mtao

#include <iostream>
#include <Eigen/Dense>
#include <concepts>

namespace Eigen {
    template <int D, typename Derived>
        inline auto& get(Eigen::DenseCoeffsBase<Derived, WriteAccessors>& p) { return p.coeffRef(D); }

    template <int D, typename Derived>
        inline const auto get(const Eigen::DenseCoeffsBase<Derived,ReadOnlyAccessors>& p) { return p.coeff(D); }

pfmoore

data = {}
data["extend"] = function (data, t)
    for n, recipe in ipairs(t) do
        for i, component in ipairs(recipe["ingredients"]) do
            cname = component[1] or component["name"]
            camt = component[2] or component["amount"]
            print('"' .. recipe["name"] .. '","' .. cname .. '",' .. camt)
        end
    end
end