From 3645173678ed16a68beffaa000275507a3f0bae2 Mon Sep 17 00:00:00 2001
From: nightwing <amirjanyan@gmail.com>
Date: Mon, 8 Feb 2016 11:31:35 +0400
Subject: [PATCH 1/4] update treehugger

---
 .../treehugger/lib/acorn/dist/acorn.js        | 194 +++++++++---------
 .../treehugger/lib/acorn/dist/acorn_loose.js  |  51 +++--
 node_modules/treehugger/lib/demo.js           |  42 ++--
 .../treehugger/lib/treehugger/js/parse.js     |   2 +-
 4 files changed, 157 insertions(+), 132 deletions(-)

diff --git a/node_modules/treehugger/lib/acorn/dist/acorn.js b/node_modules/treehugger/lib/acorn/dist/acorn.js
index 61d3c3ca..5bc12693 100644
--- a/node_modules/treehugger/lib/acorn/dist/acorn.js
+++ b/node_modules/treehugger/lib/acorn/dist/acorn.js
@@ -47,7 +47,7 @@ pp.checkPropClash = function (prop, propHash) {
 
   if (this.options.ecmaVersion >= 6) {
     if (name === "__proto__" && kind === "init") {
-      if (propHash.proto) this.raise(key.start, "Redefinition of __proto__ property");
+      if (propHash.proto) this.raiseRecoverable(key.start, "Redefinition of __proto__ property");
       propHash.proto = true;
     }
     return;
@@ -56,7 +56,7 @@ pp.checkPropClash = function (prop, propHash) {
   var other = propHash[name];
   if (other) {
     var isGetSet = kind !== "init";
-    if ((this.strict || isGetSet) && other[kind] || !(isGetSet ^ other.init)) this.raise(key.start, "Redefinition of property");
+    if ((this.strict || isGetSet) && other[kind] || !(isGetSet ^ other.init)) this.raiseRecoverable(key.start, "Redefinition of property");
   } else {
     other = propHash[name] = {
       init: false,
@@ -99,7 +99,7 @@ pp.parseExpression = function (noIn, refDestructuringErrors) {
 // operators like `+=`.
 
 pp.parseMaybeAssign = function (noIn, refDestructuringErrors, afterLeftParse) {
-  if (this.type == _tokentype.types._yield && this.inGenerator) return this.parseYield();
+  if (this.inGenerator && this.isContextual("yield")) return this.parseYield();
 
   var validateDestructuring = false;
   if (!refDestructuringErrors) {
@@ -191,7 +191,7 @@ pp.parseMaybeUnary = function (refDestructuringErrors) {
     this.next();
     node.argument = this.parseMaybeUnary();
     this.checkExpressionErrors(refDestructuringErrors, true);
-    if (update) this.checkLVal(node.argument);else if (this.strict && node.operator === "delete" && node.argument.type === "Identifier") this.raise(node.start, "Deleting local variable in strict mode");
+    if (update) this.checkLVal(node.argument);else if (this.strict && node.operator === "delete" && node.argument.type === "Identifier") this.raiseRecoverable(node.start, "Deleting local variable in strict mode");
     return this.finishNode(node, update ? "UpdateExpression" : "UnaryExpression");
   }
   var startPos = this.start,
@@ -263,18 +263,16 @@ pp.parseExprAtom = function (refDestructuringErrors) {
   switch (this.type) {
     case _tokentype.types._super:
       if (!this.inFunction) this.raise(this.start, "'super' outside of function or class");
+
     case _tokentype.types._this:
       var type = this.type === _tokentype.types._this ? "ThisExpression" : "Super";
       node = this.startNode();
       this.next();
       return this.finishNode(node, type);
 
-    case _tokentype.types._yield:
-      if (this.inGenerator) this.unexpected();
-
     case _tokentype.types.name:
       // quick hack to allow async and await
-      if (this.value == "async" && /^[ \t]+function\b/.test(this.input.slice(this.end))) {
+      if (this.value == "async" && /^[ \t]*(function\b|\(|\w+[ \t]*=>)/.test(this.input.slice(this.end))) {
         node = this.startNode();
         this.next();
         return this.parseExprAtom(refDestructuringErrors);
@@ -313,10 +311,6 @@ pp.parseExprAtom = function (refDestructuringErrors) {
     case _tokentype.types.bracketL:
       node = this.startNode();
       this.next();
-      // check whether this is array comprehension or regular array
-      if (this.options.ecmaVersion >= 7 && this.type === _tokentype.types._for) {
-        return this.parseComprehension(node, false);
-      }
       node.elements = this.parseExprList(_tokentype.types.bracketR, true, true, refDestructuringErrors);
       return this.finishNode(node, "ArrayExpression");
 
@@ -364,10 +358,6 @@ pp.parseParenAndDistinguishExpression = function (canBeArrow) {
   if (this.options.ecmaVersion >= 6) {
     this.next();
 
