code.rs

type person = Streamer(string) | Mr(string)

let kirJs = Streamer("KirJS")

let mrLapteuh = Mr("Lapteuh")

let say = person =>
  switch person {
  | Streamer(name) => name ++ ": " ++ "Yes, mr. Lapteuh." ++ "\n"
  | Mr(name) => "Mr. " ++ name ++ ": " ++ "Say my name!" ++ "\n"
  }

let persons = [mrLapteuh, kirJs]

Js.Array.forEach(p => Js.Console.log(say(p)), persons)