Implement WeakMap.prototype.clear function.

R=rossberg@chromium.org
BUG=v8:2753
TEST=mjsunit/harmony/collections

Review URL: https://codereview.chromium.org/18352002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15421 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/collection.js

@@ -295,6 +295,16 @@ function WeakMapDelete(key) {
 }
 
 
+function WeakMapClear() {
+  if (!IS_WEAKMAP(this)) {
+    throw MakeTypeError('incompatible_method_receiver',
+                        ['WeakMap.prototype.clear', this]);
+  }
+  // Replace the internal table with a new empty table.
+  %WeakMapInitialize(this);
+}
+
+
 // -------------------------------------------------------------------
 
 function SetUpWeakMap() {
@@ -309,7 +319,8 @@ function SetUpWeakMap() {
     "get", WeakMapGet,
     "set", WeakMapSet,
     "has", WeakMapHas,
-    "delete", WeakMapDelete
+    "delete", WeakMapDelete,
+    "clear", WeakMapClear
   ));
 }
 

test/mjsunit/harmony/collections.js

@@ -377,17 +377,39 @@ for (var i = 9; i >= 0; i--) {
   assertEquals(i, m.size);
 }
 
-// Test clear
-var a = new Set();
-s.add(42);
-assertTrue(s.has(42));
-s.clear();
-assertFalse(s.has(42));
-assertEquals(0, s.size);
 
-var m = new Map();
-m.set(42, true);
-assertTrue(m.has(42));
-m.clear();
-assertFalse(m.has(42));
-assertEquals(0, m.size);
+// Test Set clear
+(function() {
+  var s = new Set();
+  s.add(42);
+  assertTrue(s.has(42));
+  assertEquals(1, s.size);
+  s.clear();
+  assertFalse(s.has(42));
+  assertEquals(0, s.size);
+})();
+
+
+// Test Map clear
+(function() {
+  var m = new Map();
+  m.set(42, true);
+  assertTrue(m.has(42));
+  assertEquals(1, m.size);
+  m.clear();
+  assertFalse(m.has(42));
+  assertEquals(0, m.size);
+})();
+
+
+// Test WeakMap clear
+(function() {
+  var k = new Object();
+  var w = new WeakMap();
+  w.set(k, 23);
+  assertTrue(w.has(k));
+  assertEquals(23, w.get(k));
+  w.clear();
+  assertFalse(w.has(k));
+  assertEquals(undefined, w.get(k));
+})();