/* */ 
"format cjs";
"use strict";

var _babelToolsProtectJs2 = require("./../../babel/tools/protect.js");

var _babelToolsProtectJs3 = _interopRequireDefault(_babelToolsProtectJs2);

// 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

var _tokentype = require("./tokentype");

var _state = require("./state");

var _identifier = require("./identifier");

var _util = require("./util");

_babelToolsProtectJs3["default"](module);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

var pp = _state.Parser.prototype;

// 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.

pp.checkPropClash = function (prop, propHash) {
  if (this.options.ecmaVersion >= 6 && (prop.computed || prop.method || prop.shorthand)) return;
  var key = prop.key,
      name = undefined;
  switch (key.type) {
    case "Identifier":
      name = key.name;break;
    case "Literal":
      name = String(key.value);break;
    default:
      return;
  }
  var kind = prop.kind;
  if (this.options.ecmaVersion >= 6) {
    if (name === "__proto__" && kind === "init") {
      if (propHash.proto) this.raise(key.start, "Redefinition of __proto__ property");
      propHash.proto = true;
    }
    return;
  }
  var other = undefined;
  if (_util.has(propHash, name)) {
    other = propHash[name];
    var isGetSet = kind !== "init";
    if ((this.strict || isGetSet) && other[kind] || !(isGetSet ^ other.init)) this.raise(key.start, "Redefinition of property");
  } else {
    other = propHash[name] = {
      init: false,
      get: false,
      set: false
    };
  }
  other[kind] = true;
};

// ### 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 optional arguments are used to
// forbid the `in` operator (in for loops initalization expressions)
// and provide reference for storing '=' operator inside shorthand
// property assignment in contexts where both object expression
// and object pattern might appear (so it's possible to raise
// delayed syntax error at correct position).

pp.parseExpression = function (noIn, refShorthandDefaultPos) {
  var start = this.markPosition();
  var expr = this.parseMaybeAssign(noIn, refShorthandDefaultPos);
  if (this.type === _tokentype.types.comma) {
    var node = this.startNodeAt(start);
    node.expressions = [expr];
    while (this.eat(_tokentype.types.comma)) node.expressions.push(this.parseMaybeAssign(noIn, refShorthandDefaultPos));
    return this.finishNode(node, "SequenceExpression");
  }
  return expr;
};

// Parse an assignment expression. This includes applications of
// operators like `+=`.

pp.parseMaybeAssign = function (noIn, refShorthandDefaultPos, afterLeftParse) {
  if (this.type == _tokentype.types._yield && this.inGenerator) return this.parseYield();

  var failOnShorthandAssign = undefined;
  if (!refShorthandDefaultPos) {
    refShorthandDefaultPos = { start: 0 };
    failOnShorthandAssign = true;
  } else {
    failOnShorthandAssign = false;
  }
  var start = this.markPosition();
  if (this.type == _tokentype.types.parenL || this.type == _tokentype.types.name) this.potentialArrowAt = this.start;
  var left = this.parseMaybeConditional(noIn, refShorthandDefaultPos);
  if (afterLeftParse) left = afterLeftParse.call(this, left, start);
  if (this.type.isAssign) {
    var node = this.startNodeAt(start);
    node.operator = this.value;
    node.left = this.type === _tokentype.types.eq ? this.toAssignable(left) : left;
    refShorthandDefaultPos.start = 0; // reset because shorthand default was used correctly
    this.checkLVal(left);
    if (left.parenthesizedExpression) {
      var errorMsg = undefined;
      if (left.type === "ObjectPattern") {
        errorMsg = "`({a}) = 0` use `({a} = 0)`";
      } else if (left.type === "ArrayPattern") {
        errorMsg = "`([a]) = 0` use `([a] = 0)`";
      }
      if (errorMsg) {
        this.raise(left.start, "You're trying to assign to a parenthesized expression, eg. instead of " + errorMsg);
      }
    }
    this.next();
    node.right = this.parseMaybeAssign(noIn);
    return this.finishNode(node, "AssignmentExpression");
  } else if (failOnShorthandAssign && refShorthandDefaultPos.start) {
    this.unexpected(refShorthandDefaultPos.start);
  }
  return left;
};

// Parse a ternary conditional (`?:`) operator.

