code: def line_column(self) -> Tuple[int, int]:
          
          ln = self.input.count("\n", 0, self.offset)
          c = (self.offset if ln == 0 else
               self.offset - self.input.rfind("\n", 0, self.offset) - 1)
          return (ln + 1, c)
docs: Return line and column coordinates.