The problem isn't the declarative filtering per se. The problem is the draconian limit on the number of filters. Given that we can compile regular expressions t

The problem isn't the declarative filtering per se. The problem is the draconian limit on the number of filters. Given that we can compile regular expressions to DFAs and evaluate them in O(len(url)) time no matter how many patterns we have, there's little reason to place an arbitrary cap on the sophistication of an extension's filtering.