[jordwalke]

Except when you're in the top level - in which case you don't use `in`. Oh, and don't forget all the nuance of interleaving imperative commands. I'm an experienced OCaml dev and this trips me up (the "ml compared" section of the docs lists some common pitfalls that Reason resolves).

[tom_mellior]

Ah, but here you seem to be talking about when to write 'in'. Reading it is much simpler: Just ignore that it's there, and voilà, you're set.

(I'm an experienced OCaml dev and := versus <- trips me up from time to time when choosing which one to write, but not when reading code.)