Fast word count function in Vim

Question

I am trying to display a live word count in the vim statusline. I do this by setting my status line in my .vimrc and inserting a function into it. The idea of this function

Answer 1

Here is a refinement of Abslom Daak's answer that also works in visual mode.

function! WordCount()
  let s:old_status = v:statusmsg
  let position = getpos(".")
  exe ":silent normal g\<c-g>"
  let stat = v:statusmsg
  let s:word_count = 0
  if stat != '--No lines in buffer--'
    if stat =~ "^Selected"
      let s:word_count = str2nr(split(v:statusmsg)[5])
    else
      let s:word_count = str2nr(split(v:statusmsg)[11])
    end
    let v:statusmsg = s:old_status
  end
  call setpos('.', position)
  return s:word_count 
endfunction

Included in the status line as before. Here is a right-aligned status line:

set statusline=%=%{WordCount()}\ words\

Answer 2

Since vim now supports this natively:

:echo wordcount().words

Answer 3

Here's a usable version of Rodrigo Queiro's idea. It doesn't change the status bar, and it restores the statusmsg variable.

function WordCount()
  let s:old_status = v:statusmsg
  exe "silent normal g\<c-g>"
  let s:word_count = str2nr(split(v:statusmsg)[11])
  let v:statusmsg = s:old_status
  return s:word_count
endfunction

This seems to be fast enough to include directly in the status line, e.g.:

:set statusline=wc:%{WordCount()}

Answer 4

I'm new to Vim scripting, but I might suggest

function WordCount()
    redir => l:status
    exe "silent normal g\<c-g>"
    redir END
    return str2nr(split(l:status)[11])
endfunction

as being a bit cleaner since it does not overwrite the existing status line.

My reason for posting is to point out that this function has a puzzling bug: namely, it breaks the append command. Hitting A should drop you into insert mode with the cursor positioned to the right of the final character on the line. However, with this custom status bar enabled it will put you to the left of the final character.

Anyone have any idea what causes this?