CL -- Common Lisp EL -- Emacs Lisp Having now read "Macros in Scheme" and the first four parts of "An Introduction To Macro Expansion Algorithms" I am still not convinced that CL's macro facility is in such shambles. It seems that Scheme's need for "hygenic" macros comes from its "feature" of having each symbol name a variable or a function, but not both simultaneously and its apparent lack of CL style packages. One example that shows the "symbol names function" vs "symbol names variable" problem is (let ((cons '())) (push "ghengis" cons) (push "khubla" cons) cons) This is a problem in Scheme because CONS is defined to be a function for constructing lists. Within this LET it is rebound to be a variable holding an empty list. In CL, function and variable bindings are separate. CONS is defined as a function by the standard, but carries no variable definition [it is unbound], therefore, LET is free to establish a local variable binding for CONS and PUSH will not be confused because it will use the function binding for CONS. This form evaluates correctly in CL and EL. One example that can be fixed by use of packages is [Scheme form]: (let* ((cons (lambda (name) (case name ((phil) '("three-card monte")) ((dick) '("secret plan to end the war" "agnew" "not a crook")) ((jimmy) '("why not the best")) ((ron) '("abolish the draft" "balance the budget")) (else '())))) (scams (cons 'phil))) (push (car (cons 'jimmy)) scams) (push (cadr (cons 'ron)) scams) scams) If the application really needs a function named CONS with different behavior that CL's CONS, a new package should be defined which shadows the CONS symbol [CL form]: (defpackage FOO (:use CL) (:shadow CONS)) (in-package :FOO) (labels ((cons (name) (case name ((phil) '("three-card monte")) ((dick) '("secret plan to end the war" "agnew" "not a crook")) ((jimmy) '("why not the best")) ((ron) '("abolish the draft" "balance the budget")) (t nil)))) (let ((scams (cons 'phil))) (push (car (cons 'jimmy)) scams) (push (cadr (cons 'ron)) scams) scams) Now, when CONS is seen in the code, one will know that it is the application's definition. When CL:CONS is seen, one will know that it is CL's definition. Craig Lanning E-Mail: CraigL(a)InternetX.net