Added order by functions

src/cpl_query/_query/order_by.py

@@ -0,0 +1,28 @@
+from collections import Callable
+
+from cpl_query.extension.iterable_abc import IterableABC
+from cpl_query.extension.ordered_iterable_abc import OrderedIterableABC
+
+
+def order_by_query(_list: IterableABC, _func: Callable) -> OrderedIterableABC:
+    result = OrderedIterableABC(_func)
+    _list.sort(key=_func)
+    result.extend(_list)
+    return result
+
+
+def order_by_descending_query(_list: IterableABC, _func: Callable) -> OrderedIterableABC:
+    result = OrderedIterableABC(_func)
+    _list.sort(key=_func, reverse=True)
+    result.extend(_list)
+    return result
+
+
+def then_by_query(_list: OrderedIterableABC, _func: Callable) -> OrderedIterableABC:
+    _list.sort(key=_func)
+    return _list
+
+
+def then_by_descending_query(_list: OrderedIterableABC, _func: Callable) -> OrderedIterableABC:
+    _list.sort(key=_func, reverse=True)
+    return _list