var xxx = do {
  fun a(x: Number, y: Number) = "$(x * 10)$(y * 10)"
  fun a(x: String, y: String) = "$x$y"
  fun a(x: Object, y: Object) = "$(x.a * 10)$(y.a * 10)"
  ---
  a
}
---
[
  123 xxx 999,
  "a" xxx "b",
  {a: 1} xxx {a: 2}
]