No worries asking vim (or Emacs) questions related to Perl. If it's about Perl, you're loved. If it's about vi(m) you're also loved. If it's about Emacs, some will love you ;)

I've never thought about wrapping output before. I wrap my subs in the following way in my .vimrc.

function GetPerlFold()
  if getline(v:lnum) =~ '^\s*sub\s'
    return ">1"
  elseif getline(v:lnum) =~ '\}\s*$'
    let my_perlnum = v:lnum
    let my_perlmax = line("$")
    while (1)
      let my_perlnum = my_perlnum + 1
      if my_perlnum > my_perlmax
        return "<1"
      endif
      let my_perldata = getline(my_perlnum)
      if my_perldata =~ '^\s*\(\#.*\)\?$'
        " do nothing
      elseif my_perldata =~ '^\s*sub\s'
        return "<1"
      else
        return "="
      endif
    endwhile
  else
    return "="
  endif
endfunction
setlocal foldexpr=GetPerlFold()
setlocal foldmethod=expr
[download]

I'm very curious to find out how this ends up. Never thought of having folds in a dumper output before.

Please supply an example output so that there's something to test/work with. Preferably, within your OP so that everyone has a chance to see it.