pax_global_header 0000666 0000000 0000000 00000000064 13414611235 0014512 g ustar 00root root 0000000 0000000 52 comment=16a63aae80db90713fb1f7d378c5d591c2ce15ff
goto-chg-1.7.3/ 0000775 0000000 0000000 00000000000 13414611235 0013231 5 ustar 00root root 0000000 0000000 goto-chg-1.7.3/LICENSE 0000664 0000000 0000000 00000043176 13414611235 0014251 0 ustar 00root root 0000000 0000000 GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
The licenses for most software are designed to take away your
freedom to share and change it. By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users. This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software is covered by
the GNU Lesser General Public License instead.) You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it
in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have. You must make sure that they, too, receive or can get the
source code. And you must show them these terms so they know their
rights.
We protect your rights with two steps: (1) copyright the software, and
(2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.
Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software. If the software is modified by someone else and passed on, we
want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.
Finally, any free program is threatened constantly by software
patents. We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary. To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.
The precise terms and conditions for copying, distribution and
modification follow.
GNU GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License. The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language. (Hereinafter, translation is included without limitation in
the term "modification".) Each licensee is addressed as "you".
Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope. The act of
running the Program is not restricted, and the output from the Program
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does.
1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of this License
along with the Program.
You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.
2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
a) You must cause the modified files to carry prominent notices
stating that you changed the files and the date of any change.
b) You must cause any work that you distribute or publish, that in
whole or in part contains or is derived from the Program or any
part thereof, to be licensed as a whole at no charge to all third
parties under the terms of this License.
c) If the modified program normally reads commands interactively
when run, you must cause it, when started running for such
interactive use in the most ordinary way, to print or display an
announcement including an appropriate copyright notice and a
notice that there is no warranty (or else, saying that you provide
a warranty) and that users may redistribute the program under
these conditions, and telling the user how to view a copy of this
License. (Exception: if the Program itself is interactive but
does not normally print such an announcement, your work based on
the Program is not required to print an announcement.)
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works. But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Program.
In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.
3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms of
Sections 1 and 2 above provided that you also do one of the following:
a) Accompany it with the complete corresponding machine-readable
source code, which must be distributed under the terms of Sections
1 and 2 above on a medium customarily used for software interchange; or,
b) Accompany it with a written offer, valid for at least three
years, to give any third party, for a charge no more than your
cost of physically performing source distribution, a complete
machine-readable copy of the corresponding source code, to be
distributed under the terms of Sections 1 and 2 above on a medium
customarily used for software interchange; or,
c) Accompany it with the information you received as to the offer
to distribute corresponding source code. (This alternative is
allowed only for noncommercial distribution and only if you
received the program in object code or executable form with such
an offer, in accord with Subsection b above.)
The source code for a work means the preferred form of the work for
making modifications to it. For an executable work, complete source
code means all the source code for all modules it contains, plus any
associated interface definition files, plus the scripts used to
control compilation and installation of the executable. However, as a
special exception, the source code distributed need not include
anything that is normally distributed (in either source or binary
form) with the major components (compiler, kernel, and so on) of the
operating system on which the executable runs, unless that component
itself accompanies the executable.
If distribution of executable or object code is made by offering
access to copy from a designated place, then offering equivalent
access to copy the source code from the same place counts as
distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.
4. You may not copy, modify, sublicense, or distribute the Program
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense or distribute the Program is
void, and will automatically terminate your rights under this License.
However, parties who have received copies, or rights, from you under
this License will not have their licenses terminated so long as such
parties remain in full compliance.
5. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify or
distribute the Program or its derivative works. These actions are
prohibited by law if you do not accept this License. Therefore, by
modifying or distributing the Program (or any work based on the
Program), you indicate your acceptance of this License to do so, and
all its terms and conditions for copying, distributing or modifying
the Program or works based on it.
6. Each time you redistribute the Program (or any work based on the
Program), the recipient automatically receives a license from the
original licensor to copy, distribute or modify the Program subject to
these terms and conditions. You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties to
this License.
7. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License. If you cannot
distribute so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you
may not distribute the Program at all. For example, if a patent
license would not permit royalty-free redistribution of the Program by
all those who receive copies directly or indirectly through you, then
the only way you could satisfy both it and this License would be to
refrain entirely from distribution of the Program.
If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
apply and the section as a whole is intended to apply in other
circumstances.
