grid_reader_cursor_start_of_line
grid_reader_cursor_start_of_line(gr, 0);
grid_reader_cursor_start_of_line(gr, 1);
grid_reader_cursor_start_of_line(gr, 0);
void grid_reader_cursor_start_of_line(struct grid_reader *, int);
grid_reader_cursor_start_of_line(&gr, 1);