On 20 January 2005 17:39, Sven Panne wrote:

Alain Cremieux wrote:

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As I see it: we could change all the operations in Data.Set/Data.Map to be right-biased, but that's a fair bit of work and might introduce new bugs.

If someone wants to do this work, it needs to be done fairly quickly (i.e. in the next couple of weeks) because we plan to release GHC 6.4 with the new code, and we won't be able to make further library changes until 6.6. Any volunteers?

Cheers, Simon

Hi, If everyone agrees on what's to be done, I volunteer for doing it. Alain

I'm not sure if we should really do this, I was just trying to find out the reason for this bias change. Perhaps adding a BIG comment in the new API is enough.

Right. I think the concensus is that we don't need to systematically change the bias in Data.Map, but we do need to document the change carefully for those porting old code. For the most part, old code will continue to work without changes because we've kept the old APIs. The exception (Data.Set.union) was pointed out by Ross, but it's unlikely to affect "normal" uses of union. Cheers, Simon