lilium-sumcheck 0.1.0

generic Sumcheck implementation for Lilium
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

use crate::sumcheck::{Env, Var};
use crate::symbolic::compute::MvPoly;
use ark_ff::Field;
use std::ops::{Add, AddAssign, Mul, MulAssign, Sub};

#[derive(Debug, Clone)]
pub(crate) enum Expression<F, V, C> {
    Add(Box<Self>, Box<Self>),
    Sub(Box<Self>, Box<Self>),
    Mul(Box<Self>, Box<Self>),
    Var(V),
    Challenge(C),
    Const(F),
}

impl<F, V, C> Expression<F, V, C> {
    fn bin_op<O>(self, other: Self, f: O) -> Self
    where
        O: Fn(Box<Self>, Box<Self>) -> Self,
    {
        f(Box::new(self), Box::new(other))
    }
}

impl<F: Field, V: Clone, C: Clone> Var<F> for Expression<F, V, C> {}

impl<F: Field, V, C> Add for Expression<F, V, C> {
    type Output = Self;

    fn add(self, rhs: Self) -> Self::Output {
        self.bin_op(rhs, Expression::Add)
    }
}

impl<F: Field, V: Clone, C: Clone> Add<&Self> for Expression<F, V, C> {
    type Output = Self;

    fn add(self, rhs: &Self) -> Self::Output {
        self.bin_op(rhs.clone(), Expression::Add)
    }
}

impl<F: Field, V, C> Sub for Expression<F, V, C> {
    type Output = Self;

    fn sub(self, rhs: Self) -> Self::Output {
        self.bin_op(rhs, Expression::Sub)
    }
}

impl<F: Field, V: Clone, C: Clone> Sub<&Self> for Expression<F, V, C> {
    type Output = Self;

    fn sub(self, rhs: &Self) -> Self::Output {
        self.bin_op(rhs.clone(), Expression::Sub)
    }
}

impl<F: Field, V, C> Mul for Expression<F, V, C> {
    type Output = Self;

    fn mul(self, rhs: Self) -> Self::Output {
        self.bin_op(rhs, Expression::Mul)
    }
}

impl<F: Field, V: Clone, C: Clone> Mul<&Self> for Expression<F, V, C> {
    type Output = Self;

    fn mul(self, rhs: &Self) -> Self::Output {
        self.bin_op(rhs.clone(), Expression::Mul)
    }
}

impl<F: Field, V, C> Add<F> for Expression<F, V, C> {
    type Output = Self;

    fn add(self, rhs: F) -> Self::Output {
        let rhs = Expression::Const(rhs);
        self.bin_op(rhs, Expression::Add)
    }
}

impl<F: Field, V, C> Sub<F> for Expression<F, V, C> {
    type Output = Self;

    fn sub(self, rhs: F) -> Self::Output {
        let rhs = Expression::Const(rhs);
        self.bin_op(rhs, Expression::Sub)
    }
}

impl<F: Field, V, C> Mul<F> for Expression<F, V, C> {
    type Output = Self;

    fn mul(self, rhs: F) -> Self::Output {
        let rhs = Expression::Const(rhs);
        self.bin_op(rhs, Expression::Mul)
    }
}

impl<F: Field, V: Clone, C: Clone> AddAssign<&Self> for Expression<F, V, C> {
    fn add_assign(&mut self, rhs: &Self) {
        *self = self.clone() + rhs;
    }
}

impl<F: Field, V: Clone, C: Clone> MulAssign<F> for Expression<F, V, C> {
    fn mul_assign(&mut self, rhs: F) {
        *self = self.clone() * rhs;
    }
}

pub(crate) struct ExpEnv;

impl<F, V, C> Env<F, Expression<F, V, C>, V, C> for ExpEnv
where
    F: Field,
    V: Clone,
    C: Clone,
{
    fn get(&self, i: V) -> Expression<F, V, C> {
        Expression::Var(i)
    }
    fn get_chall(&self, chall_idx: C) -> Expression<F, V, C> {
        Expression::Challenge(chall_idx)
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
pub enum VarOrChall<V, C> {
    Var(V),
    Challenge(C),
}

/// Evaluates expression tree into a mv polynomial.
pub(crate) fn compute_mv_poly<F, V, C>(exp: Expression<F, V, C>) -> MvPoly<F, VarOrChall<V, C>>
where
    F: Field,
    V: Eq + Ord + Clone,
    C: Eq + Ord + Clone,
{
    use Expression::*;
    let f = compute_mv_poly;
    match exp {
        Add(e1, e2) => f(*e1) + f(*e2),
        Sub(e1, e2) => f(*e1) - f(*e2),
        Mul(e1, e2) => f(*e1) * f(*e2),
        Var(var) => MvPoly::new(VarOrChall::Var(var), F::one()),
        Const(c) => MvPoly::new_const(c),
        Challenge(c) => MvPoly::new(VarOrChall::Challenge(c), F::one()),
    }
}