Vim：如何拆分命令行参数？

*<f-args>*
To allow commands to pass their arguments on to a user-defined function,there
is a special form <f-args> ("function args").  This splits the command
arguments at spaces and tabs,quotes each argument individually,and the
<f-args> sequence is replaced by the comma-separated list of quoted arguments.
See the Mycmd example below.  If no arguments are given <f-args> is removed.
   To embed whitespace into an argument of <f-args>,prepend a backslash.
<f-args> replaces every pair of backslashes () with one backslash.  A
backslash followed by a character other than white space or a backslash
remains unmodified.  Overview:

    command        <f-args> ~
    XX ab          'ab'
    XX ab         'ab'
    XX a b        'a b'
    XX a  b       'a ','b'
    XX ab        'ab'
    ....

但是最基本的例子不起作用：

function! TestFunc(...)
  echo a:0
  echo a:000
endfunction

command! -nargs=? TestFunc call TestFunc(<f-args>)

-------------------------------------------------

>  :TestFunc foo bar bla bla,fooo
>  1
>  ['foo bar bla bla,fooo']

>  :TestFunc foo bar
>  1
>  ['foo bar']

我有一堆由空格分割的参数,但是vim将其视为一个.为什么会这样？

副问题(它可以以某种方式配置为以逗号分割参数吗？)