bottlesOfBeer.swift

extension Int { 
    func bottlesOfBeer() {
        let bottles = "\(self) bottle" + (self == 1 ? "" : "s")
        let what    = " of beer on the wall"

        println("\(bottles + what), \(bottles) of beer.")
        print("Take one down, pass it around, ")

        if self == 1 {
            println("no more bottles\(what).")
        }
        else if self > 0 {
            let next = self - 1
            println("\(next) bottle" + (next == 1 ? "" : "s") + what + ".\n")
            next.bottlesOfBeer()
        }
    }
}