emacs lisp mapcar doesn't apply function to all elements?
- by Stephen
Hi, I have a function that takes a list and replaces some elements. I have constructed it as a closure so that the free variable cannot be modified outside of the function.
(defun transform (elems)
(lexical-let ( (elems elems) )
(lambda (seq)
(let (e)
(while (setq e (car elems))
(setf (nth e seq) e)
(setq elems (cdr elems)))
seq))))
I call this on a list of lists.
(defun tester (seq-list)
(let ( (elems '(1 3 5)) )
(mapcar (transform elems) seq-list)))
=> ((10 1 8 3 6 5 4 3 2 1) ("a" "b" "c" "d" "e" "f"))
It does not seem to apply the function to the second element of the list provided to tester(). However, if I explicitly apply this function to the individual elements, it works...
(defun tester (seq-list)
(let ( (elems '(1 3 5)) )
(list (funcall (transform elems) (car seq-list))
(funcall (transform elems) (cadr seq-list)))))
=> ((10 1 8 3 6 5 4 3 2 1) ("a" 1 "c" 3 "e" 5))
If I write a simple function using the same concepts as above, mapcar seems to work... What could I be doing wrong?
(defun transform (x)
(lexical-let ( (x x) )
(lambda (y)
(+ x y))))
(defun tester (seq)
(let ( (x 1) )
(mapcar (transform x) seq)))
(tester (list 1 3))
=> (2 4)
Thanks
