Bugfix for QuickCheck 1.1.0.0

[Johan Tibell]

On Sun, Aug 31, 2008 at 11:19 AM, Patrick Perry <patperry at stanford.edu> wrote:
> "variant" takes a generator and an integer, and produces a generator.  Here
> is how it works in the new version:
>
> First, n gets written in binary:
>
> e.g.
>
> n = 10011
>
> Then, we replace "1" with "fst . split". and we replace "0" with "snd .
> split".
>
> n' = l . r . r . l . l where l = fst . split
>                                      r = snd . split
>
> Then, we apply the resulting function to the generator
>
> g' = n' g0
>
>
> The run time is O (log n).
>
> In the old version, "split" gets called n times, so the run time is O(n).
>  For certain double values, variant gets called with n on the order of 2^30,
> hence the hang in QuickCheck.  The new version of variant employs the same
> algorithm as in QuickCheck2.

Thanks for the explanation!

Cheers,

Johan