-    if (this.options.ecmaVersion >= 7 && this.type === _tokentype.types._for) {
-      return this.parseComprehension(this.startNodeAt(startPos, startLoc), true);
-    }
-
     var innerStartPos = this.start,
         innerStartLoc = this.startLoc;
     var exprList = [],
@@ -444,8 +434,8 @@ pp.parseNew = function () {
   if (this.options.ecmaVersion >= 6 && this.eat(_tokentype.types.dot)) {
     node.meta = meta;
     node.property = this.parseIdent(true);
-    if (node.property.name !== "target") this.raise(node.property.start, "The only valid meta property for new is new.target");
-    if (!this.inFunction) this.raise(node.start, "new.target can only be used in functions");
+    if (node.property.name !== "target") this.raiseRecoverable(node.property.start, "The only valid meta property for new is new.target");
+    if (!this.inFunction) this.raiseRecoverable(node.start, "new.target can only be used in functions");
     return this.finishNode(node, "MetaProperty");
   }
   var startPos = this.start,
@@ -536,13 +526,13 @@ pp.parsePropertyValue = function (prop, isPattern, isGenerator, startPos, startL
     var paramCount = prop.kind === "get" ? 0 : 1;
     if (prop.value.params.length !== paramCount) {
       var start = prop.value.start;
-      if (prop.kind === "get") this.raise(start, "getter should have no params");else this.raise(start, "setter should have exactly one param");
+      if (prop.kind === "get") this.raiseRecoverable(start, "getter should have no params");else this.raiseRecoverable(start, "setter should have exactly one param");
     }
-    if (prop.kind === "set" && prop.value.params[0].type === "RestElement") this.raise(prop.value.params[0].start, "Setter cannot use rest params");
+    if (prop.kind === "set" && prop.value.params[0].type === "RestElement") this.raiseRecoverable(prop.value.params[0].start, "Setter cannot use rest params");
   } else if (this.options.ecmaVersion >= 6 && !prop.computed && prop.key.type === "Identifier") {
     prop.kind = "init";
     if (isPattern) {
-      if (this.keywords.test(prop.key.name) || (this.strict ? this.reservedWordsStrictBind : this.reservedWords).test(prop.key.name)) this.raise(prop.key.start, "Binding " + prop.key.name);
+      if (this.keywords.test(prop.key.name) || (this.strict ? this.reservedWordsStrictBind : this.reservedWords).test(prop.key.name) || this.inGenerator && prop.key.name == "yield") this.raiseRecoverable(prop.key.start, "Binding " + prop.key.name);
       prop.value = this.parseMaybeDefault(startPos, startLoc, prop.key);
     } else if (this.type === _tokentype.types.eq && refDestructuringErrors) {
       if (!refDestructuringErrors.shorthandAssign) refDestructuringErrors.shorthandAssign = this.start;
@@ -581,21 +571,27 @@ pp.initFunction = function (node) {
 // Parse object or class method.
 
 pp.parseMethod = function (isGenerator) {
-  var node = this.startNode();
+  var node = this.startNode(),
+      oldInGen = this.inGenerator;
+  this.inGenerator = isGenerator;
   this.initFunction(node);
   this.expect(_tokentype.types.parenL);
   node.params = this.parseBindingList(_tokentype.types.parenR, false, false);
   if (this.options.ecmaVersion >= 6) node.generator = isGenerator;
   this.parseFunctionBody(node, false);
+  this.inGenerator = oldInGen;
   return this.finishNode(node, "FunctionExpression");
 };
 
 // Parse arrow function expression with given parameters.
 
 pp.parseArrowExpression = function (node, params) {
+  var oldInGen = this.inGenerator;
+  this.inGenerator = false;
   this.initFunction(node);
   node.params = this.toAssignableList(params, true);
   this.parseFunctionBody(node, true);
+  this.inGenerator = oldInGen;
   return this.finishNode(node, "ArrowFunctionExpression");
 };
 
@@ -611,12 +607,11 @@ pp.parseFunctionBody = function (node, isArrowFunction) {
     // Start a new scope with regard to labels and the `inFunction`
     // flag (restore them to their old value afterwards).
     var oldInFunc = this.inFunction,
-        oldInGen = this.inGenerator,
         oldLabels = this.labels;
-    this.inFunction = true;this.inGenerator = node.generator;this.labels = [];
+    this.inFunction = true;this.labels = [];
     node.body = this.parseBlock(true);
     node.expression = false;
-    this.inFunction = oldInFunc;this.inGenerator = oldInGen;this.labels = oldLabels;
+    this.inFunction = oldInFunc;this.labels = oldLabels;
   }
 
