6 This file presents some general information about XEmacs. It is
7 primarily about the changes in recent XEmacs versions and its release
10 Use `C-c C-f' to move to the next equal level of outline, and
11 `C-c C-b' to move to previous equal level. `C-h m' will give more
12 info about the Outline mode. Many commands are also available through
15 Users who would like to know which capabilities have been introduced
16 in each release should look at the appropriate section of this file.
17 Starting with version 20.0, XEmacs includes ChangeLogs, which can be
18 consulted for a more detailed list of changes.
20 Users interested in some of the details of how XEmacs differs from GNU
21 Emacs should read the section "What's Different?" near the end of this
24 N.B. The term "GNU Emacs" refers to any release of Emacs Version
25 19 from the Free Software Foundation's GNU Project. (We do not
26 say just "Emacs" as Richard M. Stallman ["RMS"] prefers, because
27 it is clearly a more generic term.) The term "XEmacs" refers to
28 this program or to its predecessors "Era" and "Lucid Emacs". The
29 predecessor of all these program is called "Emacs 18". When no
30 particular version is implied, "Emacs" will be used.
33 * Changes in XEmacs 21.2
34 ========================
36 ** Interactive searching and matching case improvements:
37 Case sensitiveness in searching operations is controled by the variable
38 `case-fold-search' (if non-nil, case is ignored while searching). This
39 mechanism has now been slightly improved in the case of an interactive
40 search: if the search string (or regexp) happens to contain uppercase
41 characters, the searching is forced to be case-sensitive, regardless of
42 the value of `case-fold-search'. This behavior affects all functions
43 performing interactive searches, like `zap-to-char', `tags-search',
46 ** You can now create "indirect buffers", like in GNU Emacs. An
47 indirect buffer shares its text with another buffer ("base buffer"),
48 but has its own major mode, local variables, extents, and narrowing.
49 An indirect buffer has a name of its own, distinct from those of the
50 base buffer and all other buffers. An indirect buffer cannot itself
51 be visiting a file (though its base buffer can be). The base buffer
52 cannot itself be indirect.
54 Use (make-indirect-buffer BASE-BUFFER NAME) to make an indirect buffer
55 named NAME whose base is BASE-BUFFER. If BASE-BUFFER is an indirect
56 buffer, its base buffer is used as the base for the new buffer.
58 You can make an indirect buffer current, or switch to it in a window,
59 just as you would a non-indirect buffer.
61 The function `buffer-base-buffer', given an indirect buffer, returns
62 its base buffer. It returns nil when given an ordinary buffer (not
63 indirect). `buffer-indirect-children' returns a list of the indirect
64 children of a base buffer.
67 * Lisp and internal changes in XEmacs 21.2
68 ==========================================
70 ** Functions for decoding base64 encoding are now available; see
71 `base64-encode-region', `base64-encode-string', `base64-decode-region'
72 and `base64-decode-string'.
74 ** Many basic lisp operations are now faster.
75 This is especially the case when running a Mule-enabled XEmacs.
77 A general overhaul of the lisp engine should produce a speedup of 1.4
78 in a Latin-1 XEmacs, and 2.1 in a Mule XEmacs. These numbers were
79 obtained running (byte-compile "simple.el"), which should be a pretty
80 typical test of `pure' lisp.
82 Lisp hash tables have been re-implemented. The Common Lisp style hash
83 table interface has been made standard, and moved from cl.el into fast
84 C code (See the section on hash tables in the XEmacs Lisp Reference).
85 A speedup factor of 3 can be expected with code that makes intensive
88 The garbage collector has been tuned, leading to a speedup of 1.16.
90 The family of functions that iterate over lists, like `memq', and
91 `rassq', have been made a little faster (typically 1.3).
93 Lisp function calls are faster, by approximately a factor of two.
94 However, defining inline functions (via defsubst) still make sense.
96 And finally, a few functions have had dramatic performance
97 improvements. For example, (last long-list) is now 30 times faster.
