diff options
| -rw-r--r-- | lisp/emacs-lisp/seq.el | 10 | ||||
| -rw-r--r-- | test/lisp/emacs-lisp/seq-tests.el | 12 |
2 files changed, 21 insertions, 1 deletions
diff --git a/lisp/emacs-lisp/seq.el b/lisp/emacs-lisp/seq.el index b40c424e303..3da33dac4aa 100644 --- a/lisp/emacs-lisp/seq.el +++ b/lisp/emacs-lisp/seq.el @@ -4,7 +4,7 @@ ;; Author: Nicolas Petton <nicolas@petton.fr> ;; Keywords: sequences -;; Version: 2.20 +;; Version: 2.21 ;; Package: seq ;; Maintainer: emacs-devel@gnu.org @@ -110,6 +110,14 @@ name to be bound to the rest of SEQUENCE." "Return the number of elements of SEQUENCE." (length sequence)) +(defun seq-first (sequence) + "Return the first element of SEQUENCE." + (seq-elt sequence 0)) + +(defun seq-rest (sequence) + "Return a sequence of the elements of SEQUENCE except the first one." + (seq-drop sequence 1)) + (cl-defgeneric seq-do (function sequence) "Apply FUNCTION to each element of SEQUENCE, presumably for side effects. Return SEQUENCE." diff --git a/test/lisp/emacs-lisp/seq-tests.el b/test/lisp/emacs-lisp/seq-tests.el index 989ec3cf9e0..0f11bd9714c 100644 --- a/test/lisp/emacs-lisp/seq-tests.el +++ b/test/lisp/emacs-lisp/seq-tests.el @@ -424,5 +424,17 @@ Evaluate BODY for each created sequence. (should (eq (seq-into vec 'vector) vec)) (should (eq (seq-into str 'string) str)))) +(ert-deftest test-seq-first () + (let ((lst '(1 2 3)) + (vec [1 2 3])) + (should (eq (seq-first lst) 1)) + (should (eq (seq-first vec) 1)))) + +(ert-deftest test-seq-rest () + (let ((lst '(1 2 3)) + (vec [1 2 3])) + (should (equal (seq-rest lst) '(2 3))) + (should (equal (seq-rest vec) [2 3])))) + (provide 'seq-tests) ;;; seq-tests.el ends here |