dashu_int/
cmp.rs

1//! Comparisons operators.
2
3use dashu_base::AbsOrd;
4
5use crate::{
6    arch::word::Word,
7    ibig::IBig,
8    repr::TypedReprRef::{self, *},
9    ubig::UBig,
10    Sign::*,
11};
12use core::cmp::Ordering;
13
14/// Compare lhs with rhs of the same length as numbers.
15#[inline]
16pub fn cmp_same_len(lhs: &[Word], rhs: &[Word]) -> Ordering {
17    debug_assert!(lhs.len() == rhs.len());
18    lhs.iter().rev().cmp(rhs.iter().rev())
19}
20
21/// Compare lhs with rhs as numbers. The leading zero words of the input must be trimmed.
22///
23/// # Panics
24///
25/// Panic if lhs or rhs has leading zero words (including the case where lhs == 0 or rhs == 0)
26pub fn cmp_in_place(lhs: &[Word], rhs: &[Word]) -> Ordering {
27    debug_assert!(*lhs.last().unwrap() != 0 && *rhs.last().unwrap() != 0);
28    lhs.len()
29        .cmp(&rhs.len())
30        .then_with(|| cmp_same_len(lhs, rhs))
31}
32
33impl<'a> PartialOrd for TypedReprRef<'a> {
34    #[inline]
35    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
36        Some(self.cmp(other))
37    }
38}
39
40impl<'a> Ord for TypedReprRef<'a> {
41    #[inline]
42    fn cmp(&self, other: &Self) -> Ordering {
43        match (*self, *other) {
44            (RefSmall(dword0), RefSmall(dword1)) => dword0.cmp(&dword1),
45            (RefSmall(_), RefLarge(_)) => Ordering::Less,
46            (RefLarge(_), RefSmall(_)) => Ordering::Greater,
47            (RefLarge(words0), RefLarge(words1)) => cmp_in_place(words0, words1),
48        }
49    }
50}
51
52impl Ord for UBig {
53    #[inline]
54    fn cmp(&self, other: &UBig) -> Ordering {
55        self.repr().cmp(&other.repr())
56    }
57}
58
59impl PartialOrd for UBig {
60    #[inline]
61    fn partial_cmp(&self, other: &UBig) -> Option<Ordering> {
62        Some(self.cmp(other))
63    }
64}
65
66impl Ord for IBig {
67    #[inline]
68    fn cmp(&self, other: &IBig) -> Ordering {
69        let (lhs_sign, lhs_mag) = self.as_sign_repr();
70        let (rhs_sign, rhs_mag) = other.as_sign_repr();
71        match (lhs_sign, rhs_sign) {
72            (Positive, Positive) => lhs_mag.cmp(&rhs_mag),
73            (Positive, Negative) => Ordering::Greater,
74            (Negative, Positive) => Ordering::Less,
75            (Negative, Negative) => rhs_mag.cmp(&lhs_mag),
76        }
77    }
78}
79
80impl PartialOrd for IBig {
81    #[inline]
82    fn partial_cmp(&self, other: &IBig) -> Option<Ordering> {
83        Some(self.cmp(other))
84    }
85}
86
87impl AbsOrd for UBig {
88    #[inline]
89    fn abs_cmp(&self, rhs: &Self) -> Ordering {
90        self.0.as_typed().cmp(&rhs.0.as_typed())
91    }
92}
93impl AbsOrd for IBig {
94    #[inline]
95    fn abs_cmp(&self, rhs: &Self) -> Ordering {
96        self.0.as_sign_typed().1.cmp(&rhs.0.as_sign_typed().1)
97    }
98}
99impl AbsOrd<UBig> for IBig {
100    #[inline]
101    fn abs_cmp(&self, rhs: &UBig) -> Ordering {
102        self.0.as_sign_typed().1.cmp(&rhs.0.as_typed())
103    }
104}
105impl AbsOrd<IBig> for UBig {
106    #[inline]
107    fn abs_cmp(&self, rhs: &IBig) -> Ordering {
108        self.0.as_typed().cmp(&rhs.0.as_sign_typed().1)
109    }
110}
dashu_int/cmp.rs

dashu_int/
cmp.rs
