%---------------------------------------------------------------------------%
% vim: ts=4 sw=4 et ft=mercury
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%
% This is a regression test for a bug in switch detection
% where it was preferring incomplete switches to complete
% one-case switches, and hence inferring the wrong determinism.

%---------------------------------------------------------------------------%

:- module switch_detection_bug.

:- interface.

:- type note
    --->    note(rank, modifier, octave).

:- type rank
    --->    c
    ;       d
    ;       e
    ;       f
    ;       g
    ;       a
    ;       b.

:- type modifier
    --->    natural
    ;       sharp
    ;       flat.

:- type octave == int.

:- type qualifier
    --->    maj
    ;       min.

:- pred next_topnote(note::in, qualifier::in, note::out) is multi.

%---------------------------------------------------------------------------%

:- implementation.

next_topnote(note(c, _, Oct), _,   note(d, natural, Oct)).
next_topnote(note(d, _, Oct), _,   note(c, natural, Oct)).
next_topnote(note(d, _, Oct), maj, note(e, natural, Oct)).
next_topnote(note(d, _, Oct), min, note(e, flat,    Oct)).
next_topnote(note(e, _, Oct), _,   note(d, natural, Oct)).
next_topnote(note(e, _, Oct), _,   note(f, natural, Oct)).
next_topnote(note(f, _, Oct), maj, note(e, natural, Oct)).
next_topnote(note(f, _, Oct), min, note(e, flat,    Oct)).
next_topnote(note(g, _, Oct), _,   note(f, natural, Oct)).
next_topnote(note(g, _, Oct), min, note(a, flat,    Oct)).
next_topnote(note(g, _, Oct), maj, note(a, natural, Oct)).
next_topnote(note(a, _, Oct), _,   note(g, natural, Oct)).
next_topnote(note(a, _, Oct), min, note(b, flat,    Oct)).
next_topnote(note(a, _, Oct), maj, note(b, natural, Oct)).
next_topnote(note(b, _, Oct), maj, note(a, natural, Oct)).
next_topnote(note(b, _, Oct), min, note(a, flat,    Oct)).

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