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 ** You can now create "indirect buffers", like in GNU Emacs. An
37 indirect buffer shares its text with another buffer ("base buffer"),
38 but has its own major mode, local variables, extents, and narrowing.
39 An indirect buffer has a name of its own, distinct from those of the
40 base buffer and all other buffers. An indirect buffer cannot itself
41 be visiting a file (though its base buffer can be). The base buffer
42 cannot itself be indirect.
44 Use (make-indirect-buffer BASE-BUFFER NAME) to make an indirect buffer
45 named NAME whose base is BASE-BUFFER. If BASE-BUFFER is an indirect
46 buffer, its base buffer is used as the base for the new buffer.
48 You can make an indirect buffer current, or switch to it in a window,
49 just as you would a non-indirect buffer.
51 The function `buffer-base-buffer', given an indirect buffer, returns
52 its base buffer. It returns nil when given an ordinary buffer (not
53 indirect). `buffer-indirect-children' returns a list of the indirect
54 children of a base buffer.
57 * Lisp and internal changes in XEmacs 21.2
58 ==========================================
60 ** Functions for decoding base64 encoding are now available; see
61 `base64-encode-region', `base64-encode-string', `base64-decode-region'
62 and `base64-decode-string'.
64 ** Many basic lisp operations are now faster.
65 This is especially the case when running a Mule-enabled XEmacs.
67 A general overhaul of the lisp engine should produce a speedup of 1.4
68 in a Latin-1 XEmacs, and 2.1 in a Mule XEmacs. These numbers were
69 obtained running (byte-compile "simple.el"), which should be a pretty
70 typical test of `pure' lisp.
72 Lisp hash tables have been re-implemented. The Common Lisp style hash
73 table interface has been made standard, and moved from cl.el into fast
74 C code (See the section on hash tables in the XEmacs Lisp Reference).
75 A speedup factor of 3 can be expected with code that makes intensive
78 The garbage collector has been tuned, leading to a speedup of 1.16.
80 The family of functions that iterate over lists, like `memq', and
81 `rassq', have been made a little faster (typically 1.3).
83 Lisp function calls are faster, by approximately a factor of two.
84 However, defining inline functions (via defsubst) still make sense.
86 And finally, a few functions have had dramatic performance
87 improvements. For example, (last long-list) is now 30 times faster.
89 Of course, your mileage will vary.
91 Many operations do not see any improvement. Surprisingly, running
92 (font-lock-refontify-buffer) does not use the Lisp engine much at all.
93 Speeding up your favorite slow operation is an excellent project to
94 improve XEmacs. Don't forget to profile!
96 ** XEmacs finally has an automated test suite!
97 Although this is not yet very sophisticated, it is already responsible
98 for several important bug fixes in XEmacs. To try it out, simply use
99 the makefile target `make check' after building XEmacs.
101 ** New hash table implementation
102 As was pointed out above, the standard interface to hash tables is now
103 the Common Lisp interface, as described in Common Lisp, the Language
104 (CLtL2, by Steele). The older interface (functions with names
105 containing the phrase `hashtable') will continue to work, but the
106 preferred interface now has names containing the phrase `hash-table'.
108 Here's the executive overview: create hash tables using
109 make-hash-table, and use gethash, puthash, remhash, maphash and
110 clrhash to manipulate entries in the hash table. See the (updated)
111 Lisp Reference Manual for details.
113 ** Lisp code handles circular lists much more robustly.
114 Many basic lisp functions used to loop forever when given a circular
115 list. Now this is more likely to trigger a `circular-list' error.
116 Printing a circular list now results in something like this:
118 (progn (setq x (cons 'foo 'foo)) (setcdr x x) x)
119 ==> (foo ... <circular list>)
121 An extra bonus is that checking for circularities is not just
122 friendlier, but actually faster than checking for quit.
125 * Changes in XEmacs 21.0
126 ========================
128 ** XEmacs has been unbundled into constituent installable packages.
129 See the Info documentation under "Packages" for more information.
130 See the file `etc/PACKAGES' in the distribution for a partial list of
131 packages available at the time of the 21.0 release.
133 ** XEmacs is now supported under Microsoft Windows 95/98 and Windows
134 NT operating systems. For starters, look at the XEmacs on Windows FAQ
135 at <URL:http://jagor.srce.hr/~hniksic/xemacs-on-windows-faq.txt>. To
136 discuss Windows-specific issues, subscribe to the mailing list at
137 <xemacs-nt-request@xemacs.org>.
139 ** XEmacs will now use `XEmacs' as its application class if it finds
140 any `XEmacs' resources in the resource database. Otherwise, it will
141 continue to use the `Emacs' class.
143 ** The options menu has been ported to Custom.
144 This means that each entry in the options menu acts as if you had customized
145 the corresponding variable by hand. ### WARNING: there is currently no
146 upgrading function to help you port your old options settings to the new
147 format. Consequently, if you want to modify the options for XEmacs 21, you
148 will have to set them all again through the menu, and remove the code loading
149 .xemacs-options from your .emacs.