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of any
such claims; this section has the sole purpose of protecting the
integrity of the free software distribution system, which is
implemented by public license practices. Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is willing
to distribute software through any other system and a licensee cannot
impose that choice.
This section is intended to make thoroughly clear what is believed to
be a consequence of the rest of this License.
8. If the distribution and/or use of the Program is restricted in
certain countries either by patents or by copyrighted interfaces, the
original copyright holder who places the Program under this License
may add an explicit geographical distribution limitation excluding
those countries, so that distribution is permitted only in or among
countries not thus excluded. In such case, this License incorporates
the limitation as if written in the body of this License.
9. The Free Software Foundation may publish revised and/or new versions
of the General Public License from time to time. Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.
Each version is given a distinguishing version number. If the Program
specifies a version number of this License which applies to it and "any
later version", you have the option of following the terms and conditions
either of that version or of any later version published by the Free
Software Foundation. If the Program does not specify a version number of
this License, you may choose any version ever published by the Free Software
Foundation.
10. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the author
to ask for permission. For software which is copyrighted by the Free
Software Foundation, write to the Free Software Foundation; we sometimes
make exceptions for this. Our decision will be guided by the two goals
of preserving the free status of all derivatives of our free software and
of promoting the sharing and reuse of software generally.
NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
REPAIR OR CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
{description}
Copyright (C) {year} {fullname}
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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
Also add information on how to contact you by electronic and paper mail.
If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) year name of author
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License. Of course, the commands you use may
be called something other than `show w' and `show c'; they could even be
mouse-clicks or menu items--whatever suits your program.
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the program, if
necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program
`Gnomovision' (which makes passes at compilers) written by James Hacker.
{signature of Ty Coon}, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your program into
proprietary programs. If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library. If this is what you want to do, use the GNU Lesser General
Public License instead of this License.
goto-chg-1.7.3/goto-chg.el 0000664 0000000 0000000 00000041137 13414611235 0015270 0 ustar 00root root 0000000 0000000 ;;; goto-chg.el --- goto last change
;;--------------------------------------------------------------------
;;
;; Copyright (C) 2002-2008,2013 David Andersson
;;
;; 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
;;
;;-------------------------------------------------------------------
;;
;; Author: David Andersson
;; Maintainer: Vasilij Schneidermann
;; Created: 16 May 2002
;; Version: 1.7.3
;; Keywords: convenience, matching
;; URL: https://github.com/emacs-evil/goto-chg
;;
;;; Commentary:
;;
;; Goto Last Change
;;
;; Goto the point of the most recent edit in the buffer.
;; When repeated, goto the second most recent edit, etc.
;; Negative argument, C-u -, for reverse direction.
;; Works by looking into buffer-undo-list to find points of edit.
;;
;; You would probably like to bind this command to a key.
;; For example in your ~/.emacs:
;;
;; (require 'goto-chg)
;;
;; (global-set-key [(control ?.)] 'goto-last-change)
;; (global-set-key [(control ?,)] 'goto-last-change-reverse)
;;
;; Works with emacs-19.29, 19.31, 20.3, 20.7, 21.1, 21.4, 22.1 and 23.1
;; Works with XEmacs-20.4 and 21.4 (but see todo about `last-command' below)
;;
;;--------------------------------------------------------------------
;; History
;;
;; Ver 1.7.3 2019-01-07 Vasilij Schneidermann
;; Fix errors when used with persistent undo
;; Ver 1.7.2 2018-01-05 Vasilij Schneidermann
;; Fix byte-compiler warnings again
;; Ver 1.7.1 2017-12-31 Vasilij Schneidermann
;; Fix byte-compiler warnings
;; Ver 1.7 2017-09-17 Vasilij Schneidermann
;; Make it work with undo-tree-mode (see
;; )
;; Ver 1.6 2013-12-12 David Andersson
;; Add keywords; Cleanup comments
;; Ver 1.5 2013-12-11 David Andersson
;; Autoload and document `goto-last-change-reverse'
;; Ver 1.4 2008-09-20 David Andersson
;; Improved property change description; Update comments.
;; Ver 1.3 2007-03-14 David Andersson
;; Added `goto-last-change-reverse'
;; Ver 1.2 2003-04-06 David Andersson
;; Don't let repeating error depthen glc-probe-depth.
;; Ver 1.1 2003-04-06 David Andersson
;; Zero arg describe changes. Negative arg go back.
