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? -- David Roundy http://www.darcs.net _______________________________________________ darcs-users mailing list [email protected] http://lists.osuosl.org/mailman/listinfo/darcs-users
