text: // Copyright 2013 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  (function() {
  
  "use strict";
  
  %CheckIsBootstrapping();
  
  var GlobalFunction = global.Function;
  
  // ----------------------------------------------------------------------------
  
  // Generator functions and objects are specified by ES6, sections 15.19.3 and
  // 15.19.4.
  
  function GeneratorObjectNext(value) {
    if (!IS_GENERATOR(this)) {
      throw MakeTypeError(kIncompatibleMethodReceiver,
                          '[Generator].prototype.next', this);
    }
  
    var continuation = %GeneratorGetContinuation(this);
    if (continuation > 0) {
      // Generator is suspended.
      if (DEBUG_IS_ACTIVE) %DebugPrepareStepInIfStepping(this);
      try {
        return %_GeneratorNext(this, value);
      } catch (e) {
        %GeneratorClose(this);
        throw e;
      }
    } else if (continuation == 0) {
      // Generator is already closed.
      return { value: void 0, done: true };
    } else {
      // Generator is running.
      throw MakeTypeError(kGeneratorRunning);
    }
  }
  
  
  function GeneratorObjectThrow(exn) {
    if (!IS_GENERATOR(this)) {
      throw MakeTypeError(kIncompatibleMethodReceiver,
                          '[Generator].prototype.throw', this);
    }
  
    var continuation = %GeneratorGetContinuation(this);
    if (continuation > 0) {
      // Generator is suspended.
      try {
        return %_GeneratorThrow(this, exn);
      } catch (e) {
        %GeneratorClose(this);
        throw e;
      }
    } else if (continuation == 0) {
      // Generator is already closed.
      throw exn;
    } else {
      // Generator is running.
      throw MakeTypeError(kGeneratorRunning);
    }
  }
  
  
  function GeneratorObjectIterator() {
    return this;
  }
  
  
  function GeneratorFunctionConstructor(arg1) {  // length == 1
    var source = NewFunctionString(arguments, 'function*');
    var global_proxy = %GlobalProxy(global);
    // Compile the string in the constructor and not a helper so that errors
    // appear to come from here.
    var f = %_CallFunction(global_proxy, %CompileString(source, true));
    %FunctionMarkNameShouldPrintAsAnonymous(f);
    return f;
  }
  
  // ----------------------------------------------------------------------------
  
  // Both Runtime_GeneratorNext and Runtime_GeneratorThrow are supported by
  // neither Crankshaft nor TurboFan, disable optimization of wrappers here.
  %NeverOptimizeFunction(GeneratorObjectNext);
  %NeverOptimizeFunction(GeneratorObjectThrow);
  
  // Set up non-enumerable functions on the generator prototype object.
  var GeneratorObjectPrototype = GeneratorFunctionPrototype.prototype;
  InstallFunctions(GeneratorObjectPrototype,
                   DONT_ENUM,
                   ["next", GeneratorObjectNext,
                    "throw", GeneratorObjectThrow]);
  
  %FunctionSetName(GeneratorObjectIterator, '[Symbol.iterator]');
  %AddNamedProperty(GeneratorObjectPrototype, symbolIterator,
      GeneratorObjectIterator, DONT_ENUM | DONT_DELETE | READ_ONLY);
  %AddNamedProperty(GeneratorObjectPrototype, "constructor",
      GeneratorFunctionPrototype, DONT_ENUM | READ_ONLY);
  %AddNamedProperty(GeneratorObjectPrototype,
      symbolToStringTag, "Generator", DONT_ENUM | READ_ONLY);
  %InternalSetPrototype(GeneratorFunctionPrototype, GlobalFunction.prototype);
  %AddNamedProperty(GeneratorFunctionPrototype,
      symbolToStringTag, "GeneratorFunction", DONT_ENUM | READ_ONLY);
  %AddNamedProperty(GeneratorFunctionPrototype, "constructor",
      GeneratorFunction, DONT_ENUM | READ_ONLY);
  %InternalSetPrototype(GeneratorFunction, GlobalFunction);
  %SetCode(GeneratorFunction, GeneratorFunctionConstructor);
  
  })();
  