Using setf is a nice example of something which a macro can do which a function cannot (as well as being a good example of code-is-data). Lots of posts discuss

Using setf is a nice example of something which a macro can do which a function cannot (as well as being a good example of code-is-data). Lots of posts discussing lisp macrology lack that kind of compelling use case. The 'magic' used by setf is a 'destructuring bind': http://dunsmor.com/lisp/onlisp/onlisp_22.html http://dunsmor.com/lisp/onlisp/onlisp_22.html