static LS fileInfoHintsWithDate(File f) {
  new LS hints;
  if (f == null) ret hints;
  
  if (f.isFile()) {
    //hints.add("file");
    hints.add(n2(fileSize(f)) + " bytes";
    hints.add("modified " + renderFileDateWithSeconds(f));
  } else if (f.isDirectory())
    hints.add("dir");
  else
    hints.add("not found");
    
  ret hints;
}