "Literal");
+
+    case tt._null: case tt._true: case tt._false:
+      var node = startNode();
+      node.value = token.type.atomValue;
+      node.raw = token.type.keyword;
+      next();
+      return finishNode(node, "Literal");
+
+    case tt.parenL:
+      var start = storeCurrentPos();
+      next();
+      var val = parseExpression();
+      expect(tt.parenR);
+      if (eat(tt.arrow)) {
+        return parseArrowExpression(startNodeAt(start), val.expressions || (isDummy(val) ? [] : [val]));
+      }
+      if (options.preserveParens) {
+        var par = startNodeAt(start);
+        par.expression = val;
+        val = finishNode(par, "ParenthesizedExpression");
+      }
+      return val;
+
+    case tt.bracketL:
+      var node = startNode();
+      pushCx();
+      node.elements = parseExprList(tt.bracketR, true);
+      return finishNode(node, "ArrayExpression");
+
+    case tt.braceL:
+      return parseObj();
+
+    case tt._class:
+      return parseObj(true);
+
+    case tt._function:
+      var node = startNode();
+      next();
+      return parseFunction(node, false);
+
+    case tt._new:
+      return parseNew();
+
+    case tt._yield:
+      var node = startNode();
+      next();
+      if (semicolon() || canInsertSemicolon()) {
+        node.delegate = false;
+        node.argument = null;
+      } else {
+        node.delegate = eat(tt.star);
+        node.argument = parseExpression(true);
+      }
+      return finishNode(node, "YieldExpression");
+
+    case tt.template:
+      return parseTemplate();
+
+    default:
+      return dummyIdent();
+    }
+  }
+
+  function parseNew() {
+    var node = startNode(), startIndent = curIndent, line = curLineStart;
+    next();
+    var start = storeCurrentPos();
+    node.callee = parseSubscripts(parseExprAtom(), start, true, startIndent, line);
+    if (token.type == tt.parenL) {
+      pushCx();
+      node.arguments = parseExprList(tt.parenR);
+    } else {
+      node.arguments = [];
+    }
+    return finishNode(node, "NewExpression");
+  }
+
+  function parseTemplateElement() {
+    var elem = startNodeAt(options.locations ? [token.start + 1, token.startLoc.offset(1)] : token.start + 1);
+    elem.value = token.value;
+    elem.tail = input.charCodeAt(token.end - 1) !== 123; // '{'
+    var endOff = elem.tail ? 1 : 2;
+    var endPos = options.locations ? [token.end - endOff, token.endLoc.offset(-endOff)] : token.end - endOff;
+    next();
+    return finishNodeAt(elem, "TemplateElement", endPos);
+  }
+
+  function parseTemplate() {
+    var node = startNode();
+    node.expressions = [];
+    var curElt = parseTemplateElement();
+    node.quasis = [curElt];
+    while (!curElt.tail) {
+      var next = parseExpression();
+      if (isDummy(next)) {
+        node.quasis[node.quasis.length - 1].tail = true;
+        break;
+      }
+      node.expressions.push(next);
+      if (token.type === tt.templateContinued) {
+        node.quasis.push(curElt = parseTemplateElement());
+      } else {
+        curElt = startNode();
+        curElt.value = {cooked: "", raw: ""};
+        curElt.tail = true;
+        node.quasis.push(curElt);
+      }
+    }
+    return finishNode(node, "TemplateLiteral");
+  }
+
+  function parseObj(isClass, isStatement) {
+    var node = startNode();
+    if (isClass) {
+      next();
+      if (token.type === tt.name) node.id = parseIdent();
+      else if (isStatement) node.id = dummyIdent();
+      node.superClass = eat(tt._extends) ? parseExpression() : null;
+      node.body = startNode();
+      node.body.body = [];
+    } else {
+      node.properties = [];
+    }
+    pushCx();
+    var indent = curIndent + 1, line = curLineStart;
+    eat(tt.braceL);
+    if (curIndent + 1 < indent) { indent = curIndent; line = curLineStart; }
+    while (!closes(tt.braceR, indent, line)) {
+      var prop = startNode(), isGenerator;
+      if (options.ecmaVersion >= 6) {
+        if (isClass) {
+          prop['static'] = false;
+        } else {
+          prop.method = false;
+          prop.shorthand = false;
+        }
+        isGenerator = eat(tt.star);
+      }
+      parsePropertyName(prop);
+      if (isDummy(prop.key)) { if (isDummy(parseExpression(true))) next(); eat(tt.comma); continue; }
+      if (isClass) {
+        if (prop.key.type === "Identifier" && !prop.computed && prop.key.name === "static" &&
+            (token.type != tt.parenL && token.type != tt.braceL)) {
+          prop['static'] = true;
+          isGenerator = eat(tt.star);
+          parsePropertyName(prop);
+        } else {
+          prop['static'] = false;
+        }
+      }
+      if (!isClass && eat(tt.colon)) {
+        prop.kind = "init";
+        prop.value = parseExpression(true);
+      } else if (options.ecmaVersion >= 6 && (token.type === tt.parenL || token.type === tt.braceL)) {
+        if (isClass) {
+          prop.kind = "";
+        } else {
+          prop.kind = "init";
+          prop.method = true;
+        }
+        prop.value = parseMethod(isGenerator);
+      } else if (options.ecmaVersion >= 5 && prop.key.type === "Identifier" &&
+                 !prop.computed && (prop.key.name === "get" || prop.key.name === "set") &&
+                 (token.type != tt.comma && token.type != tt.braceR)) {
+        prop.kind = prop.key.name;
+        parsePropertyName(prop);
+        prop.value = parseMethod(false);
+      } else if (isClass) {
+        prop.kind = "";
+        prop.value = parseMethod(isGenerator);
+      } else {
+        prop.kind = "init";
+        prop.value = options.ecmaVersion >= 6 ? prop.key : dummyIdent();
+        prop.shorthand = true;
+      }
+
+      if (isClass) {
