Thanks for the examples. Point 3 is interesting but most of the gain
there could probably be had by telling the user to use (bigmap `union`
smallmap). My guess is that the user has a good idea which argument is
larger/smaller.
On Wed, Feb 23, 2011 at 12:45 AM, Max Bolingbroke
Personally I don't find any of these *particularly* compelling. But a ~6% slowdown for this functionality is not too bad - have you had a chance to look at the core to see if the cause of the slowdown manifests itself at that level? Perhaps it is possible to tweak the code to make this cheaper.
I did look at the core for test :: HashMap Int Int -> HashMap Int Int test hm = insert 42 12 hm And I didn't see anything that looked particularly bad. The core uses unboxed values everywhere possible and the recursive function (i.e. inserts) returns an unboxed pair (# Int#, Tree k v #). The code for O(1) size i here: https://github.com/tibbe/unordered-containers/commit/77bc43acad2eb6b29472cd6...
Also, what was the size of the collections you used in your benchmark? I would expect the relative cost of maintaining the size to get lower as you increased the size of the collection.
I tried with 2^12. Johan