pp.parseMaybeConditional = function (noIn, refShorthandDefaultPos) {
  var start = this.markPosition();
  var expr = this.parseExprOps(noIn, refShorthandDefaultPos);
  if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
  if (this.eat(_tokentype.types.question)) {
    var node = this.startNodeAt(start);
    node.test = expr;
    node.consequent = this.parseMaybeAssign();
    this.expect(_tokentype.types.colon);
    node.alternate = this.parseMaybeAssign(noIn);
    return this.finishNode(node, "ConditionalExpression");
  }
  return expr;
};

// Start the precedence parser.

pp.parseExprOps = function (noIn, refShorthandDefaultPos) {
  var start = this.markPosition();
  var expr = this.parseMaybeUnary(refShorthandDefaultPos);
  if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
  return this.parseExprOp(expr, 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.

pp.parseExprOp = function (left, leftStart, minPrec, noIn) {
  var prec = this.type.binop;
  if (prec != null && (!noIn || this.type !== _tokentype.types._in)) {
    if (prec > minPrec) {
      var node = this.startNodeAt(leftStart);
      node.left = left;
      node.operator = this.value;
      var op = this.type;
      this.next();
      var start = this.markPosition();
      node.right = this.parseExprOp(this.parseMaybeUnary(), start, op.rightAssociative ? prec - 1 : prec, noIn);
      this.finishNode(node, op === _tokentype.types.logicalOR || op === _tokentype.types.logicalAND ? "LogicalExpression" : "BinaryExpression");
      return this.parseExprOp(node, leftStart, minPrec, noIn);
    }
  }
  return left;
};

// Parse unary operators, both prefix and postfix.

pp.parseMaybeUnary = function (refShorthandDefaultPos) {
  if (this.type.prefix) {
    var node = this.startNode(),
        update = this.type === _tokentype.types.incDec;
    node.operator = this.value;
    node.prefix = true;
    this.next();
    node.argument = this.parseMaybeUnary();
    if (refShorthandDefaultPos && refShorthandDefaultPos.start) this.unexpected(refShorthandDefaultPos.start);
    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");
    return this.finishNode(node, update ? "UpdateExpression" : "UnaryExpression");
  }
  var start = this.markPosition();
  var expr = this.parseExprSubscripts(refShorthandDefaultPos);
  if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
  while (this.type.postfix && !this.canInsertSemicolon()) {
    var node = this.startNodeAt(start);
    node.operator = this.value;
    node.prefix = false;
    node.argument = expr;
    this.checkLVal(expr);
    this.next();
    expr = this.finishNode(node, "UpdateExpression");
  }
  return expr;
};

// Parse call, dot, and `[]`-subscript expressions.

pp.parseExprSubscripts = function (refShorthandDefaultPos) {
  var start = this.markPosition();
  var expr = this.parseExprAtom(refShorthandDefaultPos);
  if (refShorthandDefaultPos && refShorthandDefaultPos.start) return expr;
  return this.parseSubscripts(expr, start);
};

pp.parseSubscripts = function (base, start, noCalls) {
  if (!noCalls && this.eat(_tokentype.types.doubleColon)) {
    var node = this.startNodeAt(start);
    node.object = base;
    node.callee = this.parseNoCallExpr();
    return this.parseSubscripts(this.finishNode(node, "BindExpression"), start, noCalls);
  } else if (this.eat(_tokentype.types.dot)) {
    var node = this.startNodeAt(start);
    node.object = base;
    node.property = this.parseIdent(true);
    node.computed = false;
    return this.parseSubscripts(this.finishNode(node, "MemberExpression"), start, noCalls);
  } else if (this.eat(_tokentype.types.bracketL)) {
    var node = this.startNodeAt(start);
    node.object = base;
    node.property = this.parseExpression();
    node.computed = true;
    this.expect(_tokentype.types.bracketR);
    return this.parseSubscripts(this.finishNode(node, "MemberExpression"), start, noCalls);
  } else if (!noCalls && this.eat(_tokentype.types.parenL)) {
    var node = this.startNodeAt(start);
    node.callee = base;
    node.arguments = this.parseExprList(_tokentype.types.parenR, this.options.features["es7.trailingFunctionCommas"]);
    return this.parseSubscripts(this.finishNode(node, "CallExpression"), start, noCalls);
  } else if (this.type === _tokentype.types.backQuote) {
    var node = this.startNodeAt(start);
    node.tag = base;
    node.quasi = this.parseTemplate();
    return this.parseSubscripts(this.finishNode(node, "TaggedTemplateExpression"), start, noCalls);
  }return base;
};

// Parse a no-call expression (like argument of `new` or `::` operators).