99 Of course, your mileage will vary.
101 Many operations do not see any improvement. Surprisingly, running
102 (font-lock-refontify-buffer) does not use the Lisp engine much at all.
103 Speeding up your favorite slow operation is an excellent project to
104 improve XEmacs. Don't forget to profile!
106 ** XEmacs finally has an automated test suite!
107 Although this is not yet very sophisticated, it is already responsible
108 for several important bug fixes in XEmacs. To try it out, simply use
109 the makefile target `make check' after building XEmacs.
111 ** New hash table implementation
112 As was pointed out above, the standard interface to hash tables is now
113 the Common Lisp interface, as described in Common Lisp, the Language
114 (CLtL2, by Steele). The older interface (functions with names
115 containing the phrase `hashtable') will continue to work, but the
116 preferred interface now has names containing the phrase `hash-table'.
118 Here's the executive overview: create hash tables using
119 make-hash-table, and use gethash, puthash, remhash, maphash and
120 clrhash to manipulate entries in the hash table. See the (updated)
121 Lisp Reference Manual for details.
123 ** Lisp code handles circular lists much more robustly.
124 Many basic lisp functions used to loop forever when given a circular
125 list. Now this is more likely to trigger a `circular-list' error.
126 Printing a circular list now results in something like this:
128 (progn (setq x (cons 'foo 'foo)) (setcdr x x) x)
129 ==> (foo ... <circular list>)
131 An extra bonus is that checking for circularities is not just
132 friendlier, but actually faster than checking for quit.
135 * Changes in XEmacs 21.0
136 ========================
138 ** XEmacs has been unbundled into constituent installable packages.
139 See the Info documentation under "Packages" for more information.
140 See the file `etc/PACKAGES' in the distribution for a partial list of
141 packages available at the time of the 21.0 release.
143 ** XEmacs is now supported under Microsoft Windows 95/98 and Windows
144 NT operating systems. For starters, look at the XEmacs on Windows FAQ
145 at <URL:http://jagor.srce.hr/~hniksic/xemacs-on-windows-faq.txt>. To
146 discuss Windows-specific issues, subscribe to the mailing list at
147 <xemacs-nt-request@xemacs.org>.
149 ** XEmacs will now use `XEmacs' as its application class if it finds
150 any `XEmacs' resources in the resource database. Otherwise, it will
151 continue to use the `Emacs' class.
153 ** The options menu has been ported to Custom.
154 This means that each entry in the options menu acts as if you had customized
155 the corresponding variable by hand. ### WARNING: there is currently no
156 upgrading function to help you port your old options settings to the new
157 format. Consequently, if you want to modify the options for XEmacs 21, you
158 will have to set them all again through the menu, and remove the code loading
159 .xemacs-options from your .emacs.
161 ** When the Zmacs region is active, `M-x query-replace' and the other
162 replace commands now operate on the region contents only.
164 ** Using the new `-private' option, you can make XEmacs use a private
167 ** The `imenu' package has been ported to XEmacs and is available as a
170 ** `echo-keystrokes' can now be a floating-point number, so that you
171 can set it to intervals shorter than one second.
173 (setq echo-keystrokes 0.1)
175 ** The new command `center-to-window-line' works like `recenter'
176 (bound to `C-l'), only it does not redisplay the whole display area.
178 ** The M-. command will now first search through exact tags matches,
179 and then through inexact matches, as one would expect.
181 ** The new variable `user-full-name' can be used to customize one's
182 name when using the Emacs mail and news reading facilities.
184 Normally, `user-full-name' is a function that returns the full name of
185 a user or UID, as specified by the system -- for instance,
186 (user-full-name "root") returns something like "Super-User". However,
187 when the function is called without arguments, it will return the
188 value of the `user-full-name' variable. The `user-full-name' variable
189 is initialized using the environment variable NAME and (failing that)
190 the user's system name.