+        node.body.body.push(finishNode(prop, "MethodDefinition"));
+        semicolon();
+      } else {
+        node.properties.push(finishNode(prop, "Property"));
+        eat(tt.comma);
+      }
+    }
+    popCx();
+    if (!eat(tt.braceR)) {
+      // If there is no closing brace, make the node span to the start
+      // of the next token (this is useful for Tern)
+      lastEnd = token.start;
+      if (options.locations) lastEndLoc = token.startLoc;
+    }
+    if (isClass) {
+      semicolon();
+      finishNode(node.body, "ClassBody");
+      return finishNode(node, isStatement ? "ClassDeclaration" : "ClassExpression");
+    } else {
+      return finishNode(node, "ObjectExpression");
+    }
+  }
+
+  function parsePropertyName(prop) {
+    if (options.ecmaVersion >= 6) {
+      if (eat(tt.bracketL)) {
+        prop.computed = true;
+        prop.key = parseExpression();
+        expect(tt.bracketR);
+        return;
+      } else {
+        prop.computed = false;
+      }
+    }
+    var key = (token.type === tt.num || token.type === tt.string) ? parseExprAtom() : parseIdent();
+    prop.key = key || dummyIdent();
+  }
+
+  function parsePropertyAccessor() {
+    if (token.type === tt.name || token.type.keyword) return parseIdent();
+  }
+
+  function parseIdent() {
+    var node = startNode();
+    node.name = token.type === tt.name ? token.value : token.type.keyword;
+    next();
+    return finishNode(node, "Identifier");
+  }
+
+  function initFunction(node) {
+    node.id = null;
+    node.params = [];
+    if (options.ecmaVersion >= 6) {
+      node.defaults = [];
+      node.rest = null;
+      node.generator = false;
+      node.expression = false;
+    }
+  }
+
+  // Convert existing expression atom to assignable pattern
+  // if possible.
+
+  function toAssignable(node) {
+    if (options.ecmaVersion >= 6 && node) {
+      switch (node.type) {
+        case "ObjectExpression":
+          node.type = "ObjectPattern";
+          var props = node.properties;
+          for (var i = 0; i < props.length; i++) {
+            props[i].value = toAssignable(props[i].value);
+          }
+          break;
+
+        case "ArrayExpression":
+          node.type = "ArrayPattern";
+          var elms = node.elements;
+          for (var i = 0; i < elms.length; i++) {
+            elms[i] = toAssignable(elms[i]);
+          }
+          break;
+
+        case "SpreadElement":
+          node.argument = toAssignable(node.argument);
+          break;
+
+        case "AssignmentExpression":
+          node.type = "AssignmentPattern";
+          break;
+      }
+    }
+    return checkLVal(node);
+  }
+
+  function parseFunctionParams(node, params) {
+    var defaults = [], hasDefaults = false;
+
+    if (!params) {
+      pushCx();
+      params = parseExprList(tt.parenR);
+    }
+    for (var i = 0; i < params.length; i++) {
+      var param = params[i], defValue = null;
+      if (param.type === "AssignmentExpression") {
+        defValue = param.right;
+        param = param.left;
+      }
+      param = toAssignable(param);
+      if (param.type === "SpreadElement") {
+        param = param.argument;
+        if (i === params.length - 1) {
+          node.rest = param;
+          continue;
+        }
+      }
+      node.params.push(param);
+      defaults.push(defValue);
+      if (defValue) hasDefaults = true;
+    }
+
+    if (hasDefaults) node.defaults = defaults;
+  }
+
+  function parseFunction(node, isStatement) {
+    initFunction(node);
+    if (options.ecmaVersion >= 6) {
+      node.generator = eat(tt.star);
+    }
+    if (token.type === tt.name) node.id = parseIdent();
+    else if (isStatement) node.id = dummyIdent();
+    parseFunctionParams(node);
+    node.body = parseBlock();
+    return finishNode(node, isStatement ? "FunctionDeclaration" : "FunctionExpression");
+  }
+
+  function parseMethod(isGenerator) {
+    var node = startNode();
+    initFunction(node);
+    parseFunctionParams(node);
+    node.generator = isGenerator || false;
+    node.expression = options.ecmaVersion >= 6 && token.type !== tt.braceL;
+    node.body = node.expression ? parseExpression(true) : parseBlock();
+    return finishNode(node, "FunctionExpression");
+  }
+
+  function parseArrowExpression(node, params) {
+    initFunction(node);
+    parseFunctionParams(node, params);
+    node.expression = token.type !== tt.braceL;
+    node.body = node.expression ? parseExpression(true) : parseBlock();
+    return finishNode(node, "ArrowFunctionExpression");
+  }
+
+  function parseExport() {
+    var node = startNode();
+    next();
+    node['default'] = eat(tt._default);
+    node.specifiers = node.source = null;
+    if (node['default']) {
+      node.declaration = parseExpression();
+      semicolon();
+    } else if (token.type.keyword) {
+      node.declaration = parseStatement();
+    } else {
+      node.declaration = null;
+      parseSpecifierList(node, "Export");
+    }
+    semicolon();
+    return finishNode(node, "ExportDeclaration");
+  }
+
+  function parseImport() {
+    var node = startNode();
+    next();
+    if (token.type === tt.string) {
+      node.specifiers = [];
+      node.source = parseExprAtom();
+      node.kind = '';
+    } else {
+      if (token.type === tt.name && token.value !== "from") {
+        var elt = startNode();
+        elt.id = parseIdent();
+        elt.name = null;
+        elt['default'] = true;
+        finishNode(elt, "ImportSpecifier");
+        eat(tt.comma);
+      }
+      parseSpecifierList(node, "Import");
+      var specs = node.specifiers;
+      for (var i = 0; i < specs.length; i++) specs[i]['default'] = false;
+      if (elt) node.specifiers.unshift(elt);
