Performance improvements

src/cpl_query/extension/list.py

@@ -1,4 +1,4 @@
-from typing import Iterable as IterableType
+from typing import Iterator
 
 from cpl_query.iterable.iterable import Iterable
 
@@ -7,9 +7,18 @@ class List(Iterable):
     r"""Implementation of :class: `cpl_query.extension.iterable.Iterable`
     """
 
-    def __init__(self, t: type = None, values: IterableType = None):
+    def __init__(self, t: type = None, values: Iterator = None):
         Iterable.__init__(self, t, values)
 
+    def __getitem__(self, *args):
+        return self._values.__getitem__(*args)
+
+    def __setitem__(self, *args):
+        self._values.__setitem__(*args)
+
+    def __delitem__(self, *args):
+        self._values.__delitem__(*args)
+
     def to_enumerable(self) -> 'EnumerableABC':
         r"""Converts :class: `cpl_query.iterable.iterable_abc.IterableABC` to :class: `cpl_query.enumerable.enumerable_abc.EnumerableABC`