   // If this is a strict mode function, verify that argument names
@@ -676,7 +671,8 @@ pp.parseIdent = function (liberal) {
   var node = this.startNode();
   if (liberal && this.options.allowReserved == "never") liberal = false;
   if (this.type === _tokentype.types.name) {
-    if (!liberal && (this.strict ? this.reservedWordsStrict : this.reservedWords).test(this.value) && (this.options.ecmaVersion >= 6 || this.input.slice(this.start, this.end).indexOf("\\") == -1)) this.raise(this.start, "The keyword '" + this.value + "' is reserved");
+    if (!liberal && (this.strict ? this.reservedWordsStrict : this.reservedWords).test(this.value) && (this.options.ecmaVersion >= 6 || this.input.slice(this.start, this.end).indexOf("\\") == -1)) this.raiseRecoverable(this.start, "The keyword '" + this.value + "' is reserved");
+    if (!liberal && this.inGenerator && this.value === "yield") this.raiseRecoverable(this.start, "Can not use 'yield' as identifier inside a generator");
     node.name = this.value;
   } else if (liberal && this.type.keyword) {
     node.name = this.type.keyword;
@@ -702,38 +698,7 @@ pp.parseYield = function () {
   return this.finishNode(node, "YieldExpression");
 };
 
-// Parses array and generator comprehensions.
-
-pp.parseComprehension = function (node, isGenerator) {
-  node.blocks = [];
-  while (this.type === _tokentype.types._for) {
-    var block = this.startNode();
-    this.next();
-    this.expect(_tokentype.types.parenL);
-    block.left = this.parseBindingAtom();
-    this.checkLVal(block.left, true);
-    this.expectContextual("of");
-    block.right = this.parseExpression();
-    this.expect(_tokentype.types.parenR);
-    node.blocks.push(this.finishNode(block, "ComprehensionBlock"));
-  }
-  node.filter = this.eat(_tokentype.types._if) ? this.parseParenExpression() : null;
-  node.body = this.parseExpression();
-  this.expect(isGenerator ? _tokentype.types.parenR : _tokentype.types.bracketR);
-  node.generator = isGenerator;
-  return this.finishNode(node, "ComprehensionExpression");
-};
-
 },{"./state":"/src\\state.js","./tokentype":"/src\\tokentype.js"}],"/src\\identifier.js":[function(_dereq_,module,exports){
-// 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.
-
 // Reserved word lists for various dialects of the language
 
 "use strict";
@@ -756,7 +721,7 @@ var ecma5AndLessKeywords = "break case catch continue debugger default do else f
 
 var keywords = {
   5: ecma5AndLessKeywords,
-  6: ecma5AndLessKeywords + " let const class extends export import yield super"
+  6: ecma5AndLessKeywords + " const class extends export import super"
 };
 
 exports.keywords = keywords;
@@ -866,7 +831,7 @@ var _whitespace = _dereq_("./whitespace");
 exports.isNewLine = _whitespace.isNewLine;
 exports.lineBreak = _whitespace.lineBreak;
 exports.lineBreakG = _whitespace.lineBreakG;
-var version = "2.7.0";
+var version = "2.7.1";
 
 exports.version = version;
 // The main exported interface (under `self.acorn` when in the
@@ -920,6 +885,8 @@ pp.raise = function (pos, message) {
   throw err;
 };
 
+pp.raiseRecoverable = pp.raise;
+
 pp.curPosition = function () {
   if (this.options.locations) {
     return new _locutil.Position(this.curLine, this.pos - this.lineStart);
@@ -1161,15 +1128,15 @@ pp.parseMaybeDefault = function (startPos, startLoc, left) {
 pp.checkLVal = function (expr, isBinding, checkClashes) {
   switch (expr.type) {
     case "Identifier":
-      if (this.strict && this.reservedWordsStrictBind.test(expr.name)) this.raise(expr.start, (isBinding ? "Binding " : "Assigning to ") + expr.name + " in strict mode");
+      if (this.strict && this.reservedWordsStrictBind.test(expr.name)) this.raiseRecoverable(expr.start, (isBinding ? "Binding " : "Assigning to ") + expr.name + " in strict mode");
       if (checkClashes) {
-        if (_util.has(checkClashes, expr.name)) this.raise(expr.start, "Argument name clash");
+        if (_util.has(checkClashes, expr.name)) this.raiseRecoverable(expr.start, "Argument name clash");
         checkClashes[expr.name] = true;
       }
       break;
 
     case "MemberExpression":
-      if (isBinding) this.raise(expr.start, (isBinding ? "Binding" : "Assigning to") + " member expression");
+      if (isBinding) this.raiseRecoverable(expr.start, (isBinding ? "Binding" : "Assigning to") + " member expression");
       break;
 
     case "ObjectPattern":
@@ -1274,8 +1241,8 @@ var 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,
+  // setters and other features. The default is 6.
+  ecmaVersion: 6,
   // Source type ("script" or "module") for different semantics
   sourceType: "script",
   // `onInsertedSemicolon` can be a callback that will be called
@@ -1623,6 +1590,8 @@ var _state = _dereq_("./state");
 
 var _whitespace = _dereq_("./whitespace");
 
+var _identifier = _dereq_("./identifier");
+
 var pp = _state.Parser.prototype;
 
 // ### Statement parsing
@@ -1653,6 +1622,21 @@ pp.parseTopLevel = function (node) {
 var loopLabel = { kind: "loop" },
     switchLabel = { kind: "switch" };
 
