ios - I want multiple non-random numbers in swift -

i using swift , want have number of duplicatable patterns throughout game.

ideally have sort of shared class worked sort of (this sort of pseudo-swift code):

class randomnumberutility {     static var sharedinstance = randomnumberutility()     var random1 : random()     var random2 : random()      func seedrandom1(seed : int){         random1 = random(seed)     }     func seedrandom2(seed : int){         random2 = random(seed)     }     func getrandom1() -> int {         return random1.next(1,10)     }     func getrandom2() -> int {         return random2.next(1,100)     } } 

then, begin series, anywhere in program go this:

randomnumberutility.sharedinstance.seednumber1(7) randomnumberutility.sharedinstance.seednumber2(12) 

and know (for example) first 4 times called

randomnumberutility.sharedinstance.getrandom1() 

i same values (for example: 6, 1, 2, 6) continue until @ point seeded number again, , either exact same series (if used same seed), or different series (if used different seed).

and want have multiple series of numbers (random1 & random2) @ same time.

i not sure how begin turn actual swift class.

here possible implementation. uses jrand48 pseudo random number generator, produces 32-bit numbers. prng not arc4random(), has advantage state stored in user-supplied array, multiple instances can run independently.

struct randomnumbergenerator {     // 48 bit internal state jrand48()     private var state : [uint16] = [0, 0, 0]      // return pseudo-random number in range 0 ... upper_bound-1:     mutating func next(upper_bound: uint32) -> uint32 {          // implementation avoiding "module bias" problem,         // taken from: http://stackoverflow.com/a/10989061/1187415,         // swift translation here: http://stackoverflow.com/a/26550169/1187415          let range = uint32.max - uint32.max % upper_bound         var rnd : uint32         {             rnd = uint32(truncatingbitpattern: jrand48(&state))         } while rnd >= range          return rnd % upper_bound     }      mutating func seed(newseed : int) {         state[0] = uint16(truncatingbitpattern: newseed)         state[1] = uint16(truncatingbitpattern: (newseed >> 16))         state[2] = uint16(truncatingbitpattern: (newseed >> 32))     } } 

example:

var rnd1 = randomnumbergenerator() rnd1.seed(7) var rnd2 = randomnumbergenerator() rnd2.seed(12)  println(rnd1.next(10)) // 2 println(rnd1.next(10)) // 8 println(rnd1.next(10)) // 1  println(rnd2.next(10)) // 6 println(rnd2.next(10)) // 0 println(rnd2.next(10)) // 5 

if rnd1 seeded same value above produces same numbers again:

rnd1.seed(7) println(rnd1.next(10)) // 2 println(rnd1.next(10)) // 8 println(rnd1.next(10)) // 1