From 43a554bb4e6cde485a2845cabade9fbb786edc8f Mon Sep 17 00:00:00 2001
From: Ivan Levkivskyi <levkivskyi@gmail.com>
Date: Tue, 24 May 2016 10:46:51 +0200
Subject: [PATCH 1/2] Short subsection on annotating coroutines

---
 pep-0484.txt | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/pep-0484.txt b/pep-0484.txt
index 01957bed..681d111d 100644
--- a/pep-0484.txt
+++ b/pep-0484.txt
@@ -1015,6 +1015,39 @@ In such cases the default value may be specified as a literal
 ellipsis, i.e. the above example is literally what you would write.
 
 
+Annotating generator functions and coroutines
+---------------------------------------------
+
+The return type of generator functions can be annotated by
+the generic type ``Generator`` provided by ``typing.py`` module::
+
+  def echo_round() -> Generator[int, float, str]:
+      res = yield
+      while res:
+          res = yield round(res)
+      return 'OK'
+
+Coroutines introduced in PEP 492 are annotated with the same syntax as
+ordinary functions. However, the return type annotation corresponds to the
+type of ``await`` expression, not to the coroutine type::
+
+  async def spam(ignored: int) -> str:
+      return 'spam'
+
+  async def foo():
+      bar = await spam(42) # type: str
+
+The ``typing.py`` module also provides generic ABCs ``Awaitable``,
+``AsyncIterable``, and ``AsyncIterator`` for situations where more precise
+types cannot be specified::
+
+  def op() -> typing.Awaitable[str]:
+      if cond:
+          return spam(42)
+      else:
+          return asyncio.Future(...)
+
+
 Compatibility with other uses of function annotations
 =====================================================
 

From 30ec2751a96be037a02879b6c551b7a00d05a596 Mon Sep 17 00:00:00 2001
From: Ivan Levkivskyi <levkivskyi@gmail.com>
Date: Tue, 24 May 2016 20:21:18 +0200
Subject: [PATCH 2/2] response to comments: clarify Generator params

---
 pep-0484.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pep-0484.txt b/pep-0484.txt
index 681d111d..781e23ef 100644
--- a/pep-0484.txt
+++ b/pep-0484.txt
@@ -1019,7 +1019,8 @@ Annotating generator functions and coroutines
 ---------------------------------------------
 
 The return type of generator functions can be annotated by
-the generic type ``Generator`` provided by ``typing.py`` module::
+the generic type ``Generator[yield_type, send_type,
+return_type]`` provided by ``typing.py`` module::
 
   def echo_round() -> Generator[int, float, str]:
       res = yield