src/Pure/Isar/antiquote.ML

       ("Malformed antiquotation: " ^ quote ("@{" ^ s ^ "}") ^ Position.str_of pos);
 
     val res =
       Source.of_string s
       |> Symbol.source false
-      |> T.source false (K (lex, Scan.empty_lexicon)) pos
+      |> T.source NONE (K (lex, Scan.empty_lexicon)) pos
       |> T.source_proper
       |> Source.source T.stopper (Scan.error (Scan.bulk antiq)) NONE
       |> Source.exhaust;
   in (case res of [x] => x | _ => err "") handle ERROR msg => err msg end;