Question

I’m trying to write a function which checks if every element in the list x has property a, so I wrote:

(defun check (a x)
  (if (listp x)
    (eval (cons 'and (mapcar #'a x)))))

but it doesn’t work. (Basically I want a to be the name of a function, say blablabla, and in the body of the check-function, by #'a I want to mean the function blablabla, instead of a function called a.) Now the code above doesn’t work. I think in Lisp one should be able to plug in functions. How can I fix it?

(It is literally my first day on lisp, so it might be a stupid question 😉
and BTW I’m using Lispworks 6.0 personal version.)

Answer 1

There is no need to use the sharp-quote syntax here. Its purpose is to use a function name in a variable position, but a is a variable already. Just write a instead of #'a.