192 The behavior of the `user-full-name' function with an argument
193 specified is unchanged.
195 ** The new command `M-x customize-changed-options' lets you customize
196 all the options whose default values have changed in recent Emacs
197 versions. You specify a previous Emacs version number as argument,
198 and the command creates a customization buffer showing all the
199 customizable options whose default values were changed since that
202 If you don't specify a particular version number argument, then the
203 customization buffer shows all the customizable options for which
204 Emacs versions of changes are recorded.
206 ** The new command `add-log-convert' can be used to convert the
207 old-style (pre-20.3) ChangeLog buffers to new style, for
208 consistency. A reminder: if you wish to revert to old-style
209 ChangeLogs instead, customize the value of `add-log-time-format'
212 ** The new command `zap-up-to-char' is now available. It is similar
213 to `zap-to-char', except that it does not delete the searched-for
214 character. It is not bound to a key by default.
216 ** You can now store a number into a register with `C-u NUMBER C-x r n'
217 REG, increment it by INC with `C-u INC C-x r + REG' (to increment by
218 one, omit C-u INC), and insert it in the buffer with `C-x r g REG'.
219 This is useful for writing keyboard macros.
221 ** The M-: command, when given a prefix argument, will now insert its
222 result to the current buffer.
224 ** The `C-h c' command, when given a prefix argument, will now insert
225 the message into the current buffer.
227 ** Horizontally split windows may now be dragged using the mouse.
228 Because of this, the dividers between vertical windows are always
229 visible. To turn it off, set `vertical-divider-always-visible-p' to
232 ** XEmacs/Mule (internationalization) changes.
234 *** Mule support now works on TTY's. Use `set-terminal-coding-system'
235 and `set-keyboard-coding-system' to specify the coding system of your
236 display and keyboard.
238 *** Egg/SJ3 input method is now officially supported. Quail and
239 Egg/Skk have been available through the generalized Leim since 20.3.
241 *** Localized Japanese menubars are available if XEmacs is built with
242 XFONTSET and either the X11 libraries are built with X_LOCALE defined
243 or the native C libraries support Japanese localization. This has
244 been available since 20.3, only it hasn't been announced before.
246 ** Jamie Zawinski's `gdb-highlight' extension is now distributed with
247 the `debug' package. gdb-highlight makes most objects printed in a
248 gdb buffer be mouse-sensitive: as text shows up in the buffer, it is
249 parsed, and objects which are recognized have context-sensitive
250 commands attached to them. To use it, add the following to `.emacs':
252 (add-hook 'gdb-mode-hook (lambda () (require 'gdb-highlight)))
254 ** The package popper.el is now included in the edit-utils package.
255 It has been greatly enhanced with respect to the one once included
256 with the ilisp package and should work well under XEmacs 21.0.
260 *** Multiline macros are now handled, both as they affect indentation,
261 and as recognized syntax. New syntactic symbol cpp-macro-cont is
262 assigned to second and subsequent lines of a multiline macro
265 *** A new style "user" which captures all non-hook-ified
266 (i.e. top-level) .emacs file variable setings and customizations.
267 Style "cc-mode" is an alias for "user" and is deprecated. "gnu" style
268 is still the default however.
270 *** "java" style now conforms to Sun's JDK coding style.
272 *** There are new commands c-beginning-of-defun, c-end-of-defun which
273 are alternatives which you could bind to C-M-a and C-M-e if you prefer
274 them. They do not have key bindings by default.
276 *** New and improved implementations of M-a (c-beginning-of-statement)
277 and M-e (c-end-of-statement).
279 *** C++ namespace blocks are supported, with new syntactic symbols
280 namespace-open, namespace-close, and innamespace.
282 *** File local variable settings of c-file-style and c-file-offsets
283 makes the style variables local to that buffer only.
285 *** New indentation functions c-lineup-close-paren,
286 c-indent-one-line-block, c-lineup-dont-change.
