Generator objects can suspend

src/ast.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1946 matching lines @@
   KeyedAccessStoreMode store_mode_ : 5;  // Windows treats as signed,
                                          // must have extra bit.
   SmallMapList receiver_types_;
 };
 
 
 class Yield: public Expression {
  public:
   DECLARE_NODE_TYPE(Yield)
 
+  enum Kind {
+    INITIAL,     // The initial yield that returns the unboxed generator object.
+    SUSPEND,     // A normal yield: { value: EXPRESSION, done: false }
+    DELEGATING,  // A yield*.
+    FINAL        // A return: { value: EXPRESSION, done: true }
+  };
+
   Expression* generator_object() const { return generator_object_; }
   Expression* expression() const { return expression_; }
-  bool is_delegating_yield() const { return is_delegating_yield_; }
+  Kind yield_kind() const { return yield_kind_; }
   virtual int position() const { return pos_; }
 
  protected:
   Yield(Isolate* isolate,
         Expression* generator_object,
         Expression* expression,
-        bool is_delegating_yield,
+        Kind yield_kind,
         int pos)
       : Expression(isolate),
         generator_object_(generator_object),
         expression_(expression),
-        is_delegating_yield_(is_delegating_yield),
+        yield_kind_(yield_kind),
         pos_(pos) { }
 
  private:
   Expression* generator_object_;
   Expression* expression_;
-  bool is_delegating_yield_;
+  Kind yield_kind_;
   int pos_;
 };
 
 
 class Throw: public Expression {
  public:
   DECLARE_NODE_TYPE(Throw)
 
   Expression* exception() const { return exception_; }
   virtual int position() const { return pos_; }
@@ skipping 961 matching lines @@
                             Expression* value,
                             int pos) {
     Assignment* assign =
         new(zone_) Assignment(isolate_, op, target, value, pos);
     assign->Init(isolate_, this);
     VISIT_AND_RETURN(Assignment, assign)
   }
 
   Yield* NewYield(Expression *generator_object,
                   Expression* expression,
-                  bool is_delegating_yield,
+                  Yield::Kind yield_kind,
                   int pos) {
     Yield* yield = new(zone_) Yield(
-        isolate_, generator_object, expression, is_delegating_yield, pos);
+        isolate_, generator_object, expression, yield_kind, pos);
     VISIT_AND_RETURN(Yield, yield)
   }
 
   Throw* NewThrow(Expression* exception, int pos) {
     Throw* t = new(zone_) Throw(isolate_, exception, pos);
     VISIT_AND_RETURN(Throw, t)
   }
 
   FunctionLiteral* NewFunctionLiteral(
       Handle<String> name,
@@ skipping 40 matching lines @@
  private:
   Isolate* isolate_;
   Zone* zone_;
   Visitor visitor_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_