How to sort the output of lfs.dir

[Mingranina Gingranina <mingranina@...>]

 Dear List,
 Hello,

 In the following function defined in Fontsampler for quick overview
of all fonts in a directory hierarchy, I need the output to be sorted
 alphabetically. How can I do that?

 function dirtree(dir)
  assert(dir and dir ~= "", "directory parameter is missing or empty")
  if string.sub(dir, -1) == "/" then
    dir=string.sub(dir, 1, -2)
  end

  local function yieldtree(dir)
    for entry in lfs.dir(dir) do
      if not entry:match("^%.") then
        entry=dir.."/"..entry
     	  if not lfs.isdir(entry) then
     	    coroutine.yield(entry,lfs.attributes(entry))
     	  end
     	  if lfs.isdir(entry) then
     	    yieldtree(entry)
     	  end
      end
    end
  end

  return coroutine.wrap(function() yieldtree(dir) end)
end

 Any help would be gratefully appreciated.

 Thanks,
 Mingranina