Is there a way to make use of two custom, complete functions in Vimscript?

Question

Is there a way to achieve the following in Vim?

command! -nargs=* -complete=customlist,CustomFunc1 -complete=customlist,CustomFunc2 Foo call MyFunction(

        

Answer 1

There's no built-in way for vim to do this. What I'd do in this situation is embed the logic into the completion function. When you set -complete=customlist,CompletionFunction, the specified function is invoked with three arguments, in this order:

• The current argument
• The entire command line up to this point
• The cursor position

So, you can analyze these and call another function depending on whether it looks like you're on the second parameter. Here's an example:

command! -nargs=* -complete=customlist,FooComplete Foo call Foo()
function! Foo(...)
  " ...
endfunction

function! FooComplete(current_arg, command_line, cursor_position)
  " split by whitespace to get the separate components:
  let parts = split(a:command_line, '\s\+')

  if len(parts) > 2
    " then we're definitely finished with the first argument:
    return SecondCompletion(a:current_arg)
  elseif len(parts) > 1 && a:current_arg =~ '^\s*$'
    " then we've entered the first argument, but the current one is still blank:
    return SecondCompletion(a:current_arg)
  else
    " we're still on the first argument:
    return FirstCompletion(a:current_arg)
  endif
endfunction

function! FirstCompletion(arg)
  " ...
endfunction

function! SecondCompletion(arg)
  " ...
endfunction

One problem with this example is that it would fail for completions that contain whitespace, so if that's a possibility, you're going to have to make more careful checks.