On Sat, Oct 9, 2010 at 11:02 AM, Thomas DuBuisson
All, I have updated the ticket/patch for this proposal [1]. It seems the community has agreed on
class RandomGen g where next :: g -> (Int, g) genRange :: g -> (Int,Int) genRange _ = (minBound, maxBound)
class (RandomGen g) => SplittableGen g where split :: g -> (g, g)
Notice SPJs good catch that SplittableGen should be constrained by RandomGen is there (lacking discussion, but its hard to imagine objection). I'm not sure what you, Jan, mean by removing Read and Show constraints as I don't see any.
I was mis-remembering the following as a class constraint on RandomGen: data StdGen = ... -- Abstract instance RandomGen StdGen where ... instance Read StdGen where ... instance Show StdGen where ... (http://www.haskell.org/onlinelibrary/random.html) This makes it hard to impossible to implement splitting of StdGen both efficiently and correctly. -Jan