+pp.isLet = function () {
+  if (this.type !== _tokentype.types.name || this.options.ecmaVersion < 6 || this.value != "let") return false;
+  _whitespace.skipWhiteSpace.lastIndex = this.pos;
+  var skip = _whitespace.skipWhiteSpace.exec(this.input);
+  var next = this.pos + skip[0].length,
+      nextCh = this.input.charCodeAt(next);
+  if (nextCh === 91 || nextCh == 123) return true; // '{' and '['
+  if (_identifier.isIdentifierStart(nextCh, true)) {
+    for (var pos = next + 1; _identifier.isIdentifierChar(this.input.charCodeAt(pos, true)); ++pos) {}
+    var ident = this.input.slice(next, pos);
+    if (!this.isKeyword(ident)) return true;
+  }
+  return false;
+};
+
 // Parse a single statement.
 //
 // If expecting a statement and finding a slash operator, parse a
@@ -1662,7 +1646,13 @@ var loopLabel = { kind: "loop" },
 
 pp.parseStatement = function (declaration, topLevel) {
   var starttype = this.type,
-      node = this.startNode();
+      node = this.startNode(),
+      kind = undefined;
+
+  if (this.isLet()) {
+    starttype = _tokentype.types._var;
+    kind = "let";
+  }
 
   // Most types of statements are recognized by the keyword they
   // start with. Many are trivial to parse, some require a bit of
@@ -1693,10 +1683,10 @@ pp.parseStatement = function (declaration, topLevel) {
       return this.parseThrowStatement(node);
     case _tokentype.types._try:
       return this.parseTryStatement(node);
-    case _tokentype.types._let:case _tokentype.types._const:
-      if (!declaration) this.unexpected(); // NOTE: falls through to _var
-    case _tokentype.types._var:
-      return this.parseVarStatement(node, starttype);
+    case _tokentype.types._const:case _tokentype.types._var:
+      kind = kind || this.value;
+      if (!declaration && kind != "var") this.unexpected();
+      return this.parseVarStatement(node, kind);
     case _tokentype.types._while:
       return this.parseWhileStatement(node);
     case _tokentype.types._with:
@@ -1709,7 +1699,7 @@ pp.parseStatement = function (declaration, topLevel) {
     case _tokentype.types._import:
       if (!this.options.allowImportExportEverywhere) {
         if (!topLevel) this.raise(this.start, "'import' and 'export' may only appear at the top level");
-        // if (!this.inModule) this.raise(this.start, "'import' and 'export' may appear only with 'sourceType: module'");
+        if (!this.inModule) this.raise(this.start, "'import' and 'export' may appear only with 'sourceType: module'");
       }
       return starttype === _tokentype.types._import ? this.parseImport(node) : this.parseExport(node);
 
@@ -1776,13 +1766,14 @@ pp.parseForStatement = function (node) {
   this.labels.push(loopLabel);
   this.expect(_tokentype.types.parenL);
   if (this.type === _tokentype.types.semi) return this.parseFor(node, null);
-  if (this.type === _tokentype.types._var || this.type === _tokentype.types._let || this.type === _tokentype.types._const) {
+  var isLet = this.isLet();
+  if (this.type === _tokentype.types._var || this.type === _tokentype.types._const || isLet) {
     var _init = this.startNode(),
-        varKind = this.type;
+        kind = isLet ? "let" : this.value;
     this.next();
-    this.parseVar(_init, true, varKind);
+    this.parseVar(_init, true, kind);
     this.finishNode(_init, "VariableDeclaration");
-    if ((this.type === _tokentype.types._in || this.options.ecmaVersion >= 6 && this.isContextual("of")) && _init.declarations.length === 1 && !(varKind !== _tokentype.types._var && _init.declarations[0].init)) return this.parseForIn(node, _init);
+    if ((this.type === _tokentype.types._in || this.options.ecmaVersion >= 6 && this.isContextual("of")) && _init.declarations.length === 1 && !(kind !== "var" && _init.declarations[0].init)) return this.parseForIn(node, _init);
     return this.parseFor(node, _init);
   }
   var refDestructuringErrors = { shorthandAssign: 0, trailingComma: 0 };
@@ -1846,7 +1837,7 @@ pp.parseSwitchStatement = function (node) {
       if (isCase) {
         cur.test = this.parseExpression();
       } else {
-        if (sawDefault) this.raise(this.lastTokStart, "Multiple default clauses");
+        if (sawDefault) this.raiseRecoverable(this.lastTokStart, "Multiple default clauses");
         sawDefault = true;
         cur.test = null;
       }
@@ -2003,13 +1994,13 @@ pp.parseForIn = function (node, init) {
 
