Contract Source Code:
//SPDX-License-Identifier: NONE
pragma solidity ^0.8.7;
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
//import "hardhat/console.sol";
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// $GOOF token contract
// Utility token for modifying goofball NFTs
//
// https://www.goofballgang.com
contract NFTContract {
function ownerOf(uint256 tokenId) external view returns (address owner) {}
function walletOfOwner(address _owner) public view returns (uint256[] memory) {}
}
contract GoofToken is Ownable, ERC20("Goofball Gang Token", "GOOF"), ERC20Burnable {
uint256 public constant DAILY_RATE = 10 ether;
uint256 public constant START_TIME = 1634250000; /* ~Oct 15th 2021 */
uint256 public constant TIME_BLOCKSIZE = 10_000;
uint256 public constant BONUS_TIME_LIMIT_1 = 1638316800; /* Dec 1st 2021 */
uint256 public constant BONUS_TIME_LIMIT_2 = 1640995200; /* Jan 1st 2022 */
uint256 public constant MIN_NAME_LENGTH = 2;
uint256 public constant MAX_NAME_LENGTH = 30;
event ChangeCommit(uint256 indexed tokenId, uint256 price, bytes changeData);
event NameChange(uint256 indexed tokenId, bytes newName);
NFTContract private delegate;
uint256 public nameChangePrice = 1000 ether;
uint256 public distributionEndTime = 1798761600; /* Jan 1st 2027 */
uint256 public gweiPerGoof = 0;
/**
We stash 16 last update timestamps in every 256 bit word by using only 16
bits for the last update time.
Every 16 bit value encodes 10,000 seconds (TIME_BLOCKSIZE) since START_TIME (Nov 1st 2021),
so we can encode an interval of 20 years.
*/
mapping(uint256 => uint256) public lastUpdateMap;
mapping(uint256 => bytes) public goofNameMap;
mapping(bytes => uint256) public nameOwnerMap;
mapping(address => uint256) public permittedContracts;
constructor(address nftContract, uint256 initialSupply) {
delegate = NFTContract(nftContract);
_mint(msg.sender, initialSupply);
}
function getUpdateTime(uint256 id) public view returns (uint256 updateTime) {
uint256 value = lastUpdateMap[id >> 4];
value = (value >> ((id & 0xF) << 4)) & 0xFFFF;
return value * TIME_BLOCKSIZE + START_TIME;
}
function setUpdateTime(uint256 id, uint256 time) internal returns (uint256 roundedTime) {
require(time > START_TIME, "invalid time");
uint256 currentValue = lastUpdateMap[id >> 4];
uint256 shift = ((id & 0xF) << 4);
uint256 mask = ~(0xFFFF << shift);
// Round up block time
uint256 newEncodedValue = (time - START_TIME + TIME_BLOCKSIZE - 1) / TIME_BLOCKSIZE;
lastUpdateMap[id >> 4] = ((currentValue & mask) | (newEncodedValue << shift));
return newEncodedValue * TIME_BLOCKSIZE + START_TIME;
}
function setPermission(address addr, uint256 permitted) public onlyOwner {
permittedContracts[addr] = permitted;
}
function setGweiPerGoof(uint256 value) public onlyOwner {
gweiPerGoof = value;
}
function getName(uint256 id) public view returns (string memory) {
return string(abi.encodePacked(goofNameMap[id]));
}
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
function setNameChangePrice(uint256 price) public onlyOwner {
nameChangePrice = price;
}
function setDistributionEndTime(uint256 endTime) public onlyOwner {
distributionEndTime = endTime;
}
function getInitialGrant(uint256 t) public pure returns (uint256) {
if (t < BONUS_TIME_LIMIT_1) {
return 1000 ether;
}
if (t < BONUS_TIME_LIMIT_2) {
return 500 ether;
} else {
return 0;
}
}
function getGrantBetween(uint256 beginTime, uint256 endTime) public pure returns (uint256) {
if (beginTime > BONUS_TIME_LIMIT_2) {
return ((endTime - beginTime) * DAILY_RATE) / 86400;
}
uint256 weightedTime = 0;
if (beginTime < BONUS_TIME_LIMIT_1) {
weightedTime += (min(endTime, BONUS_TIME_LIMIT_1) - beginTime) * 4;
}
if (beginTime < BONUS_TIME_LIMIT_2 && endTime > BONUS_TIME_LIMIT_1) {
weightedTime += (min(endTime, BONUS_TIME_LIMIT_2) - max(beginTime, BONUS_TIME_LIMIT_1)) * 2;
}
if (endTime > BONUS_TIME_LIMIT_2) {
weightedTime += endTime - max(beginTime, BONUS_TIME_LIMIT_2);
}
return (weightedTime * DAILY_RATE) / 86400;
}
function claim(uint256 tokenId) internal returns (uint256) {
uint256 lastUpdate = getUpdateTime(tokenId);
// Round up by block
uint256 timeUpdate = min(block.timestamp, distributionEndTime);
timeUpdate = setUpdateTime(tokenId, timeUpdate);
if (lastUpdate == START_TIME) {
return getInitialGrant(timeUpdate);
} else {
return getGrantBetween(lastUpdate, timeUpdate);
}
}
function claimReward(uint256[] memory id) public {
uint256 totalReward = 0;
for (uint256 i = 0; i < id.length; i++) {
require(delegate.ownerOf(id[i]) == msg.sender, "id not owned");
totalReward += claim(id[i]);
}
if (totalReward > 0) {
_mint(msg.sender, totalReward);
}
}
function claimFull() public {
claimFullFor(msg.sender);
}
function claimFullFor(address addr) public {
uint256[] memory id = delegate.walletOfOwner(addr);
uint256 totalReward = 0;
for (uint256 i = 0; i < id.length; i++) {
totalReward += claim(id[i]);
}
if (totalReward > 0) {
_mint(addr, totalReward);
}
}
function mint(uint256 amount) public onlyOwner {
_mint(msg.sender, amount);
}
// burn tokens, allowing sent ETH to be converted according to gweiPerGoof
function burnTokens(uint256 amount) private {
if (msg.value > 0 && gweiPerGoof > 0) {
uint256 converted = (msg.value * 1 gwei) / gweiPerGoof;
if (converted >= amount) {
amount = 0;
} else {
amount -= converted;
}
}
if (amount > 0) {
_burn(msg.sender, amount);
