Improved cpl-query & added first types from discord

src/cpl_query/_query/select.py

@@ -0,0 +1,19 @@
+from typing import Callable
+
+from cpl_query.extension.iterable_abc import IterableABC
+
+
+def select_query(_list: IterableABC, _f: Callable) -> any:
+    result = IterableABC()
+    result.extend(_f(_o) for _o in _list)
+    return result
+
+
+def select_many_query(_list: IterableABC, _f: Callable) -> any:
+    result = IterableABC()
+    # The line below is pain. I don't understand anything of it...
+    # written on 09.11.2022 by Sven Heidemann
+    elements = [_a for _o in _list for _a in _f(_o)]
+
+    result.extend(elements)
+    return result

src/cpl_query/extension/iterable.py

@@ -14,6 +14,7 @@ from cpl_query._query.for_each import for_each_query
 from cpl_query._query.max_min import max_query, min_query
 from cpl_query._query.order_by import order_by_descending_query, order_by_query
 from cpl_query._query.reverse import reverse_query
+from cpl_query._query.select import select_query, select_many_query
 from cpl_query._query.single import single_or_default_query, single_query
 from cpl_query._query.skip_take import (skip_last_query, skip_query,
                                         take_last_query, take_query)
@@ -94,6 +95,12 @@ class Iterable(IterableABC):
     def single_or_default(self) -> Optional[any]:
         return single_or_default_query(self)
 
+    def select(self, _f: Callable) -> IterableABC:
+        return self.__to_self(select_query(self, _f))
+
+    def select_many(self, _f: Callable) -> IterableABC:
+        return self.__to_self(select_many_query(self, _f))
+
     def skip(self, index: int) -> IterableABC:
         return self.__to_self(skip_query(self, index))