Error when trying to use Pipe First in rtop

If you've been exploring ReasonML, you might have run into a problem where the Pipe First operator doesn't seem to work in rtop. You get the error message:

Error: Unbound value |.

Well, it turns out that that's just the way it is. Pipe First doesn't work in rtop. rtop uses regular, native OCaml's utop, which doesn't have Pipe First. Your compiled Reason programs can use it, because they rely on Bucklescript rather than native OCaml.

This behavior may change in the future, but it's as it is right now.