function tlen(T)
    local count = 0
    for _ in pairs(T) do count = count + 1 end
    return count
end

function copyPrototype(type, name, newName)
    if not data.raw[type][name] then
        error("type " .. type .. " " .. name .. " doesn't exist")
    end
    local p = table.deepcopy(data.raw[type][name])
    p.name = newName
    if p.minable and p.minable.result then
        p.minable.result = newName
    end
    if p.place_result then
        p.place_result = newName
    end
    if p.result then
        p.result = newName
    end
    if p.results then
        for _, result in pairs(p.results) do
            if result.name == name then
                result.name = newName
            end
        end
    end
    return p
end