On Oct 14, 2009, at 20:38, Carlos Konstanski wrote:
> SVBRONZE> (let ((roles '(roles_dealer)))
> (reduce #'(lambda (&optional x y)
> (cond ((and x y) (format nil "~a = true OR
> ~a = true" x y))
> ((and x (not y)) (format nil "~a =
> true" x))
> (t "")))
> (mapcar #'(lambda (role)
> (string-downcase (symbol-name role)))
This is an improper use of REDUCE even if the behavior with one
argument were what you wanted. If you give it more than two arguments,
say (a b c), you will get the result:
a = true OR b = true = true OR c = true
Instead, use the :key option to REDUCE or move the addition of "~a =
true" into the MAPCAR.
If you only wanted this to work for 0, 1, or 2 arguments, then
replacing REDUCE with APPLY will make the above code work.
Also, STRING-DOWNCASE takes a string designator, so the use of SYMBOL-
NAME is unnecessary.
Kevin Reid <http://switchb.org/kpreid/>