// SPDX-License-Identifier: MIT

// Copyright (c) 2018 The VeChainThor developers

// Distributed under the GNU Lesser General Public License v3.0 software license, see the accompanying
// file LICENSE or <https://www.gnu.org/licenses/lgpl-3.0.html>

pragma solidity 0.8.20;

library Strings {

    function strConcat(string memory _a, string memory _b) internal pure returns (string memory) {
        bytes memory _ba = bytes(_a);
        bytes memory _bb = bytes(_b);

        string memory ab = new string(_ba.length + _bb.length);
        bytes memory bab = bytes(ab);
        uint k = 0;
        for (uint i = 0; i < _ba.length; i++) bab[k++] = _ba[i];
        for (uint i = 0; i < _bb.length; i++) bab[k++] = _bb[i];
        return string(bab);
    }

    function uint2str(uint256 i) internal pure returns (string memory) {
        if (i == 0) return "0";
        uint j = i;
        uint len;
        while (j != 0){
            len++;
            j /= 10;
        }
        j = i;
        bytes memory bstr = new bytes(len);
        uint k = len - 1;
        while (j != 0){
            bstr[k--] = bytes1(uint8(48 + j % 10));
            j /= 10;
        }
        return string(bstr);
    }

}