On Tue, 2010-09-14 at 16:44 -0700, Thomas DuBuisson wrote:
The "split" routine in the RandomGen seems to be a sore spot for some people and is perceived to have few users (even as a percentage of RandomGen users). I propose:
1) Making a class "SplittableGen":
class SplittableGen g where split :: g -> (g, g)
2) (re)moving the "split" routine from the RandomGen class.
See ticket 4314 [1] for the patch.
There has been reasonable discussion on this (20 messages by my count). Responses seem to break down into 3 unknown, 1 against, and 7 for some sort of change: Yes, and add extra change X (BOS) Yes (Duncan, Ian, TomMD) With a modification to the class structure (Henning, Felipe, Nicolas) No, this breaks things without cause (Milan) Unknown/neutral (Isaac, Ivan, Brandon) I'd say the "Yes" and "with modification" votes have it. As it's pretty close (4 - 3) with one group calling or a "clean split" and the other calling for change that is backward compatible, a last round of discussion that might bring more peoples thoughts in could be beneficial. Discussion still ends on the 8th so I will re-summarize and make a patch this weekend. The two positions: The "Clean Break" would involve removing "split" from the RandomGen class and making a new class "SplittableGen" for this operation. The thought here is that not all generators can have a "split". Users of "split" would have to be explicit of their need for a Splittable generator. The backward compatible change would keep "split" as a member of class "RandomGen" for which all instances would be constrained to also be instances of the "BasicRandomGen" class. BasicRandomGen would contain the traditional routines (next, genRange). Cheers, Thomas P.S. My position hasn't changed and I have nothing more to add to what's been said, see the threads history for any refresher.