writeB :: Char -> BufferM ()
writeB c = do
  deleteN 1
  insertB c

-- | Write the list into the buffer at current point.
writeB :: Char -> BufferM ()
writeB c = do
  deleteN 1
  insertB c

-- | Write the list into the buffer at current point.
writeB c = do
  deleteN 1
  insertB c

-- | Write the list into the buffer at current point.