[improvement] sort out utils (#2672)

packages/utils/use/index.js

@@ -2,7 +2,16 @@ import useBem from './bem';
 import useSfc from './sfc';
 import useI18n from './i18n';
 
-export default function (name) {
+export function use(name) {
   name = 'van-' + name;
   return [useSfc(name), useBem(name), useI18n(name)];
 }
+
+export function useSlots({ $slots, $scopedSlots }) {
+  return (name, props) => {
+    if ($scopedSlots[name]) {
+      return $scopedSlots[name](props);
+    }
+    return $slots[name];
+  };
+}