I've been very impressed with the way Bruce Eckel deals with it in his books. All of the examples are automatically built so that he can veryify that they actually compile.

Makes me start to think about a test/example system where the examples of a script are also some of it's tests. That way as you change your code the tests don't just point out errors in code but also where you need to update your examples to reflect changes in the code. Hmmmm.......

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