[Haskell-cafe] Potential problem with AC-Vector-Fancy package
andrewcoppin at btinternet.com
Thu Aug 11 19:45:08 CEST 2011
On 10/08/2011 11:04 PM, Dave Tapley wrote:
> Is anyone maintaining the AC-Vector-Fancy package?
> I haven't had a reply from the latest maintainer (Andrew Coppin) on
> Hackage, so I thought I'd open it up to cafe:
Oh, right. I haven't checked my mailbox recently...
> I think I have found a problem with the union function:
> If you look here: http://hpaste.org/49889
> You will see that line 4 gives a different result to lines 6, 8, 10;
> this shouldn't be the case because union is commutative.
AC-Vector-Fancy is merely a "fancy" facard over AC-Vector. So the bug is
actually with AC-Vector.
Looking at my source code, the true bug is in Data.BoundingBox.Range
[which provides the engine that all the other bounding box types use).
The actual bug turns out to by face-slappingly stupid: it's a typo in
one of the variable names.
I'll go get that fixed... and then maybe write some QuickCheck properties.
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