Warp wrote:

>   Wait a minute... Exactly how do you create a random number generator in
> Haskell?
> 
>   Not being able to create a RNG function would be rather restrictive in
> many applications...

You write a function that takes a PRNG state and returns a random number 
and a new PRNG state.

(That is, if you want *psuedo*-random numbers. If you're after truly 
random numbers, you'll obviously need to perform some kind of I/O to get 
them, since true randomness comes only from physical sources.)

This is a common idiom in Haskell; write a function that takes an 
initial state and returns an answer and a new, modified state. In fact, 
there's even a standard monad for automating this so you don't have to 
manually pass the state around by hand all the time.

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