// SPDX-License-Identifier: GPL3

pragma solidity =0.8.0;

interface IStateHolder {
    function init() external;

    function getProxy() external view returns (address);

    function setProxy() external;

    function toJSON() external view returns (string memory);

    function toJSON(uint256 start, uint256 l) external view returns (string memory);

    function getStateSize() external view returns (uint256);

    function exists(string calldata varName) external view returns (bool);

    function getDataType(string calldata varName) external view returns (string memory dataType);

    function clear(string calldata varName) external returns (string memory oldDataType, bytes memory oldVal);

    function setBytes(string calldata varName, bytes calldata val) external returns (bytes memory);

    function getBytes(string calldata varName) external view returns (bytes memory);

    function setString(string calldata varName, string calldata val) external returns (string memory);

    function getString(string calldata varName) external view returns (string memory);

    function setBool(string calldata varName, bool val) external returns (bool);

    function getBool(string calldata varName) external view returns (bool);

    function getUint256(string calldata varName) external view returns (uint256);

    function setUint256(string calldata varName, uint256 val) external returns (uint256);

    function getAddress(string calldata varName) external view returns (address);

    function setAddress(string calldata varName, address val) external returns (address);
}