GeezerVison

Tools/clinic/clinic.py:536: error: Incompatible types in assignment (expression has type "list[Iterable[Parameter] | Parameter]", variable has type "list[Iterable[Parameter]]")  [assignment]
Tools/clinic/clinic.py:553: error: Argument 1 to "extend" of "list" has incompatible type "Iterable[Parameter]"; expected "Iterable[Iterable[Parameter]]"  [arg-type]
Tools/clinic/clinic.py:584: error: Argument 1 to "append" of "list" has incompatible type "tuple[Iterable[Parameter], ...]"; expected "Iterable[Parameter]"  [arg-type]
Tools/clinic/clinic.py:586: error: Argument "key" to "sort" of "list" has incompatible type "Callable[[Sized], int]"; expected "Callable[[Iterable[Parameter]], SupportsDunderLT[Any] | SupportsDunderGT[Any]]"  [arg-type]

--- a/Tools/clinic/clinic.py
+++ b/Tools/clinic/clinic.py
@@ -28,7 +28,7 @@
 import textwrap
 import traceback

-from collections.abc import Callable
+from collections.abc import Callable, Iterable, Iterator, Sequence
 from types import FunctionType, NoneType
 from typing import (
     Any,
@@ -516,7 +516,11 @@ class PythonLanguage(Language):
     checksum_line = "#/*[{dsl_name} end generated code: {arguments}]*/"


-def permute_left_option_groups(l):
+SequenceOfParameterGroups = Sequence[Iterable["Parameter"]]
+ParameterTuple = tuple["Parameter", ...]
+
+
+def permute_left_option_groups(l: SequenceOfParameterGroups) -> Iterator[ParameterTuple]:
     """
     Given [(1,), (2,), (3,)], should yield:
        ()
@@ -525,13 +529,13 @@ def permute_left_option_groups(l):
        (1, 2, 3)
     """
     yield tuple()
-    accumulator = []
+    accumulator: list[Parameter] = []
     for group in reversed(l):
         accumulator = list(group) + accumulator
         yield tuple(accumulator)


-def permute_right_option_groups(l):
+def permute_right_option_groups(l: SequenceOfParameterGroups) -> Iterator[ParameterTuple]:
     """
     Given [(1,), (2,), (3,)], should yield:
       ()
@@ -540,13 +544,17 @@ def permute_right_option_groups(l):
       (1, 2, 3)
     """
     yield tuple()
-    accumulator = []
+    accumulator: list[Parameter] = []
     for group in l:
         accumulator.extend(group)
         yield tuple(accumulator)


-def permute_optional_groups(left, required, right):
+def permute_optional_groups(
+    left: SequenceOfParameterGroups,
+    required: Iterable[Parameter],
+    right: SequenceOfParameterGroups
+) -> tuple[ParameterTuple, ...]:
     """
     Generator function that computes the set of acceptable
     argument lists for the provided iterables of
@@ -561,7 +569,7 @@ def permute_optional_groups(left, required, right):
         if left:
             raise ValueError("required is empty but left is not")

-    accumulator = []
+    accumulator: list[ParameterTuple] = []
     counts = set()
     for r in permute_right_option_groups(right):
         for l in permute_left_option_groups(left):