;; Autoload. Remove message using nil in stead of an empty string.
;; Ver 1.0 2002-05-18 David Andersson
;; Initial version
;;
;;--------------------------------------------------------------------
;;
;;todo: Rename "goto-chg.el" -> "gotochange.el" or "goto-chgs" ?
;;todo: Rename function goto-last-change -> goto-last-edit ?
;;todo: Rename adjective "-last-" -> "-latest-" or "-most-recent-" ?
;;todo: There are some, maybe useful, funcs for region undo
;; in simple.el in emacs 20. Take a look.
;;todo: Add functionality to visit changed point in text order, not only in
;; chronological order. (Naa, highlight-changes-mode does that).
;;todo: Inverse indication that a change has been saved or not
;;todo: Highlight the range of text involved in the last change?
;;todo: See session-jump-to-last-change in session.el?
;;todo: Unhide invisible text (e.g. outline mode) like isearch do.
;;todo: XEmacs sets last-command to `t' after an error, so you cannot reverse
;; after "No furter change info". Should we bother?
;;todo: Try distinguish "No further change info" (end of truncated undo list)
;; and "No further changes" (end of a complete undo list).
;;
;;--------------------------------------------------------------------
;;; Code:
(defvar glc-default-span 8 "*goto-last-change don't visit the same point twice. glc-default-span tells how far around a visited point not to visit again.")
(defvar glc-current-span 8 "Internal for goto-last-change.\nA copy of glc-default-span or the ARG passed to goto-last-change.")
(defvar glc-probe-depth 0 "Internal for goto-last-change.\nIt is non-zero between successive goto-last-change.")
(defvar glc-direction 1 "Direction goto-last-change moves towards.")
;;todo: Find begin and end of line, then use it somewhere
(defun glc-center-ellipsis (str maxlen &optional ellipsis)
"Truncate STRING in the middle to length MAXLEN.
If STRING is max MAXLEN just return the string.
Optional third argument is the replacement, which defaults to \"...\"."
(if (<= (length str) maxlen)
str
;; else
(let* ((lipsis (or ellipsis "..."))
(i (/ (- maxlen (length lipsis)) 2)))
(concat (substring str 0 i)
lipsis
(substring str (- i))))))
(defun glc-adjust-pos2 (pos p1 p2 adj)
;; Helper function to glc-adjust-pos
;; p1, p2: interval where an edit occured
;; adj: amount of text added (positive) or removed (negativ) by the edit
;; Return pos if well before p1, or pos+adj if well after p2, or nil if too close
(cond ((<= pos (- p1 glc-current-span))
pos)
((> pos (+ p2 glc-current-span))
(+ pos adj))
((zerop glc-current-span)
p1)
(t
nil)))
(defun glc-adjust-pos (pos e)
"Given POS, a buffer position before the edit E, compute and return
the \"same\" buffer position after E happened.
Exception: return nil if POS is closer than `glc-current-span' to the edit E.
\nInsertion edits before POS returns a larger value.
Deletion edits before POS returns a smaller value.
\nThe edit E is an entry from the `buffer-undo-list'. See for details."
(cond ((atom e) ; nil==cmd boundary, or, num==changed pos
pos)
((numberp (car e)) ; (beg . end)==insertion
(glc-adjust-pos2 pos (car e) (car e) (- (cdr e) (car e))))
((stringp (car e)) ; (string . pos)==deletion
(glc-adjust-pos2 pos (abs (cdr e)) (+ (abs (cdr e)) (length (car e))) (- (length (car e)))))
((null (car e)) ; (nil prop val beg . end)==prop change
(glc-adjust-pos2 pos (nth 3 e) (nthcdr 4 e) 0))
(t ; (marker . dist)==marker moved
pos)))
;; If recursive in stead of iterative (while), it tends to fill the call stack.
;; (Isn't it tail optimized?)
(defun glc-adjust-list (r)
"R is list of edit entries in chronological order.
Pick the point of the first edit entry and update that point with
the second, third, etc, edit entries. Return the final updated point,
or nil if the point was closer than `glc-current-span' to some edit in R.
\nR is basically a reversed slice from the buffer-undo-list."
(if r
;; Get pos
(let ((pos (glc-get-pos (car r))))
(setq r (cdr r))
;; Walk back in reverse list
(while (and r pos)
(setq pos (glc-adjust-pos pos (car r))
r (cdr r)))
pos)
;; else
nil))
(defun glc-get-pos (e)
"If E represents an edit, return a position value in E, the position
where the edit took place. Return nil if E represents no real change.
