Ranges of keys

[szaydel]

I think it would be nice to have ranges of keys, which are stored as members of a set. One should be able to define a range of any given name, and optionally add keys for any wrapped function to this set. Any number of sets should be possible. This would make it easier to selectively expire groups of keys prematurely, if necessary. I can see a use case for this being where a change made to some data elements will result in no-longer valid cached entries, but their expiration originally set on the wrapped function or functions has not yet been reached.