288 *** Improvements (hopefully!) to the way CC Mode is loaded. You
289 should now be able to do a (require 'cc-mode) to get the entire
290 package loaded properly for customization in your .emacs file. A new
291 variable c-initialize-on-load controls this and is t by default.
293 ** In Text mode, now only blank lines separate paragraphs.
294 This makes it possible to get the full benefit of Adaptive Fill mode
295 in Text mode, and other modes derived from it (such as Mail mode).
296 TAB in Text mode now runs the command indent-relative; this makes a
297 practical difference only when you use indented paragraphs.
299 As a result, the old Indented Text mode is now identical to Text mode,
300 and is an alias for it.
302 If you want spaces at the beginning of a line to start a paragraph,
303 use the new mode, Paragraph Indent Text mode.
305 ** Changes to Gnus, the XEmacs newsreader.
307 *** New functionality for using Gnus as an offline newsreader has been
308 added. A plethora of new commands and modes have been added. See the
309 Gnus manual for the full story.
311 *** The nndraft backend has returned, but works differently than
312 before. All Message buffers are now also articles in the nndraft
313 group, which is created automatically.
315 *** `gnus-alter-header-function' can now be used to alter header
318 *** `gnus-summary-goto-article' now accept Message-ID's.
320 *** A new Message command for deleting text in the body of a message
321 outside the region: `C-c C-v'.
323 *** You can now post to component group in nnvirtual groups with
326 *** `nntp-rlogin-program' -- new variable to ease customization.
328 *** `C-u C-c C-c' in `gnus-article-edit-mode' will now inhibit
329 re-highlighting of the article buffer.
331 *** New element in `gnus-boring-article-headers' -- `long-to'.
333 *** `M-i' symbolic prefix command. See the section "Symbolic
334 Prefixes" in the Gnus manual for details.
336 *** `L' and `I' in the summary buffer now take the symbolic prefix
337 `a' to add the score rule to the "all.SCORE" file.
339 *** `gnus-simplify-subject-functions' variable to allow greater
340 control over simplification.
342 *** `A T' -- new command for fetching the current thread.
344 *** `/ T' -- new command for including the current thread in the
347 *** `M-RET' is a new Message command for breaking cited text.
349 *** \\1-expressions are now valid in `nnmail-split-methods'.
351 *** The `custom-face-lookup' function has been removed.
352 If you used this function in your initialization files, you must
353 rewrite them to use `face-spec-set' instead.
355 *** Cancelling now uses the current select method. Symbolic prefix
356 `a' forces normal posting method.
358 *** New command to translate M******** sm*rtq**t*s into proper text
361 *** For easier debugging of nntp, you can set `nntp-record-commands'
364 *** nntp now uses ~/.authinfo, a .netrc-like file, for controlling
365 where and how to send AUTHINFO to NNTP servers.
367 *** A command for editing group parameters from the summary buffer
370 *** A history of where mails have been split is available.
372 *** A new article date command has been added -- `article-date-iso8601'.
374 *** Subjects can be simplified when threading by setting
375 `gnus-score-thread-simplify'.
377 *** A new function for citing in Message has been added --
378 `message-cite-original-without-signature'.
380 *** `article-strip-all-blank-lines' -- new article command.
382 *** A new Message command to kill to the end of the article has
385 *** A minimum adaptive score can be specified by using the
386 `gnus-adaptive-word-minimum' variable.
388 *** The "lapsed date" article header can be kept continually
389 updated by the `gnus-start-date-timer' command.
391 *** Web listserv archives can be read with the nnlistserv backend.
393 *** Old dejanews archives can now be read by nnweb.
395 *** Byte-compilation of user-specs now works under XEmacs.
397 ** The `dir' files are no longer essential for functioning of the Info
398 subsystem. If the `dir' file does not exist in an Info directory, the
399 relevant information will be generated on-the-fly.
