tracks/ocaml/exercises/hexadecimal/example.ml in trackler-2.2.1.110 vs tracks/ocaml/exercises/hexadecimal/example.ml in trackler-2.2.1.111

@@ -1,9 +1,9 @@
-open Core
+open Base
 
 let digit_to_int c =
   match c with
-  | '0'..'9'  -> Some (int_of_char(c) - 48)
+  | '0'..'9'  -> Some (Char.to_int(c) - 48)
   | 'a'..'f'  -> Some (Char.to_int(c) - 97 + 10)
   | 'A'..'F'  -> Some (Char.to_int(c) - 97 + 10)
   | _ -> None
 
 let to_int hex_str =