On Sat, 1 Nov 2008, David Roundy wrote: > On Thu, Oct 30, 2008 at 05:58:52AM +0000, Ganesh Sittampalam wrote: >> On Wed, 29 Oct 2008, Jason Dagit wrote: >> >>> On Wed, Oct 29, 2008 at 1:35 PM, Ganesh Sittampalam <[EMAIL PROTECTED]> >>> wrote: >>>> Hi David, >>>> >>>> No rush to deal with this one, I'm just sending it in case you want to >>>> and so that others can review it. >>>> >>>> This addresses a different quadratic blowup I found when running >>>> whatsnew -sl on a directory with lots of files in it. It's a nice >>>> advert for type witnesses being very helpful in creating confidence >>>> in a refactoring. >>> >>> Yes, the GADT stuff makes refactoring quite nice. >>> >>> I looked at this patch bundle, I don't really see any problems with >>> it, but I didn't look that closely. Do you think it would be hard to >>> write QuickCheck properties that compare the new implementation with >>> the old one? My reasoning is this: the old implementation was simpler >>> and easier to inspect, so we can use it as a test answer oracle with >>> reasonable confidence. >> >> Yes, I think it would be quite easy to write properties - the tricky bit >> is generating the selection function. I don't think the old implementation >> was actually simpler though, as it relied on commuteWhatWeCan which isn't >> really very simply. >> >> For what it's worth I'm reasonably confident that I've reproduced the old >> behaviour, though obviously QuickCheck properties wouldn't hurt. I think >> my preferred approach to doing that would be to write them for the >> specification I claim in the comments, and then to check both old and new >> against the properties. > > It looks good to me, and is going in. I agree with your suggestion of how > to implement tests. Can't coarbitrary be used to generate the selection > function?
Probably, but coarbitrary always confuses the hell out of me until I think about it for a while, so I don't know off the top of my head. Now you mention it, it certainly fits with what I understand it is for, but I'd have to check into the details to be sure. Ganesh _______________________________________________ darcs-users mailing list [email protected] http://lists.osuosl.org/mailman/listinfo/darcs-users
