Don't just check errors, handle them gracefully (2016)

This post is an extract from my presentation at the recent GoCon spring conference in Tokyo, Japan. Errors are just values I’ve spent a lot of time thinking about the best way to handle errors in Go programs. I really wanted there to be a single way to do error handling, something that we could teach all Go programmers by rote, just as we might teach mathematics, or the alphabet. However, I have concluded that there is no single way to handle errors. Instead, I believe Go’s error handling can be classified into the three core strategies. Sentinel errors The first category of error handling is what I call sentinel errors. if err == ErrSomething { … } The name descends from the practice in computer programming of using a specific value to signify that no further processing is possible. So to with Go, we use specific values to signify an error. Examples include values like io.EOF or low level errors like the constants in the syscall package, like syscall.ENOENT . There are even s ... Read full article.