Update OCaml code with pattern guards.

Now the missing piece for recognizing urls is
regexp support.

ocaml/main.ml

@@ -1,5 +1,16 @@
+(* Regexp required here *)
+let is_youtube_url url =
+  match url with
+  | "http://www.youtube.com/" -> true
+  | _ -> false;;
+
+(* Maybe have a list of functions and
+ * iter on all the items in the list *)
 let evaluate str =
-  str;;
+  match str with
+  | str when is_youtube_url str -> "that's youtube"
+  | _ -> str;;
+
 
 try
   while true do
@@ -7,6 +18,6 @@ try
     let line = read_line () in
     let answer = evaluate line in
     print_endline answer
-  done;
+  done
 with
   End_of_file -> print_endline "Bye!";;