Poor performance of Basic compared to Cuckoo about hashtables

[infinity0]

Have you tried Data.HashMap from unordered-containers? As I mentioned here, although it is a pure data structure, it is actually faster than this library (including Cuckoo), as indicated by benchmarks ran by @ninegua on an internal company use-case from a year ago. Since you're doing this now, perhaps you could try that out? Would be interested to see the numbers for someone else's use-case.

[infinity0]

i.e. just wrap it in a MutVar or something, that's what we did

[brianhuffman]

Around the same time I opened this ticket, we switched our application to use an IORef around an ordinary Data.Map. (The keys in our application are Word64s, so something like Data.IntMap would probably be better, except Data.IntMap keys are fixed to Int, which is not guaranteed to have 64 bits.) It turned out that this was fast enough not to be a bottleneck, so we've left it at that.