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