This package allows you to define several typesafe indizes on a set. You can query the set with an SQL-like set of query operations. This package was developed as a successor of Data.IxSet. It is meant to be more space efficient, since it uses Data.IntSet and Data.TrieMap as an underlying represenation. It also has the potential to be fast, since indizes don't need to be recalculated after each query and since Patricia trees perform quite well for intersection and union. This package comes without warranties. Although I use it without problems in a large web project it is neither properly tested nor benchmarked. Patches or suggestions for improvement are welcome. If you like, start an issue on github.