arrange to create prototypes for generators

src/generators.js

 // Copyright 2013 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
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-"use strict";
+// TODO(wingo): Give link to specification. For now, the following diagram is
+// the spec:
+// http://wiki.ecmascript.org/lib/exe/fetch.php?cache=cache&media=harmony:es6_generator_object_model_3-29-13.png
 
-var $Symbol = global.Symbol;
+var GeneratorFunctionPrototype = function () {};
+function GeneratorFunction() {};
+var GeneratorIteratorPrototype = new $Object;
 
-function SymbolConstructor(x) {
-  var value =
-    IS_SYMBOL(x) ? x : %CreateSymbol(IS_UNDEFINED(x) ? x : ToString(x));
-  if (%_IsConstructCall()) {
-    %_SetValueOf(this, value);
-  } else {
-    return value;
-  }
+function GeneratorIteratorNext() {
+  // TODO(wingo): Implement.
 }
 
-function SymbolGetName() {
-  var symbol = IS_SYMBOL_WRAPPER(this) ? %_ValueOf(this) : this;
-  if (!IS_SYMBOL(symbol)) {
-    throw MakeTypeError(
-        'incompatible_method_receiver', ["Symbol.prototype.name", this]);
-  }
-  return %SymbolName(symbol);
+function GeneratorIteratorSend(value) {
+  // TODO(wingo): Implement.
 }
 
-function SymbolToString() {
-  throw MakeTypeError('symbol_to_string');
+function GeneratorIteratorThrow(exn) {
+  // TODO(wingo): Implement.
 }
 
-function SymbolValueOf() {
-  // NOTE: Both Symbol objects and values can enter here as
-  // 'this'. This is not as dictated by ECMA-262.
-  if (!IS_SYMBOL(this) && !IS_SYMBOL_WRAPPER(this)) {
-    throw MakeTypeError(
-        'incompatible_method_receiver', ["Symbol.prototype.valueOf", this]);
-  }
-  return %_ValueOf(this);
+function GeneratorIteratorClose() {
+  // TODO(wingo): Implement.
 }
 
-//-------------------------------------------------------------------
+function SetUpGenerators() {
+  %CheckIsBootstrapping();
+  // TODO(wingo): What are the right flags here?  Should these objects
+  // be extensible?  They are user-visible.
+  %SetPrototype(GeneratorFunction, $Function);
+  %FunctionSetPrototype(GeneratorFunction, GeneratorFunctionPrototype);
 
-function SetUpSymbol() {
-  %CheckIsBootstrapping();
+  %SetProperty(GeneratorFunctionPrototype, 'constructor', GeneratorFunction,
+               DONT_ENUM | DONT_DELETE | READ_ONLY);
+  %FunctionSetPrototype(GeneratorFunctionPrototype, GeneratorIteratorPrototype);

[rossberg, 2013/04/09 16:44:14]

Don't you also need to set GeneratorIteratorPrototype.constructor somewhere?

 
-  %SetCode($Symbol, SymbolConstructor);
-  %FunctionSetPrototype($Symbol, new $Symbol());
-  %SetProperty($Symbol.prototype, "constructor", $Symbol, DONT_ENUM);
-
-  InstallGetter($Symbol.prototype, "name", SymbolGetName);
-  InstallFunctions($Symbol.prototype, DONT_ENUM, $Array(
-    "toString", SymbolToString,
-    "valueOf", SymbolValueOf
-  ));
+  InstallFunctions(GeneratorIteratorPrototype,
+                   DONT_ENUM | DONT_DELETE | READ_ONLY,
+                   $Array("next", GeneratorIteratorNext,

[rossberg, 2013/04/09 16:44:14]

Nit: Use array literal here.

+                          "send", GeneratorIteratorSend,
+                          "throw", GeneratorIteratorThrow,
+                          "close", GeneratorIteratorClose));
 }
 
-SetUpSymbol();
+SetUpGenerators();