pp.parseNoCallExpr = function () {
  var start = this.markPosition();
  return this.parseSubscripts(this.parseExprAtom(), start, true);
};

// 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 `{}`.

pp.parseExprAtom = function (refShorthandDefaultPos) {
  var node = undefined,
      canBeArrow = this.potentialArrowAt == this.start;
  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._do:
      if (this.options.features["es7.doExpressions"]) {
        var _node = this.startNode();
        this.next();
        var oldInFunction = this.inFunction;
        var oldLabels = this.labels;
        this.labels = [];
        this.inFunction = false;
        _node.body = this.parseBlock();
        this.inFunction = oldInFunction;
        this.labels = oldLabels;
        return this.finishNode(_node, "DoExpression");
      }

    case _tokentype.types.name:
      var start = this.markPosition();
      node = this.startNode();
      var id = this.parseIdent(this.type !== _tokentype.types.name);

      //
      if (this.options.features["es7.asyncFunctions"]) {
        // async functions!
        if (id.name === "async" && !this.canInsertSemicolon()) {
          // arrow functions
          if (this.type === _tokentype.types.parenL) {
            var expr = this.parseParenAndDistinguishExpression(start, true, true);
            if (expr && expr.type === "ArrowFunctionExpression") {
              return expr;
            } else {
              node.callee = id;
              if (!expr) {
                node.arguments = [];
              } else if (expr.type === "SequenceExpression") {
                node.arguments = expr.expressions;
              } else {
                node.arguments = [expr];
              }
              return this.parseSubscripts(this.finishNode(node, "CallExpression"), start);
            }
          } else if (this.type === _tokentype.types.name) {
            id = this.parseIdent();
            this.expect(_tokentype.types.arrow);
            return this.parseArrowExpression(node, [id], true);
          }

          // normal functions
          if (this.type === _tokentype.types._function && !this.canInsertSemicolon()) {
            this.next();
            return this.parseFunction(node, false, false, true);
          }
        } else if (id.name === "await") {
          if (this.inAsync) return this.parseAwait(node);
        }
      }
      //

      if (canBeArrow && !this.canInsertSemicolon() && this.eat(_tokentype.types.arrow)) return this.parseArrowExpression(this.startNodeAt(start), [id]);
      return id;

    case _tokentype.types.regexp:
      var value = this.value;
      node = this.parseLiteral(value.value);
      node.regex = { pattern: value.pattern, flags: value.flags };
      return node;

    case _tokentype.types.num:case _tokentype.types.string:
      return this.parseLiteral(this.value);

    case _tokentype.types._null:case _tokentype.types._true:case _tokentype.types._false:
      node = this.startNode();
      node.value = this.type === _tokentype.types._null ? null : this.type === _tokentype.types._true;
      node.raw = this.type.keyword;
      this.next();
      return this.finishNode(node, "Literal");

    case _tokentype.types.parenL:
      return this.parseParenAndDistinguishExpression(null, null, canBeArrow);

    case _tokentype.types.bracketL:
      node = this.startNode();
      this.next();
      // check whether this is array comprehension or regular array
      if ((this.options.ecmaVersion >= 7 || this.options.features["es7.comprehensions"]) && this.type === _tokentype.types._for) {
        return this.parseComprehension(node, false);
      }
      node.elements = this.parseExprList(_tokentype.types.bracketR, true, true, refShorthandDefaultPos);
      return this.finishNode(node, "ArrayExpression");

    case _tokentype.types.braceL:
      return this.parseObj(false, refShorthandDefaultPos);

    case _tokentype.types._function:
      node = this.startNode();
      this.next();
      return this.parseFunction(node, false);

    case _tokentype.types.at:
      this.parseDecorators();

    case _tokentype.types._class:
      node = this.startNode();
      this.takeDecorators(node);
      return this.parseClass(node, false);

    case _tokentype.types._new:
      return this.parseNew();

    case _tokentype.types.backQuote:
      return this.parseTemplate();

    case _tokentype.types.doubleColon:
      node = this.startNode();
      this.next();
      node.object = null;
      var callee = node.callee = this.parseNoCallExpr();
      if (callee.type !== "MemberExpression") this.raise(callee.start, "Binding should be performed on object property.");
      return this.finishNode(node, "BindExpression");

    default:
      this.unexpected();
  }
};

pp.parseLiteral = function (value) {
  var node = this.startNode();
  node.value = value;
  node.raw = this.input.slice(this.start, this.end);
  this.next();
  return this.finishNode(node, "Literal");
};