401 This behavior can be customized, look for `Info-auto-generate-directory'
402 and `Info-save-auto-generated-dir' in the `info' customization group.
405 * Lisp and internal changes in XEmacs 21.0
406 ==========================================
408 ** It is now possible to build XEmacs with support for 31-bit Lisp
409 integers (normally, Lisp integers are only 28 bits wide on 32-bit
410 machines.) Configure with --use-minimal-tagbits to test. With this
411 change, the maximum buffer size on 32-bit machines is increased from
412 128M to 1G. This setting will be made default in a future XEmacs
415 ** Specifier changes.
417 *** When instantiating a specifier, the window locale now has a higher
418 precedence than the buffer locale. This is because the window locale
419 is more specific than the buffer locale.
421 *** The new macro `let-specifier' can be used to temporarily add
422 specifications to specifiers. See the documentation for details.
424 *** The new specifiers `vertical-scrollbar-visible-p' and
425 `horizontal-scrollbar-visible-p' may be used to control scrollbar
426 visibility. Previously, the only way to remove a scrollbar was to set
427 its size to 0. This method is still supported for backward
430 *** The new specifiers `scrollbar-on-left-p' and `scrollbar-on-top-p'
431 may be used to control the position of the vertical and horizontal
432 toolbar. Previously, their position could be changed only through the
435 *** The new draggable vertical dividers between windows may be turned
436 off using the `vertical-divider-always-visible-p' specifier. When
437 this is set to nil, the vertical dividers between windows are shown
438 only when needed, and they are not draggable.
440 Other properties of the vertical dividers may be controlled using
441 `vertical-divider-shadow-thickness', `vertical-divider-line-width' and
442 `vertical-divider-spacing' specifiers, which see.
444 ** Frame focus management changes.
446 *** When the variable focus-follows-mouse is non-nil, `select-frame'
447 no longer permanently selects a different frame. The frame selection
448 is temporary and is reverted when the current command terminates, much
449 like the buffer selected by `set-buffer'. This is the same as in FSF
452 *** The new function `focus-frame' sets the window system focus to
453 FRAME (and selects it), regardless of the value of
454 `focus-follows-mouse'. Doing this is not well behaved, so be
455 absolutely sure that you want this.
457 The code that uses `select-frame' only to get the window manager focus
458 should be changed to use `set-frame-focus' instead, so that they keep
459 working when `focus-follows-mouse' is non-nil.
461 *** The special forms `save-selected-frame' and `with-selected-frame'
462 can now be used to temporarily change selected frame.
464 *** The behavior of `other-frame' command (`C-x 5 o') is unaffected by
467 ** The function `select-window' now has an optional second argument
468 NORECORD which if non-nil inhibits the recording of a buffer change.
470 ** The function `vertical-motion' now correctly handles the second,
471 optional WINDOW argument. A new third argument PIXELS, if non-nil,
472 indicates that the returned motion should be in pixels.
474 ** The new function `vertical-motion-pixels' is similar to
475 vertical-motion but takes as input a vertical motion in pixels.
477 ** The new functions window-text-area-pixel-{width,height,edges} can
478 be used to obtain information about the text-displaying area of a
481 ** The new functions `shrink-window-pixels' and `enlarge-window-pixels'
482 can be used to adjust the size of a window by a pixel amount.
484 ** The new function `window-displayed-text-pixel-height' can be used
485 to determine the height of the text actually displayed in a window.
487 ** The arithmetic comparison functions <, >, =, /= now accept a
488 variable number of arguments.
490 This means that if you want to test whether A < B < C, you can write
491 it as (< A B C) instead of (and (< A B) (< B C)). Likewise,
492 (apply #'> LIST) now tests if LIST is monotonously increasing -- and
495 ** The XEmacs hashtables now have a consistent read/print syntax.