+    }
+    semicolon();
+    return finishNode(node, "ImportDeclaration");
+  }
+
+  function parseSpecifierList(node, prefix) {
+    var elts = node.specifiers = [];
+    if (token.type === tt.star) {
+      var elt = startNode();
+      next();
+      if (token.type === tt.name && token.value === "as") {
+        next();
+        elt.name = parseIdent();
+      }
+      elts.push(finishNode(elt, prefix + "BatchSpecifier"));
+    } else {
+      var indent = curIndent, line = curLineStart, continuedLine = nextLineStart;
+      pushCx();
+      eat(tt.braceL);
+      if (curLineStart > continuedLine) continuedLine = curLineStart;
+      while (!closes(tt.braceR, indent + (curLineStart <= continuedLine ? 1 : 0), line)) {
+        var elt = startNode();
+        if (token.type === tt.star) {
+          next();
+          if (token.type === tt.name && token.value === "as") {
+            next();
+            elt.name = parseIdent();
+          }
+          finishNode(elt, prefix + "BatchSpecifier");
+        } else {
+          if (token.type === tt.name && token.value === "from") break;
+          elt.id = parseIdent();
+          if (token.type === tt.name && token.value === "as") {
+            next();
+            elt.name = parseIdent();
+          } else {
+            elt.name = null;
+          }
+          finishNode(elt, prefix + "Specifier");
+        }
+        elts.push(elt);
+        eat(tt.comma);
+      }
+      eat(tt.braceR);
+      popCx();
+    }
+    if (token.type === tt.name && token.value === "from") {
+      next();
+      node.source = parseExprAtom();
+    } else {
+      node.source = null;
+    }
+  }
+
+  function parseExprList(close, allowEmpty) {
+    var indent = curIndent, line = curLineStart, elts = [];
+    next(); // Opening bracket
+    while (!closes(close, indent + 1, line)) {
+      if (eat(tt.comma)) {
+        elts.push(allowEmpty ? null : dummyIdent());
+        continue;
+      }
+      var elt = parseExpression(true);
+      if (isDummy(elt)) {
+        if (closes(close, indent, line)) break;
+        next();
+      } else {
+        elts.push(elt);
+      }
+      eat(tt.comma);
+    }
+    popCx();
+    if (!eat(close)) {
+      // If there is no closing brace, make the node span to the start
+      // of the next token (this is useful for Tern)
+      lastEnd = token.start;
+      if (options.locations) lastEndLoc = token.startLoc;
+    }
+    return elts;
+  }
+});
diff --git a/bundles/org.eclipse.orion.client.javascript/web/acorn/util/walk.js b/bundles/org.eclipse.orion.client.javascript/web/acorn/util/walk.js
new file mode 100644
index 0000000..117f56f
--- /dev/null
+++ b/bundles/org.eclipse.orion.client.javascript/web/acorn/util/walk.js
@@ -0,0 +1,351 @@
+// AST walker module for Mozilla Parser API compatible trees
+
+(function(mod) {
+  if (typeof exports == "object" && typeof module == "object") return mod(exports); // CommonJS
+  if (typeof define == "function" && define.amd) return define(["exports"], mod); // AMD
+  mod((this.acorn || (this.acorn = {})).walk = {}); // Plain browser env
+})(function(exports) {
+  "use strict";
+
+  // A simple walk is one where you simply specify callbacks to be
+  // called on specific nodes. The last two arguments are optional. A
+  // simple use would be
+  //
+  //     walk.simple(myTree, {
+  //         Expression: function(node) { ... }
+  //     });
+  //
+  // to do something with all expressions. All Parser API node types
+  // can be used to identify node types, as well as Expression,
+  // Statement, and ScopeBody, which denote categories of nodes.
+  //
+  // The base argument can be used to pass a custom (recursive)
+  // walker, and state can be used to give this walked an initial
+  // state.
+  exports.simple = function(node, visitors, base, state) {
+    if (!base) base = exports.base;
+    function c(node, st, override) {
+      var type = override || node.type, found = visitors[type];
+      base[type](node, st, c);
+      if (found) found(node, st);
+    }
+    c(node, state);
+  };
+
+  // An ancestor walk builds up an array of ancestor nodes (including
+  // the current node) and passes them to the callback as the state parameter.
+  exports.ancestor = function(node, visitors, base, state) {
+    if (!base) base = exports.base;
+    if (!state) state = [];
+    function c(node, st, override) {
+      var type = override || node.type, found = visitors[type];
+      if (node != st[st.length - 1]) {
+        st = st.slice();
+        st.push(node);
+      }
+      base[type](node, st, c);
+      if (found) found(node, st);
+    }
+    c(node, state);
+  };
+
+  // A recursive walk is one where your functions override the default
+  // walkers. They can modify and replace the state parameter that's
+  // threaded through the walk, and can opt how and whether to walk
+  // their child nodes (by calling their third argument on these
+  // nodes).
+  exports.recursive = function(node, state, funcs, base) {
+    var visitor = funcs ? exports.make(funcs, base) : base;
+    function c(node, st, override) {
+      visitor[override || node.type](node, st, c);
+    }
+    c(node, state);
+  };
+
+  function makeTest(test) {
+    if (typeof test == "string")
+      return function(type) { return type == test; };
+    else if (!test)
+      return function() { return true; };
+    else
+      return test;
+  }
+
+  function Found(node, state) { this.node = node; this.state = state; }
+
+  // Find a node with a given start, end, and type (all are optional,
+  // null can be used as wildcard). Returns a {node, state} object, or
+  // undefined when it doesn't find a matching node.
