functional-fizzBuzz.swift

let numbers = AnySequence { () -> AnyGenerator<Int> in
    var i = 1
    return anyGenerator {
        return i++
    }
}.lazy

let fizzes = numbers.map{ $0 % 3 == 0 ? "Fizz" : "" }
let buzzes = numbers.map{ $0 % 5 == 0 ? "Buzz" : "" }

let pattern = zip(fizzes, buzzes).lazy.map { (fizz, buzz) in fizz + buzz }
let fizzbuzz = zip(pattern, numbers).lazy.map { (p, n) in p.isEmpty ? String(n) : p }


for fb in fizzbuzz.prefix(100) {
    print(fb)
}