pp.parseParenExpression = function () {
  this.expect(_tokentype.types.parenL);
  var val = this.parseExpression();
  this.expect(_tokentype.types.parenR);
  return val;
};

pp.parseParenAndDistinguishExpression = function (start, isAsync, canBeArrow) {
  start = start || this.markPosition();
  var val = undefined;
  if (this.options.ecmaVersion >= 6) {
    this.next();

    if ((this.options.features["es7.comprehensions"] || this.options.ecmaVersion >= 7) && this.type === _tokentype.types._for) {
      return this.parseComprehension(this.startNodeAt(start), true);
    }

    var innerStart = this.markPosition(),
        exprList = [],
        first = true;
    var refShorthandDefaultPos = { start: 0 },
        spreadStart = undefined,
        innerParenStart = undefined,
        optionalCommaStart = undefined;
    while (this.type !== _tokentype.types.parenR) {
      if (first) {
        first = false;
      } else {
        this.expect(_tokentype.types.comma);
        if (this.type === _tokentype.types.parenR && this.options.features["es7.trailingFunctionCommas"]) {
          optionalCommaStart = this.start;
          break;
        }
      }

      if (this.type === _tokentype.types.ellipsis) {
        var spreadNodeStart = this.markPosition();
        spreadStart = this.start;
        exprList.push(this.parseParenItem(this.parseRest(), spreadNodeStart));
        break;
      } else {
        if (this.type === _tokentype.types.parenL && !innerParenStart) {
          innerParenStart = this.start;
        }
        exprList.push(this.parseMaybeAssign(false, refShorthandDefaultPos, this.parseParenItem));
      }
    }
    var innerEnd = this.markPosition();
    this.expect(_tokentype.types.parenR);

    if (canBeArrow && !this.canInsertSemicolon() && this.eat(_tokentype.types.arrow)) {
      if (innerParenStart) this.unexpected(innerParenStart);
      return this.parseParenArrowList(start, exprList, isAsync);
    }

    if (!exprList.length) {
      if (isAsync) {
        return;
      } else {
        this.unexpected(this.lastTokStart);
      }
    }
    if (optionalCommaStart) this.unexpected(optionalCommaStart);
    if (spreadStart) this.unexpected(spreadStart);
    if (refShorthandDefaultPos.start) this.unexpected(refShorthandDefaultPos.start);

    if (exprList.length > 1) {
      val = this.startNodeAt(innerStart);
      val.expressions = exprList;
      this.finishNodeAt(val, "SequenceExpression", innerEnd);
    } else {
      val = exprList[0];
    }
  } else {
    val = this.parseParenExpression();
  }

  if (this.options.preserveParens) {
    var par = this.startNodeAt(start);
    par.expression = val;
    return this.finishNode(par, "ParenthesizedExpression");
  } else {
    val.parenthesizedExpression = true;
    return val;
  }
};

pp.parseParenArrowList = function (start, exprList, isAsync) {
  return this.parseArrowExpression(this.startNodeAt(start), exprList, isAsync);
};

pp.parseParenItem = function (node, start) {
  return node;
};

// 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

var empty = [];

pp.parseNew = function () {
  var node = this.startNode();
  var meta = this.parseIdent(true);
  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");
    return this.finishNode(node, "MetaProperty");
  }
  node.callee = this.parseNoCallExpr();
  if (this.eat(_tokentype.types.parenL)) node.arguments = this.parseExprList(_tokentype.types.parenR, this.options.features["es7.trailingFunctionCommas"]);else node.arguments = empty;
  return this.finishNode(node, "NewExpression");
};

// Parse template expression.

pp.parseTemplateElement = function () {
  var elem = this.startNode();
  elem.value = {
    raw: this.input.slice(this.start, this.end).replace(/\r\n?/g, "\n"),
    cooked: this.value
  };
  this.next();
  elem.tail = this.type === _tokentype.types.backQuote;
  return this.finishNode(elem, "TemplateElement");
};

pp.parseTemplate = function () {
  var node = this.startNode();
  this.next();
  node.expressions = [];
  var curElt = this.parseTemplateElement();
  node.quasis = [curElt];
  while (!curElt.tail) {
    this.expect(_tokentype.types.dollarBraceL);
    node.expressions.push(this.parseExpression());
    this.expect(_tokentype.types.braceR);
    node.quasis.push(curElt = this.parseTemplateElement());
  }
  this.next();
  return this.finishNode(node, "TemplateLiteral");
};

