bigdecimal 0.4.10

Arbitrary precision decimal numbers
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173


mod impl_div {
    use super::*;

    macro_rules! impl_case {
        ($name:ident: $numerator:literal / $denominator:literal => $quotient:literal) => {
            #[test]
            fn $name() {
                let a: BigDecimal = $numerator.parse().unwrap();
                let b: BigDecimal = $denominator.parse().unwrap();
                let c: BigDecimal = $quotient.parse().unwrap();

                let q = a.clone() / b.clone();
                assert_eq!(q, c);
                assert_eq!(q.scale, c.scale);
                assert_eq!(a.clone() / &b, c);
                assert_eq!(&a / b.clone(), c);
                assert_eq!(&a / &b, c);
            }
        };
    }

    impl_case!(zero_over_one: "0" / "1" => "0");
    impl_case!(zero_over_ten: "0" / "10" => "0");
    impl_case!(two_over_one: "2" / "1" => "2");
    impl_case!(div_2e1_one: "2e1" / "1" => "2e1");
    impl_case!(div_10_10: "10" / "10" => "1");
    impl_case!(div_100_10d0: "100" / "10.0" => "1e1");

    impl_case!(div_20d0_200: "20.0" / "200" => "0.1");
    impl_case!(div_4_2: "4" / "2" => "2");
    impl_case!(div_15_3: "15" / "3" => "5");
    impl_case!(div_1_2: "1" / "2" => "0.5");
    impl_case!(div_1_2en2: "1" / "2e-2" => "5e1");
    impl_case!(div_1_0d2: "1" / "0.2" => "5");
    impl_case!(div_1d0_0d02: "1.0" / "0.02" => "5e1");
    impl_case!(div_1_0d020: "1" / "0.020" => "5e1");
    impl_case!(div_1d0_0d020: "1.0" / "0.020" => "5e1");
    impl_case!(div_5d0_4d00: "5.0" / "4.00" => "1.25");
    impl_case!(div_5d0_4d000: "5.0" / "4.000" => "1.25");
    impl_case!(div_5_4d000: "5" / "4.000" => "1.25");
    impl_case!(div_5_4: "5" / "4" => "125e-2");
    impl_case!(div_100_5: "100" / "5" => "20");
    impl_case!(div_n50_5: "-50" / "5" => "-10");
    impl_case!(div_200_n5: "200" / "-5" => "-40.");
    impl_case!(div_1_3: "1" / "3" => ".3333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333");
    impl_case!(div_n2_n3: "-2" / "-3" => ".6666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666667");
    impl_case!(div_n12d34_1d233: "-12.34" / "1.233" => "-10.00811030008110300081103000811030008110300081103000811030008110300081103000811030008110300081103001");
    impl_case!(div_125348_352d2283: "125348" / "352.2283" => "355.8714617763535752237966114591019517738921035021887792661748076460636467881768727839301952739175132");
    impl_case!(div_22_7: "22" / "7" => "3.142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857143");

    #[test]
    #[should_panic(expected = "Division by zero")]
    fn test_division_by_zero_panics() {
        let x = BigDecimal::from_str("3.14").unwrap();
        let _r = x / 0;
    }

    #[test]
    #[should_panic(expected = "Division by zero")]
    fn test_division_by_zero_panics_v2() {
        let x = BigDecimal::from_str("3.14").unwrap();
        let _r = x / BigDecimal::zero();
    }

    #[test]
    fn test_division_by_large_number() {
        let n = 1u8;
        let d: BigDecimal = "79437738588056219546528239237352667078".parse().unwrap();

        let quotient_n_ref_d = n / &d;
        let quotient_n_d = n / d.clone();
        assert_eq!(quotient_n_ref_d, quotient_n_d);

        let expected: BigDecimal = "1.258847517281104957975270408416632052090243053529147458917576143852500316808428812104171430669001064E-38".parse().unwrap();
        assert_eq!(quotient_n_ref_d, expected);
    }
}

#[test]
fn divide_by_f32_infinity() {
    let num: BigDecimal = "123".parse().unwrap();
    let quotient = num / f32::INFINITY;
    assert!(quotient.is_zero());
}

#[test]
fn divide_by_f32_nan() {
    let num: BigDecimal = "123".parse().unwrap();
    let quotient = num / f32::NAN;
    assert!(quotient.is_zero());
}

#[test]
fn divide_by_f64_infinity() {
    let num: BigDecimal = "123".parse().unwrap();
    let quotient = num / f64::INFINITY;
    assert!(quotient.is_zero());
}

#[test]
fn divide_by_f64_nan() {
    let num: BigDecimal = "123".parse().unwrap();
    let quotient = num / f64::NAN;
    assert!(quotient.is_zero());
}

macro_rules! impl_case {
    ($name:ident: num / $denom:literal => $expected:literal)  => {
        #[test]
        fn $name() {
            let num = numerator();
            let den = $denom;

            let expected: BigDecimal = $expected.parse().unwrap();

            {
                let quotient = &num / den;
                assert_eq!(&quotient, &expected);
            }

            let quotient = num / den;
            assert_eq!(quotient, expected);
        }
    };
    ($name:ident: $numer:literal / den => $expected:literal)  => {
        #[test]
        fn $name() {
            let num = $numer;
            let den = denominator();

            let expected: BigDecimal = $expected.parse().unwrap();

            {
                let quotient = num / &den;
                assert_eq!(&quotient, &expected);
            }

            let quotient = num / den;
            assert_eq!(quotient, expected);
        }
    }
}

mod dec123_over_float {
    use super::*;

    fn numerator() -> BigDecimal {
        "123".parse().unwrap()
    }

    impl_case!(divide_by_one: num / 1.0 => "123");
    impl_case!(divide_by_neg_one: num / -1.0 => "-123");
    impl_case!(divide_by_two: num / 2.0 => "61.5");
    impl_case!(divide_by_neg_two: num / -2.0 => "-61.5");
    impl_case!(divide_by_half: num / 0.25 => "492");

    impl_case!(divide_by_0d3: num / 0.3 => "410.0000000000000151730480032104732806385410274753293198491224660103204812897069364682009036747721645");
    impl_case!(divide_by_n10d01: num / -10.01 => "-12.28771228771228797395438676755509642184314950109407611037730443717479254091338404424812715057130341");
}

mod num_float_over_dec123 {
    use super::*;

    fn denominator() -> BigDecimal {
        "123".parse().unwrap()
    }

    impl_case!(num_one: 1.0 / den => "0.008130081300813008130081300813008130081300813008130081300813008130081300813008130081300813008130081301");
    impl_case!(num_123: 123.0 / den => "1");
    impl_case!(num_676d5: 676.5 / den => "5.5");
}