/// <summary>
/// Return a dict that maps slot names to slot values, but only include slots that have been assigned to.
/// Looks up slots in base types as well as the current type.
///
/// Sort-of Python equivalent (doesn't look up base slots, while the real code does):
/// return dict([(slot, getattr(self, slot)) for slot in type(self).__slots__ if hasattr(self, slot)])
///
/// Return null if the object has no __slots__, or empty dict if it has __slots__ but none are initialized.
/// </summary>
private static PythonDictionary GetInitializedSlotValues(object obj) {
PythonDictionary initializedSlotValues = new PythonDictionary();
IList<PythonType> mro = DynamicHelpers.GetPythonType(obj).ResolutionOrder;
object slots;
object slotValue;
foreach (object type in mro) {
if (PythonOps.TryGetBoundAttr(type, Symbols.Slots, out slots)) {
List<string> slotNames = NewTypeMaker.SlotsToList(slots);
foreach (string slotName in slotNames) {
if (slotName == "__dict__") continue;
// don't reassign same-named slots from types earlier in the MRO
if (initializedSlotValues.__contains__(slotName)) continue;
if (PythonOps.TryGetBoundAttr(obj, SymbolTable.StringToId(slotName), out slotValue)) {
initializedSlotValues[slotName] = slotValue;
}
}
}
}
if (initializedSlotValues.__len__() == 0) return null;
return initializedSlotValues;
}