nanvm_lib/vm/bigint/
div.rs

1use core::ops::Div;
2
3use crate::vm::{Any, BigInt, IVm};
4
5impl<A: IVm> Div for BigInt<A> {
6    type Output = Result<Self, Any<A>>;
7
8    /// The quotient of [`BigInt::div_mod`].
9    fn div(self, rhs: Self) -> Self::Output {
10        self.div_mod(rhs).map(|(quotient, _)| quotient)
11    }
12}
13
14#[cfg(test)]
15mod tests {
16    use crate::vm::bigint::test_util::{T, int, pos};
17
18    #[test]
19    fn truncates_toward_zero() {
20        assert_eq!((int(10) / int(3)).unwrap(), int(3));
21        assert_eq!((int(-10) / int(3)).unwrap(), int(-3));
22        assert_eq!((int(10) / int(-3)).unwrap(), int(-3));
23        assert_eq!((int(-10) / int(-3)).unwrap(), int(3));
24    }
25
26    #[test]
27    fn exact_division() {
28        assert_eq!((int(12) / int(4)).unwrap(), int(3));
29    }
30
31    #[test]
32    fn zero_dividend() {
33        assert_eq!((int(0) / int(5)).unwrap(), T::default());
34    }
35
36    #[test]
37    fn dividend_smaller_than_divisor_truncates_to_zero() {
38        assert_eq!((int(3) / int(10)).unwrap(), T::default());
39    }
40
41    #[test]
42    fn zero_divisor_throws() {
43        assert!((int(5) / int(0)).is_err());
44    }
45
46    #[test]
47    fn multi_word_dividend() {
48        // 2^64 / 2 = 2^63
49        let a = pos([0, 1]);
50        let b: T = 2u64.into();
51        assert_eq!((a / b).unwrap(), (1u64 << 63).into());
52    }
53
54    #[test]
55    fn multi_word_result() {
56        // (3 * 2^64) / 3 = 2^64
57        let a = pos([0, 3]);
58        let b: T = 3u64.into();
59        assert_eq!((a / b).unwrap(), pos([0, 1]));
60    }
61}
nanvm_lib/vm/bigint/div.rs

nanvm_lib/vm/bigint/
div.rs
