chore(task): improve sghi.task module typings (#33)

Mark all `Task` implementations as final and mark all overridden
methods as so.

src/sghi/task/__init__.py

@@ -14,7 +14,9 @@
 )
 from functools import reduce
 from logging import Logger, getLogger
-from typing import TYPE_CHECKING, Any, Generic, TypeVar, cast
+from typing import TYPE_CHECKING, Any, Generic, TypeVar, cast, final
+
+from typing_extensions import override
 
 from ..disposable import Disposable, ResourceDisposedError
 from ..disposable import not_disposed as _nd_factory
@@ -161,6 +163,7 @@ def of_callable(source_callable: Callable[[_IT], _OT]) -> Task[_IT, _OT]:
 # =============================================================================
 
 
+@final
 class Chain(Task[Callable[[_IT], Any], "Chain[Any]"], Generic[_IT]):
     """
     A :class:`Task` that wraps a value and applies a transformation (or series
@@ -195,6 +198,7 @@ def value(self) -> _IT:
         """
         return self._value
 
+    @override
     def execute(self, an_input: Callable[[_IT], _OT]) -> Chain[_OT]:
         """Perform the given transformation on the wrapped value and wrap the
         result in a new ``Chain`` instance.
@@ -212,6 +216,7 @@ def execute(self, an_input: Callable[[_IT], _OT]) -> Chain[_OT]:
         return Chain(bind(self._value))
 
 
+@final
 class Consume(Task[_IT, _IT], Generic[_IT]):
     """A :class:`Task` that applies an action to it's inputs.
 
@@ -259,11 +264,13 @@ def _compose_accept(an_input: _IT) -> None:
 
         return Consume(accept=_compose_accept)
 
+    @override
     def execute(self, an_input: _IT) -> _IT:
         self._accept(an_input)
         return an_input
 
 
+@final
 class Pipe(Task[_IT, _OT], Generic[_IT, _OT]):
     """A :class:`Task` that pipes its input through a ``Sequence`` of tasks.
 
@@ -295,6 +302,7 @@ def tasks(self) -> Sequence[Task[Any, Any]]:
         """
         return self._tasks
 
+    @override
     def execute(self, an_input: _IT) -> _OT:
         """
         Apply the given input to the :class:`tasks <Task>` that comprise this
@@ -334,6 +342,7 @@ def execute(self, an_input: _IT) -> _OT:
 not_disposed = _nd_factory(exc_factory=ConcurrentExecutorDisposedError)
 
 
+@final
 class ConcurrentExecutor(
     Task[_IT, Iterable[Future[_OT]]],
     Disposable,
@@ -384,7 +393,7 @@ def __init__(
         wait_for_completion: bool = True,
         executor: Executor | None = None,
     ):
-        """Initialize a new `ConcurrentExecutor` instance with the given
+        """Initialize a new ``ConcurrentExecutor`` instance with the given
         properties.
 
         :param tasks: The tasks to be executed concurrently. This MUST not be
@@ -408,6 +417,7 @@ def __init__(
         self._logger: Logger = getLogger(type_fqn(self.__class__))
 
     @not_disposed
+    @override
     def __enter__(self) -> Self:
         super().__enter__()
         if not self._wait_for_completion:
@@ -419,6 +429,7 @@ def __enter__(self) -> Self:
         return self
 
     @property
+    @override
     def is_disposed(self) -> bool:
         return self._is_disposed
 
@@ -432,6 +443,7 @@ def tasks(self) -> Sequence[Task[_IT, _OT]]:
         """
         return self._tasks
 
+    @override
     def dispose(self) -> None:
         """
         Shutdown the underlying :class:`~concurrent.futures.Executor` powering
@@ -463,6 +475,7 @@ def dispose(self) -> None:
         self._is_disposed = True
 
     @not_disposed
+    @override
     def execute(self, an_input: _IT) -> Iterable[Future[_OT]]:
         """Execute the tasks concurrently with the given input.
 
@@ -532,6 +545,7 @@ def _do_execute_task(self, task: Task[_IT, _OT], an_input: _IT) -> _OT:
 # =============================================================================
 
 
+@final
 class _OfCallable(Task[_IT, _OT]):
     __slots__ = ("_source_callable",)
 
@@ -541,6 +555,7 @@ def __init__(self, source_callable: Callable[[_IT], _OT]):
         self._source_callable: Callable[[_IT], _OT]
         self._source_callable = source_callable
 
+    @override
     def execute(self, an_input: _IT) -> _OT:
         return self._source_callable(an_input)