Type Traversable.traverse() better, start types of submodule

1 files changed, 21 insertions, 18 deletions

diff --git a/git/util.py b/git/util.py
index eccaa74e..c7c8d07f 100644
--- a/git/util.py
+++ b/git/util.py
@@ -4,6 +4,9 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
+from .exc import InvalidGitRepositoryError
+import os.path as osp
+from .compat import is_win
 import contextlib
 from functools import wraps
 import getpass
@@ -20,9 +23,11 @@ from unittest import SkipTest
 from urllib.parse import urlsplit, urlunsplit
 import warnings
 
+# from git.objects.util import Traversable
+
 # typing ---------------------------------------------------------
 
-from typing import (Any, AnyStr, BinaryIO, Callable, Dict, Generator, IO, Iterator, List,
+from typing import (Any, AnyStr, BinaryIO, Callable, Dict, Generator, IO, Iterable as typIter, Iterator, List,
                     Optional, Pattern, Sequence, Tuple, TypeVar, Union, cast, TYPE_CHECKING, overload)
 
 import pathlib
@@ -32,8 +37,11 @@ if TYPE_CHECKING:
     from git.repo.base import Repo
     from git.config import GitConfigParser, SectionConstraint
 
-from .types import PathLike, Literal, SupportsIndex, HSH_TD, Files_TD
+from .types import PathLike, Literal, SupportsIndex, HSH_TD, Total_TD, Files_TD
+
+T_IterableObj = TypeVar('T_IterableObj', bound=Union['IterableObj', typIter], covariant=True)
 
+# So IterableList[Head] is subtype of IterableList[IterableObj]
 # ---------------------------------------------------------------------
 
 
@@ -49,11 +57,6 @@ from gitdb.util import (  # NOQA @IgnorePep8
     hex_to_bin,             # @UnusedImport
 )
 
-from .compat import is_win
-import os.path as osp
-
-from .exc import InvalidGitRepositoryError
-
 
 # NOTE:  Some of the unused imports might be used/imported by others.
 # Handle once test-cases are back up and running.
@@ -181,6 +184,7 @@ else:
     # no need for any work on linux
     def to_native_path_linux(path: PathLike) -> PathLike:
         return path
+
     to_native_path = to_native_path_linux
 
 
@@ -433,7 +437,7 @@ class RemoteProgress(object):
     Handler providing an interface to parse progress information emitted by git-push
     and git-fetch and to dispatch callbacks allowing subclasses to react to the progress.
     """
-    _num_op_codes = 9
+    _num_op_codes: int = 9
     BEGIN, END, COUNTING, COMPRESSING, WRITING, RECEIVING, RESOLVING, FINDING_SOURCES, CHECKING_OUT = \
         [1 << x for x in range(_num_op_codes)]
     STAGE_MASK = BEGIN | END
@@ -746,8 +750,6 @@ class Stats(object):
      files = number of changed files as int"""
     __slots__ = ("total", "files")
 
-    from git.types import Total_TD, Files_TD
-
     def __init__(self, total: Total_TD, files: Dict[PathLike, Files_TD]):
         self.total = total
         self.files = files
@@ -931,10 +933,7 @@ class BlockingLockFile(LockFile):
         # END endless loop
 
 
-T = TypeVar('T', bound='IterableObj')
-
-
-class IterableList(List[T]):
+class IterableList(List[T_IterableObj]):
 
     """
     List of iterable objects allowing to query an object by id or by named index::
@@ -1046,7 +1045,7 @@ class Iterable(object):
     @classmethod
     def list_items(cls, repo, *args, **kwargs):
         """
-        Deprecaated, use IterableObj instead.
+        Deprecated, use IterableObj instead.
         Find all items of this type - subclasses can specify args and kwargs differently.
         If no args are given, subclasses are obliged to return all items if no additional
         arguments arg given.
@@ -1068,12 +1067,15 @@ class Iterable(object):
 
 class IterableObj():
     """Defines an interface for iterable items which is to assure a uniform
-    way to retrieve and iterate items within the git repository"""
+    way to retrieve and iterate items within the git repository
+
+    Subclasses = [Submodule, Commit, Reference, PushInfo, FetchInfo, Remote]"""
+
     __slots__ = ()
     _id_attribute_ = "attribute that most suitably identifies your instance"
 
     @classmethod
-    def list_items(cls, repo: 'Repo', *args: Any, **kwargs: Any) -> IterableList[T]:
+    def list_items(cls, repo: 'Repo', *args: Any, **kwargs: Any) -> IterableList[T_IterableObj]:
         """
         Find all items of this type - subclasses can specify args and kwargs differently.
         If no args are given, subclasses are obliged to return all items if no additional
@@ -1087,7 +1089,8 @@ class IterableObj():
         return out_list
 
     @classmethod
-    def iter_items(cls, repo: 'Repo', *args: Any, **kwargs: Any) -> Iterator[T]:
+    def iter_items(cls, repo: 'Repo', *args: Any, **kwargs: Any
+                   ) -> Iterator[T_IterableObj]:
         # return typed to be compatible with subtypes e.g. Remote
         """For more information about the arguments, see list_items
         :return:  iterator yielding Items"""