car on cons gets nil

Question

I define an alist like this:

 (setq major-mode-list
  '(((emacs-lisp-mode inferior-emacs-lisp-mode) . ("Elisp" "Emacs"))
    ((haskell-mode) . ("Haskell" "Haskell"))
    ))

And match current major-mode with this function:

 (defun major-mode-icon-3 ()
   (let* ((match (assoc
                  (car (mapcar
                        (lambda (element)
                          (member (buffer-local-value 'major-mode (current-buffer))
                                  element))
                        (map-keys major-mode-list)))
                  major-mode-list))
          (name (car (cdr match)))
          (icon (car (cdr (cdr match)))))
     )
   )

Function works correct in ((emacs-lisp-mode inferior-emacs-lisp-mode) . ("Elisp" "Emacs")).

But not correct in ((haskell-mode) . ("Haskell" "Haskell")). The function will return nil because of (car (haskell-mode)).

Question: How to correct this function?

Answer 1

There are two methods. One simple methods is (remove nil '(nil nil (clojure-mode) nil nil ..). This answer is from IRC channel #emacs.

And another method is to use cl-some which is from Google search:

 (cl-some
    (lambda (elem)
      (when (not (null elem))
        elem))
    (mapcar
     (lambda (element)
       (member major-mode element))
     (map-keys major-mode-list)))

Better way is use cl-assoc-if as @npostavs suggest.