Merge pull request #619 from skinny121/class_property

Fix __class__

vm/src/obj/objfunction.rs

@@ -27,6 +27,18 @@ pub fn init(context: &PyContext) {
         context.new_rustfunc(member_get),
     );
 
+    let data_descriptor_type = &context.data_descriptor_type;
+    context.set_attr(
+        &data_descriptor_type,
+        "__get__",
+        context.new_rustfunc(data_get),
+    );
+    context.set_attr(
+        &data_descriptor_type,
+        "__set__",
+        context.new_rustfunc(data_set),
+    );
+
     let classmethod_type = &context.classmethod_type;
     context.set_attr(
         &classmethod_type,
@@ -83,6 +95,26 @@ fn member_get(vm: &mut VirtualMachine, mut args: PyFuncArgs) -> PyResult {
     }
 }
 
+fn data_get(vm: &mut VirtualMachine, mut args: PyFuncArgs) -> PyResult {
+    match args.shift().get_attr("fget") {
+        Some(function) => vm.invoke(function, args),
+        None => {
+            let attribute_error = vm.context().exceptions.attribute_error.clone();
+            Err(vm.new_exception(attribute_error, String::from("Attribute Error")))
+        }
+    }
+}
+
+fn data_set(vm: &mut VirtualMachine, mut args: PyFuncArgs) -> PyResult {
+    match args.shift().get_attr("fset") {
+        Some(function) => vm.invoke(function, args),
+        None => {
+            let attribute_error = vm.context().exceptions.attribute_error.clone();
+            Err(vm.new_exception(attribute_error, String::from("Attribute Error")))
+        }
+    }
+}
+
 // Classmethod type methods:
 fn classmethod_get(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     trace!("classmethod.__get__ {:?}", args.args);

vm/src/obj/objobject.rs

@@ -161,6 +161,11 @@ pub fn init(context: &PyContext) {
 
     context.set_attr(&object, "__new__", context.new_rustfunc(new_instance));
     context.set_attr(&object, "__init__", context.new_rustfunc(object_init));
+    context.set_attr(
+        &object,
+        "__class__",
+        context.new_data_descriptor(object_class, object_class_setter),
+    );
     context.set_attr(&object, "__eq__", context.new_rustfunc(object_eq));
     context.set_attr(&object, "__ne__", context.new_rustfunc(object_ne));
     context.set_attr(&object, "__lt__", context.new_rustfunc(object_lt));
@@ -190,6 +195,20 @@ fn object_init(vm: &mut VirtualMachine, _args: PyFuncArgs) -> PyResult {
     Ok(vm.ctx.none())
 }
 
+// TODO Use PyClassRef for owner to enforce type
+fn object_class(_obj: PyObjectRef, owner: PyObjectRef, _vm: &mut VirtualMachine) -> PyObjectRef {
+    owner
+}
+
+fn object_class_setter(
+    instance: PyObjectRef,
+    _value: PyObjectRef,
+    vm: &mut VirtualMachine,
+) -> PyResult {
+    let type_repr = vm.to_pystr(&instance.typ())?;
+    Err(vm.new_type_error(format!("can't change class of type '{}'", type_repr)))
+}
+
 fn object_dict(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     match args.args[0].payload {
         PyObjectPayload::Class { ref dict, .. } | PyObjectPayload::Instance { ref dict, .. } => {

vm/src/obj/objtype.rs

@@ -39,11 +39,6 @@ pub fn init(context: &PyContext) {
         "__mro__",
         context.new_member_descriptor(type_mro),
     );
-    context.set_attr(
-        &type_type,
-        "__class__",
-        context.new_member_descriptor(type_new),
-    );
     context.set_attr(&type_type, "__repr__", context.new_rustfunc(type_repr));
     context.set_attr(
         &type_type,