const createFilter = (queryString: string) => { return (restaurant: RestaurantItem) => { return ( restaurant.value.toLowerCase().indexOf(queryString.toLowerCase()) === 0 ) } }

这段代码是使用了 TypeScript 语法，TypeScript 是 JavaScript 的超集，可以为 JavaScript 提供类型检查和更好的开发体验。

这段代码定义了一个名为 `createFilter` 的函数，该函数接受一个 `queryString` 参数，返回一个函数。返回的函数接受一个 `restaurant` 参数，类型为 `RestaurantItem`，并返回一个布尔值。

这里使用了箭头函数的语法，`restaurant.value.toLowerCase().indexOf(queryString.toLowerCase()) === 0` 表示判断 `restaurant` 对象中的 `value` 属性是否以 `queryString` 开头。如果是，返回 `true`，否则返回 `false`。

如果你不熟悉 TypeScript 语法，可以先学习一下，这样就可以更好地理解 Element Plus 的文档了。

相关问题

将代码转化成vue3格式let timeout: NodeJS.Timeout const querySearchAsync = (queryString: string, cb: (arg: any) => void) => { const results = queryString ? links.value.filter(createFilter(queryString)) : links.value clearTimeout(timeout) timeout = setTimeout(() => { cb(results) }, 3000 * Math.random()) }

将代码转化为Vue3格式：

import { ref } from 'vue';

let timeout: ReturnType<typeof setTimeout>;
const querySearchAsync = (queryString: string, cb: (arg: any) => void) => {
  const links = ref<LinkItem[]>([]); // 假设已经定义了 LinkItem 类型的数组 links
  const createFilter = (queryString: string) => (link: LinkItem) =>
    link.value.indexOf(queryString) >= 0 || link.link.indexOf(queryString) >= 0;
  const results = queryString ? links.value.filter(createFilter(queryString)) : links.value;
  clearTimeout(timeout);
  timeout = setTimeout(() => {
    cb(results);
  }, 3000 * Math.random());
};

在这个例子中，我们引入了Vue3的`ref`函数，并使用它来定义了一个名为`links`的响应式数组，假设已经定义了`LinkItem`类型。然后我们将`links`数组作为过滤器的数据源，使用`createFilter`函数来创建一个过滤函数，根据传入的查询字符串过滤数据。最后，我们使用`clearTimeout`和`setTimeout`函数来实现一个简单的延迟回调，将过滤后的结果传递给回调函数`cb`。

需要注意的是，由于`timeout`变量的类型是`NodeJS.Timeout`，而Vue3中没有直接提供这个类型，所以我们使用`ReturnType<typeof setTimeout>`来推导出`setTimeout`函数的返回类型，从而得到`timeout`变量的类型。

优化此代码 const openKeys = ref<string[]>([]) const selectedKeys = ref<string[]>([]) const { currentMenu, currentMenuTree, currentMenuList } = storeToRefs( useLayoutStore(), ) const rootSubmenuKeys = currentMenuList.value.filter((v: any) => { if (v.type === 0) { return v.parentId } }) watch( () => currentMenu, () => { openKeys.value = [currentMenu.value?.parentId] selectedKeys.value = [currentMenu.value?.id] }, { immediate: true }, ) const router = useRouter() /** * 点击事件 * @param e 事件对象 */ const handleClick = (e: any) => { const item = currentMenuList.value.find((_) => _.id === e.key) if (item) { router.push(item.path) } } /** * SubMenu 展开/关闭的回调 * @param e 展开的openKeys */ const onOpenChange = (e: any) => { const latestOpenKey = e.find((key: any) => openKeys.value.indexOf(key) === -1) if (rootSubmenuKeys.indexOf(latestOpenKey) === -1) { openKeys.value = e } else { openKeys.value = latestOpenKey ? [latestOpenKey] : [] } }

There are a few optimizations that could be made to this code:

1. Instead of using `ref` for `openKeys` and `selectedKeys`, you can use `reactive` to make the code more concise:

   const state = reactive({
     openKeys: [],
     selectedKeys: [],
   })

2. Instead of using `storeToRefs` to convert the store state to refs, you can use the `toRefs` function, which is shorter and more concise:

   const { currentMenu, currentMenuTree, currentMenuList } = toRefs(useLayoutStore())

3. Instead of using `watch` to watch the `currentMenu` state changes, you can use a computed property to update the `openKeys` and `selectedKeys` arrays:

   const selectedMenu = computed(() => {
     const item = currentMenuList.value.find((_) => _.id === currentMenu.value?.id)
     return [item?.id] || []
   })

   const parentMenu = computed(() => {
     const item = currentMenuList.value.find((_) => _.id === currentMenu.value?.parentId)
     return [item?.id] || []
   })

   watch([selectedMenu, parentMenu], ([selected, parent]) => {
     state.selectedKeys = selected
     state.openKeys = parent
   })

4. Instead of using `router.push` in the `handleClick` function, you can use the `router.push` method directly in the template:

   <Menu.Item :key="item.id" :to="item.path">{{ item.name }}</Menu.Item>

5. Finally, instead of using `rootSubmenuKeys` to filter the list of menu items, you can use a computed property to filter the list of menu items based on their type:

   const subMenuItems = computed(() => {
     return currentMenuList.value.filter((v: any) => v.type === 0 && v.parentId)
   })

By applying these optimizations, the code can be simplified and made more concise.