appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly

      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly

      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly

      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly

这种使用 `async` 和 `await` 的风格在语言中相对较新。

但它使处理异步代码变得容易很多。

这种相同的语法（或几乎相同）最近也包含在现代版本的 JavaScript 中（在浏览器和 NodeJS 中）。

但在此之前，处理异步代码非常复杂和困难。

在以前版本的 Python，你可以使用多线程或者 <a href="https://www.gevent.org/" class="external-link" target="_blank">Gevent</a>。但代码的理解、调试和思考都要复杂许多。

在以前版本的 NodeJS / 浏览器 JavaScript 中，你会使用"回调"，因此也可能导致<a href="http://callbackhell.com/" class="external-link" target="_blank">回调地狱</a>。

## 协程

}

func ExampleLastIndex() {
	fmt.Println(bytes.Index([]byte("go gopher"), []byte("go")))
	fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("go")))
	fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("rodent")))
	// Output:
	// 0
	// 3
	// -1
}

func ExampleLastIndexAny() {
	fmt.Println(bytes.LastIndexAny([]byte("go gopher"), "MüQp"))
	fmt.Println(bytes.LastIndexAny([]byte("go 地鼠"), "地大"))

      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly

      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly

      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly

      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly