在Transcrypt Python to JavaScript 编译器中实现协程时，我遇到了以下奇怪的问题。
Transcrypt 使用 CPython 3.6 的本机解析器来生成 AST。对于异步全局函数 defs，它会生成一个 AsyncFunctionDef 节点。但是对于异步方法，它没有！尽管如此，CPython 本身似乎可以正确编译异步方法。
所以下面这段代码使用 CPython 运行，但 Transcrypt 无法运行它，因为 CPython 的 AST 模块生成的 AST 似乎缺少方法的 AsyncFunctionDef 节点（与全局函数相反）。
因此，以下代码不会生成 AsyncFunctionDef 节点：
class C:
def __init__ (self):
self.aTime = 2
async def g (self, waw, asio):
print ('g0')
await waw (self.aTime, asio)
print ('g1')
我错过了什么？官方支持异步方法，不是吗？在PEP 492中找不到任何具体内容。
该示例的完整代码为：
from org.transcrypt.stubs.browser import __pragma__, __envir__
# Note that CPython will ignore all pragma's
# Provide waitAWhile for Transcrypt
__pragma__ ('js', '{}', '''
function waitAWhile (aTime, asio) {
return new Promise (resolve => {
setTimeout (() => {
resolve (aTime);
}, 1000 * aTime);
});
}
''')
# Provide waitAWhile for CPython
__pragma__ ('skip') # Compile time, needed because import is done compile time
import asyncio
def waitAWhile (aTime, asio):
return asio.sleep (aTime)
__pragma__ ('noskip')
# Actual code to be tested
async def f (waw, asio):
print ('f0')
await waw (2, asio)
print ('f1')
class C:
def __init__ (self):
self.aTime = 2
async def g (self, waw, asio):
print ('g0')
await waw (self.aTime, asio)
print ('g1')
c = C ()
# Just call async functions for Transcrypt, since in the browser JavaScript is event driven by default
if __envir__.executor_name == __envir__.transpiler_name:
f (waitAWhile, None)
c.g (waitAWhile, None)
c.g (waitAWhile, None)
f (waitAWhile, None)
# Create event loop and tasks for CPython, since it isn't event driven by default
else:
eventLoop = asyncio.get_event_loop ()
tasks = [
eventLoop.create_task (f (waitAWhile, asyncio)),
eventLoop.create_task (c.g (waitAWhile, asyncio)),
eventLoop.create_task (c.g (waitAWhile, asyncio)),
eventLoop.create_task (f (waitAWhile, asyncio)),
]
waitingTasks = asyncio.wait (tasks)
eventLoop.run_until_complete (waitingTasks)
eventLoop.close ()