Code Craft

Handling Errors

Love truth, and pardon error.

—Voltaire

Errors happen. We’ve seen how to discover them and when to do so. The question now is: What do you do about them? This is the hard part. The answer largely depends on circumstance and the gravity of an error—whether it’s possible to rectify the problem and retry the operation or to carry on regardless. Often there is no such luxury; the error may even herald the beginning of the end. The best you can do is clean up and exit sharply, before anything else goes wrong.

To make this kind of decision, you must be informed. You need to know a few key pieces of information about the error:

Where it came from

This is quite distinct from where it’s going to be handled. Is the source a core system component ...