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a22674efa6
Estimated hours taken: 0.5 library/int.m: Fix a bug in the definition of `div'. tests/hard_coded/division_test.m: Add some new regression tests for the above-mentioned bug.
84 lines
2.2 KiB
Mathematica
84 lines
2.2 KiB
Mathematica
% test the handling of `//', rem, div, and mod.
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% the first pair should truncate towards zero.
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% the second pair should truncate towards negative infinity.
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:- module division_test.
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:- interface.
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:- import_module io.
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:- pred main(io__state::di, io__state::uo) is det.
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:- implementation.
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:- import_module int.
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main -->
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(
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{ quot_test(3, 8, 0, 3) }, % 3 / 8 = 0 + 3/8
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{ quot_test(5, 8, 0, 5) }, % 5 / 8 = 0 + 5/8
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{ quot_test(7, 2, 3, 1) }, % 7 / 2 = 3 + 1/2
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{ quot_test(100, 13, 7, 9) } % 100 / 13 = 7 + 9/13
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->
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io__write_string("`//' test succeeded\n")
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;
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io__write_string("`//' test failed\n")
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),
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(
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{ rem_test(3, 8, 0, 3) }, % 3 / 8 = 0 + 3/8
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{ rem_test(5, 8, 0, 5) }, % 5 / 8 = 0 + 5/8
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{ rem_test(7, 2, 3, 1) }, % 7 / 2 = 3 + 1/2
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{ rem_test(100, 13, 7, 9) } % 100 / 13 = 7 + 9/13
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->
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io__write_string("rem test succeeded\n")
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;
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io__write_string("rem test failed\n")
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),
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(
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{ div_test(3, 8, 0, 3) }, % 3 / 8 = 0 + 3/8
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{ div_test(5, 8, 0, 5) }, % 5 / 8 = 0 + 5/8
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{ div_test(7, 2, 3, 1) }, % 7 / 2 = 3 + 1/2
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{ div_test(100, 13, 7, 9) } % 100 / 13 = 7 + 9/13
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->
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io__write_string("div test succeeded\n")
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;
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io__write_string("div test failed\n")
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),
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(
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{ mod_test(3, 8, 0, 3) }, % 3 / 8 = 0 + 3/8
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{ mod_test(5, 8, 0, 5) }, % 5 / 8 = 0 + 5/8
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{ mod_test(7, 2, 3, 1) }, % 7 / 2 = 3 + 1/2
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{ mod_test(100, 13, 7, 9) } % 100 / 13 = 7 + 9/13
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->
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io__write_string("mod test succeeded\n")
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;
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io__write_string("mod test failed\n")
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).
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:- pred quot_test(int::in, int::in, int::in, int::in) is semidet.
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quot_test(Num, Div, Quot, _Rem) :-
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Num // Div = Quot,
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(-Num) // Div = -Quot,
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(-Num) // (-Div) = Quot,
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Num // (-Div) = -Quot.
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:- pred rem_test(int::in, int::in, int::in, int::in) is semidet.
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rem_test(Num, Div, _Quot, Rem) :-
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Num rem Div = Rem,
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(-Num) rem Div = -Rem,
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(-Num) rem (-Div) = -Rem,
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Num rem (-Div) = Rem.
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:- pred div_test(int::in, int::in, int::in, int::in) is semidet.
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div_test(Num, Div, Quot, _Rem) :-
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Num div Div = Quot,
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(-Num) div Div = -Quot - 1,
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(-Num) div (-Div) = Quot,
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Num div (-Div) = -Quot - 1.
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:- pred mod_test(int::in, int::in, int::in, int::in) is semidet.
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mod_test(Num, Div, _Quot, Rem) :-
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Num mod Div = Rem,
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(-Num) mod Div = Div - Rem,
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(-Num) mod (-Div) = -Rem,
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Num mod (-Div) = -(Div - Rem).
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