ilamanov

pragma solidity ^0.5.0;

// Mapping from owner to list of owned token IDs
mapping(address => uint256[]) private _ownedTokens;

// Mapping from token ID to index of the owner tokens list
mapping(uint256 => uint256) private _ownedTokensIndex;

// Array with all token ids, used for enumeration
uint256[] private _allTokens;

ilamanov

pragma solidity ^0.5.0;


function _mint(address to, uint256 tokenId) internal {
    _tokenOwner[tokenId] = to;
    _ownedTokensCount[to].increment();
}

function _burn(address owner, uint256 tokenId) internal {
    _ownedTokensCount[owner].decrement();

ilamanov

pragma solidity ^0.5.0;

// Mapping from token ID to approved address
mapping (uint256 => address) private _tokenApprovals;

function approve(address to, uint256 tokenId) public {
    address owner = ownerOf(tokenId);
    require(to != owner, "ERC721: approval to current owner");

    require(msg.sender == owner || isApprovedForAll(owner, msg.sender),

ilamanov

pragma solidity ^0.5.0;

function transferFrom(address from, address to, uint256 tokenId) public {
    // ...
    _ownedTokensCount[from].decrement();
    _ownedTokensCount[to].increment();
    _tokenOwner[tokenId] = to;
    // ...
}

ilamanov

pragma solidity ^0.5.0;

// Mapping from token ID to owner
mapping (uint256 => address) private _tokenOwner;

// Mapping from owner to number of owned token
mapping (address => Counters.Counter) private _ownedTokensCount;

function balanceOf(address owner) public view returns (uint256) {
    require(owner != address(0), "ERC721: balance query for the zero address");

ilamanov

pragma solidity ^0.4.20;

interface ERC721 {
    function name() public view returns (string);
    function symbol() public view returns (string);
    function tokenURI(uint256 _tokenId) public view returns (string);

    function totalSupply() public view returns (uint256);
    function tokenByIndex(uint256 _index) public view returns (uint256);
    function tokenOfOwnerByIndex(address _owner, uint256 _index) public view returns (uint256);

ilamanov

/**
 *Submitted for verification at Etherscan.io on 2020-12-12
*/

// File contracts/libs/IERC165.sol

// File: openzeppelin-solidity/contracts/introspection/IERC165.sol
pragma solidity ^0.5.0;

/**

ilamanov

/// @title A 6x6 chess engine with negamax search
/// @author fiveoutofnine
/// @notice Docstrings below are written from the perspective of black (i.e. written as if the
/// engine is always black). However, due to negamax's symmetric nature, the engine may be used for
/// white as well.
contract Engine {
    using Chess for uint256;
    using Engine for uint256;

    /// @notice Searches for the ``best'' move.

ilamanov

/// @title A library that generates HTML art for fiveoutofnine (an on-chain 6x6 chess engine)
/// The art is generated as HTML code with in-line CSS (0 JS) 
contract fiveoutofnineART {
    /// @notice Takes in data for a given fiveoutofnine NFT and outputs its metadata in JSON form.
    /// @param _internalId A bitpacked uint256 where the first 128 bits are the game ID, and the
    /// last 128 bits are the move ID within the game.
    /// @param _move A struct with information about the player's move and engine's response (see
    /// {Chess-Move}).
    /// @return Base 64-encoded JSON of metadata generated from `_internalId` and `_move`.
    function getMetadata(uint256 _internalId, Chess.Move memory _move)

ilamanov

contract Example {
  function playMove(uint256 _board) internal {
      uint256 rotated = _board.rotate();
      // ...
  }
}