What is the “Execute Around” idiom?

Question

What is this \"Execute Around\" idiom (or similar) I\'ve been hearing about? Why might I use it, and why might I not want to use it?

Answer 1

This reminds me of the strategy design pattern. Notice that the link I pointed to includes Java code for the pattern.

Obviously one could perform "Execute Around" by making initialization and cleanup code and just passing in a strategy, which will then always be wrapped in initialization and cleanup code.

As with any technique used to reduce code repetition, you should not use it until you have at least 2 cases where you need it, perhaps even 3 (a la the YAGNI principle). Keep in mind that the removing code repetition reduces maintenance (fewer copies of code means less time spent copying fixes across each copy), but also increases maintenance (more total code). Thus, the cost of this trick is that you are adding more code.

This type of technique is useful for more than just initialization and cleanup. It's also good for when you want to make it easier to call your functions (e.g. you could use it in a wizard so that the "next" and "previous" buttons don't need giant case statements to decide what to do to go to the next/previous page.