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

This is not possible to do with a regular hash table in any language. You'll either have to iterate through the entire keyset, attempting to match the key to your regex, or use a different data structure.

You should choose a data structure that is appropriate to the problem you're trying to solve. If you have to match against any arbitrary regular expression, I don't know of a good solution. If the class of regular expressions you'll be using is more restrictive, you might be able to use a data structure such as a trie or suffix tree.