Hashtable/dictionary/map lookup with regular expressions

Question

I\'m trying to figure out if there\'s a reasonably efficient way to perform a lookup in a dictionary (or a hash, or a map, or whatever your favorite language calls it) where the

Answer 1

The problem has nothing to do with regular expressions - you'd have the same problem with a dictionary with keys as functions of lambdas. So the problem you face is figuring is there a way of classifying your functions to figure which will return true or not and that isn't a search problem because f(x) is not known in general before hand.

Distributed programming or caching answer sets assuming there are common values of x may help.

-- DM