token.sol

gistfile1.txt

// SPDX-License-Identifier: GPL-3.0-or-later

pragma solidity 0.8.9;

contract Token {
    uint256 totalSupply;
    
    string public name;
    string public symbol;
    
    address public owner;
    
    mapping(address => uint256) balanceOf;
    mapping(address => mapping(address => uint256)) allowance;
    
    event Transfer(address indexed from, address indexed to, uint256 indexed value);
    event Approval(address indexed from, address indexed to, uint256 indexed value);
    
    constructor(string memory name_, string memory symbol_, uint256 supply) {
        name = name_;
        symbol = symbol_;
        totalSupply = supply;
        balanceOf[msg.sender] = supply;
        owner = msg.sender;
        emit Transfer(address(0), msg.sender, supply);
    }
    
    function approve(address spender, uint256 value) external {
        allowance[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
    }

    function transfer(address to, uint256 value) external returns (bool) {
        balanceOf[msg.sender] -= value;
        balanceOf[to] += value;
        emit Transfer(msg.sender, to, value);
        return true;
    }
    
    function transferFrom(address from, address to, uint256 value) external returns (bool) {
        allowance[from][msg.sender] -= value;
        balanceOf[msg.sender] -= value;
        balanceOf[to] += value;
        emit Transfer(from, to, value);
        return true;
    }
    
    function mint(address to, uint256 value) external {
        require(msg.sender == owner, "!owner");
        balanceOf[to] += value;
        totalSupply += value;
        emit Transfer(address(0), to, value);
    }
}