code: def t_B_SEQUENCE_COMPACT_START(self, t):
          r
  
          indent_status, curr_depth, next_depth = self.get_indent_status(t)
  
          if indent_status == 'INDENT':
              self.indent_stack.append(next_depth)
              return t
  
          msg = dedent("""
              expected 'INDENT', got  {indent_status!r}
              current_depth:          {curr_depth}
              next_depth:             {next_depth}
              token:                  {t}
          """).format(**vars())
  
          raise YAMLUnknownSyntaxError(msg)
docs: r"""
            \-\ + (?=  -\   )
            #          ^ ^ sequence indicator
          | \-\ + (?=  [\{\[]\   |  [^:\n]*:\s   )
            #            ^ ^          ^^^ map indicator
            #            ^ ^ flow indicator