little lisp-problem/question with &optionel / &key... 

here are two test-programs to explore keyword and optional paramters

 

 

this test-program works

 

(defun test1 (liste  add  &key (add-on/off))

  (loop for i in liste 

    when (equal add-on/off 'on)

    collect (+ i add)

    else collect i))

 

(test1 '(1 2 3 4 5) 100 :add-on/off 'on)

 

 

this version with &optional don't work... why? 

 

(defun test2 (liste  add &optional (x 10) &key (add-on/off))

  (loop for i in liste 

    when (equal add-on/off 'on)

    collect (+ i add x)

    else collect i))

 

(test2 '(1 2 3 4 5) 100 :add-on/off 'on)

 

> Error: While compiling test2 :
>        Bad lambda list : (liste add &key add-on/off &optional (x 10)), in process Listener-1(7).

 

 

 

thanx for help

andré

 

 

You should use option or keyword only.

thanx, that's the way it works

a.