+  exports.findNodeAt = function(node, start, end, test, base, state) {
+    test = makeTest(test);
+    try {
+      if (!base) base = exports.base;
+      var c = function(node, st, override) {
+        var type = override || node.type;
+        if ((start == null || node.start <= start) &&
+            (end == null || node.end >= end))
+          base[type](node, st, c);
+        if (test(type, node) &&
+            (start == null || node.start == start) &&
+            (end == null || node.end == end))
+          throw new Found(node, st);
+      };
+      c(node, state);
+    } catch (e) {
+      if (e instanceof Found) return e;
+      throw e;
+    }
+  };
+
+  // Find the innermost node of a given type that contains the given
+  // position. Interface similar to findNodeAt.
+  exports.findNodeAround = function(node, pos, test, base, state) {
+    test = makeTest(test);
+    try {
+      if (!base) base = exports.base;
+      var c = function(node, st, override) {
+        var type = override || node.type;
+        if (node.start > pos || node.end < pos) return;
+        base[type](node, st, c);
+        if (test(type, node)) throw new Found(node, st);
+      };
+      c(node, state);
+    } catch (e) {
+      if (e instanceof Found) return e;
+      throw e;
+    }
+  };
+
+  // Find the outermost matching node after a given position.
+  exports.findNodeAfter = function(node, pos, test, base, state) {
+    test = makeTest(test);
+    try {
+      if (!base) base = exports.base;
+      var c = function(node, st, override) {
+        if (node.end < pos) return;
+        var type = override || node.type;
+        if (node.start >= pos && test(type, node)) throw new Found(node, st);
+        base[type](node, st, c);
+      };
+      c(node, state);
+    } catch (e) {
+      if (e instanceof Found) return e;
+      throw e;
+    }
+  };
+
+  // Find the outermost matching node before a given position.
+  exports.findNodeBefore = function(node, pos, test, base, state) {
+    test = makeTest(test);
+    if (!base) base = exports.base;
+    var max;
+    var c = function(node, st, override) {
+      if (node.start > pos) return;
+      var type = override || node.type;
+      if (node.end <= pos && (!max || max.node.end < node.end) && test(type, node))
+        max = new Found(node, st);
+      base[type](node, st, c);
+    };
+    c(node, state);
+    return max;
+  };
+
+  // Used to create a custom walker. Will fill in all missing node
+  // type properties with the defaults.
+  exports.make = function(funcs, base) {
+    if (!base) base = exports.base;
+    var visitor = {};
+    for (var type in base) visitor[type] = base[type];
+    for (var type in funcs) visitor[type] = funcs[type];
+    return visitor;
+  };
+
+  function skipThrough(node, st, c) { c(node, st); }
+  function ignore(_node, _st, _c) {}
+
+  // Node walkers.
+
+  var base = exports.base = {};
+  base.Program = base.BlockStatement = function(node, st, c) {
+    for (var i = 0; i < node.body.length; ++i)
+      c(node.body[i], st, "Statement");
+  };
+  base.Statement = skipThrough;
+  base.EmptyStatement = ignore;
+  base.ExpressionStatement = function(node, st, c) {
+    c(node.expression, st, "Expression");
+  };
+  base.IfStatement = function(node, st, c) {
+    c(node.test, st, "Expression");
+    c(node.consequent, st, "Statement");
+    if (node.alternate) c(node.alternate, st, "Statement");
+  };
+  base.LabeledStatement = function(node, st, c) {
+    c(node.body, st, "Statement");
+  };
+  base.BreakStatement = base.ContinueStatement = ignore;
+  base.WithStatement = function(node, st, c) {
+    c(node.object, st, "Expression");
+    c(node.body, st, "Statement");
+  };
+  base.SwitchStatement = function(node, st, c) {
+    c(node.discriminant, st, "Expression");
+    for (var i = 0; i < node.cases.length; ++i) {
+      var cs = node.cases[i];
+      if (cs.test) c(cs.test, st, "Expression");
+      for (var j = 0; j < cs.consequent.length; ++j)
+        c(cs.consequent[j], st, "Statement");
+    }
+  };
+  base.ReturnStatement = base.YieldExpression = function(node, st, c) {
+    if (node.argument) c(node.argument, st, "Expression");
+  };
+  base.ThrowStatement = base.SpreadElement = function(node, st, c) {
+    c(node.argument, st, "Expression");
+  };
+  base.TryStatement = function(node, st, c) {
+    c(node.block, st, "Statement");
+    if (node.handler) c(node.handler.body, st, "ScopeBody");
+    if (node.finalizer) c(node.finalizer, st, "Statement");
+  };
+  base.WhileStatement = function(node, st, c) {
+    c(node.test, st, "Expression");
+    c(node.body, st, "Statement");
+  };
+  base.DoWhileStatement = base.WhileStatement;
+  base.ForStatement = function(node, st, c) {
+    if (node.init) c(node.init, st, "ForInit");
+    if (node.test) c(node.test, st, "Expression");
+    if (node.update) c(node.update, st, "Expression");
+    c(node.body, st, "Statement");
+  };
+  base.ForInStatement = base.ForOfStatement = function(node, st, c) {
+    c(node.left, st, "ForInit");
+    c(node.right, st, "Expression");
+    c(node.body, st, "Statement");
+  };
+  base.ForInit = function(node, st, c) {
+    if (node.type == "VariableDeclaration") c(node, st);
+    else c(node, st, "Expression");
+  };
+  base.DebuggerStatement = ignore;
+
+  base.FunctionDeclaration = function(node, st, c) {
+    c(node, st, "Function");
+  };
+  base.VariableDeclaration = function(node, st, c) {
+    for (var i = 0; i < node.declarations.length; ++i) {
