;;; etags.el --- etags facility for Emacs
-
-;; Copyright (C) 1985, 1986, 1988, 1989, 1992, 1993, 1994, 1995
+;; Copyright (C) 1985, 1986, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1998
;; Free Software Foundation, Inc.
;; Author: Roland McGrath <roland@gnu.ai.mit.edu>
;;; Code:
+(require 'ring)
+
;;;###autoload
(defvar tags-file-name nil
"*File name of tags table.
;; Make M-x set-variable tags-file-name like M-x visit-tags-table.
;;;###autoload (put 'tags-file-name 'variable-interactive "fVisit tags table: ")
-(defgroup etags "Tags tables"
+(defgroup etags nil "Tags tables"
:group 'tools)
;;;###autoload
:group 'etags
:type '(choice (const :tag "Do" t)
(const :tag "Don't" nil)
- (const :tag "Ask" ask-user)))
+ (other :tag "Ask" ask-user)))
(defcustom tags-revert-without-query nil
"*Non-nil means reread a TAGS table without querying, if it has changed."
:group 'etags
:type 'function)
+(defcustom find-tag-marker-ring-length 16
+ "*Length of marker rings `find-tag-marker-ring' and `tags-location-ring'."
+ :group 'etags
+ :type 'integer
+ :version "20.3")
+
+(defvar find-tag-marker-ring (make-ring find-tag-marker-ring-length)
+ "Ring of markers which are locations from which \\[find-tag] was invoked.")
+
(defvar default-tags-table-function nil
"If non-nil, a function to choose a default tags file for a buffer.
This function receives no arguments and should return the default
tags table file to use for the current buffer.")
-(defvar tags-location-stack nil
- "List of markers which are locations visited by \\[find-tag].
+(defvar tags-location-ring (make-ring find-tag-marker-ring-length)
+ "Ring of markers which are locations visited by \\[find-tag].
Pop back to the last location with \\[negative-argument] \\[find-tag].")
\f
;; Tags table state.
(defvar tags-table-format-hooks '(etags-recognize-tags-table
recognize-empty-tags-table)
- "List of functions to be called in a tags table buffer to identify
-the type of tags table. The functions are called in order, with no arguments,
+ "List of functions to be called in a tags table buffer to identify the type of tags table.
+The functions are called in order, with no arguments,
until one returns non-nil. The function should make buffer-local bindings
of the format-parsing tags function variables if successful.")
(set (make-local-variable 'tags-table-files) nil)
(set (make-local-variable 'tags-completion-table) nil)
(set (make-local-variable 'tags-included-tables) nil)
+ (setq find-tag-marker-ring (make-ring find-tag-marker-ring-length))
+ (setq tags-location-ring (make-ring find-tag-marker-ring-length))
;; Value is t if we have found a valid tags table buffer.
(let ((hooks tags-table-format-hooks))
(while (and hooks
(error "File %s is not a valid tags table" local-tags-file-name)))))
(defun tags-reset-tags-tables ()
- "Reset tags state to cancel effect of any previous \\[visit-tags-table]
-or \\[find-tag]."
+ "Reset tags state to cancel effect of any previous \\[visit-tags-table] or \\[find-tag]."
(interactive)
(setq tags-file-name nil
- tags-location-stack nil
+ tags-location-ring (progn
+ (mapcar (lambda (m)
+ (set-marker m nil))
+ tags-location-ring)
+ (make-ring find-tag-marker-ring-length))
+ find-tag-marker-ring (progn
+ (mapcar (lambda (m)
+ (set-marker m nil))
+ find-tag-marker-ring)
+ (make-ring find-tag-marker-ring-length))
tags-table-list nil
tags-table-computed-list nil
tags-table-computed-list-for nil
If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
+A marker representing the point when this command is onvoked is pushed
+onto a ring and may be popped back to with \\[pop-tag-mark].
+Contrast this with the ring of marks gone to by the command.
+
See documentation of variable `tags-file-name'."
(interactive (find-tag-interactive "Find tag: "))
(let ((local-find-tag-hook find-tag-hook))
(if (eq '- next-p)
;; Pop back to a previous location.
