[es6] Introduce %ToInteger and %ToLength.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 0059a6a64801c462be7b301e0f609d750f1a71af..ca941ce4e21a0c6c0a6b6eb9cc54e8ffd3441054 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -133,6 +133,27 @@ MaybeHandle<Object> Object::ToNumber(Handle<Object> input) {
 
 
 // static
+MaybeHandle<Object> Object::ToInteger(Isolate* isolate, Handle<Object> input) {
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, input, ToNumber(input), Object);
+  return isolate->factory()->NewNumber(DoubleToInteger(input->Number()));
+}
+
+
+// static
+MaybeHandle<Object> Object::ToInt32(Isolate* isolate, Handle<Object> input) {
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, input, ToNumber(input), Object);
+  return isolate->factory()->NewNumberFromInt(DoubleToInt32(input->Number()));
+}
+
+
+// static
+MaybeHandle<Object> Object::ToUint32(Isolate* isolate, Handle<Object> input) {
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, input, ToNumber(input), Object);
+  return isolate->factory()->NewNumberFromUint(DoubleToUint32(input->Number()));
+}
+
+
+// static
 MaybeHandle<String> Object::ToString(Isolate* isolate, Handle<Object> input) {
   while (true) {
     if (input->IsString()) {
@@ -159,6 +180,19 @@ MaybeHandle<String> Object::ToString(Isolate* isolate, Handle<Object> input) {
 }
 
 
+// static
+MaybeHandle<Object> Object::ToLength(Isolate* isolate, Handle<Object> input) {
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, input, ToNumber(input), Object);
+  double len = DoubleToInteger(input->Number());
+  if (len <= 0.0) {
+    len = 0.0;
+  } else if (len >= kMaxSafeInteger) {
+    len = kMaxSafeInteger;
+  }
+  return isolate->factory()->NewNumber(len);
+}
+
+
 bool Object::BooleanValue() {
   if (IsBoolean()) return IsTrue();
   if (IsSmi()) return Smi::cast(this)->value() != 0;