\nE is an entry in the buffer-undo-list."
(cond ((numberp e) e) ; num==changed position
((atom e) nil) ; nil==command boundary
((numberp (car e)) (cdr e)) ; (beg . end)==insertion
((stringp (car e)) (abs (cdr e))) ; (string . pos)==deletion
((null (car e)) (nthcdr 4 e)) ; (nil ...)==text property change
((atom (car e)) nil) ; (t ...)==file modification time
(t nil))) ; (marker ...)==marker moved
(defun glc-get-descript (e &optional n)
"If E represents an edit, return a short string describing E.
Return nil if E represents no real change.
\nE is an entry in the buffer-undo-list."
(let ((nn (or (format "T-%d: " n) "")))
(cond ((numberp e) "New position") ; num==changed position
((atom e) nil) ; nil==command boundary
((numberp (car e)) ; (beg . end)==insertion
(if (and n (< n 2))
(format "%sInserted %d chars \"%s\"" nn (- (cdr e) (car e))
(glc-center-ellipsis (buffer-substring (car e) (cdr e)) 60))
;; else
;; An older insert. The inserted text cannot easily be computed.
;; Just show the char count.
(format "%sInserted %d chars" nn (- (cdr e) (car e)))))
((stringp (car e)) ; (string . pos)==deletion
(format "%sDeleted \"%s\"" nn (glc-center-ellipsis (car e) 60)))
((null (car e)) ; (nil ...)==text property change
(format "%sProperty change" nn))
((atom (car e)) nil) ; (t ...)==file modification time
(t nil)))) ; (marker ...)==marker moved
(defun glc-is-positionable (e)
"Return non-nil if E is an insertion, deletion or text property change.
\nE is an entry in the buffer-undo-list."
(and (not (numberp e)) (glc-get-pos e)))
(defun glc-is-filetime (e)
"Return t if E indicates a buffer became \"modified\",
that is, it was previously saved or unchanged. Nil otherwise."
(and (listp e) (eq (car e) t)))
(defvar buffer-undo-tree)
(declare-function undo-list-transfer-to-tree "undo-tree.el")
(declare-function undo-tree-current "undo-tree.el")
(declare-function undo-tree-node-p "undo-tree.el")
(declare-function undo-tree-node-undo "undo-tree.el")
(declare-function undo-tree-node-previous "undo-tree.el")
;;;###autoload
(defun goto-last-change (arg)
"Go to the point where the last edit was made in the current buffer.
Repeat the command to go to the second last edit, etc.
\nTo go back to more recent edit, the reverse of this command, use \\[goto-last-change-reverse]
or precede this command with \\[universal-argument] - (minus).
\nIt does not go to the same point twice even if there has been many edits
there. I call the minimal distance between distinguishable edits \"span\".
Set variable `glc-default-span' to control how close is \"the same point\".
Default span is 8.
The span can be changed temporarily with \\[universal-argument] right before \\[goto-last-change]:
\\[universal-argument] set current span to that number,
\\[universal-argument] (no number) multiplies span by 4, starting with default.
The so set span remains until it is changed again with \\[universal-argument], or the consecutive
repetition of this command is ended by any other command.
\nWhen span is zero (i.e. \\[universal-argument] 0) subsequent \\[goto-last-change] visits each and
every point of edit and a message shows what change was made there.
In this case it may go to the same point twice.
\nThis command uses undo information. If undo is disabled, so is this command.
At times, when undo information becomes too large, the oldest information is
discarded. See variable `undo-limit'."
(interactive "P")
(cond ((not (eq this-command last-command))
;; Start a glc sequence
;; Don't go to current point if last command was an obvious edit
;; (yank or self-insert, but not kill-region). Makes it easier to
;; jump back and forth when copying seleced lines.
