filter_map is only available in recent Stdlib

src/Tiny_httpd.ml

@@ -396,7 +396,7 @@ module Headers = struct
                 | _       -> None
               in
               let cookies =
-                List.filter_map fn_eq (String.split_on_char ';' v) @ cookies
+                U.filter_map fn_eq (String.split_on_char ';' v) @ cookies
               in
               (headers, cookies)
             end

src/Tiny_httpd_util.ml

@@ -102,6 +102,18 @@ let split_on_slash s : _ list =
   done;
   List.rev !l
 
+let filter_map f l =
+  let rec fn = function
+    | [] -> []
+    | x::l ->
+       begin
+         match f x with
+         | None -> fn l
+         | Some x -> x::fn l
+       end
+  in
+  fn l
+
 (*$= & ~printer:Q.Print.(list string)
   ["a"; "b"] (split_on_slash "/a/b")
   ["coucou"; "lol"] (split_on_slash "/coucou/lol")

src/Tiny_httpd_util.mli

@@ -40,3 +40,7 @@ val pp_date : Format.formatter -> Unix.tm -> unit
     for expiration date of cookies.
     @since 0.12
 *)
+
+val filter_map : ('a -> 'b option) -> 'a list -> 'b list
+(** filter_map, now in Stdlib
+    @since 0.12 *)