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

A variation of Guy Gur-Ari's refinement that

• only counts words if spell checking is enabled,
• counts the number of selected words in visual mode
• keeps mute outside of insert and normal mode, and
• hopefully is more agnostic to the system language (when different from english)

function! StatuslineWordCount()
  if !&l:spell
    return ''
  endif

  if empty(getline(line('$')))
    return ''
  endif
  let mode = mode()
  if !(mode ==# 'v' || mode ==# 'V' || mode ==# "\" || mode =~# '[ni]')
    return ''
  endif

  let s:old_status = v:statusmsg
  let position = getpos('.')
  let stat = v:statusmsg
  let s:word_count = 0
  exe ":silent normal g\"
  try
    if mode ==# 'v' || mode ==# 'V'
      let s:word_count = split(split(v:statusmsg, ';')[1])[0]
    elseif mode ==# "\"
      let s:word_count = split(split(v:statusmsg, ';')[2])[0]
    elseif mode =~# '[ni]'
      let s:word_count = split(split(v:statusmsg, ';')[2])[3]
    end
  " index out of range
  catch /^Vim\%((\a\+)\)\=:E\%(684\|116\)/
    return ''
  endtry
  let v:statusmsg = s:old_status
  call setpos('.', position)

  return "\ \|\ " . s:word_count . 'w'
endfunction

that can be appended to the statusline by, say,

    set statusline+=%.10{StatuslineWordCount()}     " wordcount