refactor!: completely wipe out pyuv

pynvim has been using asyncio as the only available event loop
implementation, since python 3.4. Remove all the pyuv-related codes

Author: wookayin

pynvim/msgpack_rpc/event_loop/__init__.py

@@ -1,6 +1,6 @@
 """Event loop abstraction subpackage.
 
-Tries to use pyuv as a backend, falling back to the asyncio implementation.
+We use python's built-in asyncio as the backend.
 """
 
 from pynvim.msgpack_rpc.event_loop.asyncio import AsyncioEventLoop as EventLoop

pynvim/msgpack_rpc/event_loop/asyncio.py

@@ -1,12 +1,4 @@
-"""Event loop implementation that uses the `asyncio` standard module.
-
-The `asyncio` module was added to python standard library on 3.4, and it
-provides a pure python implementation of an event loop library. It is used
-as a fallback in case pyuv is not available(on python implementations other
-than CPython).
-
-"""
-from __future__ import absolute_import
+"""Event loop implementation that uses the `asyncio` standard module."""
 
 import asyncio
 import logging
@@ -22,9 +14,10 @@
 debug, info, warn = (logger.debug, logger.info, logger.warning,)
 
 loop_cls = asyncio.SelectorEventLoop
+
 if os.name == 'nt':
+    import msvcrt  # pylint: disable=import-error
     from asyncio.windows_utils import PipeHandle  # type: ignore[attr-defined]
-    import msvcrt
 
     # On windows use ProactorEventLoop which support pipes and is backed by the
     # more powerful IOCP facility

pynvim/msgpack_rpc/event_loop/base.py

@@ -28,6 +28,10 @@
     Literal['child']
 ]
 
+# TODO: Since pynvim now supports python 3, the only available backend of the
+# msgpack_rpc BaseEventLoop is the built-in asyncio (see #294). We will have
+# to remove some unnecessary abstractions as well as greenlet. See also #489
+
 
 class BaseEventLoop(ABC):
 

pynvim/msgpack_rpc/event_loop/uv.py

@@ -23,7 +23,6 @@
 ]
 
 extras_require = {
-    'pyuv': ['pyuv>=1.0.0'],
     'test': tests_require,
 }
 

setup.py

@@ -25,7 +25,6 @@ extras = test
 deps =
   pytest-timeout
 # cov: pytest-cov
-# pyuv: pyuv
 # setenv =
 #   cov: PYTEST_ADDOPTS=--cov=. {env:PYTEST_ADDOPTS:}
 # passenv = PYTEST_ADDOPTS