Hello, I have a question regarding 'Data.Map' api, filed an issue https://github.com/haskell/containers/issues/708 And may be I can ask here at the same time? I'm not sure why|Data.Map|doesn't have a key range based visiting API, I figured out I can do it this way: |indexKeyRange :: IndexKey -> IndexKey -> Map IndexKey Object -> [(IndexKey, Object)] indexKeyRange !minKey !maxKey = toList . takeWhileAntitone (<= maxKey) . dropWhileAntitone (< minKey) | But wouldn't it save the computation needed to re-balance the intermediate tree generated ? Or that re-balancing can be optimized out actually ? I am creating an in-memory graph database, using|Data.Map.Strict.Map|as business object indices with specified object attributes. The typical scenario will be querying a small number of entries by key range, out of possibly all business objects of a certain class globally, so the implementation above would work, but not reasonable by far as it seems. I think a lazy list returned by mere node visiting (i.e. no new node creation) would satisfy my needs, or I missed something ? Thanks, Compl