151 ** When the Zmacs region is active, `M-x query-replace' and the other
152 replace commands now operate on the region contents only.
154 ** Using the new `-private' option, you can make XEmacs use a private
157 ** The `imenu' package has been ported to XEmacs and is available as a
160 ** `echo-keystrokes' can now be a floating-point number, so that you
161 can set it to intervals shorter than one second.
163 (setq echo-keystrokes 0.1)
165 ** The new command `center-to-window-line' works like `recenter'
166 (bound to `C-l'), only it does not redisplay the whole display area.
168 ** The M-. command will now first search through exact tags matches,
169 and then through inexact matches, as one would expect.
171 ** The new variable `user-full-name' can be used to customize one's
172 name when using the Emacs mail and news reading facilities.
174 Normally, `user-full-name' is a function that returns the full name of
175 a user or UID, as specified by the system -- for instance,
176 (user-full-name "root") returns something like "Super-User". However,
177 when the function is called without arguments, it will return the
178 value of the `user-full-name' variable. The `user-full-name' variable
179 is initialized using the environment variable NAME and (failing that)
180 the user's system name.
182 The behavior of the `user-full-name' function with an argument
183 specified is unchanged.
185 ** The new command `M-x customize-changed-options' lets you customize
186 all the options whose default values have changed in recent Emacs
187 versions. You specify a previous Emacs version number as argument,
188 and the command creates a customization buffer showing all the
189 customizable options whose default values were changed since that
192 If you don't specify a particular version number argument, then the
193 customization buffer shows all the customizable options for which
194 Emacs versions of changes are recorded.
196 ** The new command `add-log-convert' can be used to convert the
197 old-style (pre-20.3) ChangeLog buffers to new style, for
198 consistency. A reminder: if you wish to revert to old-style
199 ChangeLogs instead, customize the value of `add-log-time-format'
202 ** The new command `zap-up-to-char' is now available. It is similar
203 to `zap-to-char', except that it does not delete the searched-for
204 character. It is not bound to a key by default.
206 ** You can now store a number into a register with `C-u NUMBER C-x r n'
207 REG, increment it by INC with `C-u INC C-x r + REG' (to increment by
208 one, omit C-u INC), and insert it in the buffer with `C-x r g REG'.
209 This is useful for writing keyboard macros.
211 ** The M-: command, when given a prefix argument, will now insert its
212 result to the current buffer.
214 ** The `C-h c' command, when given a prefix argument, will now insert
215 the message into the current buffer.
217 ** Horizontally split windows may now be dragged using the mouse.
218 Because of this, the dividers between vertical windows are always
219 visible. To turn it off, set `vertical-divider-always-visible-p' to
222 ** XEmacs/Mule (internationalization) changes.
224 *** Mule support now works on TTY's. Use `set-terminal-coding-system'
225 and `set-keyboard-coding-system' to specify the coding system of your
226 display and keyboard.
228 *** Egg/SJ3 input method is now officially supported. Quail and
229 Egg/Skk have been available through the generalized Leim since 20.3.
231 *** Localized Japanese menubars are available if XEmacs is built with
232 XFONTSET and either the X11 libraries are built with X_LOCALE defined
233 or the native C libraries support Japanese localization. This has
234 been available since 20.3, only it hasn't been announced before.
236 ** Jamie Zawinski's `gdb-highlight' extension is now distributed with
237 the `debug' package. gdb-highlight makes most objects printed in a
238 gdb buffer be mouse-sensitive: as text shows up in the buffer, it is
239 parsed, and objects which are recognized have context-sensitive
240 commands attached to them. To use it, add the following to `.emacs':
242 (add-hook 'gdb-mode-hook (lambda () (require 'gdb-highlight)))
244 ** The package popper.el is now included in the edit-utils package.
245 It has been greatly enhanced with respect to the one once included
246 with the ilisp package and should work well under XEmacs 21.0.
250 *** Multiline macros are now handled, both as they affect indentation,
251 and as recognized syntax. New syntactic symbol cpp-macro-cont is
252 assigned to second and subsequent lines of a multiline macro
255 *** A new style "user" which captures all non-hook-ified
256 (i.e. top-level) .emacs file variable setings and customizations.
257 Style "cc-mode" is an alias for "user" and is deprecated. "gnu" style
258 is still the default however.
260 *** "java" style now conforms to Sun's JDK coding style.
262 *** There are new commands c-beginning-of-defun, c-end-of-defun which
263 are alternatives which you could bind to C-M-a and C-M-e if you prefer
264 them. They do not have key bindings by default.
266 *** New and improved implementations of M-a (c-beginning-of-statement)
267 and M-e (c-end-of-statement).
269 *** C++ namespace blocks are supported, with new syntactic symbols
270 namespace-open, namespace-close, and innamespace.
