Using PEG's, another representation of grammars, packrat parsers provide an elegant and powerful parsing algorithm. The generated parser can parse inputs very efficiently by packrat parsing. The packrat parsing is the recursive descent parsing algorithm that is accelerated using memoization. Unlike common packrat parsers, PackCC can support direct and indirect left-recursive grammar rules. By using packrat parsing, any input can be parsed in linear time. Therefore, to allow packrat parsing, left recursion must be eliminated. Packrat is a scheming, oversized rat from the sewers. The spiders are particularly dense in packrat dens. One issue Prunella struggled with is hoarding, outlined in the episode "Prunella the Packrat". At the southwestern end of the lake is Packrat Peak at in elevation.