pads :: Token a => Int -> [[SExpr a]] -> String
pads n s =
  let s' = bracket .
        map (bracket . map showSExpr) $ s
  in replicate (n - length s') ' ' ++ s'
pads :: Token a => Int -> [[SExpr a]] -> String
pads n s =
  let s' = bracket .
        map (bracket . map showSExpr) $ s
  in replicate (n - length s') ' ' ++ s'
pads n s =
  let s' = bracket .
        map (bracket . map showSExpr) $ s
  in replicate (n - length s') ' ' ++ s'