Actually, I think Elixir's pattern matching is slightly worse than OCaml simply because there's no in-built syntax for multiple matches pointing to the same clause. Ex:

    (* In OCaml *)
    type t = A | B | C | D
    match A with
    | A | B -> "something"
    | C | D -> "else"

And in elixir:

    case :a do
      a when a in [:a, :b] -> "something"
      a when a in [:c, :d] -> "else"
    end

And of course, you lose exhaustiveness from type information, but that's a preference.

But, more to the point, I think what GP's referring to is partial function definitions via pattern matching on the arguments. That is intoxicating, and I wish OCaml had that.