Simple Solidity Contract Implementation

SolidityContract.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @title Simple read-write contract written in Solidity
/// @author jtriley.eth
/// @notice This is designed to be functionally identical to ./YulContract.sol
/// This is for educational purposes only, do not use in production.
contract SolidityContract {

    /// @notice emitted when _myNumber is set
    /// @param setter Indexed address of the number setter
    /// @param oldNumber Last number stored
    /// @param newNumber New number stored
    event MyNumberSet(
        address indexed setter,
        uint256 oldNumber,
        uint256 newNumber
    );
    
    /// @notice internal state variable
    uint256 internal _myNumber;
    
    /// @notice Reads _myNumber from state
    /// @return _myNumber state variable
    function read() public view returns (uint256) {
        return _myNumber;
    }

    /// @notice Sets _myNumber, emits MyNumberSet
    /// @param newNumber New number to be set
    function set(uint256 newNumber) public {
        uint256 oldNumber = _myNumber;
        _myNumber = newNumber;
        emit MyNumberSet(msg.sender, oldNumber, newNumber);
    }
    
    /// @notice Fallback, always returns 42 params not used
    /// @return The number 42 encoded in bytes
    fallback(bytes calldata) external returns (bytes memory) {
        return abi.encode(42);
    }
}