[Python-checkins] cpython (merge 3.5 -> default): Add Awaitable, AsyncIterable, AsyncIterator to typing.py. (Merge 3.5->3.6)

[guido.van.rossum]

https://hg.python.org/cpython/rev/ad855c779bf3
changeset:   99430:ad855c779bf3
parent:      99427:ea576db13827
parent:      99429:e9aeae1b2ea9
user:        Guido van Rossum <guido at dropbox.com>
date:        Thu Dec 03 17:32:05 2015 -0800
summary:
  Add Awaitable, AsyncIterable, AsyncIterator to typing.py. (Merge 3.5->3.6)

files:
  Lib/test/test_typing.py |  61 +++++++++++++++++++++++++++++
  Lib/typing.py           |  15 +++++++
  2 files changed, 76 insertions(+), 0 deletions(-)


diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -1,3 +1,4 @@
+import asyncio
 import pickle
 import re
 import sys
@@ -960,6 +961,36 @@
                 pass
 
 
+T_a = TypeVar('T')
+
+
+class AwaitableWrapper(typing.Awaitable[T_a]):
+
+    def __init__(self, value):
+        self.value = value
+
+    def __await__(self) -> typing.Iterator[T_a]:
+        yield
+        return self.value
+
+
+class AsyncIteratorWrapper(typing.AsyncIterator[T_a]):
+
+    def __init__(self, value: typing.Iterable[T_a]):
+        self.value = value
+
+    def __aiter__(self) -> typing.AsyncIterator[T_a]:
+        return self
+
+    @asyncio.coroutine
+    def __anext__(self) -> T_a:
+        data = yield from self.value
+        if data:
+            return data
+        else:
+            raise StopAsyncIteration
+
+
 class CollectionsAbcTests(TestCase):
 
     def test_hashable(self):
@@ -984,6 +1015,36 @@
         assert isinstance(it, typing.Iterator[int])
         assert not isinstance(42, typing.Iterator)
 
+    def test_awaitable(self):
+        async def foo() -> typing.Awaitable[int]:
+            return await AwaitableWrapper(42)
+        g = foo()
+        assert issubclass(type(g), typing.Awaitable[int])
+        assert isinstance(g, typing.Awaitable)
+        assert not isinstance(foo, typing.Awaitable)
+        assert issubclass(typing.Awaitable[Manager],
+                          typing.Awaitable[Employee])
+        assert not issubclass(typing.Awaitable[Employee],
+                              typing.Awaitable[Manager])
+        g.send(None)  # Run foo() till completion, to avoid warning.
+
+    def test_async_iterable(self):
+        base_it = range(10)  # type: Iterator[int]
+        it = AsyncIteratorWrapper(base_it)
+        assert isinstance(it, typing.AsyncIterable)
+        assert isinstance(it, typing.AsyncIterable)
+        assert issubclass(typing.AsyncIterable[Manager],
+                          typing.AsyncIterable[Employee])
+        assert not isinstance(42, typing.AsyncIterable)
+
+    def test_async_iterator(self):
+        base_it = range(10)  # type: Iterator[int]
+        it = AsyncIteratorWrapper(base_it)
+        assert isinstance(it, typing.AsyncIterator)
+        assert issubclass(typing.AsyncIterator[Manager],
+                          typing.AsyncIterator[Employee])
+        assert not isinstance(42, typing.AsyncIterator)
+
     def test_sized(self):
         assert isinstance([], typing.Sized)
         assert not isinstance(42, typing.Sized)
diff --git a/Lib/typing.py b/Lib/typing.py
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -28,6 +28,9 @@
 
     # ABCs (from collections.abc).
     'AbstractSet',  # collections.abc.Set.
+    'Awaitable',
+    'AsyncIterator',
+    'AsyncIterable',
     'ByteString',
     'Container',
     'Hashable',
@@ -1261,6 +1264,18 @@
 Hashable = collections_abc.Hashable  # Not generic.
 
 
+class Awaitable(Generic[T_co], extra=collections_abc.Awaitable):
+    __slots__ = ()
+
+
+class AsyncIterable(Generic[T_co], extra=collections_abc.AsyncIterable):
+    __slots__ = ()
+
+
+class AsyncIterator(AsyncIterable[T_co], extra=collections_abc.AsyncIterator):
+    __slots__ = ()
+
+
 class Iterable(Generic[T_co], extra=collections_abc.Iterable):
     __slots__ = ()
 

-- 
Repository URL: https://hg.python.org/cpython