Files
mercury/tests/valid_seq/constraint_proof_bug_lib.m
2020-11-15 08:02:47 +11:00

70 lines
1.6 KiB
Mathematica

%---------------------------------------------------------------------------%
% vim: ts=4 sw=4 et ft=mercury
%---------------------------------------------------------------------------%
:- module constraint_proof_bug_lib.
:- interface.
:- type date.
:- type code.
:- type field(T1, T2)
---> d(T1)
; c(T2).
:- type dep_op == string.
:- typeclass constrainable(T) where [
pred apply_op(T::in, dep_op::in, T::in) is semidet
].
:- instance constrainable(date).
:- instance constrainable(code).
:- instance constrainable(field(T, T2))
<= (constrainable(T), constrainable(T2)).
:- pred get_date_date(int::out, int::out, int::out, date::in) is det.
:- implementation.
:- type code == int.
:- type date
---> d(int).
get_date_date(Y, M, D, _Date) :-
Y=1999, M=6, D=25.
:- instance constrainable(date) where [
pred(apply_op/3) is apply_op_dates
].
:- pred apply_op_dates(date::in, dep_op::in, date::in) is semidet.
apply_op_dates(D1, "=", D2) :-
get_date_date(Y1, M1, Day1, D1),
get_date_date(Y1, M1, Day1, D2).
:- instance constrainable(code) where [
pred(apply_op/3) is apply_op_codes
].
:- pred apply_op_codes(code::in, dep_op::in, code::in) is semidet.
apply_op_codes(D1, "=", D2) :-
compare((=), D1, D2).
:- instance constrainable(field(T, T2)) <=
(constrainable(T), constrainable(T2))
where [
pred(apply_op/3) is apply_op_fields
].
:- pred apply_op_fields(field(T, T2)::in, dep_op::in, field(T, T2)::in)
is semidet <= (constrainable(T), constrainable(T2)).
apply_op_fields(d(D1), Op, d(D2)) :-
apply_op(D1, Op, D2).
apply_op_fields(c(D1), Op, c(D2)) :-
apply_op(D1, Op, D2).