Mark Carroll writes:

The "dice" function gives you back the new state of the rng which maybe you should keep around to start the next set of rolls with. ("main" throws it away with "snd".) I'd certainly be interested to see how this could be written more nicely. I avoided making the list of die rolls an infinitely long lazy list in case we wanted to use the same RNG for other stuff too

Okay, since you've already done his homework for him... :-) main = do r <- newStdGen print (dice 4 r) dice :: Integer -> StdGen -> [Integer] dice n g = take n $ randomRs (1,6) g -kzm -- If I haven't seen further, it is by standing in the footprints of giants

Mark Carroll writes:

On 17 Dec 2002, Ketil Z. Malde wrote: (snip)

...

dice :: Integer -> StdGen -> [Integer] dice n g = take n $ randomRs (1,6) g

Can we still do this concisely and get the new state of the rng back out the other end after the die has been thrown a few times?

Oops; I missed that part!

Or are things like newStdGen meant to be so cheap that it's fine to use lots of different RNGs instead of one that you thread through everything?

I've no idea - I've always used StdGen's as if they were going out of style. (You can, of course, `split` them and get two for the price of one) -kzm -- If I haven't seen further, it is by standing in the footprints of giants

Mark Carroll writes:

On 17 Dec 2002, Ketil Z. Malde wrote:

Ah - I was never sure what to make of that - I normally just use the GHC online Haddockised stuff which tells me no more than the type signatures, but I suppose "split" must be more than (\x->(x,x))!

Well, as SPJ said, you can browse the library report. Basically, it splits a random generator, so that you can pass it to a function and forget about it. -kzm -- If I haven't seen further, it is by standing in the footprints of giants