Add io.{Reader,Writer} (#14013)

stdlib/@tests/stubtest_allowlists/py314.txt

@@ -129,9 +129,6 @@ importlib.machinery.__all__
 importlib.machinery.AppleFrameworkLoader
 importlib.util.__all__
 importlib.util.Loader
-io.__all__
-io.Reader
-io.Writer
 ipaddress._IPAddressBase.version
 logging.handlers.SysLogHandler.__init__
 marshal.dump
@@ -299,6 +296,13 @@ typing(_extensions)?\.IO\.writelines
 .*\.ForwardRef\.__owner__
 .*\.ForwardRef\.__stringifier_dict__
 
+# These protocols use ABC hackery at runtime.
+io.Reader.__class_getitem__
+io.Reader.read
+io.Writer.__class_getitem__
+io.Writer.write
+
+
 # =============================================================
 # Allowlist entries that cannot or should not be fixed; >= 3.13
 # =============================================================

stdlib/io.pyi

@@ -20,7 +20,7 @@ from _io import (
     open as open,
     open_code as open_code,
 )
-from typing import Final
+from typing import Final, Protocol, TypeVar
 
 __all__ = [
     "BlockingIOError",
@@ -44,11 +44,17 @@ __all__ = [
     "SEEK_END",
 ]
 
+if sys.version_info >= (3, 14):
+    __all__ += ["Reader", "Writer"]
+
 if sys.version_info >= (3, 11):
     from _io import text_encoding as text_encoding
 
     __all__ += ["DEFAULT_BUFFER_SIZE", "IncrementalNewlineDecoder", "text_encoding"]
 
+_T_co = TypeVar("_T_co", covariant=True)
+_T_contra = TypeVar("_T_contra", contravariant=True)
+
 SEEK_SET: Final = 0
 SEEK_CUR: Final = 1
 SEEK_END: Final = 2
@@ -58,3 +64,10 @@ class IOBase(_IOBase, metaclass=abc.ABCMeta): ...
 class RawIOBase(_RawIOBase, IOBase): ...
 class BufferedIOBase(_BufferedIOBase, IOBase): ...
 class TextIOBase(_TextIOBase, IOBase): ...
+
+if sys.version_info >= (3, 14):
+    class Reader(Protocol[_T_co]):
+        def read(self, size: int = ..., /) -> _T_co: ...
+
+    class Writer(Protocol[_T_contra]):
+        def write(self, data: _T_contra, /) -> int: ...