+      var decl = node.declarations[i];
+      if (decl.init) c(decl.init, st, "Expression");
+    }
+  };
+
+  base.Function = function(node, st, c) {
+    c(node.body, st, "ScopeBody");
+  };
+  base.ScopeBody = function(node, st, c) {
+    c(node, st, "Statement");
+  };
+
+  base.Expression = skipThrough;
+  base.ThisExpression = ignore;
+  base.ArrayExpression = function(node, st, c) {
+    for (var i = 0; i < node.elements.length; ++i) {
+      var elt = node.elements[i];
+      if (elt) c(elt, st, "Expression");
+    }
+  };
+  base.ObjectExpression = function(node, st, c) {
+    for (var i = 0; i < node.properties.length; ++i)
+      c(node.properties[i], st);
+  };
+  base.FunctionExpression = base.ArrowFunctionExpression = base.FunctionDeclaration;
+  base.SequenceExpression = base.TemplateLiteral = function(node, st, c) {
+    for (var i = 0; i < node.expressions.length; ++i)
+      c(node.expressions[i], st, "Expression");
+  };
+  base.UnaryExpression = base.UpdateExpression = function(node, st, c) {
+    c(node.argument, st, "Expression");
+  };
+  base.BinaryExpression = base.AssignmentExpression = base.LogicalExpression = function(node, st, c) {
+    c(node.left, st, "Expression");
+    c(node.right, st, "Expression");
+  };
+  base.ConditionalExpression = function(node, st, c) {
+    c(node.test, st, "Expression");
+    c(node.consequent, st, "Expression");
+    c(node.alternate, st, "Expression");
+  };
+  base.NewExpression = base.CallExpression = function(node, st, c) {
+    c(node.callee, st, "Expression");
+    if (node.arguments) for (var i = 0; i < node.arguments.length; ++i)
+      c(node.arguments[i], st, "Expression");
+  };
+  base.MemberExpression = function(node, st, c) {
+    c(node.object, st, "Expression");
+    if (node.computed) c(node.property, st, "Expression");
+  };
+  base.Identifier = base.Literal = base.ExportDeclaration = base.ImportDeclaration = ignore;
+
+  base.TaggedTemplateExpression = function(node, st, c) {
+    c(node.tag, st, "Expression");
+    c(node.quasi, st);
+  };
+  base.ClassDeclaration = base.ClassExpression = function(node, st, c) {
+    if (node.superClass) c(node.superClass, st, "Expression");
+    for (var i = 0; i < node.body.body.length; i++)
+      c(node.body.body[i], st);
+  };
+  base.MethodDefinition = base.Property = function(node, st, c) {
+    if (node.computed) c(node.key, st, "Expression");
+    c(node.value, st, "Expression");
+  };
+  base.ComprehensionExpression = function(node, st, c) {
+    for (var i = 0; i < node.blocks.length; i++)
+      c(node.blocks[i].right, st, "Expression");
+    c(node.body, st, "Expression");
+  };
+
+  // NOTE: the stuff below is deprecated, and will be removed when 1.0 is released
+
+  // A custom walker that keeps track of the scope chain and the
+  // variables defined in it.
+  function makeScope(prev, isCatch) {
+    return {vars: Object.create(null), prev: prev, isCatch: isCatch};
+  }
+  function normalScope(scope) {
+    while (scope.isCatch) scope = scope.prev;
+    return scope;
+  }
+  exports.scopeVisitor = exports.make({
+    Function: function(node, scope, c) {
+      var inner = makeScope(scope);
+      for (var i = 0; i < node.params.length; ++i)
+        inner.vars[node.params[i].name] = {type: "argument", node: node.params[i]};
+      if (node.id) {
+        var decl = node.type == "FunctionDeclaration";
+        (decl ? normalScope(scope) : inner).vars[node.id.name] =
+          {type: decl ? "function" : "function name", node: node.id};
+      }
+      c(node.body, inner, "ScopeBody");
+    },
+    TryStatement: function(node, scope, c) {
+      c(node.block, scope, "Statement");
+      if (node.handler) {
+        var inner = makeScope(scope, true);
+        inner.vars[node.handler.param.name] = {type: "catch clause", node: node.handler.param};
+        c(node.handler.body, inner, "ScopeBody");
+      }
+      if (node.finalizer) c(node.finalizer, scope, "Statement");
+    },
+    VariableDeclaration: function(node, scope, c) {
+      var target = normalScope(scope);
+      for (var i = 0; i < node.declarations.length; ++i) {
+        var decl = node.declarations[i];
+        target.vars[decl.id.name] = {type: "var", node: decl.id};
+        if (decl.init) c(decl.init, scope, "Expression");
+      }
+    }
+  });
+
+});
diff --git a/bundles/org.eclipse.orion.client.javascript/web/eslint/lib/load-rules-async.js b/bundles/org.eclipse.orion.client.javascript/web/eslint/lib/load-rules-async.js
index 13c961b..cd23bd5 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/eslint/lib/load-rules-async.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/eslint/lib/load-rules-async.js
@@ -18,8 +18,9 @@
 'logger',
 'javascript/finder',
 'estraverse',
+'acorn/acorn',
 'orion/editor/stylers/application_javascript/syntax'
-], function(util, Logger, Finder, Estraverse, JsSyntax) {
+], function(util, Logger, Finder, Estraverse, Acorn, JsSyntax) {
 	
     var rules = {
         "curly" : {
@@ -186,7 +187,7 @@
         						var tokens = context.getTokens(node.callee, 0, 1);
         						if(tokens && tokens.length > 0) {
         							var last = tokens[tokens.length-1];
-        							if(last.type !== 'Punctuator' || last.value !== '(') {
+        							if(/*last.value !== '('*/last.type !== Acorn.tokTypes.parenL) {
         								//if there s no opening parenthesis its safe to assume they are missing
         								context.report(node.callee, 'Missing parentheses invoking constructor.', null, tokens[0]);
