错误HH600:编译失败的ParserError: Expected '，‘但得到了’；

Question

当我在运行纱线硬帽子编译时收到此错误时，我正在做链接哈克顿课程"DeFi Staking：链接代码“：

ParserError: Expected '，‘但得到’；

错误HH600:编译失败

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.7;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

error Staking__TransferFailed();
error Stakig__NeedsMoteThanZero();


contract Staking {
    IERC20 public s_stakingToken;
    ERC20 public s_rewardToken;
    // somones address -> how much they staked
    mapping(address => uint256) public s_balances;

   // mapping of how much each address has been paid
   mapping(address => uint256) public s_userRewardPerTokenPaid;

   // a mapping of how much rewards each address has to claim
   mapping(address => uint256) public s_rewards;

uint256 public constant REWARD_RATE =100;
uint256 public s_totalSupply;
uint256 public s_rewardPerTokenStored;
uint256 public s_lastUpdateTime;

modifier updateReward(address account){
    s_rewardPerTokenStored = rewardPerToken();
    s_lasrUpdateTime = block.timestamp;
    s_rewards[account] = earned(account);
    s_userRewardPerTokenPaid[account] = s_rewardPerTokenStored;
    _;
}

modifier moreThanZero(uint256 amount){
    if( amount ==0){
        revert Stakig__NeedsMoteThanZero();
    }
    _;

}
    


constructor(address stakingToken, address rewardToken) {
    s_stakingToken = IER20(stakingToken);
    s_rewardToken = IER20(rewardToken);
}

function earned(address account) public view returns (uint256){
    uint256 currentBlanace = s_balances[account];
    // how much they have paid alredy
    uint256 amountPaid = s_userRewardPerToken[account];
    uint256 currentRewardPerToken = rewardPerToken();
    uint256 pastRewards = s_rewards[account];
    uint256 _earned = ((currentBalance *(currentRewardPerToken - amountPaid)/1e18) + 
        pastRewards;
    return _earned; 

}



function rewardPerToken public view returns(uint256) {
    if (s_totalSupply ==0){
        return s_rewardPerTokenStored;
    }
    return s_rewardPerTokenStored + (((block.timestamp -s_lastUpdateTime) * REWARD_RATE * 1e18/ s_totalSupply);
}

function stake(uint256 amount) external updateReward(msg.sender) moreThanZero(amount) {
    s_balances[msg.sender] = s_balances[msg.sender] + amount;
    s_totalSupply = s_totalSupply + amount;
    // emit event
    bool success = s_stakingToken.transferFrom(msg.sender, address(this), amount);
    // require(success, "Failed");
    if(!success) {
        revert Staking__TransferFailed();
    }

}

}

function withdraw(uint256 amount) external updateReward(msg.sender) moreThanZero(amount) {
    s_balances[msg.sender] = s_balances[msg.sender] - amount;
    s_totalSupply = s_totalSupply - amount; 
    bool success = s_stakingToken.transfer(msg.sender, amount);
    if(!success) {
        revert Staking__TransferFailed();
    }

}

function claimReward() external updateReward(msg.sender) {
    uint256 reward = s_rewards[msg.sender];
    bool succes = s_rewardToken.transfer(msg.sender, reward);
    if(!success){
        revert Staking__TransferFailed();
    }
    

}

}

Answer 1

在此：

function rewardPerToken public view returns(uint256) {
    if (s_totalSupply ==0){
        return s_rewardPerTokenStored;
    }
    return s_rewardPerTokenStored + (((block.timestamp -s_lastUpdateTime) *     REWARD_RATE * 1e18/ s_totalSupply);
}

你忘了函数括号。它应该看起来像function rewardPerToken()