[m-users.] Confused my det/multi error message, full disjunction of type in place.

[Julien Fischer]

On Sun, 4 Dec 2022, Sean Charles (emacstheviking) wrote:

> And the code, I just don't understand, as usual, what the compiler is
> trying to tell me. The io.nl/2 is det, so that can't fail, and
> presumably the field update can't fail either. And why hasn't this
> error been raised on all the other cases?
> 
> 
>      59 :- pred write_(fstate::in, fstate::out, fi::in, io::di, io::uo) is det.
>      60
>      61 write_(!S, nl, !IO) :-
>      62     io.nl(!IO),
>      63     !:S = !.S ^nl_written := yes.
>      64
>      65 write_(!S, brace_o, !IO) :-
>      66     write_(!S, s("{"), !IO),
>      67     !:S = !.S ^tab_size := !.S ^tab_size+1.
                                                     ^^^
>      68     write_(!S, nl, !IO).

Presuambly, the period marked above is actually supposed to be a comma.
(Because it's a period, you have two clauses that match nl.)

Julien.