GeneratorFunction() makes generator instances

src/generator.js

Index: src/generator.js
diff --git a/src/generator.js b/src/generator.js
index 5e61091565567bf9d516a45d0efd72add6aa33af..d2e53ee7cafb070317de32af9837c8c8fcdaa580 100644
--- a/src/generator.js
+++ b/src/generator.js
@@ -65,6 +65,24 @@ function GeneratorObjectThrow(exn) {
   return %_GeneratorThrow(this, exn);
 }
 
+function GeneratorFunctionPrototypeConstructor(x) {
+  if (%_IsConstructCall()) {
+    throw MakeTypeError('not_constructor', ['GeneratorFunctionPrototype']);
+  }
+}
+
+function GeneratorFunctionConstructor(arg1) {  // length == 1
+  var n = %_ArgumentsLength();
+  if (n > 0) {
+    var formals = new InternalArray(n - 1);
+    for (var i = 0; i < n - 1; i++) formals[i] = %_Arguments(i);
+    return NewFunction(formals, ToString(%_Arguments(n - 1)), true);
+  } else {
+    return NewFunction(new InternalArray(0), '', true);
+  }
+}
+
+
 function SetUpGenerators() {
   %CheckIsBootstrapping();
   var GeneratorObjectPrototype = GeneratorFunctionPrototype.prototype;
@@ -76,9 +94,11 @@ function SetUpGenerators() {
   %SetProperty(GeneratorObjectPrototype, "constructor",
                GeneratorFunctionPrototype, DONT_ENUM | DONT_DELETE | READ_ONLY);
   %SetPrototype(GeneratorFunctionPrototype, $Function.prototype);
+  %SetCode(GeneratorFunctionPrototype, GeneratorFunctionPrototypeConstructor);
   %SetProperty(GeneratorFunctionPrototype, "constructor",
                GeneratorFunction, DONT_ENUM | DONT_DELETE | READ_ONLY);
   %SetPrototype(GeneratorFunction, $Function);
+  %SetCode(GeneratorFunction, GeneratorFunctionConstructor);
 }
 
 SetUpGenerators();