Make ControllerVector generic on Controller_T

src/fastcs/controllers/controller_vector.py

@@ -3,9 +3,10 @@
 from fastcs.attributes import AnyAttributeIO
 from fastcs.controllers.base_controller import BaseController
 from fastcs.controllers.controller import Controller
+from fastcs.util import Controller_T
 
 
-class ControllerVector(MutableMapping[int, Controller], BaseController):
+class ControllerVector(MutableMapping[int, Controller_T], BaseController):
     """Controller containing Attributes and indexed sub Controllers
 
     The sub controllers registered with this Controller should be instances of the same
@@ -15,12 +16,12 @@ class ControllerVector(MutableMapping[int, Controller], BaseController):
 
     def __init__(
         self,
-        children: Mapping[int, Controller],
+        children: Mapping[int, Controller_T],
         description: str | None = None,
         ios: Sequence[AnyAttributeIO] | None = None,
     ) -> None:
         super().__init__(description=description, ios=ios)
-        self._children: dict[int, Controller] = {}
+        self._children: dict[int, Controller_T] = {}
         for index, child in children.items():
             self[index] = child
 
@@ -31,15 +32,15 @@ def add_sub_controller(self, name: str, sub_controller: BaseController):
             "E.g., vector[1] = Controller()"
         )
 
-    def __getitem__(self, key: int) -> Controller:
+    def __getitem__(self, key: int) -> Controller_T:
         try:
             return self._children[key]
         except KeyError as exception:
             raise KeyError(
                 f"ControllerVector does not have Controller with key {key}"
             ) from exception
 
-    def __setitem__(self, key: int, value: Controller) -> None:
+    def __setitem__(self, key: int, value: Controller_T) -> None:
         if not isinstance(key, int):
             msg = f"Expected int, got {key}"
             raise TypeError(msg)

src/fastcs/methods/method.py

@@ -1,17 +1,13 @@
 from asyncio import iscoroutinefunction
 from collections.abc import Callable, Coroutine
 from inspect import Signature, getdoc, signature
-from typing import TYPE_CHECKING, Generic, TypeVar
+from typing import Generic
 
 from fastcs.tracer import Tracer
-
-if TYPE_CHECKING:
-    from fastcs.controllers import BaseController  # noqa: F401
+from fastcs.util import Controller_T
 
 MethodCallback = Callable[..., Coroutine[None, None, None]]
 """Generic protocol for all `Controller` Method callbacks"""
-Controller_T = TypeVar("Controller_T", bound="BaseController")  # noqa: F821
-"""Generic `Controller` class that an unbound method must be called with as `self`"""
 
 
 class Method(Generic[Controller_T], Tracer):

src/fastcs/util.py

@@ -1,4 +1,11 @@
 import re
+from typing import TYPE_CHECKING, TypeVar
+
+if TYPE_CHECKING:
+    from fastcs.controllers import BaseController  # noqa: F401
+
+Controller_T = TypeVar("Controller_T", bound="BaseController")  # noqa: F821
+"""Generic `Controller` class that an unbound method must be called with as `self`"""
 
 ONCE = float("inf")
 """Sentinel value to call a ``scan`` or io ``update`` method once on start up"""