I believe the |> operator has been around for a while -- I've seen it used in some older Standard ML code, but just as a user-defined operator and not part of t

I believe the |> operator has been around for a while -- I've seen it used in some older Standard ML code, but just as a user-defined operator and not part of the basis library. F# included it in the core library for the language and it was fairly popular there for structuring heavily-nested expressions into a more-human-readable "pipeline". OCaml added it to the Core library fairly recently, as has (I believe) Elixir.