LibJS: Pass "this" as an Object* to NativeFunction callbacks

Instead of every NativeFunction callback having to ask the Interpreter
for the current "this" value and then converting it to an Object etc,
just pass "this" as an Object* directly.

Libraries/LibJS/GlobalObject.cpp

@@ -11,14 +11,14 @@ namespace JS {
 
 GlobalObject::GlobalObject()
 {
-    put_native_function("print", [](Interpreter&, Vector<Value> arguments) -> Value {
+    put_native_function("print", [](Object*, Vector<Value> arguments) -> Value {
         for (auto& argument : arguments)
             printf("%s ", argument.to_string().characters());
         return js_undefined();
     });
-    put_native_function("gc", [](Interpreter& interpreter, Vector<Value>) -> Value {
+    put_native_function("gc", [](Object* this_object, Vector<Value>) -> Value {
         dbg() << "Forced garbage collection requested!";
-        interpreter.heap().collect_garbage();
+        this_object->heap().collect_garbage();
         return js_undefined();
     });
 }

Libraries/LibJS/NativeFunction.cpp

@@ -30,7 +30,7 @@
 
 namespace JS {
 
-NativeFunction::NativeFunction(AK::Function<Value(Interpreter&, Vector<Value>)> native_function)
+NativeFunction::NativeFunction(AK::Function<Value(Object*, Vector<Value>)> native_function)
     : m_native_function(move(native_function))
 {
 }
@@ -41,7 +41,9 @@ NativeFunction::~NativeFunction()
 
 Value NativeFunction::call(Interpreter& interpreter, Vector<Value> arguments)
 {
-    return m_native_function(interpreter, move(arguments));
+    auto this_value = interpreter.this_value();
+    ASSERT(this_value.is_object());
+    return m_native_function(this_value.as_object(), move(arguments));
 }
 
 }

Libraries/LibJS/NativeFunction.h

@@ -33,7 +33,7 @@ namespace JS {
 
 class NativeFunction final : public Function {
 public:
-    explicit NativeFunction(AK::Function<Value(Interpreter&, Vector<Value>)>);
+    explicit NativeFunction(AK::Function<Value(Object*, Vector<Value>)>);
     virtual ~NativeFunction() override;
 
     virtual Value call(Interpreter&, Vector<Value>) override;
@@ -42,7 +42,7 @@ private:
     virtual bool is_native_function() const override { return true; }
     virtual const char* class_name() const override { return "NativeFunction"; }
 
-    AK::Function<Value(Interpreter&, Vector<Value>)> m_native_function;
+    AK::Function<Value(Object*, Vector<Value>)> m_native_function;
 };
 
 }

Libraries/LibJS/Object.cpp

@@ -63,7 +63,7 @@ void Object::put(String property_name, Value value)
     m_properties.set(property_name, move(value));
 }
 
-void Object::put_native_function(String property_name, AK::Function<Value(Interpreter&, Vector<Value>)> native_function)
+void Object::put_native_function(String property_name, AK::Function<Value(Object*, Vector<Value>)> native_function)
 {
     put(property_name, heap().allocate<NativeFunction>(move(native_function)));
 }

Libraries/LibJS/Object.h

@@ -41,7 +41,7 @@ public:
     Value get(String property_name) const;
     void put(String property_name, Value);
 
-    void put_native_function(String property_name, AK::Function<Value(Interpreter&, Vector<Value>)>);
+    void put_native_function(String property_name, AK::Function<Value(Object*, Vector<Value>)>);
     void put_native_property(String property_name, AK::Function<Value(Object*)> getter, AK::Function<void(Object*, Value)> setter);
 
     virtual bool is_function() const { return false; }

Libraries/LibJS/ObjectPrototype.cpp

@@ -37,13 +37,11 @@ ObjectPrototype::ObjectPrototype()
 {
     set_prototype(nullptr);
 
-    put_native_function("hasOwnProperty", [](Interpreter& interpreter, Vector<Value> arguments) -> Value {
-        dbg() << "hasOwnProperty";
+    put_native_function("hasOwnProperty", [](Object* this_object, Vector<Value> arguments) -> Value {
+        ASSERT(this_object);
         if (arguments.is_empty())
             return js_undefined();
-        Value this_value = interpreter.this_value();
-        ASSERT(this_value.is_object());
-        return Value(this_value.as_object()->has_own_property(arguments[0].to_string()));
+        return Value(this_object->has_own_property(arguments[0].to_string()));
     });
 }
 

Libraries/LibJS/StringPrototype.cpp

@@ -34,25 +34,27 @@
 
 namespace JS {
 
+
+
 StringPrototype::StringPrototype()
 {
     put_native_property(
-        "length", [](Object* object) {
-            ASSERT(object->is_string_object());
-            return Value((i32) static_cast<const StringObject*>(object)->primitive_string()->string().length());
+        "length", [](Object* this_object) {
+        ASSERT(this_object);
+            ASSERT(this_object->is_string_object());
+            return Value((i32) static_cast<const StringObject*>(this_object)->primitive_string()->string().length());
         },
         nullptr);
-    put_native_function("charAt", [](Interpreter& interpreter, Vector<Value> arguments) -> Value {
+    put_native_function("charAt", [](Object* this_object, Vector<Value> arguments) -> Value {
+        ASSERT(this_object);
         i32 index = 0;
         if (!arguments.is_empty())
             index = arguments[0].to_i32();
-        Value this_value = interpreter.this_value();
-        ASSERT(this_value.is_object());
-        ASSERT(this_value.as_object()->is_string_object());
-        auto underlying_string = static_cast<const StringObject*>(this_value.as_object())->primitive_string()->string();
+        ASSERT(this_object->is_string_object());
+        auto underlying_string = static_cast<const StringObject*>(this_object)->primitive_string()->string();
         if (index < 0 || index >= static_cast<i32>(underlying_string.length()))
-            return js_string(interpreter.heap(), String::empty());
-        return js_string(interpreter.heap(), underlying_string.substring(index, 1));
+            return js_string(this_object->heap(), String::empty());
+        return js_string(this_object->heap(), underlying_string.substring(index, 1));
     });
 }
 

Libraries/LibWeb/Bindings/DocumentWrapper.cpp

@@ -36,7 +36,7 @@ namespace Bindings {
 DocumentWrapper::DocumentWrapper(Document& document)
     : NodeWrapper(document)
 {
-    put_native_function("getElementById", [this](JS::Interpreter&, Vector<JS::Value> arguments) -> JS::Value {
+    put_native_function("getElementById", [this](JS::Object*, Vector<JS::Value> arguments) -> JS::Value {
         if (arguments.is_empty())
             return JS::js_null();
         auto id = arguments[0].to_string();

Libraries/LibWeb/DOM/Document.cpp

@@ -341,7 +341,7 @@ JS::Interpreter& Document::interpreter()
     if (!m_interpreter) {
         m_interpreter = make<JS::Interpreter>();
 
-        m_interpreter->global_object().put_native_function("alert", [](JS::Interpreter&, Vector<JS::Value> arguments) -> JS::Value {
+        m_interpreter->global_object().put_native_function("alert", [](JS::Object*, Vector<JS::Value> arguments) -> JS::Value {
             if (arguments.size() < 1)
                 return JS::js_undefined();
             GUI::MessageBox::show(arguments[0].to_string(), "Alert", GUI::MessageBox::Type::Information);