daniellehrner

address[] memory addressKeys = getAddressKeys("balanceKeys");

function getAddressKeys(bytes32 _listId) external view returns (address[] memory) {
  // get the number of keys with _listId "balanceKeys"
  uint256 size = getUInt256(keccak256(abi.encodePacked(_listId, "KEY_SIZE")));
  
  // create an address array with the size of the list
  address[] memory keys = new address[](size);
  
  // iterate over the list

daniellehrner

addAddressKey("balanceKeys", "0x12...");

function addAddressKey(bytes32 _listId, address _value) external {
  // get the number of keys with _listId "balanceKeys"
  uint256 size = getUInt256(keccak256(abi.encodePacked(_listId, "KEY_SIZE")));
  
  // the new index (end of the list) is equal to the size of the keys
  uint256 index = size;
  
  // store _value as last item in the list

daniellehrner

_balances[_who] = _balances[_who] / (10 ** 16)

daniellehrner

  function setBalance(address _who, uint256 _value) external {
    _balances[_who] = _value;
  }

daniellehrner

function setBalance(address _who, uint256 _value) external {
  setUInt256(
    // computes the Ethereum-SHA-3 (Keccak-256) hash
    keccak256(      
      // performs packed encoding of the given arguments, 
      // as the hash function only accepts one argument
      abi.encodePacked(
        // we use a hardcoded string to create a different 
        // hash for the same dynamic value
        "balance", 

daniellehrner

mapping(bytes32 => uint256) internal uInt256Storage;

function getUInt256(bytes32 _key) external view returns (uint256) {
  return uInt256Storage[_key];
}

function setUInt256(bytes32 _key, uint256 _value) external {
  uInt256Storage[_key] = _value;
}