 fixed recursion depth that is gradually increased
        until finding the longest match.

        Example::

            from pip._vendor import pyparsing as pp
            pp.ParserElement.enable_left_recursion()

            E = pp.Forward("E")
            num = pp.Word(pp.nums)
            # match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
            E <<= E + '+' - num | num

            print(E.parse_string("1+2+3"))

        Recursion search naturally memoizes matches of ``Forward`` elements and may
        thus skip reevaluation of parse actions during backtracking. This may break
        programs with parse actions which rely on strict ordering of side-effects.

        Parameters:

        - ``cache_size_limit`` - (default=``None``) - memoize at most this many
          ``Forward`` elements during matching; if ``None`` (the default),
          memoize all ``Forward`` elements.

        Bounded Recursion parsing works similar but not identical to Packrat parsing,
        thus the two cannot be used together. Use ``force=True`` to disable any
        previous, conflicting settings.
        ú0Packrat and Bounded Recursion are not compatibleNr