}
}
// Buy items
function commitChange(
uint256 tokenId,
uint256 pricePaid,
bytes memory changeData
) public payable {
require(delegate.ownerOf(tokenId) == msg.sender, "not owner");
burnTokens(pricePaid);
emit ChangeCommit(tokenId, pricePaid, changeData);
}
function isValidName(bytes memory nameBytes) public pure returns (bool) {
if (nameBytes.length < MIN_NAME_LENGTH || nameBytes.length > MAX_NAME_LENGTH) {
return false;
}
uint8 prevChar = 32;
for (uint256 i = 0; i < nameBytes.length; i++) {
uint8 ch = uint8(nameBytes[i]);
if (ch == 32 && prevChar == 32) {
return false; // no repeated spaces (and also checks first character)
}
// allow letter, numbers, punctuation, but no risk of HTML tags (<>) or
// impersonating another goofball (# sign)
if (!(ch >= 32 && ch <= 126) || ch == 60 || ch == 62 || ch == 35) {
return false;
}
prevChar = ch;
}
if (prevChar == 32) {
// No trailing space
return false;
}
return true;
}
function toLower(bytes memory name) private pure returns (bytes memory) {
bytes memory lowerCased = new bytes(name.length);
for (uint256 i = 0; i < name.length; i++) {
uint8 ch = uint8(name[i]);
if (ch >= 65 && ch <= 90) {
lowerCased[i] = bytes1(
ch +
97 - /* 'a' */
65 /* 'A' */
);
} else {
lowerCased[i] = bytes1(ch);
}
}
return lowerCased;
}
function changeName(uint256 tokenId, bytes memory newName) public payable {
require(newName.length == 0 || isValidName(newName), "not valid name");
require(delegate.ownerOf(tokenId) == msg.sender, "not owner");
bytes memory lowerCased = toLower(newName);
if (newName.length > 0) {
uint256 nameOwner = nameOwnerMap[lowerCased];
// 0 = nobody, other number is id + 1
require(nameOwner == 0 || nameOwner == tokenId + 1, "name duplicate");
}
burnTokens(nameChangePrice);
bytes memory currentName = goofNameMap[tokenId];
if (currentName.length > 0) {
delete nameOwnerMap[toLower(currentName)];
}
goofNameMap[tokenId] = newName;
if (newName.length > 0) {
nameOwnerMap[lowerCased] = tokenId + 1;
}
emit NameChange(tokenId, newName);
}
function permittedMint(address destination, uint256 amount) public {
require(permittedContracts[msg.sender] == 1);
_mint(destination, amount);
}
function permittedBurn(address src, uint256 amount) public {
require(permittedContracts[msg.sender] == 1);
_burn(src, amount);
}
function permittedTransfer(
address src,
address dest,
uint256 amount
) public {
require(permittedContracts[msg.sender] == 1);
_transfer(src, dest, amount);
}
function withdrawBalance(address to, uint256 amount) external onlyOwner {
if (amount == 0) {
amount = address(this).balance;
}
// https://consensys.github.io/smart-contract-best-practices/recommendations/#dont-use-transfer-or-send
// solhint-disable-next-line avoid-low-level-calls
(bool success, ) = payable(to).call{value: amount}("");
require(success, "Transfer failed.");
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_setOwner(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_setOwner(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_setOwner(newOwner);
}
function _setOwner(address newOwner) private {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless this function is
* overridden;
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
uint256 currentAllowance = _allowances[sender][_msgSender()];
require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
unchecked {
_approve(sender, _msgSender(), currentAllowance - amount);
}
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
uint256 currentAllowance = _allowances[_msgSender()][spender];
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(_msgSender(), spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `sender` to `recipient`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(
address sender,
address recipient,
uint256 amount
) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
uint256 senderBalance = _balances[sender];
require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[sender] = senderBalance - amount;
}
_balances[recipient] += amount;
emit Transfer(sender, recipient, amount);
_afterTokenTransfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
_balances[account] += amount;
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
}
_totalSupply -= amount;
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../ERC20.sol";
import "../../../utils/Context.sol";
/**
* @dev Extension of {ERC20} that allows token holders to destroy both their own
* tokens and those that they have an allowance for, in a way that can be
* recognized off-chain (via event analysis).
*/
abstract contract ERC20Burnable is Context, ERC20 {
/**
* @dev Destroys `amount` tokens from the caller.
*
* See {ERC20-_burn}.
*/
function burn(uint256 amount) public virtual {
_burn(_msgSender(), amount);
}
/**
* @dev Destroys `amount` tokens from `account`, deducting from the caller's
* allowance.
*
* See {ERC20-_burn} and {ERC20-allowance}.
*
* Requirements:
*
* - the caller must have allowance for ``accounts``'s tokens of at least
* `amount`.
*/
function burnFrom(address account, uint256 amount) public virtual {
uint256 currentAllowance = allowance(account, _msgSender());
require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance");
unchecked {
_approve(account, _msgSender(), currentAllowance - amount);
}
_burn(account, amount);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}