// SPDX-License-Identifier: MIT

pragma solidity ^0.8.13;

library AddressUtils {
    // This is the hex encoding of the string 'abcdefghijklmnopqrstuvwxyz'
    // It is used as a constant to lookup the characters of the hex address
    bytes32 constant lookup =
        0x3031323334353637383961626364656600000000000000000000000000000000;

    /**
     * @dev An optimised function to compute the sha3 of the lower-case
     *      hexadecimal representation of an Ethereum address.
     * @param addr The address to hash
     * @return ret The SHA3 hash of the lower-case hexadecimal encoding of the
     *         input address.
     */
    function sha3HexAddress(address addr) internal pure returns (bytes32 ret) {
        assembly {
            for {
                let i := 40
            } gt(i, 0) {} {
                i := sub(i, 1)
                mstore8(i, byte(and(addr, 0xf), lookup))
                addr := div(addr, 0x10)
                i := sub(i, 1)
                mstore8(i, byte(and(addr, 0xf), lookup))
                addr := div(addr, 0x10)
            }

            ret := keccak256(0, 40)
        }
    }
}