diff options
Diffstat (limited to 'lisp/emacs-lisp/ring.el')
| -rw-r--r-- | lisp/emacs-lisp/ring.el | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/lisp/emacs-lisp/ring.el b/lisp/emacs-lisp/ring.el index 9951221c1d8..1e42c063d7f 100644 --- a/lisp/emacs-lisp/ring.el +++ b/lisp/emacs-lisp/ring.el @@ -36,16 +36,18 @@ ;;; Code: -(provide 'history) +(provide 'ring) +;;;###autoload (defun ring-p (x) "T if X is a ring; NIL otherwise." (and (consp x) (integerp (car x)) (consp (cdr x)) (integerp (car (cdr x))) (vectorp (cdr (cdr x))))) +;;;###autoload (defun make-ring (size) - "Make a ring that can contain SIZE elts" + "Make a ring that can contain SIZE elts." (cons 1 (cons 0 (make-vector (+ size 1) nil)))) (defun ring-plus1 (index veclen) @@ -80,7 +82,7 @@ item to make room." "Remove the oldest item retained on the ring." (if (ring-empty-p ring) (error "Ring empty") (let ((tl (car (cdr ring))) (vec (cdr (cdr ring)))) - (set-car (cdr ring) (ring-minus1 tl (length vec))) + (setcar (cdr ring) (ring-minus1 tl (length vec))) (aref vec tl)))) ;;; This isn't actually used in this package. I just threw it in in case @@ -105,10 +107,10 @@ item to make room." (aset vec hd (aref vec tl)) (setq tl (ring-minus1 tl len)) (setq n (- n 1)))) - (set-car ring hd) - (set-car (cdr ring) tl))))) + (setcar ring hd) + (setcar (cdr ring) tl))))) -(defun comint-mod (n m) +(defun ring-mod (n m) "Returns N mod M. M is positive. Answer is guaranteed to be non-negative, and less than m." (let ((n (% n m))) @@ -120,9 +122,8 @@ Answer is guaranteed to be non-negative, and less than m." (let ((numelts (ring-length ring))) (if (= numelts 0) (error "indexed empty ring") (let* ((hd (car ring)) (tl (car (cdr ring))) (vec (cdr (cdr ring))) - (index (comint-mod index numelts)) - (vec-index (comint-mod (+ index hd) - (length vec)))) + (index (ring-mod index numelts)) + (vec-index (ring-mod (+ index hd) (length vec)))) (aref vec vec-index))))) ;;; ring.el ends here |