(setq glc-probe-depth (if (memq last-command '(yank self-insert-command)) 1 0)
glc-direction 1
glc-current-span glc-default-span)
(if (< (prefix-numeric-value arg) 0)
(error "Negative arg: Cannot reverse as the first operation"))))
(cond ((and (null buffer-undo-list) (null buffer-undo-tree))
(error "Buffer has not been changed"))
((eq buffer-undo-list t)
(error "No change info (undo is disabled)")))
(cond ((numberp arg) ; Numeric arg sets span
(setq glc-current-span (abs arg)))
((consp arg) ; C-u's multiply previous span by 4
(setq glc-current-span (* (abs (car arg)) glc-default-span))
(message "Current span is %d chars" glc-current-span))) ;todo: keep message with "waiting" and "is saved"
(cond ((< (prefix-numeric-value arg) 0)
(setq glc-direction -1))
(t
(setq glc-direction 1)))
(let (rev ; Reversed (and filtered) undo list
pos ; The pos we look for, nil until found
(n 0) ; Steps in undo list (length of 'rev')
(l buffer-undo-list)
(passed-save-entry (not (buffer-modified-p)))
(new-probe-depth glc-probe-depth)
(undo-tree-p (bound-and-true-p undo-tree-mode))
glc-seen-canary)
;; Walk back and forth in the buffer-undo-list, each time one step deeper,
;; until we can walk back the whole list with a 'pos' that is not coming
;; too close to another edit.
(while (null pos)
(setq new-probe-depth (+ new-probe-depth glc-direction))
(if (< glc-direction 0)
(setq rev ()
n 0
l buffer-undo-list
passed-save-entry (not (buffer-modified-p))))
(if (< new-probe-depth 1)
(error "No later change info"))
(if (> n 150)
(message "working..."))
;; Walk forward in buffer-undo-list, glc-probe-depth steps.
;; Build reverse list along the way
(if (not undo-tree-p)
(while (< n new-probe-depth)
(cond ((null l)
;(setq this-command t) ; Disrupt repeat sequence
(error "No further change info"))
((glc-is-positionable (car l))
(setq n (1+ n)
rev (cons (car l) rev)))
((or passed-save-entry (glc-is-filetime (car l)))
(setq passed-save-entry t)))
(setq l (cdr l)))
(undo-list-transfer-to-tree)
(when (not glc-seen-canary)
(while (and (not (null l)) (not glc-seen-canary) (< n new-probe-depth))
(cond ((eq 'undo-tree-canary (car l)) ; used by buffer-undo-tree
(message "Canary found...")
(setq l (undo-tree-current buffer-undo-tree)
glc-seen-canary t))
((glc-is-positionable (car l))
(setq n (1+ n)
rev (cons (car l) rev)))
((or passed-save-entry (glc-is-filetime (car l)))
(setq passed-save-entry t)))
(when (not glc-seen-canary)
(setq l (cdr l)))))
(when glc-seen-canary
(while (and (< n new-probe-depth) (undo-tree-node-p l))
(cond ((null l)
;(setq this-command t) ; Disrupt repeat sequence
(error "No further change info"))
((glc-is-positionable (car (undo-tree-node-undo l)))
(setq n (1+ n)
rev (cons (car (undo-tree-node-undo l)) rev)))
((or passed-save-entry (glc-is-filetime (car (undo-tree-node-undo l))))
(setq passed-save-entry t)))
(setq l (undo-tree-node-previous l))))
(when (null l)
(error "No further change info")))
;; Walk back in reverse list, from older to newer edits.
;; Adjusting pos along the way.
(setq pos (glc-adjust-list rev)))
;; Found a place not previously visited, in 'pos'.
;; (An error have been issued if nothing (more) found.)
(if (> n 150)
(message nil)) ; remove message "working..."
(if (and (= glc-current-span 0) (glc-get-descript (car rev) n))
(message "%s" (glc-get-descript (car rev) n))
;; else
(if passed-save-entry
(message "(This change is saved)")))
(setq glc-probe-depth new-probe-depth)
(goto-char pos)))
;;;###autoload
(defun goto-last-change-reverse (arg)
"Go back to more recent changes after \\[goto-last-change] have been used.
See `goto-last-change' for use of prefix argument."
(interactive "P")
;; Negate arg, all kinds
(cond ((eq arg nil) (setq arg '-))
((eq arg '-) (setq arg nil))
((listp arg) (setq arg (list (- (car arg)))))
(t (setq arg (- arg))))
;; Make 'goto-last-change-reverse' look like 'goto-last-change'
(cond ((eq last-command this-command)
(setq last-command 'goto-last-change)))
(setq this-command 'goto-last-change)
;; Call 'goto-last-change' to do the job
(goto-last-change arg))
(provide 'goto-chg)
;;; goto-chg.el ends here