:- module bug574.
:- interface.

:- import_module io.

:- type job
    --->    job1(pred(int::in, io::di, io::uo) is det)
    ;       job2(int).

:- pred process_job(job::in, io::di, io::uo) is det.

:- implementation.

process_job(Job, !IO) :-
   (
     Job = job1(Pred),
     do_process_job1(Pred, !IO)
   ;
     Job = job2(_)
   ).

:- pred do_process_job1(pred(int, io, io)::in(pred(in, di, uo) is det),
   io::di, io::uo) is det.

do_process_job1(_, !IO).