diff options
Diffstat (limited to 'lisp/emacs-lisp')
| -rw-r--r-- | lisp/emacs-lisp/cl-lib.el | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/lisp/emacs-lisp/cl-lib.el b/lisp/emacs-lisp/cl-lib.el index 929e3dfb2f5..9ca9459987f 100644 --- a/lisp/emacs-lisp/cl-lib.el +++ b/lisp/emacs-lisp/cl-lib.el @@ -358,7 +358,13 @@ SEQ, this is like `mapcar'. With several, it is like the Common Lisp (cl--defalias 'cl-first 'car) (cl--defalias 'cl-second 'cadr) (cl--defalias 'cl-rest 'cdr) -(cl--defalias 'cl-endp 'null) + +(defun cl-endp (x) + "Return true if X is the empty list; false if it is a cons. +Signal an error if X is not a list." + (if (listp x) + (null x) + (signal 'wrong-type-argument (list 'list x 'x)))) (cl--defalias 'cl-third 'cl-caddr "Return the third element of the list X.") (cl--defalias 'cl-fourth 'cl-cadddr "Return the fourth element of the list X.") |