A pretty vim foldtext function

As shown above, prints the number of folded lines on the right. Supports signs, foldcolumn, nonumber, number and relativenumber.

Here is an excerpt from my .vimrc. Press <Space> to fold. Folds are based on syntax.

if has("folding")
  set foldenable        " enable folding
  set foldmethod=syntax " fold based on syntax highlighting
  set foldlevelstart=99 " start editing with all folds open

  " toggle folds
  nnoremap <Space> za
  vnoremap <Space> za

  set foldtext=FoldText()
  function! FoldText()
    let l:lpadding = &fdc
    redir => l:signs
      execute 'silent sign place buffer='.bufnr('%')
    redir End
    let l:lpadding += l:signs =~ 'id=' ? 2 : 0

    if exists("+relativenumber")
      if (&number)
        let l:lpadding += max([&numberwidth, strlen(line('$'))]) + 1
      elseif (&relativenumber)
        let l:lpadding += max([&numberwidth, strlen(v:foldstart - line('w0')), strlen(line('w$') - v:foldstart), strlen(v:foldstart)]) + 1
      endif
    else
      if (&number)
        let l:lpadding += max([&numberwidth, strlen(line('$'))]) + 1
      endif
    endif

    " expand tabs
    let l:start = substitute(getline(v:foldstart), '\t', repeat(' ', &tabstop), 'g')
    let l:end = substitute(substitute(getline(v:foldend), '\t', repeat(' ', &tabstop), 'g'), '^\s*', '', 'g')

    let l:info = ' (' . (v:foldend - v:foldstart) . ')'
    let l:infolen = strlen(substitute(l:info, '.', 'x', 'g'))
    let l:width = winwidth(0) - l:lpadding - l:infolen

    let l:separator = ' … '
    let l:separatorlen = strlen(substitute(l:separator, '.', 'x', 'g'))
    let l:start = strpart(l:start , 0, l:width - strlen(substitute(l:end, '.', 'x', 'g')) - l:separatorlen)
    let l:text = l:start . ' … ' . l:end

    return l:text . repeat(' ', l:width - strlen(substitute(l:text, ".", "x", "g"))) . l:info
  endfunction
endif