optimisations

tiramisu/setting.py

@@ -138,7 +138,7 @@ class OptionBag:
                    index,
                    config_bag):
         if path is None:
-            path = config_bag.context.cfgimpl_get_description().impl_get_path_by_opt(option)
+            path = option.impl_getpath(config_bag.context)
         self.path = path
         self.index = index
         self.option = option
@@ -156,6 +156,11 @@ class OptionBag:
             return True
         raise KeyError('unknown key {} for OptionBag'.format(key))
 
+    def __delattr__(self, key):
+        if key == 'properties':
+            return
+        raise KeyError('unknown key {} for ConfigBag'.format(key))
+
     def copy(self):
         kwargs = {}
         option_bag = OptionBag()