 pp.parseVar = function (node, isFor, kind) {
   node.declarations = [];
-  node.kind = kind.keyword;
+  node.kind = kind;
   for (;;) {
     var decl = this.startNode();
     this.parseVarId(decl);
     if (this.eat(_tokentype.types.eq)) {
       decl.init = this.parseMaybeAssign(isFor);
-    } else if (kind === _tokentype.types._const && !(this.type === _tokentype.types._in || this.options.ecmaVersion >= 6 && this.isContextual("of"))) {
+    } else if (kind === "const" && !(this.type === _tokentype.types._in || this.options.ecmaVersion >= 6 && this.isContextual("of"))) {
       this.unexpected();
     } else if (decl.id.type != "Identifier" && !(isFor && (this.type === _tokentype.types._in || this.isContextual("of")))) {
       this.raise(this.lastTokEnd, "Complex binding patterns require an initialization value");
@@ -2033,9 +2024,12 @@ pp.parseVarId = function (decl) {
 pp.parseFunction = function (node, isStatement, allowExpressionBody) {
   this.initFunction(node);
   if (this.options.ecmaVersion >= 6) node.generator = this.eat(_tokentype.types.star);
+  var oldInGen = this.inGenerator;
+  this.inGenerator = node.generator;
   if (isStatement || this.type === _tokentype.types.name) node.id = this.parseIdent();
   this.parseFunctionParams(node);
   this.parseFunctionBody(node, allowExpressionBody);
+  this.inGenerator = oldInGen;
   return this.finishNode(node, isStatement ? "FunctionDeclaration" : "FunctionExpression");
 };
 
@@ -2090,7 +2084,7 @@ pp.parseClass = function (node, isStatement) {
       var paramCount = method.kind === "get" ? 0 : 1;
       if (method.value.params.length !== paramCount) {
         var start = method.value.start;
-        if (method.kind === "get") this.raise(start, "getter should have no params");else this.raise(start, "setter should have exactly one param");
+        if (method.kind === "get") this.raiseRecoverable(start, "getter should have no params");else this.raiseRecoverable(start, "setter should have exactly one param");
       }
       if (method.kind === "set" && method.value.params[0].type === "RestElement") this.raise(method.value.params[0].start, "Setter cannot use rest params");
     }
@@ -2125,9 +2119,10 @@ pp.parseExport = function (node) {
   }
   if (this.eat(_tokentype.types._default)) {
     // export default ...
+    var parens = this.type == _tokentype.types.parenL;
     var expr = this.parseMaybeAssign();
     var needsSemi = true;
-    if (expr.type == "FunctionExpression" || expr.type == "ClassExpression") {
+    if (!parens && (expr.type == "FunctionExpression" || expr.type == "ClassExpression")) {
       needsSemi = false;
       if (expr.id) {
         expr.type = expr.type == "FunctionExpression" ? "FunctionDeclaration" : "ClassDeclaration";
@@ -2164,7 +2159,7 @@ pp.parseExport = function (node) {
 };
 
 pp.shouldParseExportStatement = function () {
-  return this.type.keyword;
+  return this.type.keyword || this.isLet();
 };
 
 // Parses a comma-separated list of module exports.
@@ -2249,7 +2244,7 @@ pp.parseImportSpecifiers = function () {
   return nodes;
 };
 
-},{"./state":"/src\\state.js","./tokentype":"/src\\tokentype.js","./whitespace":"/src\\whitespace.js"}],"/src\\tokencontext.js":[function(_dereq_,module,exports){
+},{"./identifier":"/src\\identifier.js","./state":"/src\\state.js","./tokentype":"/src\\tokentype.js","./whitespace":"/src\\whitespace.js"}],"/src\\tokencontext.js":[function(_dereq_,module,exports){
 // 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
@@ -2601,11 +2596,21 @@ pp.readToken_slash = function () {
   return this.finishOp(_tokentype.types.slash, 1);
 };
 
-pp.readToken_mult_modulo = function (code) {
+pp.readToken_mult_modulo_exp = function (code) {
   // '%*'
   var next = this.input.charCodeAt(this.pos + 1);
-  if (next === 61) return this.finishOp(_tokentype.types.assign, 2);
-  return this.finishOp(code === 42 ? _tokentype.types.star : _tokentype.types.modulo, 1);
+  var size = 1;
+  var tokentype = code === 42 ? _tokentype.types.star : _tokentype.types.modulo;
+
+  // exponentiation operator ** and **=
+  if (this.options.ecmaVersion >= 7 && next === 42) {
+    ++size;
+    tokentype = _tokentype.types.starstar;
+    next = this.input.charCodeAt(this.pos + 2);
+  }
+
+  if (next === 61) return this.finishOp(_tokentype.types.assign, size + 1);
+  return this.finishOp(tokentype, size);
 };
 
 pp.readToken_pipe_amp = function (code) {
@@ -2713,7 +2718,8 @@ pp.getTokenFromCode = function (code) {
       if (next === 120 || next === 88) return this.readRadixNumber(16); // '0x', '0X' - hex number
       if (this.options.ecmaVersion >= 6) {
         if (next === 111 || next === 79) return this.readRadixNumber(8); // '0o', '0O' - octal number
-        if (next === 98 || next === 66) return this.readRadixNumber(2); // '0b', '0B' - binary number
+        if (next === 98 || next === 66) return this.readRadixNumber(2) // '0b', '0B' - binary number
+        ;
       }
     // Anything else beginning with a digit is an integer, octal
     // number, or float.
@@ -2737,7 +2743,7 @@ pp.getTokenFromCode = function (code) {
 
