On 14 May 2004 18:17, Christian Maeder wrote:

Simon Marlow wrote:

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"FiniteMap Int a" performs better than "Map Int a", but not as good as "IntMap a", but the differences are unimportant for us.

How much better? I'm not keen to import something that's going to degrade performance of existing code noticeably.

Ok, I'll send you numbers (later). Are you going to reimplement FiniteMap via DData.Map (or how could existing code suffer)?

Sorry, I should have been clearer. I mean that programmers who migrate code to Data.Map will see a performance loss; that's something I'd like to avoid. Furthermore, there shouldn't be any need for Map to be slower than FiniteMap. A 10% loss in performance for FiniteMap isn't going to show up in many profiles, but it'll cause a performance degradation in *lots* of applications, so fixing it is worthwhile. Indeed, we should take the opportunity to see if the code can be tuned any further and improve on the performance of FiniteMap. Cheers, Simon