- (if (null tags-location-stack)
+ (if (ring-empty-p tags-location-ring)
(error "No previous tag locations")
- (let ((marker (car tags-location-stack)))
- ;; Pop the stack.
- (setq tags-location-stack (cdr tags-location-stack))
+ (let ((marker (ring-remove tags-location-ring 0)))
(prog1
;; Move to the saved location.
- (set-buffer (marker-buffer marker))
+ (set-buffer (or (marker-buffer marker)
+ (error "The marked buffer has been deleted")))
(goto-char (marker-position marker))
;; Kill that marker so it doesn't slow down editing.
(set-marker marker nil nil)
;; Run the user's hook. Do we really want to do this for pop?
(run-hooks 'local-find-tag-hook))))
+ ;; Record whence we came.
+ (ring-insert find-tag-marker-ring (point-marker))
(if next-p
;; Find the same table we last used.
(visit-tags-table-buffer 'same)
(not next-p)))
(set-marker marker (point))
(run-hooks 'local-find-tag-hook)
- (setq tags-location-stack
- (cons marker tags-location-stack))
+ (ring-insert tags-location-ring marker)
(current-buffer))))))
;;;###autoload
is the atom `-' (interactively, with prefix arg that is a negative number
or just \\[negative-argument]), pop back to the previous tag gone to.
+If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
+
+A marker representing the point when this command is onvoked is pushed
+onto a ring and may be popped back to with \\[pop-tag-mark].
+Contrast this with the ring of marks gone to by the command.
+
See documentation of variable `tags-file-name'."
(interactive (find-tag-interactive "Find tag: "))
(switch-to-buffer (find-tag-noselect tagname next-p regexp-p)))
is negative (interactively, with prefix arg that is a negative number or
just \\[negative-argument]), pop back to the previous tag gone to.
+If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
+
+A marker representing the point when this command is onvoked is pushed
+onto a ring and may be popped back to with \\[pop-tag-mark].
+Contrast this with the ring of marks gone to by the command.
+
See documentation of variable `tags-file-name'."
(interactive (find-tag-interactive "Find tag other window: "))
is negative (interactively, with prefix arg that is a negative number or
just \\[negative-argument]), pop back to the previous tag gone to.
+If third arg REGEXP-P is non-nil, treat TAGNAME as a regexp.
+
+A marker representing the point when this command is onvoked is pushed
+onto a ring and may be popped back to with \\[pop-tag-mark].
+Contrast this with the ring of marks gone to by the command.
+
See documentation of variable `tags-file-name'."
(interactive (find-tag-interactive "Find tag other frame: "))
(let ((pop-up-frames t))
If third arg OTHER-WINDOW is non-nil, select the buffer in another window.
+A marker representing the point when this command is onvoked is pushed
+onto a ring and may be popped back to with \\[pop-tag-mark].
+Contrast this with the ring of marks gone to by the command.
+
See documentation of variable `tags-file-name'."
(interactive (find-tag-interactive "Find tag regexp: " t))
;; We go through find-tag-other-window to do all the display hair there.
(funcall (if other-window 'find-tag-other-window 'find-tag)
regexp next-p t))
;;;###autoload (define-key esc-map [?\C-.] 'find-tag-regexp)
+
+;;;###autoload (define-key esc-map "*" 'pop-tag-mark)
+
+;;;###autoload
+(defun pop-tag-mark ()
+ "Pop back to where \\[find-tag] was last invoked.
+
+This is distinct from invoking \\[find-tag] with a negative argument
+since that pops a stack of markers at which tags were found, not from
+where they were found."
+ (interactive)
+ (if (ring-empty-p find-tag-marker-ring)
+ (error "No previous locations for find-tag invocation"))
+ (let ((marker (ring-remove find-tag-marker-ring 0)))
+ (switch-to-buffer (or (marker-buffer marker)
+ (error "The marked buffer has been deleted")))
+ (goto-char (marker-position marker))
+ (set-marker marker nil nil)))
\f
;; Internal tag finding function.
(defun select-tags-table-quit ()
"Kill the buffer and delete the selected window."
(interactive)
- (kill-buffer (current-buffer))
- (or (one-window-p)
- (delete-window)))
+ (quit-window t (selected-window)))
\f
;;; Note, there is another definition of this function in bindings.el.
;;;###autoload