         							}
@@ -488,7 +489,7 @@
         				try {
         					var tokens = context.getTokens(node);
         					var t = tokens[tokens.length - 1];
-        					if (t && t.type === "Punctuator" && t.value === ";") {  //$NON-NLS-0$  //$NON-NLS-1$
+        					if (t && /*t.value === ";"*/ t.type === Acorn.tokTypes.semi) {  //$NON-NLS-0$  //$NON-NLS-1$
         						context.report(node, "Unnecessary semicolon.", null, t /* expose the bad token */);
         					}
         				}
@@ -1111,7 +1112,7 @@
         				var tokens = context.getTokens(node);
         				var len = tokens.length;
         				var t = tokens[len - 1];
-        				if (t && t.type === "Punctuator" && t.value === ";") {  //$NON-NLS-0$  //$NON-NLS-1$
+        				if (t &&  t.type === Acorn.tokTypes.semi) {
         					return;
         				}
         				context.report(node, "Missing semicolon.", null, t /* expose the bad token */);
diff --git a/bundles/org.eclipse.orion.client.javascript/web/javascript/astManager.js b/bundles/org.eclipse.orion.client.javascript/web/javascript/astManager.js
index 376c0a1..664f034 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/javascript/astManager.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/javascript/astManager.js
@@ -13,9 +13,10 @@
 define([
 	'orion/Deferred',
 	'orion/objects',
-	'orion/serialize',
-	'javascript/lru'
-], function(Deferred, Objects, Serialize, LRU) {
+	'orion/serialize', 
+	'javascript/lru',
+	'estraverse'
+], function(Deferred, Objects, Serialize, LRU, Estraverse) {
 	/**
 	 * @description Object of error types
 	 * @since 5.0
@@ -41,7 +42,7 @@
 		this.parser = esprima;
 		this.cache = new LRU.LRU(10);
 		if (!this.parser) {
-			throw new Error("Missing parser");
+			throw new Error("Missing parser"); 
 		}
 	}
 	
@@ -91,13 +92,14 @@
 		 * @returns {Object} The AST.
 		 */
 		parse: function(text) {
+		    var tokens = [];
+		    var comments = [];
 			try {
-				var ast = this.parser.parse(text, {
-					range: true,
-					loc: true,
-					tolerant: true,
-					tokens: true,
-					attachComment: true
+				var ast = this.parser.parse_dammit(text, {
+					ranges: true,
+					locations: true,
+					onToken: tokens,
+					onComment: comments,
 				});
 			} catch (e) {
 				// The "tolerant" Esprima sometimes blows up from parse errors in initial statements of code.
@@ -110,6 +112,9 @@
 				ast.errors = ast.errors.map(Serialize.serializeError);
 			}
 			ast.source = text;
+			ast.comments = comments;
+			ast.tokens = tokens;
+			Estraverse.attachComments(ast, comments, tokens);
 			return ast;
 		},
 		/**
diff --git a/bundles/org.eclipse.orion.client.javascript/web/javascript/finder.js b/bundles/org.eclipse.orion.client.javascript/web/javascript/finder.js
index 6c313b5..13c7639 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/javascript/finder.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/javascript/finder.js
@@ -13,8 +13,9 @@
 define([
 'estraverse',
 'orion/objects',
-'eslint/conf/environments'
-], function(Estraverse, Objects, ESlintEnv) {
+'eslint/conf/environments',
+'acorn/acorn'
+], function(Estraverse, Objects, ESlintEnv, Acorn) {
 
 	/**
 	 * @name javascript.Visitor
@@ -597,12 +598,17 @@
 					idx = 0;
 					token = tokens[0];
 				if(offset >= token.range[0] && offset < token.range[1]) {
-					token.index = offset;
+					token.index = 0;
 					return token;
 				}
 				token = tokens[max];
 				if(offset >= token.range[0]) {
-					token.index = max;
+				    if(token.type === Acorn.tokTypes.eof) {
+				        token = tokens[max-1];
+				        token.index = max-1;
+				    } else {
+					   token.index = max;
+					}
 					return token;
 				}
 				token = null;
@@ -943,7 +949,8 @@
 			if(ast.tokens && ast.tokens.length > 0) {
 				var token = this.findToken(offset, ast.tokens);
 				if(token) {
-					if(token.type === 'Punctuator') {  //$NON-NLS-0$
+				    //Acorn's punctuator tokens have a type.type property
+					if(/*token.type === 'Punctuator'*/token.type && token.type.type) {  //$NON-NLS-0$
 						var index = token.index;
 						//only check back if we are at the start of the punctuator i.e. here -> {
 						if(offset === token.range[0] && index != null && index > 0) {
@@ -956,7 +963,8 @@
 							}
 						}
 					}
-					if(token.type === 'Identifier' || (token.type === 'Keyword' && token.value === 'this')) { //$NON-NLS-0$  //$NON-NLS-1$  //$NON-NLS-2$
+					/*if(token.type === 'Identifier' || (token.type === 'Keyword' && token.value === 'this')) { //$NON-NLS-0$  //$NON-NLS-1$  //$NON-NLS-2$*/
+					if(token.type === Acorn.tokTypes.name || (token.type === Acorn.tokTypes._this && token.value === 'this')) {
 						return token;
 					}
 				}
diff --git a/bundles/org.eclipse.orion.client.javascript/web/javascript/plugins/javascriptPlugin.js b/bundles/org.eclipse.orion.client.javascript/web/javascript/plugins/javascriptPlugin.js
index 37058c7..a0440b9 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/javascript/plugins/javascriptPlugin.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/javascript/plugins/javascriptPlugin.js
@@ -16,7 +16,7 @@
  */
 define([
 'orion/bootstrap',
-'esprima',
+'acorn/acorn_loose',
 'javascript/scriptResolver',
 'javascript/astManager',
 'javascript/quickFixes',
diff --git a/bundles/org.eclipse.orion.client.javascript/web/javascript/quickFixes.js b/bundles/org.eclipse.orion.client.javascript/web/javascript/quickFixes.js
