ES6: Add support for Set and Map clear method

src/collection.js

 // 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 79 matching lines @@
 
 function SetGetSize() {
   if (!IS_SET(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['Set.prototype.size', this]);
   }
   return %SetGetSize(this);
 }
 
 
+function SetClear() {
+  if (!IS_SET(this)) {
+    throw MakeTypeError('incompatible_method_receiver',
+                        ['Set.prototype.clear', this]);
+  }
+  // Replace the internal table with a new empty table.
+  %SetInitialize(this);

[arv (Not doing code reviews), 2012/11/08 21:16:28]

I first added a %SetClear before I realized that it would do exactly the same as
%SetInitialize. It might be less confusing to have SetClear? WDYT?

[Michael Starzinger, 2012/11/09 08:56:12]

That's fine, I prefer it the way it is as well. The less entry points into the
runtime the better. Should we start optimizing these entry points it's much
simpler that way.

+}
+
+
 function MapConstructor() {
   if (%_IsConstructCall()) {
     %MapInitialize(this);
   } else {
     return new $Map();
   }
 }
 
 
 function MapGet(key) {
@@ skipping 46 matching lines @@
 
 function MapGetSize() {
   if (!IS_MAP(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['Map.prototype.size', this]);
   }
   return %MapGetSize(this);
 }
 
 
+function MapClear() {
+  if (!IS_MAP(this)) {
+    throw MakeTypeError('incompatible_method_receiver',
+                        ['Map.prototype.clear', this]);
+  }
+  // Replace the internal table with a new empty table.
+  %MapInitialize(this);
+}
+
+
 function WeakMapConstructor() {
   if (%_IsConstructCall()) {
     %WeakMapInitialize(this);
   } else {
     return new $WeakMap();
   }
 }
 
 
 function WeakMapGet(key) {
@@ skipping 54 matching lines @@
 
   // Set up the constructor property on the Set and Map prototype object.
   %SetProperty($Set.prototype, "constructor", $Set, DONT_ENUM);
   %SetProperty($Map.prototype, "constructor", $Map, DONT_ENUM);
 
   // Set up the non-enumerable functions on the Set prototype object.
   InstallGetter($Set.prototype, "size", SetGetSize);
   InstallFunctions($Set.prototype, DONT_ENUM, $Array(
     "add", SetAdd,
     "has", SetHas,
-    "delete", SetDelete
+    "delete", SetDelete,
+    "clear", SetClear
   ));
 
   // Set up the non-enumerable functions on the Map prototype object.
   InstallGetter($Map.prototype, "size", MapGetSize);
   InstallFunctions($Map.prototype, DONT_ENUM, $Array(
     "get", MapGet,
     "set", MapSet,
     "has", MapHas,
-    "delete", MapDelete
+    "delete", MapDelete,
+    "clear", MapClear
   ));
 
   // Set up the WeakMap constructor function.
   %SetCode($WeakMap, WeakMapConstructor);
 
   // Set up the constructor property on the WeakMap prototype object.
   %SetProperty($WeakMap.prototype, "constructor", $WeakMap, DONT_ENUM);
 
   // Set up the non-enumerable functions on the WeakMap prototype object.
   InstallFunctions($WeakMap.prototype, DONT_ENUM, $Array(
     "get", WeakMapGet,
     "set", WeakMapSet,
     "has", WeakMapHas,
     "delete", WeakMapDelete
   ));
 })();