snarkvm_circuit_environment/helpers/
constraint.rs

1// Copyright (c) 2019-2025 Provable Inc.
2// This file is part of the snarkVM library.
3
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at:
7
8// http://www.apache.org/licenses/LICENSE-2.0
9
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16use crate::{prelude::*, *};
17use snarkvm_fields::PrimeField;
18use snarkvm_utilities::dev_eprintln;
19
20#[derive(Clone, Debug, Hash)]
21pub struct Constraint<F: PrimeField>(
22    pub(crate) Scope,
23    pub(crate) LinearCombination<F>,
24    pub(crate) LinearCombination<F>,
25    pub(crate) LinearCombination<F>,
26);
27
28impl<F: PrimeField> Constraint<F> {
29    /// Returns the number of non-zero terms required by this constraint.
30    pub(crate) fn num_nonzeros(&self) -> (u64, u64, u64) {
31        let (a, b, c) = (&self.1, &self.2, &self.3);
32        (a.num_nonzeros(), b.num_nonzeros(), c.num_nonzeros())
33    }
34
35    /// Returns `true` if the constraint is satisfied.
36    pub(crate) fn is_satisfied(&self) -> bool {
37        let a = self.1.value();
38        let b = self.2.value();
39        let c = self.3.value();
40
41        let satisfied = a * b == c;
42        if !satisfied {
43            dev_eprintln!("Failed constraint at {scope}:\n\t({a} * {b}) != {c}", scope = self.0);
44        }
45        satisfied
46    }
47
48    /// Returns a reference to the terms `(a, b, c)`.
49    pub fn to_terms(&self) -> (&LinearCombination<F>, &LinearCombination<F>, &LinearCombination<F>) {
50        (&self.1, &self.2, &self.3)
51    }
52}
53
54impl<F: PrimeField> Display for Constraint<F> {
55    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
56        let (scope, a, b, c) = (&self.0, &self.1, &self.2, &self.3);
57        let a = a.value();
58        let b = b.value();
59        let c = c.value();
60
61        match (a * b) == c {
62            true => write!(f, "Constraint {scope}:\n\t{a} * {b} == {c}\n"),
63            false => write!(f, "Constraint {scope}:\n\t{a} * {b} != {c} (Unsatisfied)\n"),
64        }
65    }
66}
snarkvm_circuit_environment/helpers/constraint.rs

snarkvm_circuit_environment/helpers/
constraint.rs
