fizzbuzz.scala

@ {
    import shapeless._
    import shapeless.nat._
    import shapeless.ops.nat._
    import shapeless.ops.hlist._
  
    trait Fizz
    trait Buzz
  
    trait Match[N <: Nat, FB] { def s: String }
    implicit def fizz[N <: Nat](implicit m: Mod.Aux[N, _3, _0]):Match[N, Fizz] = new Match[N, Fizz] { def s = "fizz" }
    implicit def buzz[N <: Nat](implicit m: Mod.Aux[N, _5, _0]):Match[N, Buzz] = new Match[N, Buzz] { def s = "buzz" }
    def noShow[N <: Nat, FB]:Match[N, FB] = new Match[N, FB] { def s = "" }
  
    case class Line[N](s: String)
    object Line {
      implicit def instance[N <: Nat](implicit f: Match[N, Fizz] = noShow[N, Fizz], b: Match[N, Buzz] = noShow[N, Buzz], toInt: ToInt[N]):Line[N] = Line[N](s"${toInt.apply}: ${f.s}${b.s}")
    }
  
    case class Lines[N <: Nat](l: List[String])
    object Lines {
      implicit def instance[N <: Nat, R <: HList, H <: HList](implicit 
        r: Range.Aux[_1, N, R], 
        l: LiftAll.Aux[Line, R, H],
        tl: ToList[H, Line[_]],
      ): Lines[N] = Lines[N](tl(l.instances).map(_.s))
    }
  
    implicitly[Lines[_16]].l.foreach(println)
  } 
1: 
2: 
3: fizz
4: 
5: buzz
6: fizz
7: 
8: 
9: fizz
10: buzz
11: 
12: fizz
13: 
14: 
15: fizzbuzz