496 This means that a hashtable will be readably printed in a
499 #s(hashtable size 2 data (key1 value1 key2 value2))
501 When XEmacs reads this form, it will create a new hashtable according
502 to description. This allows you to easily dump hashtables to files
503 using `prin1', and read them back in using `read'.
505 If `print-readably' is non-nil, a more relaxed syntax is used; for
508 #<hashtable size 2/13 data (key1 value1 key2 value2) 0x874d>
510 ** It is now possible to build XEmacs with LDAP support.
511 You will need to install a LDAP library first. The following have
513 - LDAP 3.3 from the University of Michigan
514 (get it from <URL:http://www.umich.edu/~dirsvcs/ldap/>)
515 - OpenLDAP 1.0.3 from the OpenLDAP Foundation
516 (get it from <URL:http://www.openldap.org/>)
517 - LDAP SDK 1.0 from Netscape Corp.
518 (get it from <URL:http://developer.netscape.com/>)
520 ** When profiling is in effect, a call-count of all recorded functions
521 is now calculated. This information is stored in
522 `call-count-profile-table', and is utilized by `profile-results' as
523 well as the new command `profile-call-count-results'.
525 ** It is now an error to change the value of a symbol whose name
526 starts with a colon, if it is interned in the standard obarray.
528 However, setting such a symbol to its proper value, which is that
529 symbol itself, is not an error. This is for the sake of programs that
530 support pre-19.12 XEmacs and pre-20 GNU Emacs by explicitly setting
531 these variables to themselves.
533 ** The `concat' function no longer accepts integer arguments.
535 ** The new function `string' concatenates all its argument characters
536 and returns the resulting string. This is consistent with other
537 functions, like `list', `vector', etc.
539 ** The function `temp-directory' is now available to return the
540 directory to store temporary files. On Unix this will be obtained
541 from TMPDIR, defaulting to `/tmp'.
543 ** The function load-average now accepts an optional argument
544 USE-FLOATS. If it is non-nil, the load average values are returned as
545 floating point numbers, rather than as integers to be divided by 100.
547 ** The `make-event' function now supports the TYPE and PLIST
548 arguments, which can be used to create various events from Lisp. See
549 the documentation for details.
551 ** `function-interactive' is a new function that returns the
552 interactive specification of a funcallable object.
554 ** The new `lmessage' function allows printing of a formatted message
555 with a particular label.
557 (lmessage 'progress "Processing... %d" counter)
559 This function is more convenient than `display-message' because it
560 automatically applies `format' to its arguments.
562 ** The new `lwarn' function, analogous to `lmessage', allows printing
563 a formatted warning, with a non-default CLASS or LABEL.
565 ** The new function `split-path' can now be used to explode the
566 components of a colon-separated search path into a list.
568 (split-path "foo:bar")
571 ** Specifiers and symbols whose value is a specifier are now allowed
572 as modeline specifications.
574 ** defcustom now accepts the keyword `:version'. Use this to specify
575 in which version of Emacs a certain variable's default value changed.
578 (defcustom foo-max 34 "*Maximum number of foo's allowed."
583 This information is used to control the customize-changed-options
586 ** The line number tracking in modeline is now efficient, even for
587 very large buffers. This is achieved by caching the line numbers of
588 recent buffer positions, and reusing them. This cache is used only in
589 the buffers where `line-number-mode' is in effect.
591 ** When the new GNU Malloc aka Doug Lea Malloc is available, it will
592 be used. This should result in better performance on Linux systems
595 ** The code XEmacs uses to assemble its various paths into the
596 directory hierarchy has been rewritten to support the package system.
597 Look under "Startup Paths" in the Info documentation for more
600 *** site-lisp is now longer part of the load-path by default.
601 Its use is deprecated, but you can specify --with-site-lisp=yes at the
602 configure command line to get it back.
604 *** `Info-default-directory-list' is now obsolete. If you want to
605 change the path which XEmacs uses to search for info files, set
606 `Info-directory-list' instead.