function open_bdd(path)
    local file = fs.open(path, 'r')
    local content = file.readAll()
    file.close()
    return textutils.unserialiseJSON(content)
end

function save_bdd(bdd, path)
    local file = fs.open(path, 'w')
    local content = textutils.serialiseJSON(bdd)
    file.write(content)
    file.close()
end