Re: Wanted: mapcar() without nils

[Nordlöw]

Oopps, my mistake got a parenthesis wrong...

Now it works:

(defun extract-elements (pred seq)
  "Extract a copy of SEQ containing all elements fullfilling
PRED."
  (delq nil (mapcar `(lambda (elm) (when (,pred elm) elm)) seq)))
;; Use: (extract-elements 'symbolp '(a b 1 2)) => '(a b)
;; Use: (extract-elements 'numberp '(a b 1 2)) => '(1 2)

Thanks,
Nordlöw