Expose infix viewing, replacement, mapping, and composition

runtime.ml

@@ -40,3 +40,11 @@ let () =
     try action (); assert false with Invalid_argument _ -> ())
     [(fun () -> ignore (view _hd [])); (fun () -> ignore (view _tl []));
      (fun () -> ignore (set _hd 1 [])); (fun () -> ignore (set _tl [] []))]
+
+let () =
+  let open Infix in
+  assert ((9, false) ^. _1 = 9);
+  assert ((_2 ^~ "grey") (true, 9) = (true, "grey"));
+  assert ((_1 ^% succ) (9, false) = (10, false));
+  assert (((_1 ^> _2) ^~ 3) ((true, 9), false) = ((true, 3), false));
+  assert (((_2 ^< _1) ^~ 3) ((true, 9), false) = ((true, 3), false))