LilENS.sol

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity ^0.8.10;

/// @title lil ens
/// @author Miguel Piedrafita
/// @notice A stupidly-simple namespace implementation.
contract LilENS {
	/// ERRORS ///

	/// @notice Thrown when trying to update a name you don't own
	error Unauthorized();

	/// @notice Thrown when trying to register a name that's already taken
	error AlreadyRegistered();

	/// @notice Stores the registered names and their addresses
	/// @dev This automatically generates a getter for us!
	mapping(string => address) public lookup;

	/// @notice Registers a new name, and points it to your address
	/// @param name The name to register
	function register(string memory name) public payable {
		if (lookup[name] != address(0)) revert AlreadyRegistered();

		lookup[name] = msg.sender;
	}

	/// @notice Allows the owner of a name to point it to a different address
	/// @param name The name to update
	/// @param addr The new address this name should point to
	function update(string memory name, address addr) public payable {
		if (msg.sender != lookup[name]) revert Unauthorized();

		lookup[name] = addr;
	}
}