title: OCaml |> operator
body: <p>Could someone explain what the |> operator does? This code was taken from the reference <a href="http://caml.inria.fr/pub/docs/manual-ocaml/libref/Map.html">here</a>:</p>
  
  <pre><code>let m = PairsMap.(empty |&gt; add (0,1) "hello" |&gt; add (1,0) "world")
  </code></pre>
  
  <p>I can see what it does, but I wouldn't know how to apply the |> operator otherwise.</p>
  
  <p>For that matter, I have no idea what the Module.() syntax is doing either. An explanation on that would be nice too.</p>