vim - 使 ultisnips 片段将文件保存在 vim 中

Question

我想定义一个 ultisnips 片段，它会输入一些文本然后保存文件。我检查了帮助，并认为 vimscript 执行很可能是要走的路。

我试图搜索如何做到这一点，这是我尝试过的：

snippet trigger ""
some_text
`!v w`
`!v execute ":w"`
`!v :execute ":w"`
`!v :w`
endsnippet

但他们都给了我：

File "~/.vim/bundle/ultisnips/pythonx/UltiSnips/snippet/definition/_base.py", line 442, in launch
    snippet_instance.update_textobjects()
File "~/.vim/bundle/ultisnips/pythonx/UltiSnips/text_objects/_snippet_instance.py", line 80, in update_textobjects
    if obj._update(done):
File "~/.vim/bundle/ultisnips/pythonx/UltiSnips/text_objects/_viml_code.py", line 20, in _update
    self.overwrite(_vim.eval(self._code))
File "~/.vim/bundle/ultisnips/pythonx/UltiSnips/_vim.py", line 121, in eval
    rv = vim.eval(as_vimencoding(text))
error: Vim:E121: Undefined variable: w

或类似的。如何让vim执行简单的保存后触发？