src/Tools/Code/code_ml.ML

       (ML_Class (the_single (map_filter
         (fn (name, Code_Thingol.Class (_, stmt)) => SOME (name, stmt) | _ => NONE) stmts))))
     fun modify_stmts ([stmt as (name, stmt' as Code_Thingol.Fun _)]) =
           if Code_Thingol.is_case stmt' then [] else [modify_fun stmt]
       | modify_stmts ((stmts as (_, Code_Thingol.Fun _)::_)) =
-          modify_funs (filter (Code_Thingol.is_case o snd) stmts)
+          modify_funs (filter_out (Code_Thingol.is_case o snd) stmts)
       | modify_stmts ((stmts as (_, Code_Thingol.Datatypecons _)::_)) =
           modify_datatypes stmts
       | modify_stmts ((stmts as (_, Code_Thingol.Datatype _)::_)) =
           modify_datatypes stmts
       | modify_stmts ((stmts as (_, Code_Thingol.Class _)::_)) =