Changes required by mypy async-await support (#435)

stdlib/3.4/asyncio/events.pyi

@@ -1,4 +1,4 @@
-from typing import Any, Awaitable, TypeVar, List, Callable, Tuple, Union, Dict, Generator
+from typing import Any, Awaitable, TypeVar, List, Callable, Tuple, Union, Dict, Generator, overload
 from abc import ABCMeta, abstractmethod
 from asyncio.futures import Future
 from asyncio.coroutines import coroutine
@@ -30,8 +30,15 @@ class AbstractServer:
 class AbstractEventLoop(metaclass=ABCMeta):
     @abstractmethod
     def run_forever(self) -> None: ...
+
+    # Can't use a union, see mypy issue #1873.
+    @overload
     @abstractmethod
-    def run_until_complete(self, future: Union[Awaitable[_T], Future[_T], Generator[Any, Any, _T]]) -> _T: ...
+    def run_until_complete(self, future: Generator[Any, Any, _T]) -> _T: ...
+    @overload
+    @abstractmethod
+    def run_until_complete(self, future: Awaitable[_T]) -> _T: ...
+
     @abstractmethod
     def stop(self) -> None: ...
     @abstractmethod

stdlib/3.4/asyncio/futures.pyi

@@ -1,4 +1,4 @@
-from typing import Any, Union, Callable, TypeVar, List, Generic, Iterable, Generator
+from typing import Any, Union, Callable, TypeVar, List, Generic, Iterable, Generator, Awaitable
 from .events import AbstractEventLoop
 
 __all__ = ... # type: str
@@ -14,7 +14,7 @@ class _TracebackLogger:
     def clear(self) -> None: ...
     def __del__(self) -> None: ...
 
-class Future(Iterable[_T], Generic[_T]):
+class Future(Iterable[_T], Awaitable[_T], Generic[_T]):
     _state = ...  # type: str
     _exception = ... # type: BaseException
     _blocking = False
@@ -35,3 +35,4 @@ class Future(Iterable[_T], Generic[_T]):
     def set_exception(self, exception: Union[type, BaseException]) -> None: ...
     def _copy_state(self, other: Any) -> None: ...
     def __iter__(self) -> Generator[Any, None, _T]: ...
+    def __await__(self) -> Generator[Any, None, _T]: ...

stdlib/3.4/asyncio/streams.pyi

@@ -33,7 +33,7 @@ def start_server(
         *,
         loop: events.AbstractEventLoop = ...,
         limit: int = ...,
-        **kwds: Any) -> events.AbstractServer: ...
+        **kwds: Any) -> Generator[Any, None, events.AbstractServer]: ...
 
 if hasattr(socket, 'AF_UNIX'):
     @coroutines.coroutine
@@ -42,7 +42,7 @@ if hasattr(socket, 'AF_UNIX'):
             *,
             loop: events.AbstractEventLoop = ...,
             limit: int = ...,
-            **kwds: Any): ...
+            **kwds: Any)-> Generator[Any, None, Tuple[StreamReader, StreamWriter]]: ...
 
     @coroutines.coroutine
     def start_unix_server(
@@ -51,7 +51,7 @@ if hasattr(socket, 'AF_UNIX'):
         *,
         loop: int = ...,
         limit: int = ...,
-        **kwds: Any) -> events.AbstractServer: ...
+        **kwds: Any) -> Generator[Any, None, events.AbstractServer]: ...
 
 class FlowControlMixin(protocols.Protocol): ...
 

stdlib/3.4/asyncio/tasks.pyi

@@ -1,4 +1,4 @@
-from typing import Any, TypeVar, Set, Dict, List, TextIO, Union, Tuple, Generic, Callable, Generator, Iterable, Awaitable
+from typing import Any, TypeVar, Set, Dict, List, TextIO, Union, Tuple, Generic, Callable, Generator, Iterable, Awaitable, overload
 
 __all__ = ... # type: str
 
@@ -22,7 +22,13 @@ class Task(Future[_T], Generic[_T]):
     def current_task(cls, loop: AbstractEventLoop = ...) -> Task: ...
     @classmethod
     def all_tasks(cls, loop: AbstractEventLoop = ...) -> Set[Task]: ...
-    def __init__(self, coro: Union[Awaitable[_T], Iterable[_T], Future[_T], Generator[Any, None, _T]], *, loop: AbstractEventLoop = ...) -> None: ...
+
+    # Can't use a union, see mypy issue #1873.
+    @overload
+    def __init__(self, coro: Generator[Any, None, _T], *, loop: AbstractEventLoop = ...) -> None: ...
+    @overload
+    def __init__(self, coro: Awaitable[_T], *, loop: AbstractEventLoop = ...) -> None: ...
+
     def __repr__(self) -> str: ...
     def get_stack(self, *, limit: int = ...) -> List[Any]: ...  # return List[stackframe]
     def print_stack(self, *, limit: int = ..., file: TextIO = ...) -> None: ...

stdlib/3/typing.pyi

@@ -113,11 +113,15 @@ class Generator(Iterator[_T_co], Generic[_T_co, _T_contra, _V_co]):
     @abstractmethod
     def __iter__(self) -> 'Generator[_T_co, _T_contra, _V_co]': ...
 
-class AbstractFuture(Generic[_T]): ...
-
 class Awaitable(Generic[_T_co]):
     @abstractmethod
-    def __await__(self) -> Generator[AbstractFuture[_T_co], Any, _T_co]:...
+    def __await__(self) -> Generator[Any, None, _T_co]:...
+
+# NOTE: This type does not exist in typing.py or PEP 484.
+# The parameters corrrespond to Generator, but the 4th is the original type.
+class AwaitableGenerator(Generator[_T_co, _T_contra, _V_co], Awaitable[_T_co],
+                         Generic[_T_co, _T_contra, _V_co, _S]):
+    pass
 
 class AsyncIterable(Generic[_T_co]):
     @abstractmethod