lazyArgs.scala

val g = SynthGraph {
   val f1 = "freq1".kr(0.4)
   val f2 = "freq2".kr(8)
   val d  = "detune".kr(0.90375)
   val f = LFSaw.ar(f1).madd(24, LFSaw.ar(List(f2, f2*d)).madd(3, 80)).midicps // glissando function
   val x = CombN.ar(SinOsc.ar(f)*0.04, 0.2, 0.2, 4) // echoing sine wave
   Out.ar( 0, x )
}

val src = g.sources

val prod = src.collect { case x: Product => x }
val non = src diff prod // -> empty
prod.map(_.productPrefix)
prod.map(_.productArity)

sealed trait LazyArg
case object IntArg extends LazyArg
case object StringArg extends LazyArg
case object GEArg extends LazyArg
case object LazyAsArg extends LazyArg
case object RateArg extends LazyArg
case class UnknownArg(c: Class[_]) extends LazyArg

val m: Map[LazyArg, Any] = prod.flatMap(_.productIterator).collect({
   case i: Int => IntArg -> i
   case s: String => StringArg -> s
   case ge: GE => GEArg -> ge
   case lz: Lazy => LazyAsArg -> lz
   case r: Rate => RateArg -> r
   case x => UnknownArg(x.getClass) -> x
}).toMap

m.keys.foreach(println)
// -> RateArg, GEArg, Unknown: BinaryOp...., UnaryOp....