dnaToRna = T.map dnaToRnaNt . toDna
  where
    dnaToRnaNt nt = case nt of 
      'T' -> 'U'
      _   -> nt   -- save a lot of lines 
dnaToRna = T.map dnaToRnaNt . toDna
  where
    dnaToRnaNt nt = case nt of 
      'T' -> 'U'
      _   -> nt   -- save a lot of lines 
dnaToRna = T.map dnaToRnaNt . toDna
  where
    dnaToRnaNt nt = case nt of 
      'T' -> 'U'
      _   -> nt   -- save a lot of lines 