/
goto-last-change.el
141 lines (125 loc) · 5.85 KB
/
goto-last-change.el
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
;;; goto-last-change.el --- Move point through buffer-undo-list positions -*-raw-text: t; coding: iso-8859-1;-*-
;; Copyright © 2003 Kevin Rodgers
;; Author: Kevin Rodgers <ihs_4664@yahoo.com>
;; Created: 17 Jun 2003
;; Version: $Revision: 1.2 $
;; Keywords: convenience
;; RCS: $Id: goto-last-change.el,v 1.2 2003/07/30 17:43:47 kevinr Exp kevinr $
;; Contributors:
;; Attila Lendvai <attila.lendvai@gmail.com> (line distance and auto marks)
;; This program is free software; you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; published by the Free Software Foundation; either version 2 of
;; the License, or (at your option) any later version.
;; This program is distributed in the hope that it will be
;; useful, but WITHOUT ANY WARRANTY; without even the implied
;; warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
;; PURPOSE. See the GNU General Public License for more details.
;; You should have received a copy of the GNU General Public
;; License along with this program; if not, write to the Free
;; Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
;; MA 02111-1307 USA
;;; Commentary:
;; After installing goto-last-change.el in a `load-path' directory and
;; compiling it with `M-x byte-compile-file', load it with
;; (require 'goto-last-change)
;; or autoload it with
;; (autoload 'goto-last-change "goto-last-change"
;; "Set point to the position of the last change." t)
;;
;; You may also want to bind a key to `M-x goto-last-change', e.g.
;; (global-set-key "\C-x\C-\\" 'goto-last-change)
;; goto-last-change.el was written in response to to the following:
;;
;; From: Dan Jacobson <jidanni@jidanni.org>
;; Newsgroups: gnu.emacs.bug
;; Subject: function to go to spot of last change
;; Date: Sun, 15 Jun 2003 00:15:08 +0000 (UTC)
;; Sender: news <news@main.gmane.org>
;; Message-ID: <mailman.7910.1055637181.21513.bug-gnu-emacs@gnu.org>
;; NNTP-Posting-Host: monty-python.gnu.org
;;
;;
;; Why of course, a function to get the user to the spot of last changes
;; in the current buffer(s?), that's what emacs must lack.
;;
;; How many times have you found yourself mosying [<-not in spell
;; checker!?] thru a file when you wonder, where the heck was I just
;; editing? Well, the best you can do is hit undo, ^F, and undo again,
;; to get back. Hence the "burning need" for the additional function,
;; which you might name the-jacobson-memorial-function, due to its brilliance.
;; --
;; http://jidanni.org/ Taiwan(04)25854780
;;; Code:
(provide 'goto-last-change)
(or (fboundp 'last) ; Emacs 20
(require 'cl)) ; Emacs 19
(defvar goto-last-change-undo nil
"The `buffer-undo-list' entry of the previous \\[goto-last-change] command.")
(make-variable-buffer-local 'goto-last-change-undo)
;;;###autoload
(defun goto-last-change (&optional mark-point minimal-line-distance)
"Set point to the position of the last change.
Consecutive calls set point to the position of the previous change.
With a prefix arg (optional arg MARK-POINT non-nil), set mark so \
\\[exchange-point-and-mark]
will return point to the current position."
(interactive "P")
;; (unless (buffer-modified-p)
;; (error "Buffer not modified"))
(when (eq buffer-undo-list t)
(error "No undo information in this buffer"))
(when mark-point
(push-mark))
(unless minimal-line-distance
(setq minimal-line-distance 10))
(let ((position nil)
(undo-list (if (and (eq this-command last-command)
goto-last-change-undo)
(cdr (memq goto-last-change-undo buffer-undo-list))
buffer-undo-list))
undo)
(while (and undo-list
(or (not position)
(eql position (point))
(and minimal-line-distance
;; The first invocation always goes to the last change, subsequent ones skip
;; changes closer to (point) then minimal-line-distance.
(memq last-command '(goto-last-change
goto-last-change-with-auto-marks))
(< (count-lines (min position (point-max)) (point))
minimal-line-distance))))
(setq undo (car undo-list))
(cond ((and (consp undo) (integerp (car undo)) (integerp (cdr undo)))
;; (BEG . END)
(setq position (cdr undo)))
((and (consp undo) (stringp (car undo))) ; (TEXT . POSITION)
(setq position (abs (cdr undo))))
((and (consp undo) (eq (car undo) t))) ; (t HIGH . LOW)
((and (consp undo) (null (car undo)))
;; (nil PROPERTY VALUE BEG . END)
(setq position (cdr (last undo))))
((and (consp undo) (markerp (car undo)))) ; (MARKER . DISTANCE)
((integerp undo)) ; POSITION
((null undo)) ; nil
(t (error "Invalid undo entry: %s" undo)))
(setq undo-list (cdr undo-list)))
(cond (position
(setq goto-last-change-undo undo)
(goto-char (min position (point-max))))
((and (eq this-command last-command)
goto-last-change-undo)
(setq goto-last-change-undo nil)
(error "No further undo information"))
(t
(setq goto-last-change-undo nil)
(error "Buffer not modified")))))
(defun goto-last-change-with-auto-marks (&optional minimal-line-distance)
"Calls goto-last-change and sets the mark at only the first invocations
in a sequence of invocations."
(interactive "P")
(goto-last-change (not (or (eq last-command 'goto-last-change-with-auto-marks)
(eq last-command t)))
minimal-line-distance))
;; (global-set-key "\C-x\C-\\" 'goto-last-change)
;;; goto-last-change.el ends here