I think it would be a great idea if we had a regular expression search engine, but can it be done? It seems impossible since there's no feasible way of indexing such a huge amount of data properly and displaying results in the order of relevance from what I can think of.I'm curious what the answer to this one would be.
can a regex search engine for the web be done and if so, how?
search engine;regular expressions
It can be done, and it has been done: http://www.google.com/codesearchI think it is useful here because this is in a specific domain where the users might be expected to understand regexes. I suspect in general the feature is not that useful to the vast majority of Google users so there is probably no commercial reason to do it.