That is a bit of my problem with many resources about functional programming - they cover static typing instead, which makes it not particularly well transferable to Elixir (or Clojure, or some others). In this case use different structs, as @RudManusachi mentioned, but in my experience this will quickly start to feel weird and overengineered (at least that’s my experience, but maybe I did that wrong and someone could share a success story of this approach in Elixir).
IMO Elixir needs to find its own way to do functional modeling, DDD etc, because copying from Scala or F# won’t work. I wrote something about this few years ago, but this is just scratching the surface (and not necessarily the only direction).
