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

It may be possible to get the regex compiler to do most of the work for you by concatenating the search expressions into one big regexp, separated by "|". A clever regex compiler might search for commonalities in the alternatives in such a case, and devise a more efficient search strategy than simply checking each one in turn. But I have no idea whether there are compilers which will do that.