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

// This file contains implementations for num_traits methods such as the FromPrimitive trait, One
// trait, Zero trait, and Num trait (from_str_radix).
use core::str::FromStr;

use crate::{BigFloat, BigFloatCtx};
use astro_float::Radix;
use astro_float::{self};
use nalgebra::RealField;
use num_traits::FromPrimitive;
use num_traits::Num;
use num_traits::{One, Zero};

macro_rules! from_prim {
    ($name: ident, $type:ty) => {
        fn $name(prim: $type) -> Option<Self> {
            Some(Self::from(astro_float::BigFloat::$name(
                prim,
                CTX::get_prec(),
            )))
        }
    };
}

impl<CTX: BigFloatCtx> FromPrimitive for BigFloat<CTX> {
    from_prim!(from_f64, f64);
    from_prim!(from_f32, f32);

    from_prim!(from_u8, u8);
    from_prim!(from_i8, i8);
    from_prim!(from_u16, u16);
    from_prim!(from_i16, i16);
    from_prim!(from_u32, u32);
    from_prim!(from_i32, i32);
    from_prim!(from_i64, i64);
    from_prim!(from_u64, u64);
    from_prim!(from_i128, i128);
    from_prim!(from_u128, u128);
}

impl<CTX: BigFloatCtx> Zero for BigFloat<CTX> {
    #[inline]
    fn zero() -> Self {
        Self::from(astro_float::BigFloat::from_word(0, CTX::get_prec()))
    }
    #[inline(always)]
    fn is_zero(&self) -> bool {
        self.num.is_zero()
    }
}

impl<CTX: BigFloatCtx> One for BigFloat<CTX> {
    #[inline]
    fn one() -> Self {
        Self::from(astro_float::BigFloat::from_word(1, CTX::get_prec()))
    }
    fn is_one(&self) -> bool {
        match self.num.precision() {
            Some(prec) => self.num == astro_float::BigFloat::from_word(1, prec),
            None => false,
        }
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum ParseBigFloatError {
    InvalidRadix,
    InvalidNumber,
}

impl<CTX: BigFloatCtx> Num for BigFloat<CTX> {
    type FromStrRadixErr = ParseBigFloatError;
    fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
        let radix_enum = match radix {
            2 => Radix::Bin,
            8 => Radix::Oct,
            10 => Radix::Dec,
            16 => Radix::Hex,
            _ => return Err(ParseBigFloatError::InvalidRadix),
        };

        CTX::run(|ctx| {
            let value = astro_float::BigFloat::parse(
                str,
                radix_enum,
                ctx.precision(),
                ctx.rounding_mode(),
                ctx.consts(),
            );
            if value.is_nan() {
                Err(ParseBigFloatError::InvalidNumber)
            } else {
                Ok(BigFloat::from(value))
            }
        })
    }
}

impl<CTX: BigFloatCtx> FromStr for BigFloat<CTX> {
    type Err = ParseBigFloatError;
    #[inline(always)]
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        Self::from_str_radix(s, 10)
    }
}

impl<CTX: BigFloatCtx + 'static> num_traits::Signed for BigFloat<CTX> {
    fn signum(&self) -> Self {
        if self.num.is_positive() {
            Self::one()
        } else if self.num.is_negative() {
            -Self::one()
        } else {
            Self::zero()
        }
    }
    #[inline]
    fn abs(&self) -> Self {
        BigFloat::from(self.num.abs())
    }
    #[inline]
    fn is_positive(&self) -> bool {
        self.num.is_positive()
    }
    #[inline]
    fn is_negative(&self) -> bool {
        self.num.is_negative()
    }
    fn abs_sub(&self, other: &Self) -> Self {
        (self.clone() - other.clone()).max(Self::zero())
    }
}