The error type is an interface. You can return values that contain contextual information as long as the error value you return has an Error() method returning a string.
type ParseError struct {
line int
}
func (e ParseError) Error() string {
return "Parse error at line: " + fmt.Sprint(e.line)
}
Note: The current release may vary slightly on the details. I'm using a pre-release build. But older versions are similar.
And then in the code for handling the error, you can do
switch err.(type) {
case db.IOError:
// Database exception here
case io.FileNotFoundError:
// File exception
default:
// Pass it to our caller for them to handle.
return nil, err
}
Which gives you the ability to selectively catch errors based on type.
