Macroexpand-All: an example of a simple lisp code walker

If you like to write Lisp macros, or even just use the macros other people write, you have no doubt felt the desire to see what particular macro calls expand into. The standard Common Lisp function macroexpand is very useful in this regard; however, since it only expands the topmost form in an expression, it does not necessarily show you the full result of a macro expansion.