After years of using Common Lisp, my opinion on "meta-programming" is that it's wonderful when used sparingly and in just the right way, but a bad idea 99% of t

After years of using Common Lisp, my opinion on "meta-programming" is that it's wonderful when used sparingly and in just the right way, but a bad idea 99% of the time. If it's not completely obvious what (not how) a macro does just by looking at the code that calls it, then it's almost certainly a bad macro. For example, there's a CL library, iterate, that introduces several new iteration constructs. There are a bunch of complicated macros under the hood, but as an end user I never have to think about them, and the provided interface is obvious, even without knowing anything about the iterate library. For example: (iterate (for (key . item) in alist) (collect key into keys) (collect item into items) (finally (return (values keys items)))) I would definitely consider, "Just because you can doesn't mean you should" to be the number one rule of metaprogramming.