小编Ste*_*alt的帖子

我将如何编写一个函数来检查文件在 Go 中是否可执行？给定os.FileInfo，我可以得到os.FileInfo.Mode()，但是我在尝试解析权限位时遇到了困难。

测试用例：

#!/usr/bin/env bash
function setup() {
  mkdir -p test/foo/bar
  touch test/foo/bar/{baz.txt,quux.sh}
  chmod +x test/foo/bar/quux.sh
}

function teardown() { rm -r ./test }

setup

import (
    "os"
    "path/filepath"
    "fmt"
)

func IsExectuable(mode os.FileMode) bool {
    // ???
}

func main() {
    filepath.Walk("test", func(path string, info os.FileInfo, err error) error {
        if err != nil || info.IsDir() {
            return err
        }
        fmt.Printf("%v %v", path, IsExectuable(info.Mode().Perm()))
    }
}
// should print "test/foo/bar/baz.txt false"
//              "test/foo/bar/quux.txt true" …

我想为异步函数编写一个装饰器。如何注释装饰器定义的类型？

这是我想做的一个例子：

from typing import TypeVar # will Awaitable help?
AsyncFn = TypeVar('AsyncFn') # how to narrow this type definition down to async functions?

def my_decorator(to_decorate: AsyncFn) -> AsyncFn:
    async def decorated(*args, **kwargs): # mypy keeps saying "Function is missing a type"
       return await to_decorate(*args, **kwargs)

@my_decorator
async def foo(bar: int) -> str:
    return f"async: {bar}"

@my_decorator
async def quux(spam: str, **eggs: str) -> None:
    return

foo(1) # should check
foo("baz") # mypy should yell
quux("spam") # should check
quux(1) …