// Parse an object literal or binding pattern.

pp.parseObj = function (isPattern, refShorthandDefaultPos) {
  var node = this.startNode(),
      first = true,
      propHash = {};
  node.properties = [];
  var decorators = [];
  this.next();
  while (!this.eat(_tokentype.types.braceR)) {
    if (!first) {
      this.expect(_tokentype.types.comma);
      if (this.afterTrailingComma(_tokentype.types.braceR)) break;
    } else first = false;
    while (this.type === _tokentype.types.at) {
      decorators.push(this.parseDecorator());
    }
    var prop = this.startNode(),
        isGenerator = false,
        isAsync = false,
        start = undefined;
    if (decorators.length) {
      prop.decorators = decorators;
      decorators = [];
    }
    if (this.options.features["es7.objectRestSpread"] && this.type === _tokentype.types.ellipsis) {
      prop = this.parseSpread();
      prop.type = "SpreadProperty";
      node.properties.push(prop);
      continue;
    }
    if (this.options.ecmaVersion >= 6) {
      prop.method = false;
      prop.shorthand = false;
      if (isPattern || refShorthandDefaultPos) start = this.markPosition();
      if (!isPattern) isGenerator = this.eat(_tokentype.types.star);
    }
    if (this.options.features["es7.asyncFunctions"] && this.isContextual("async")) {
      if (isGenerator || isPattern) this.unexpected();
      var asyncId = this.parseIdent();
      if (this.type === _tokentype.types.colon || this.type === _tokentype.types.parenL) {
        prop.key = asyncId;
      } else {
        isAsync = true;
        this.parsePropertyName(prop);
      }
    } else {
      this.parsePropertyName(prop);
    }
    this.parseObjPropValue(prop, start, isGenerator, isAsync, isPattern, refShorthandDefaultPos);
    this.checkPropClash(prop, propHash);
    node.properties.push(this.finishNode(prop, "Property"));
  }
  if (decorators.length) {
    this.raise(this.start, "You have trailing decorators with no property");
  }
  return this.finishNode(node, isPattern ? "ObjectPattern" : "ObjectExpression");
};

pp.parseObjPropValue = function (prop, start, isGenerator, isAsync, isPattern, refShorthandDefaultPos) {
  if (this.eat(_tokentype.types.colon)) {
    prop.value = isPattern ? this.parseMaybeDefault() : this.parseMaybeAssign(false, refShorthandDefaultPos);
    prop.kind = "init";
  } else if (this.options.ecmaVersion >= 6 && this.type === _tokentype.types.parenL) {
    if (isPattern) this.unexpected();
    prop.kind = "init";
    prop.method = true;
    prop.value = this.parseMethod(isGenerator, isAsync);
  } else if (this.options.ecmaVersion >= 5 && !prop.computed && prop.key.type === "Identifier" && (prop.key.name === "get" || prop.key.name === "set") && (this.type != _tokentype.types.comma && this.type != _tokentype.types.braceR)) {
    if (isGenerator || isAsync || isPattern) this.unexpected();
    prop.kind = prop.key.name;
    this.parsePropertyName(prop);
    prop.value = this.parseMethod(false);
    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");
    }
  } else if (this.options.ecmaVersion >= 6 && !prop.computed && prop.key.type === "Identifier") {
    prop.kind = "init";
    if (isPattern) {
      if (this.isKeyword(prop.key.name) || this.strict && (_identifier.reservedWords.strictBind(prop.key.name) || _identifier.reservedWords.strict(prop.key.name)) || !this.options.allowReserved && this.isReservedWord(prop.key.name)) this.raise(prop.key.start, "Binding " + prop.key.name);
      prop.value = this.parseMaybeDefault(start, prop.key);
    } else if (this.type === _tokentype.types.eq && refShorthandDefaultPos) {
      if (!refShorthandDefaultPos.start) refShorthandDefaultPos.start = this.start;
      prop.value = this.parseMaybeDefault(start, prop.key);
    } else {
      prop.value = prop.key;
    }
    prop.shorthand = true;
  } else this.unexpected();
};

pp.parsePropertyName = function (prop) {
  if (this.options.ecmaVersion >= 6) {
    if (this.eat(_tokentype.types.bracketL)) {
      prop.computed = true;
      prop.key = this.parseMaybeAssign();
      this.expect(_tokentype.types.bracketR);
      return prop.key;
    } else {
      prop.computed = false;
    }
  }
  return prop.key = this.type === _tokentype.types.num || this.type === _tokentype.types.string ? this.parseExprAtom() : this.parseIdent(true);
};

