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| author | Lars Ingebrigtsen <larsi@gnus.org> | 2022-06-27 12:36:37 +0200 |
|---|---|---|
| committer | Lars Ingebrigtsen <larsi@gnus.org> | 2022-06-27 12:36:37 +0200 |
| commit | dedd19a2f5cbf16c8ac8a122b0c39ee4e178b9e8 (patch) | |
| tree | e9bbab0f0aff4c41d8645dd65d36346e23b0eae9 | |
| parent | abdf35fac66ca51419ec39056df0429790ec9db9 (diff) | |
| download | emacs-dedd19a2f5cbf16c8ac8a122b0c39ee4e178b9e8.tar.gz emacs-dedd19a2f5cbf16c8ac8a122b0c39ee4e178b9e8.tar.bz2 emacs-dedd19a2f5cbf16c8ac8a122b0c39ee4e178b9e8.zip | |
Add new type predicate plistp
* lisp/subr.el (plistp): New type predicate (bug#47427). This
referred to in the error message from plist-put: "Debugger
entered--Lisp error: (wrong-type-argument plistp (a b c))".
| -rw-r--r-- | lisp/subr.el | 6 | ||||
| -rw-r--r-- | test/lisp/subr-tests.el | 9 |
2 files changed, 15 insertions, 0 deletions
diff --git a/lisp/subr.el b/lisp/subr.el index b05471f0c3e..69cff23cba8 100644 --- a/lisp/subr.el +++ b/lisp/subr.el @@ -4006,6 +4006,12 @@ Otherwise, return nil." (setq object (indirect-function object))) (and (subrp object) (eq (cdr (subr-arity object)) 'unevalled))) +(defun plistp (object) + "Non-nil if and only if OBJECT is a valid plist." + (and (listp object) + (proper-list-p object) + (zerop (mod (length object) 2)))) + (defun macrop (object) "Non-nil if and only if OBJECT is a macro." (let ((def (indirect-function object))) diff --git a/test/lisp/subr-tests.el b/test/lisp/subr-tests.el index 45dd2d71603..ced2bc5c4e5 100644 --- a/test/lisp/subr-tests.el +++ b/test/lisp/subr-tests.el @@ -1081,5 +1081,14 @@ final or penultimate step during initialization.")) (dolist (c (list ?a ?b ?α ?β)) (should-not (char-uppercase-p c)))) +(ert-deftest test-plistp () + (should (plistp nil)) + (should-not (plistp 1)) + (should (plistp '(1 2))) + (should-not (plistp '(1 . 2))) + (should (plistp '(1 2 3 4))) + (should-not (plistp '(1 2 3))) + (should-not (plistp '(1 2 3 . 4)))) + (provide 'subr-tests) ;;; subr-tests.el ends here |