index cbdb743..b983489 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/javascript/quickFixes.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/javascript/quickFixes.js
@@ -16,7 +16,8 @@
 'orion/Deferred',
 'orion/editor/textModel',
 'javascript/finder',
-], function(Objects, Deferred, TextModel, Finder) {
+'acorn/acorn'
+], function(Objects, Deferred, TextModel, Finder, Acorn) {
 	
 	/**
 	 * @description Creates a new JavaScript quick fix computer
@@ -242,7 +243,7 @@
                     var item = node.elements[idx];
                     if(item === null) {
                         var end = Finder.findToken(node.range[1], ast.tokens);
-                        if(end.value === ';') {
+                        if(end.type === Acorn.tokTypes.semi) {
                             end = ast.tokens[end.index-1];
                         }
                         //wipe all trailing entries first using the ']' token start as the end
diff --git a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/contentAssistTests.js b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/contentAssistTests.js
index 5add851..81528ee 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/contentAssistTests.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/contentAssistTests.js
@@ -17,10 +17,11 @@
 	'chai/chai',
 	'orion/objects',
 	'orion/Deferred',
-	'esprima',
+	'acorn/acorn_loose',
+	'estraverse',
 	'mocha/mocha', //mjust stay at the end, not a module
 	'doctrine' //must stay at the end, does not export a module 
-], function(ContentAssist, chai, objects, Deferred, Esprima) {
+], function(ContentAssist, chai, objects, Deferred, Acorn, Estraverse) {
 	var assert = chai.assert;
 
 	describe('Content Assist Tests', function() {
@@ -29,13 +30,18 @@
 		 * @returns {Object} The AST
 		 */
 		function parseFull(contents) {
-			var ast = Esprima.parse(contents, {
-						range: true,
-						tolerant: true,
-						comment: true,
-						tokens: true
+		    var tokens = [];
+		    var comments = [];
+			var ast = Acorn.parse_dammit(contents, {
+						ranges: true,
+					    locations: true,
+					    onToken: tokens,
+					    onComment: comments,
 					});
 			ast.source = contents;
+			ast.comments = comments;
+			ast.tokens = tokens;
+			Estraverse.attachComments(ast, comments, tokens);
 			return ast;
 		}
 	
diff --git a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/finderTests.js b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/finderTests.js
index 8089332..ac752c2 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/finderTests.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/finderTests.js
@@ -11,16 +11,17 @@
 /*eslint-env amd, node, mocha*/
 define([
 	'chai/chai',
-	'esprima',
+	'acorn/acorn_loose',
+	'acorn/acorn',
 	'javascript/finder',
 	'javascript/astManager',
 	'orion/Deferred',
 	'mocha/mocha' // not a module, leave it at the end
-], function(chai, Esprima, Finder, ASTManager, Deferred) {
+], function(chai, AcornLoose, Acorn, Finder, ASTManager, Deferred) {
 	var assert = chai.assert;
 
 	describe('Finder Tests', function() {
-		var astManager = new ASTManager.ASTManager(Esprima);
+		var astManager = new ASTManager.ASTManager(AcornLoose);
 		var editorContext = {
 			text: "",
 			/**
@@ -388,8 +389,8 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Punctuator', 'Should have found a Punctuator token');
-						assert.equal(token.value, '(', 'Should have found a ( token');
+						assert.equal(token.type, Acorn.tokTypes.parenL, 'Should have found a Punctuator token');
+						assert.equal(token.type.type, '(', 'Should have found a ( token');
 					}
 				}
 				finally {
@@ -411,7 +412,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Keyword', 'Should have found a Keyword token');
+						assert.equal(token.type, Acorn.tokTypes._function, 'Should have found a Keyword token');
 						assert.equal(token.value, 'function', 'Should have found a function token');
 					}
 				}
@@ -434,8 +435,8 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Punctuator', 'Should have found a Punctuator token');
-						assert.equal(token.value, '}', 'Should have found a } token');
+						assert.equal(token.type, Acorn.tokTypes.braceR, 'Should have found a Punctuator token');
+						assert.equal(token.type.type, '}', 'Should have found a } token');
 					}
 				}
 				finally {
@@ -457,7 +458,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Keyword', 'Should have found a Keyword token');
+						assert.equal(token.type, Acorn.tokTypes._var, 'Should have found a Keyword token');
 						assert.equal(token.value, 'var', 'Should have found a var token');
 					}
 				}
@@ -480,7 +481,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Punctuator', 'Should have found a Punctuator token');
+						assert.equal(token.type, Acorn.tokTypes.slash, 'Should have found a Punctuator token');
 						assert.equal(token.value, '/', 'Should have found a / token');
 					}
 				}
@@ -503,7 +504,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Keyword', 'Should have found a Keyword token');
+						assert.equal(token.type, Acorn.tokTypes._var, 'Should have found a Keyword token');
 						assert.equal(token.value, 'var', 'Should have found a var token');
 					}
 				}
@@ -526,7 +527,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Keyword', 'Should have found a Keyword token');
+						assert.equal(token.type, Acorn.tokTypes._function, 'Should have found a Keyword token');
 						assert.equal(token.value, 'function', 'Should have found a function token');
 					}
 				}
