Prevent <c-w>q to quit Vim when there is only one window left

Question

I wish to close windows and wipe out the associated buffers with <c-w>q but at the same time I want to prevent to quit Vim when there is only one window left.

My attempt is as follows:

vim9script
def QuitWindow()
    # Close window and wipe buffer but prevent Vim to quit if one window is
    # left.
   if winnr('$') != 1
      quit
   endif
enddef

nnoremap <c-w>q <Cmd>call QuitWindow()<cr>
nnoremap <c-w><c-q> <Cmd>call QuitWindow()<cr>

but then QuitWindow() is correctly not recognised and I am not sure how to do for recognising a function when it is defined in .vimrc and is not defined as global.

Perhaps this is not the right direction for achieving my goal?

Answer 1

For the sake of completeness and as requested by a user, here is the solution that I am currently using (based on a user comment):

vim9script
def QuitWindow()
    # Close window and wipe buffer but prevent Vim to quit if one window is
    # left.
   if winnr('$') != 1
      quit
   endif
enddef

nnoremap <c-w>q <ScriptCmd>call QuitWindow()<cr>
nnoremap <c-w><c-q> <ScriptCmd>call QuitWindow()<cr>

The trick was in using :h <ScriptCmd> that allow you to define mappings in the context of scripts. Note that in my case a QuitWindow() has script scope. Alternatively, I could have used a global scope for QuitWindow(), i.e. g:QuitWindow() but that would have polluted the global namespace.

Answer 2

I would do:

vim9script

def g:QuitWindow()
    # Close window and wipe buffer but prevent Vim to quit if one window is
    # left.
   if winnr('$') != 1
      quit
   endif
enddef

nnoremap <c-w>q <Cmd>call g:QuitWindow()<CR>