ERC-6366: Permission Token

interface IEIP6366Core {
  /**
   * MUST trigger when `_permission` are transferred, including `zero` permission transfers.
   * @param _from           Permission owner
   * @param _to             Permission receiver
   * @param _permission     Transferred subset permission of permission owner
   */
  event Transfer(address indexed _from, address indexed _to, uint256 indexed _permission);

  /**
   * MUST trigger on any successful call to `approve(address _delegatee, uint256 _permission)`.
   * @param _owner          Permission owner
   * @param _delegatee      Delegatee
   * @param _permission     Approved subset permission of permission owner
   */
  event Approval(address indexed _owner, address indexed _delegatee, uint256 indexed _permission);

  /**
   * Transfers a subset `_permission` of permission to address `_to`.
   * The function SHOULD revert if the message caller’s account permission does not have the subset
   * of the transferring permissions. The function SHOULD revert if any of transferring permissions are
   * existing on target `_to` address.
   * @param _to             Permission receiver
   * @param _permission     Subset permission of permission owner
   */
  function transfer(address _to, uint256 _permission) external returns (bool success);

  /**
   * Allows `_delegatee` to act for the permission owner's behalf, up to the `_permission`.
   * If this function is called again it overwrites the current granted with `_permission`.
   * `approve()` method SHOULD `revert` if granting `_permission` permission is not
   * a subset of all available permissions of permission owner.
   * @param _delegatee      Delegatee
   * @param _permission     Subset permission of permission owner
   */
  function approve(address _delegatee, uint256 _permission) external returns (bool success);

  /**
   * Returns the permissions of the given `_owner` address.
   */
  function permissionOf(address _owner) external view returns (uint256 permission);

  /**
   * Returns `true` if `_required` is a subset of `_permission` otherwise return `false`.
   * @param _permission     Checking permission set
   * @param _required       Required set of permission
   */
  function permissionRequire(uint256 _permission, uint256 _required) external view returns (bool isPermissioned);

  /**
   * Returns `true` if `_required` permission is a subset of `_actor`'s permissions or a subset of his delegated
   * permission granted by the `_owner`.
   * @param _owner          Permission owner
   * @param _actor          Actor who acts on behalf of the owner
   * @param _required       Required set of permission
   */
  function hasPermission(address _owner, address _actor, uint256 _required) external view returns (bool isPermissioned);

  /**
   * Returns the subset permission of the `_owner` address were granted to `_delegatee` address.
   * @param _owner          Permission owner
   * @param _delegatee      Delegatee
   */
  function delegated(address _owner, address _delegatee) external view returns (uint256 permission);
}

interface IEIP6366Error {
  /**
   * The owner or actor does not have the required permission
   */
  error AccessDenied(address _owner, address _actor, uint256 _permission);

  /**
   * Conflict between permission set
   */
  error DuplicatedPermission(uint256 _permission);

  /**
   * Data out of range
   */
  error OutOfRange();
}