     case 37:case 42:
       // '%*'
-      return this.readToken_mult_modulo(code);
+      return this.readToken_mult_modulo_exp(code);
 
     case 124:case 38:
       // '|&'
@@ -2855,10 +2861,10 @@ pp.readInt = function (radix, len) {
   for (var i = 0, e = len == null ? Infinity : len; i < e; ++i) {
     var code = this.input.charCodeAt(this.pos),
         val = undefined;
-    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 (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;
     ++this.pos;
     total = total * radix + val;
@@ -3214,7 +3220,8 @@ var types = {
   plusMin: new TokenType("+/-", { beforeExpr: true, binop: 9, prefix: true, startsExpr: true }),
   modulo: binop("%", 10),
   star: binop("*", 10),
-  slash: binop("/", 10)
+  slash: binop("/", 10),
+  starstar: binop("**", 11)
 };
 
 exports.types = types;
@@ -3248,7 +3255,6 @@ kw("switch");
 kw("throw", beforeExpr);
 kw("try");
 kw("var");
-kw("let");
 kw("const");
 kw("while", { isLoop: true });
 kw("with");
@@ -3259,7 +3265,6 @@ kw("class");
 kw("extends", beforeExpr);
 kw("export");
 kw("import");
-kw("yield", { beforeExpr: true, startsExpr: true });
 kw("null", startsExpr);
 kw("true", startsExpr);
 kw("false", startsExpr);
@@ -3305,7 +3310,10 @@ function isNewLine(code) {
 }
 
 var nonASCIIwhitespace = /[\u1680\u180e\u2000-\u200a\u202f\u205f\u3000\ufeff]/;
+
 exports.nonASCIIwhitespace = nonASCIIwhitespace;
+var skipWhiteSpace = /(?:\s|\/\/.*|\/\*[^]*?\*\/)*/g;
+exports.skipWhiteSpace = skipWhiteSpace;
 
 },{}]},{},["/src\\index.js"])("/src\\index.js")
 });
diff --git a/node_modules/treehugger/lib/acorn/dist/acorn_loose.js b/node_modules/treehugger/lib/acorn/dist/acorn_loose.js
index 512b2a06..032e3145 100644
--- a/node_modules/treehugger/lib/acorn/dist/acorn_loose.js
+++ b/node_modules/treehugger/lib/acorn/dist/acorn_loose.js
@@ -54,6 +54,19 @@ lp.parseParenExpression = function () {
 };
 
 lp.parseMaybeAssign = function (noIn) {
+  if (this.toks.isContextual("yield")) {
+    var node = this.startNode();
+    this.next();
+    if (this.semicolon() || this.canInsertSemicolon() || this.tok.type != _.tokTypes.star && !this.tok.type.startsExpr) {
+      node.delegate = false;
+      node.argument = null;
+    } else {
+      node.delegate = this.eat(_.tokTypes.star);
+      node.argument = this.parseMaybeAssign();
+    }
+    return this.finishNode(node, "YieldExpression");
+  }
+
   var start = this.storeCurrentPos();
   var left = this.parseMaybeConditional(noIn);
   if (this.tok.type.isAssign) {
@@ -193,7 +206,7 @@ lp.parseExprAtom = function () {
 
     case _.tokTypes.name:
       // quick hack to allow async and await
-      if (this.tok.value == "async" && /^[ \t]+function\b/.test(this.input.slice(this.tok.end))) {
+      if (this.value == "async" && /^[ \t]*(function\b|\(|\w+[ \t]*=>)/.test(this.input.slice(this.tok.end))) {
         node = this.startNode();
         this.next();
         return this.parseExprAtom();
@@ -264,18 +277,6 @@ lp.parseExprAtom = function () {
     case _.tokTypes._new:
       return this.parseNew();
 
-    case _.tokTypes._yield:
-      node = this.startNode();
-      this.next();
-      if (this.semicolon() || this.canInsertSemicolon() || this.tok.type != _.tokTypes.star && !this.tok.type.startsExpr) {
-        node.delegate = false;
-        node.argument = null;
-      } else {
-        node.delegate = this.eat(_.tokTypes.star);
-        node.argument = this.parseMaybeAssign();
-      }
-      return this.finishNode(node, "YieldExpression");
-
     case _.tokTypes.backQuote:
       return this.parseTemplate();
 
