import {Punycode} from "@adraffy/punycode-contracts/src/Punycode.sol";

string memory unicode = Punycode.decode("xn--ls8h"); // "💩"
string memory punycode = Punycode.encode(unicode"💩"); // "xn--ls8h"

// reverts on failure
// let me know if a tryDecode() is needed
function decode(string memory s) pure returns (string memory) 

// never fails
function encode(string memory s) pure returns (string memory)

// src == dst if no encoding required
// otherwise, (dst-32) is effectively `bytes`
function decode(uint256 src, uint256 src_len) pure returns (uint256 dst, uint256 dst_len)
function encode(uint256 src, uint256 src_len) pure returns (uint256 dst, uint256 dst_len)

// example
string memory s = "abc.xn--ls8h.com";
uint256 src;
assembly { src := add(s, 32) }
(uint256 dst, uint256 len) = Punycode.decode(src + 4, 8); // "xn--ls8h"
console2.log(len); // 4 bytes
assembly { s := sub(dst, 32) }
console2.log(s); // "💩"
bytes32 h;
assembly { h := keccak256(dst, len) }
console2.logBytes32(h); // 0xba967c160905ade030f84952644a963994eeaed3881a6b8a4e9c8cbe452ad7a2