try async generators

Author: 1st1

Diff for: asyncio/run.py

@@ -2,6 +2,7 @@
 
 __all__ = ['run', 'forever']
 
+import inspect
 import threading
 
 from . import coroutines
@@ -67,8 +68,8 @@ async def main():
     if not isinstance(threading.current_thread(), threading._MainThread):
         raise RuntimeError(
             "asyncio.run() must be called from the main thread")
-    if not coroutines.iscoroutine(coro):
-        raise ValueError("a coroutine was expected, got {!r}".format(coro))
+    # if not coroutines.iscoroutine(coro):
+    #     raise ValueError("a coroutine was expected, got {!r}".format(coro))
 
     loop = events.new_event_loop()
     try:
@@ -77,15 +78,26 @@ async def main():
         if debug:
             loop.set_debug(True)
 
-        task = loop.create_task(coro)
-        task.add_done_callback(lambda task: loop.stop())
+        if inspect.isasyncgen(coro):
+            result = None
+            loop.run_until_complete(coro.asend(None))
+            try:
+                loop.run_forever()
+            except BaseException as ex:
+                try:
+                    loop.run_until_complete(coro.athrow(ex))
+                except StopAsyncIteration as ex:
+                    if ex.args:
+                        result = ex.args[0]
+            else:
+                try:
+                    loop.run_until_complete(coro.asend(None))
+                except StopAsyncIteration as ex:
+                    if ex.args:
+                        result = ex.args[0]
 
-        try:
-            loop.run_forever()
-        except BaseException as ex:
-            result = loop.run_until_complete(task)
         else:
-            result = task.result()
+            result = loop.run_until_complete(coro)
 
         try:
             # `shutdown_asyncgens` was added in Python 3.6; not all