@@ -801,7 +802,13 @@ lp.parseTopLevel = function () {
 
 lp.parseStatement = function () {
   var starttype = this.tok.type,
-      node = this.startNode();
+      node = this.startNode(),
+      kind = undefined;
+
+  if (this.toks.isLet()) {
+    starttype = _.tokTypes._var;
+    kind = "let";
+  }
 
   switch (starttype) {
     case _.tokTypes._break:case _.tokTypes._continue:
@@ -832,8 +839,9 @@ lp.parseStatement = function () {
       this.pushCx();
       this.expect(_.tokTypes.parenL);
       if (this.tok.type === _.tokTypes.semi) return this.parseFor(node, null);
-      if (this.tok.type === _.tokTypes._var || this.tok.type === _.tokTypes._let || this.tok.type === _.tokTypes._const) {
-        var _init = this.parseVar(true);
+      var isLet = this.toks.isLet();
+      if (isLet || this.tok.type === _.tokTypes._var || this.tok.type === _.tokTypes._const) {
+        var _init = this.parseVar(true, isLet ? "let" : this.tok.value);
         if (_init.declarations.length === 1 && (this.tok.type === _.tokTypes._in || this.isContextual("of"))) {
           return this.parseForIn(node, _init);
         }
@@ -918,9 +926,8 @@ lp.parseStatement = function () {
       return this.finishNode(node, "TryStatement");
 
     case _.tokTypes._var:
-    case _.tokTypes._let:
     case _.tokTypes._const:
-      return this.parseVar();
+      return this.parseVar(false, kind || this.tok.value);
 
     case _.tokTypes._while:
       this.next();
@@ -1003,9 +1010,9 @@ lp.parseForIn = function (node, init) {
   return this.finishNode(node, type);
 };
 
-lp.parseVar = function (noIn) {
+lp.parseVar = function (noIn, kind) {
   var node = this.startNode();
-  node.kind = this.tok.type.keyword;
+  node.kind = kind;
   this.next();
   node.declarations = [];
   do {
@@ -1114,7 +1121,7 @@ lp.parseExport = function () {
     this.semicolon();
     return this.finishNode(node, "ExportDefaultDeclaration");
   }
-  if (this.tok.type.keyword) {
+  if (this.tok.type.keyword || this.toks.isLet()) {
     node.declaration = this.parseStatement();
     node.specifiers = [];
     node.source = null;
@@ -1298,7 +1305,7 @@ lp.resetTo = function (pos) {
   this.toks.exprAllowed = !ch || /[\[\{\(,;:?\/*=+\-~!|&%^<>]/.test(ch) || /[enwfd]/.test(ch) && /\b(keywords|case|else|return|throw|new|in|(instance|type)of|delete|void)$/.test(this.input.slice(pos - 10, pos));
 
   if (this.options.locations) {
-    this.toks.curLine = 1;
+    this.toks.curLine = 0;
     this.toks.lineStart = _.lineBreakG.lastIndex = 0;
     var match = undefined;
     while ((match = _.lineBreakG.exec(this.input)) && match.index < pos) {
diff --git a/node_modules/treehugger/lib/demo.js b/node_modules/treehugger/lib/demo.js
index d720aa81..bc8f3abf 100644
--- a/node_modules/treehugger/lib/demo.js
+++ b/node_modules/treehugger/lib/demo.js
@@ -1,38 +1,48 @@
 require({
     baseUrl: "lib"
-}, ["treehugger/tree", "treehugger/traverse", "treehugger/js/parse", "jquery",
+}, ["treehugger/tree", "treehugger/traverse", "treehugger/js/parse",
     "acorn/dist/acorn", "acorn/dist/acorn_loose", "acorn/dist/walk"
-], function(tree, traverse, parsejs, jq, acorn, acorn_loose) {
+], function(tree, traverse, parsejs, acorn, acorn_loose) {
+  var $ = document.querySelector.bind(document);
+  window.acorn_loose = acorn_loose;
 
-window.acorn_loose = acorn_loose
+  if (localStorage.trehuggerJsVal)
+    $("#code").value = localStorage.trehuggerJsVal;
+  if (localStorage.trehuggerAnalysisVal)
+    $("#analysis").value = localStorage.trehuggerAnalysisVal;
+  window.onbeforeunload = function() {
+    localStorage.trehuggerJsVal = $("#code").value;
+    localStorage.trehuggerAnalysisVal = $("#analysis").value;
+  };
+  
   function log(message) {
-    $("#output").val($("#output").val() + message + "\n");
+    $("#output").value = $("#output").value + message + "\n";
   }
 
   function exec() {
-    var js = $("#code").val();
-    var analysisJs = $("#analysis").val();
-    $("#output").val("");   
+    var js = $("#code").value;
+    var analysisJs = $("#analysis").value;
+    $("#output").value = "";
     
-    var t = performance.now();
-    var ast = parsejs.parse(js);
-    t -= performance.now();
-    $("#ast").val(t + "\n" + ast.toPrettyString());
     try {
+      var t = performance.now();
+      var ast = parsejs.parse(js);
+      t -= performance.now();
+      $("#ast").value = t + "\n" + ast.toPrettyString();
       eval(analysisJs);
     } catch(e) {
-      $("#output").val("JS Error");
-      console.log(e.message)
+      $("#output").value = "JS Error \n\t" + (e.stack || e.message);
+      console.log(e)
     }
   }
 
   tree.Node.prototype.log = function() {
-    $("#output").val(this.toPrettyString());
+    $("#output").value = this.toPrettyString();
   }
 
