Function move

packages/react-stately/src/data/useListData.ts:325–340

(key: Key, toIndex: number)

      });
    },
    move(key: Key, toIndex: number) {
      dispatch(state => {
        let index = state.items.findIndex(item => getKey!(item) === key);
        if (index === -1) {
          return state;
        }

        let copy = state.items.slice();
        let [item] = copy.splice(index, 1);
        copy.splice(toIndex, 0, item);
        return {
          ...state,
          items: copy
        };
      });
    },
    moveBefore(key: Key, keys: Iterable<Key>) {
      dispatch(state => {
        let toIndex = state.items.findIndex(item => getKey!(item) === key);