// Initialize empty function node.

pp.initFunction = function (node, isAsync) {
  node.id = null;
  if (this.options.ecmaVersion >= 6) {
    node.generator = false;
    node.expression = false;
  }
  if (this.options.features["es7.asyncFunctions"]) {
    node.async = !!isAsync;
  }
};

// Parse object or class method.

pp.parseMethod = function (isGenerator, isAsync) {
  var node = this.startNode();
  this.initFunction(node, isAsync);
  this.expect(_tokentype.types.parenL);
  node.params = this.parseBindingList(_tokentype.types.parenR, false, this.options.features["es7.trailingFunctionCommas"]);
  if (this.options.ecmaVersion >= 6) {
    node.generator = isGenerator;
  }
  this.parseFunctionBody(node);
  return this.finishNode(node, "FunctionExpression");
};

// Parse arrow function expression with given parameters.

pp.parseArrowExpression = function (node, params, isAsync) {
  this.initFunction(node, isAsync);
  node.params = this.toAssignableList(params, true);
  this.parseFunctionBody(node, true);
  return this.finishNode(node, "ArrowFunctionExpression");
};

// Parse function body and check parameters.

pp.parseFunctionBody = function (node, allowExpression) {
  var isExpression = allowExpression && this.type !== _tokentype.types.braceL;

  var oldInAsync = this.inAsync;
  this.inAsync = node.async;
  if (isExpression) {
    node.body = this.parseMaybeAssign();
    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 = this.inFunction,
        oldInGen = this.inGenerator,
        oldLabels = this.labels;
    this.inFunction = true;this.inGenerator = node.generator;this.labels = [];
    node.body = this.parseBlock(true);
    node.expression = false;
    this.inFunction = oldInFunc;this.inGenerator = oldInGen;this.labels = oldLabels;
  }
  this.inAsync = oldInAsync;

  // 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 (this.strict || !isExpression && node.body.body.length && this.isUseStrict(node.body.body[0])) {
    var nameHash = {},
        oldStrict = this.strict;
    this.strict = true;
    if (node.id) this.checkLVal(node.id, true);
    for (var i = 0; i < node.params.length; i++) {
      this.checkLVal(node.params[i], true, nameHash);
    }this.strict = oldStrict;
  }
};

// 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).

pp.parseExprList = function (close, allowTrailingComma, allowEmpty, refShorthandDefaultPos) {
  var elts = [],
      first = true;
  while (!this.eat(close)) {
    if (!first) {
      this.expect(_tokentype.types.comma);
      if (allowTrailingComma && this.afterTrailingComma(close)) break;
    } else first = false;

    if (allowEmpty && this.type === _tokentype.types.comma) {
      elts.push(null);
    } else {
      if (this.type === _tokentype.types.ellipsis) elts.push(this.parseSpread(refShorthandDefaultPos));else elts.push(this.parseMaybeAssign(false, refShorthandDefaultPos));
    }
  }
  return elts;
};

// Parse the next token as an identifier. If `liberal` is true (used
// when parsing properties), it will also convert keywords into
// identifiers.

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.options.allowReserved && this.isReservedWord(this.value) || this.strict && _identifier.reservedWords.strict(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");
    node.name = this.value;
  } else if (liberal && this.type.keyword) {
    node.name = this.type.keyword;
  } else {
    this.unexpected();
  }
  this.next();
  return this.finishNode(node, "Identifier");
};

// Parses await expression inside async function.

pp.parseAwait = function (node) {
  if (this.eat(_tokentype.types.semi) || this.canInsertSemicolon()) {
    this.unexpected();
  }
  node.all = this.eat(_tokentype.types.star);
  node.argument = this.parseMaybeUnary();
  return this.finishNode(node, "AwaitExpression");
};

// Parses yield expression inside generator.

pp.parseYield = function () {
  var node = this.startNode();
  this.next();
  if (this.type == _tokentype.types.semi || this.canInsertSemicolon() || this.type != _tokentype.types.star && !this.type.startsExpr) {
    node.delegate = false;
    node.argument = null;
  } else {
    node.delegate = this.eat(_tokentype.types.star);
    node.argument = this.parseMaybeAssign();
  }
  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");
};