YulToken.sol

// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

// Used in the `name()` function
bytes32 constant nameLength = 0x0000000000000000000000000000000000000000000000000000000000000009;
bytes32 constant nameData = 0x59756c20546f6b656e0000000000000000000000000000000000000000000000;

// Used in the `symbol()` function
bytes32 constant symbolLength = 0x0000000000000000000000000000000000000000000000000000000000000003;
bytes32 constant symbolData = 0x59554c0000000000000000000000000000000000000000000000000000000000;

// `bytes4(keccak256("InsufficientBalance()"))`
bytes32 constant insufficientBalanceSelector = 0xf4d678b800000000000000000000000000000000000000000000000000000000;

// `bytes4(keccak256("InsufficientAllowance(address,address)"))`
bytes32 constant insufficientAllowanceSelector = 0xf180d8f900000000000000000000000000000000000000000000000000000000;

error InsufficientBalance();
error InsufficientAllowance(address owner, address spender);

/// @title Yul ERC20
/// @author <your name here>
/// @notice For demo purposes ONLY.
contract YulERC20 {

}