函数如下：
function! s:str2uninr(s) "{{{
let slist = split(a:s,'.\@=')
let outlist = []
for i in slist
let c = char2nr(i)
if c > 255
call add(outlist, printf('\u%04X',c))
else
call add(outlist, i)
endif
endfor
return join(outlist,'')
endfunction
function! s:str2uninr_visual_replace()
let temp = @x
normal gv"xy
let @x = <SID>str2uninr(@x)
normal gv"xp
let @x = temp
endfunction
我将它映射到了<leader>u
即默认是在visual模式下输入\u
vnoremap <leader>u :call <SID>str2uninr_visual_replace()<CR>
效果截图 (上为原，下为转换后)

重装机兵