row_disabling_polynomial.hpp

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// === AUDIT STATUS ===
// internal:    { status: not started, auditors: [], date: YYYY-MM-DD }
// external_1:  { status: not started, auditors: [], date: YYYY-MM-DD }
// external_2:  { status: not started, auditors: [], date: YYYY-MM-DD }
// =====================
 
#pragma once
#include "barretenberg/common/compiler_hints.hpp"
#include "barretenberg/common/op_count.hpp"
#include "barretenberg/common/thread.hpp"
#include "barretenberg/stdlib/primitives/bool/bool.hpp"
 
#include <cstddef>
#include <vector>
namespace bb {
template <typename FF> struct RowDisablingPolynomial {
    // initialized as a constant linear polynomial = 1
    FF eval_at_0{ 1 };
    FF eval_at_1{ 1 };
 
    RowDisablingPolynomial() = default;
    void update_evaluations(FF round_challenge, size_t round_idx)
    {
        if (round_idx == 1) {
            eval_at_0 = FF{ 0 };
        }
        if (round_idx >= 2) {
            eval_at_1 *= round_challenge;
        }
    }
    static FF evaluate_at_challenge(std::vector<FF> multivariate_challenge, const size_t log_circuit_size)
    {
        FF evaluation_at_multivariate_challenge{ 1 };
 
        for (size_t idx = 2; idx < log_circuit_size; idx++) {
            evaluation_at_multivariate_challenge *= multivariate_challenge[idx];
        }
 
        return FF{ 1 } - evaluation_at_multivariate_challenge;
    }
 
    static FF evaluate_at_challenge(std::span<FF> multivariate_challenge,
                                    const std::vector<FF>& padding_indicator_array)
    {
        FF evaluation_at_multivariate_challenge{ 1 };
 
        for (size_t idx = 2; idx < padding_indicator_array.size(); idx++) {
            const FF& indicator = padding_indicator_array[idx];
            evaluation_at_multivariate_challenge *= FF{ 1 } - indicator + indicator * multivariate_challenge[idx];
        }
 
        return FF{ 1 } - evaluation_at_multivariate_challenge;
    }
};
 
} // namespace bb