@@ -549,7 +550,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Keyword', 'Should have found a Keyword token');
+						assert.equal(token.type, Acorn.tokTypes._function, 'Should have found a Keyword token');
 						assert.equal(token.value, 'function', 'Should have found a function token');
 					}
 				}
@@ -589,7 +590,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Identifier', 'Should have found an Identifier token');
+						assert.equal(token.type, Acorn.tokTypes.name, 'Should have found an Identifier token');
 						assert.equal(token.value, 'f', 'Should have found a f token');
 					}
 				}
@@ -612,7 +613,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Punctuator', 'Should have found an Punctuator token');
+						assert.equal(token.type, Acorn.tokTypes.assign, 'Should have found an Punctuator token');
 						assert.equal(token.value, '=', 'Should have found a = token');
 					}
 				}
@@ -635,7 +636,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Identifier', 'Should have found an Identifier token');
+						assert.equal(token.type, Acorn.tokTypes.name, 'Should have found an Identifier token');
 						assert.equal(token.value, 'f', 'Should have found a f token');
 					}
 				}
@@ -658,7 +659,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Keyword', 'Should have found an Keyword token');
+						assert.equal(token.type, Acorn.tokTypes._function, 'Should have found an Keyword token');
 						assert.equal(token.value, 'function', 'Should have found a function token');
 					}
 				}
@@ -681,7 +682,7 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Keyword', 'Should have found an Keyword token');
+						assert.equal(token.type, Acorn.tokTypes._function, 'Should have found an Keyword token');
 						assert.equal(token.value, 'function', 'Should have found a function token');
 					}
 				}
@@ -704,8 +705,8 @@
 						assert.fail("Should have found a token");
 					}
 					else {
-						assert.equal(token.type, 'Punctuator', 'Should have found an Punctuator token');
-						assert.equal(token.value, ')', 'Should have found a ) token');
+						assert.equal(token.type, Acorn.tokTypes.parenR, 'Should have found an Punctuator token');
+						assert.equal(token.type.type, ')', 'Should have found a ) token');
 					}
 				}
 				finally {
@@ -846,7 +847,7 @@
 						assert.fail('Should have found a token');
 					}
 					else {
-						assert.equal(token.type, 'Identifier', 'Should have found an Identifier token');
+						assert.equal(token.type, Acorn.tokTypes.name, 'Should have found an Identifier token');
 						assert.equal(token.value, 'foo', 'Should have found a foo token');
 					}
 				}
diff --git a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/occurrencesTests.js b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/occurrencesTests.js
index 029ac23..c017c0d 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/occurrencesTests.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/occurrencesTests.js
@@ -11,16 +11,16 @@
 /*eslint-env amd, node, mocha*/
 define([
 	'chai/chai',
-	'esprima',
+	'acorn/acorn_loose',
 	'javascript/astManager',
 	'orion/Deferred',
 	'javascript/occurrences',
 	'mocha/mocha'  //must stay at the end, not a module
-], function(chai, Esprima, ASTManager, Deferred, Occurrences) {
+], function(chai, Acorn, ASTManager, Deferred, Occurrences) {
 	var assert = chai.assert;
 	
 	describe('Occurrences Tests', function() {
-		var astManager = new ASTManager.ASTManager(Esprima);
+		var astManager = new ASTManager.ASTManager(Acorn);
 		var occurrences = new Occurrences.JavaScriptOccurrences(astManager);
 		var editorContext = {
 			text: "",
diff --git a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/openDeclarationTests.js b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/openDeclarationTests.js
index 7926a85..8c946ec 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/openDeclarationTests.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/openDeclarationTests.js
@@ -15,16 +15,16 @@
 	'javascript/finder',
 	'chai/chai',
 	'orion/Deferred',
-	'esprima',
+	'acorn/acorn_loose',
 	'javascript/astManager',
 	'mocha/mocha', //must stay at the end, not a module
-], function(Finder, chai, Deferred, Esprima, ASTManager) {
+], function(Finder, chai, Deferred, Acorn, ASTManager) {
 	
 	var assert = chai.assert;
 
 	describe('Open Declaration Tests', function() {
 		
-		var astManager = new ASTManager.ASTManager(Esprima);
+		var astManager = new ASTManager.ASTManager(Acorn);
 		var editorContext = {
 			text: "",
 			/**
diff --git a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/outlinerTests.js b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/outlinerTests.js
index ee9af72..078b9a9 100644
--- a/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/outlinerTests.js
+++ b/bundles/org.eclipse.orion.client.javascript/web/js-tests/javascript/outlinerTests.js
@@ -11,17 +11,17 @@
 /*eslint-env amd, node, mocha*/
 define([
 	'chai/chai',
-	'esprima',
+	'acorn/acorn_loose',
 	'javascript/astManager',
 	'orion/Deferred',
 	'javascript/outliner',
 	'mocha/mocha' //not a module, leave it at the end
-], function(chai, Esprima, ASTManager, Deferred, Outliner) {
+], function(chai, Acorn, ASTManager, Deferred, Outliner) {
 	
 	var assert = chai.assert;	
 
 	describe('Outliner Tests', function() {
-		var astManager = new ASTManager.ASTManager(Esprima);
+		var astManager = new ASTManager.ASTManager(Acorn);
 		var outliner = new Outliner.JSOutliner(astManager);
 		var context = {
 			text: "",