     
-  $("#code").keyup(exec);
-  $("#runbutton").click(exec);
+  $("#code").addEventListener("input", exec);
+  $("#runbutton").addEventListener("click", exec);
   exec();
     
 });
diff --git a/node_modules/treehugger/lib/treehugger/js/parse.js b/node_modules/treehugger/lib/treehugger/js/parse.js
index 15aa4984..92787158 100644
--- a/node_modules/treehugger/lib/treehugger/js/parse.js
+++ b/node_modules/treehugger/lib/treehugger/js/parse.js
@@ -216,7 +216,7 @@ exports.transform = function transform(n) {
         case "ArrowFunctionExpression":
             resultNode = tree.cons("Arrow", [tree.list(n.params.map(function(arg) {
                 return setIdPos(arg, tree.cons("FArg", [id(arg)]));
-            })), tree.list(n.body.body.map(transform))]);
+            })), tree.list(n.body.body ? n.body.body.map(transform) : transform(n.body))]);
             break;
         case "YieldExpression":
             resultNode = tree.cons("Yield", [transform(n.argument)]);

From b3f752e74cada9a948dce4ec49e6bc377225395a Mon Sep 17 00:00:00 2001
From: nightwing <amirjanyan@gmail.com>
Date: Mon, 8 Feb 2016 12:00:41 +0400
Subject: [PATCH 2/4] update eslint

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 48168b53..8ed3de2d 100644
--- a/package.json
+++ b/package.json
@@ -63,7 +63,7 @@
         "c9.ide.language.html.diff": "#24f3608d26",
         "c9.ide.language.javascript": "#c6d102471f",
         "c9.ide.language.javascript.immediate": "#c8b1e5767a",
-        "c9.ide.language.javascript.eslint": "#08f092da2a",
+        "c9.ide.language.javascript.eslint": "#3d3857c42e",
         "c9.ide.language.javascript.tern": "#bf1072b11a",
         "c9.ide.language.javascript.infer": "#0561c69d67",
         "c9.ide.language.jsonalyzer": "#bf12af3d0a",

From 7c188abf07c6f7f4caddd80f874a97fc513a947f Mon Sep 17 00:00:00 2001
From: nightwing <amirjanyan@gmail.com>
Date: Mon, 8 Feb 2016 13:29:06 +0400
Subject: [PATCH 3/4] enable jsx-uses-vars by default

---
 .eslintrc    | 3 +--
 package.json | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/.eslintrc b/.eslintrc
index a81f3ae3..1f36942f 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -44,9 +44,8 @@ rules:
     no-extra-semi: 3
     
     default-case: 3
-    space-after-keywords: [1, "always"]
+    keyword-spacing: [1, {"before": true, "after": true, "overrides":  { "catch": {"after": "maybe" } }}]
     space-in-parens: [1, "never"]
-    space-return-throw-case: [1, "always"]
     // space-before-function-paren: [3, {"named": "never", "anonymous": "never"}]
     spaced-comment: 3
     // valid-jsdoc: [1, { requireReturn: false, requireParamDescription: false, prefer: { "return": "return" } }]
diff --git a/package.json b/package.json
index 8ed3de2d..16187266 100644
--- a/package.json
+++ b/package.json
@@ -63,7 +63,7 @@
         "c9.ide.language.html.diff": "#24f3608d26",
         "c9.ide.language.javascript": "#c6d102471f",
         "c9.ide.language.javascript.immediate": "#c8b1e5767a",
-        "c9.ide.language.javascript.eslint": "#3d3857c42e",
+        "c9.ide.language.javascript.eslint": "#562fa7b097",
         "c9.ide.language.javascript.tern": "#bf1072b11a",
         "c9.ide.language.javascript.infer": "#0561c69d67",
         "c9.ide.language.jsonalyzer": "#bf12af3d0a",

From 03f2ee83e357e4bb250e3ee108725d0af3df593e Mon Sep 17 00:00:00 2001
From: nightwing <amirjanyan@gmail.com>
Date: Mon, 8 Feb 2016 13:43:29 +0400
Subject: [PATCH 4/4] adapt eslint_worker to new error messages

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 16187266..1a178235 100644
--- a/package.json
+++ b/package.json
@@ -63,7 +63,7 @@
         "c9.ide.language.html.diff": "#24f3608d26",
         "c9.ide.language.javascript": "#c6d102471f",
         "c9.ide.language.javascript.immediate": "#c8b1e5767a",
-        "c9.ide.language.javascript.eslint": "#562fa7b097",
+        "c9.ide.language.javascript.eslint": "#9495ab1934",
         "c9.ide.language.javascript.tern": "#bf1072b11a",
         "c9.ide.language.javascript.infer": "#0561c69d67",
         "c9.ide.language.jsonalyzer": "#bf12af3d0a",