example.ml in trackler-2.2.1.111

- old
+ new

@@ -1,6 +1,6 @@
-open Core
+open Base
 
 type 'a stack = 'a list
 
 let push (s: 'a stack) (a: 'a): 'a stack = a :: s
 let pop (s: 'a stack): ('a * 'a stack) option = match s with
@@ -15,10 +15,10 @@
    otherwise return None (to indicate matching failure). *)
 let update (s: (char stack) option) (ch: char): (char stack) option =
   match s with
   | None -> None
   | Some s ->
-    let pop_matching m = Option.filter (pop s) ~f:(fun (top, _) -> top = m)
+    let pop_matching m = Option.filter (pop s) ~f:(fun (top, _) -> Char.(top = m))
                          |> Option.map ~f:snd in
     match ch with
     | '(' | '{' | '[' -> Some (push s ch)
     | ')' -> pop_matching '('
     | '}' -> pop_matching '{'