Re: Macros: Scheme vs Common Lisp

MS> Another problem with this approach is that it breaks in the MS> following case: MS> (setq bar 23) MS> (defmacro foo () bar) MS> (defun baz () (foo)) MS> (baz) => 23 Holger> MS (setq bar 42) MS> (baz) => [still ...] 23 MS> This makes obvious that the macro dereferences the binding too MS> early. (Namely, at expansion time.) Holger> Time seems to getting near to issue a bug-report to Bruno Haible[1] Holger> ... (again the following is from ACL4.3): Can you explain to me why the above should lead to a different result? CLISP's output is exactly what I expected it to be: (setq bar 23) (defmacro foo () bar) ; this means (foo) expands to the value of BAR (defun baz () (foo)) ; this therefore expands to (defun baz () 23) (baz) => 23 ; indeed (setq baz 42) ; the definition of FOO is unchanged (foo) => 23 ; presto I have to admit, though, that this thread is furthering my conviction that using CL macros right is something fairly difficult :-) -- Cheers =8-} Chipsy Friede, Völkerverständigung und überhaupt blabla