vimscript : clear command line after `confirm`

Question

我有一个函数调用 confirm 来获取用户输入，执行一个操作，然后向用户打印一条消息:

function! PerformAction()
  let answer = confirm('Do thing?', "&Yes\n&No", 1)
  if answer == 1
    call system("do_thing")
    echo "Did thing!"
  endif
endfunction

我遇到的问题是，这最终会迫使用户在执行命令后多按一次 [Enter]，因为命令行已扩展为显示提示和消息.

是否可以防止这种情况，让用户在提示输入值后，命令行清空，执行调用系统，然后单行显示"做了什么!” 打印在命令行中，让用户可以立即继续工作？

Answer 1

如果你告诉 vim 用 :redraw 刷新屏幕，这可以解决你的问题:

function! PerformAction()
  let answer = confirm('Do thing?', "&Yes\n&No", 1)
  if answer == 1
    call system("do_thing")
    redraw
    echo "Did thing!"
  endif
endfunction

我不知道为什么会这样，但是 :redraw 在 echo 的帮助页面中提到:

                            *:echo-redraw*
            A later redraw may make the message disappear again.
            And since Vim mostly postpones redrawing until it's
            finished with a sequence of commands this happens
            quite often.  To avoid that a command from before the
            ":echo" causes a redraw afterwards (redraws are often
            postponed until you type something), force a redraw
            with the |:redraw| command.  Example: >
        :new | redraw | echo "there is a new window"