ES6: Adding support for size to Set and Map

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index b0a6b5e81427e1588a89f1c269a2b1e90c78f98b..dda592dd7545db47153b106e870e1e83a112f0a1 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -783,6 +783,15 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_SetDelete) {
 }
 
 
+RUNTIME_FUNCTION(MaybeObject*, Runtime_SetGetSize) {
+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSSet, holder, 0);
+  Handle<ObjectHashSet> table(ObjectHashSet::cast(holder->table()));
+  return Smi::FromInt(table->NumberOfElements());
+}
+
+
 RUNTIME_FUNCTION(MaybeObject*, Runtime_MapInitialize) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
@@ -842,6 +851,15 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_MapSet) {
 }
 
 
+RUNTIME_FUNCTION(MaybeObject*, Runtime_MapGetSize) {
+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSMap, holder, 0);
+  Handle<ObjectHashTable> table(ObjectHashTable::cast(holder->table()));
+  return Smi::FromInt(table->NumberOfElements());
+}
+
+
 RUNTIME_FUNCTION(MaybeObject*, Runtime_WeakMapInitialize) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);