lambdaworks_math/field/test_fields/
u64_test_field.rs

1use crate::{
2    errors::CreationError,
3    field::{
4        element::FieldElement,
5        extensions::quadratic::QuadraticExtensionField,
6        traits::{IsFFTField, IsField, IsPrimeField},
7    },
8    field::{errors::FieldError, extensions::quadratic::HasQuadraticNonResidue},
9};
10
11#[derive(Debug, Clone, PartialEq, Eq)]
12pub struct U64Field<const MODULUS: u64>;
13
14impl<const MODULUS: u64> IsField for U64Field<MODULUS> {
15    type BaseType = u64;
16
17    fn add(a: &u64, b: &u64) -> u64 {
18        ((*a as u128 + *b as u128) % MODULUS as u128) as u64
19    }
20
21    fn sub(a: &u64, b: &u64) -> u64 {
22        (((*a as u128 + MODULUS as u128) - *b as u128) % MODULUS as u128) as u64
23    }
24
25    fn neg(a: &u64) -> u64 {
26        MODULUS - a
27    }
28
29    fn mul(a: &u64, b: &u64) -> u64 {
30        ((*a as u128 * *b as u128) % MODULUS as u128) as u64
31    }
32
33    fn div(a: &u64, b: &u64) -> Result<u64, FieldError> {
34        let b_inv = &Self::inv(b)?;
35        Ok(Self::mul(a, b_inv))
36    }
37
38    fn inv(a: &u64) -> Result<u64, FieldError> {
39        if *a == 0 {
40            return Err(FieldError::InvZeroError);
41        }
42        Ok(Self::pow(a, MODULUS - 2))
43    }
44
45    fn eq(a: &u64, b: &u64) -> bool {
46        Self::from_u64(*a) == Self::from_u64(*b)
47    }
48
49    fn zero() -> u64 {
50        0
51    }
52
53    fn one() -> u64 {
54        1
55    }
56
57    fn from_u64(x: u64) -> u64 {
58        x % MODULUS
59    }
60
61    fn from_base_type(x: u64) -> u64 {
62        Self::from_u64(x)
63    }
64}
65
66impl<const MODULUS: u64> IsPrimeField for U64Field<MODULUS> {
67    type RepresentativeType = u64;
68
69    fn representative(x: &u64) -> u64 {
70        *x
71    }
72
73    /// Returns how many bits do you need to represent the biggest field element
74    /// It expects the MODULUS to be a Prime
75    fn field_bit_size() -> usize {
76        ((MODULUS - 1).ilog2() + 1) as usize
77    }
78
79    fn from_hex(hex_string: &str) -> Result<Self::BaseType, crate::errors::CreationError> {
80        let mut hex_string = hex_string;
81        // Remove 0x if it's on the string
82        let mut char_iterator = hex_string.chars();
83        if hex_string.len() > 2
84            && char_iterator.next().unwrap() == '0'
85            && char_iterator.next().unwrap() == 'x'
86        {
87            hex_string = &hex_string[2..];
88        }
89
90        u64::from_str_radix(hex_string, 16).map_err(|_| CreationError::InvalidHexString)
91    }
92
93    #[cfg(feature = "std")]
94    fn to_hex(x: &u64) -> String {
95        format!("{x:X}")
96    }
97}
98
99pub type U64TestField = U64Field<18446744069414584321>;
100
101// These params correspond to the 18446744069414584321 modulus.
102impl IsFFTField for U64TestField {
103    const TWO_ADICITY: u64 = 32;
104    const TWO_ADIC_PRIMITVE_ROOT_OF_UNITY: u64 = 1753635133440165772;
105}
106
107#[derive(Clone, Debug)]
108pub struct TestNonResidue;
109impl HasQuadraticNonResidue<U64TestField> for TestNonResidue {
110    fn residue() -> FieldElement<U64TestField> {
111        FieldElement::from(7)
112    }
113}
114
115pub type U64TestFieldExtension = QuadraticExtensionField<U64TestField, TestNonResidue>;
116
117#[cfg(test)]
118mod tests_u64_test_field {
119    use crate::field::{
120        element::FieldElement,
121        test_fields::u64_test_field::{U64TestField, U64TestFieldExtension},
122        traits::IsPrimeField,
123    };
124
125    #[test]
126    fn from_hex_for_b_is_11() {
127        assert_eq!(U64TestField::from_hex("B").unwrap(), 11);
128    }
129
130    #[test]
131    fn bit_size_of_test_field_is_64() {
132        assert_eq!(
133            <U64TestField as crate::field::traits::IsPrimeField>::field_bit_size(),
134            64
135        );
136    }
137
138    #[cfg(feature = "alloc")]
139    #[test]
140    fn test_to_subfield_vec() {
141        let a = FieldElement::<U64TestFieldExtension>::from(&[
142            FieldElement::from(1),
143            FieldElement::from(3),
144        ]);
145        let b = a.to_subfield_vec::<U64TestField>();
146        assert_eq!(b, alloc::vec![FieldElement::from(1), FieldElement::from(3)]);
147    }
148
149    #[cfg(feature = "std")]
150    #[test]
151    fn to_hex_test() {
152        let num = U64TestField::from_hex("B").unwrap();
153        assert_eq!(U64TestField::to_hex(&num), "B");
154    }
155}
lambdaworks_math/field/test_fields/u64_test_field.rs

lambdaworks_math/field/test_fields/
u64_test_field.rs
