relation_parameters.hpp

#pragma once
#include "barretenberg/ecc/curves/bn254/fr.hpp"
#include <array>
 
namespace proof_system {
 
template <typename T> struct RelationParameters {
    using DataType = T;
    static constexpr int NUM_BINARY_LIMBS_IN_GOBLIN_TRANSLATOR = 4;
    static constexpr int NUM_NATIVE_LIMBS_IN_GOBLIN_TRANSLATOR = 1;
    static constexpr int NUM_CHALLENGE_POWERS_IN_GOBLIN_TRANSLATOR = 4;
    T eta = T(0);                        // Lookup
    T beta = T(0);                       // Permutation + Lookup
    T gamma = T(0);                      // Permutation + Lookup
    T public_input_delta = T(0);         // Permutation
    T lookup_grand_product_delta = T(0); // Lookup
    T beta_sqr = T(0);
    T beta_cube = T(0);
    // eccvm_set_permutation_delta is used in the set membership gadget in eccvm/ecc_set_relation.hpp
    // We can remove this by modifying the relation, but increases complexity
    T eccvm_set_permutation_delta = T(0);
    std::array<T, NUM_BINARY_LIMBS_IN_GOBLIN_TRANSLATOR> accumulated_result = {
        T(0), T(0), T(0), T(0)
    }; // Goblin Translator
    std::array<T, NUM_BINARY_LIMBS_IN_GOBLIN_TRANSLATOR + NUM_NATIVE_LIMBS_IN_GOBLIN_TRANSLATOR> evaluation_input_x = {
        T(0), T(0), T(0), T(0), T(0)
    }; // Goblin Translator
    std::array<std::array<T, NUM_BINARY_LIMBS_IN_GOBLIN_TRANSLATOR + NUM_NATIVE_LIMBS_IN_GOBLIN_TRANSLATOR>,
               NUM_CHALLENGE_POWERS_IN_GOBLIN_TRANSLATOR>
        batching_challenge_v = { { { T(0), T(0), T(0), T(0), T(0) },
                                   { T(0), T(0), T(0), T(0), T(0) },
                                   { T(0), T(0), T(0), T(0), T(0) },
                                   { T(0), T(0), T(0), T(0), T(0) } } };
 
    static constexpr int NUM_TO_FOLD = 5;
    std::array<std::reference_wrapper<T>, NUM_TO_FOLD> to_fold = {
        eta, beta, gamma, public_input_delta, lookup_grand_product_delta
    };
 
    static RelationParameters get_random()
    {
        RelationParameters result;
        result.eta = T::random_element();
        result.beta_sqr = result.beta * result.beta;
        result.beta_cube = result.beta_sqr * result.beta;
        result.beta = T::random_element();
        result.gamma = T::random_element();
        result.public_input_delta = T::random_element();
        result.lookup_grand_product_delta = T::random_element();
        result.eccvm_set_permutation_delta = result.gamma * (result.gamma + result.beta_sqr) *
                                             (result.gamma + result.beta_sqr + result.beta_sqr) *
                                             (result.gamma + result.beta_sqr + result.beta_sqr + result.beta_sqr);
        result.accumulated_result = {
            T::random_element(), T::random_element(), T::random_element(), T::random_element()
        };
 
        result.evaluation_input_x = {
            T::random_element(), T::random_element(), T::random_element(), T::random_element(), T::random_element()
        };
        result.batching_challenge_v = {
            std::array{ T::random_element(),
                        T::random_element(),
                        T::random_element(),
                        T::random_element(),
                        T::random_element() },
            { T::random_element(), T::random_element(), T::random_element(), T::random_element(), T::random_element() },
            { T::random_element(), T::random_element(), T::random_element(), T::random_element(), T::random_element() },
            { T::random_element(), T::random_element(), T::random_element(), T::random_element(), T::random_element() },
        };
 
        return result;
    }
};
} // namespace proof_system