Fixing an infinite recursion in OCaml applicative parsers

Nine years ago, while I was still a fresh OCamlr, I gave a presentation (later turned blog post) with title First steps with Category Theory and OCaml. The idea was to show how to implement the basic typeclasses of Category Theory in OCaml, and how to use them to build a simple parser combinator library, by following what I had learned from Haskell. At the time, not knowing better, I stumbled upon an annoying issue: if you look at the code examples for the Alternative_Utils module, you will find the following commented-out code.