272 *** File local variable settings of c-file-style and c-file-offsets
273 makes the style variables local to that buffer only.
275 *** New indentation functions c-lineup-close-paren,
276 c-indent-one-line-block, c-lineup-dont-change.
278 *** Improvements (hopefully!) to the way CC Mode is loaded. You
279 should now be able to do a (require 'cc-mode) to get the entire
280 package loaded properly for customization in your .emacs file. A new
281 variable c-initialize-on-load controls this and is t by default.
283 ** In Text mode, now only blank lines separate paragraphs.
284 This makes it possible to get the full benefit of Adaptive Fill mode
285 in Text mode, and other modes derived from it (such as Mail mode).
286 TAB in Text mode now runs the command indent-relative; this makes a
287 practical difference only when you use indented paragraphs.
289 As a result, the old Indented Text mode is now identical to Text mode,
290 and is an alias for it.
292 If you want spaces at the beginning of a line to start a paragraph,
293 use the new mode, Paragraph Indent Text mode.
295 ** Changes to Gnus, the XEmacs newsreader.
297 *** New functionality for using Gnus as an offline newsreader has been
298 added. A plethora of new commands and modes have been added. See the
299 Gnus manual for the full story.
301 *** The nndraft backend has returned, but works differently than
302 before. All Message buffers are now also articles in the nndraft
303 group, which is created automatically.
305 *** `gnus-alter-header-function' can now be used to alter header
308 *** `gnus-summary-goto-article' now accept Message-ID's.
310 *** A new Message command for deleting text in the body of a message
311 outside the region: `C-c C-v'.
313 *** You can now post to component group in nnvirtual groups with
316 *** `nntp-rlogin-program' -- new variable to ease customization.
318 *** `C-u C-c C-c' in `gnus-article-edit-mode' will now inhibit
319 re-highlighting of the article buffer.
321 *** New element in `gnus-boring-article-headers' -- `long-to'.
323 *** `M-i' symbolic prefix command. See the section "Symbolic
324 Prefixes" in the Gnus manual for details.
326 *** `L' and `I' in the summary buffer now take the symbolic prefix
327 `a' to add the score rule to the "all.SCORE" file.
329 *** `gnus-simplify-subject-functions' variable to allow greater
330 control over simplification.
332 *** `A T' -- new command for fetching the current thread.
334 *** `/ T' -- new command for including the current thread in the
337 *** `M-RET' is a new Message command for breaking cited text.
339 *** \\1-expressions are now valid in `nnmail-split-methods'.
341 *** The `custom-face-lookup' function has been removed.
342 If you used this function in your initialization files, you must
343 rewrite them to use `face-spec-set' instead.
345 *** Cancelling now uses the current select method. Symbolic prefix
346 `a' forces normal posting method.
348 *** New command to translate M******** sm*rtq**t*s into proper text
351 *** For easier debugging of nntp, you can set `nntp-record-commands'
354 *** nntp now uses ~/.authinfo, a .netrc-like file, for controlling
355 where and how to send AUTHINFO to NNTP servers.
357 *** A command for editing group parameters from the summary buffer
360 *** A history of where mails have been split is available.
362 *** A new article date command has been added -- `article-date-iso8601'.
364 *** Subjects can be simplified when threading by setting
365 `gnus-score-thread-simplify'.
367 *** A new function for citing in Message has been added --
368 `message-cite-original-without-signature'.
370 *** `article-strip-all-blank-lines' -- new article command.
372 *** A new Message command to kill to the end of the article has
375 *** A minimum adaptive score can be specified by using the
376 `gnus-adaptive-word-minimum' variable.
378 *** The "lapsed date" article header can be kept continually
379 updated by the `gnus-start-date-timer' command.
381 *** Web listserv archives can be read with the nnlistserv backend.
383 *** Old dejanews archives can now be read by nnweb.
385 *** Byte-compilation of user-specs now works under XEmacs.
387 ** The `dir' files are no longer essential for functioning of the Info
388 subsystem. If the `dir' file does not exist in an Info directory, the
389 relevant information will be generated on-the-fly.
391 This behavior can be customized, look for `Info-auto-generate-directory'
392 and `Info-save-auto-generated-dir' in the `info' customization group.
395 * Lisp and internal changes in XEmacs 21.0
396 ==========================================
398 ** It is now possible to build XEmacs with support for 31-bit Lisp
399 integers (normally, Lisp integers are only 28 bits wide on 32-bit
400 machines.) Configure with --use-minimal-tagbits to test. With this
401 change, the maximum buffer size on 32-bit machines is increased from
402 128M to 1G. This setting will be made default in a future XEmacs
405 ** Specifier changes.
407 *** When instantiating a specifier, the window locale now has a higher
408 precedence than the buffer locale. This is because the window locale
409 is more specific than the buffer locale.
411 *** The new macro `let-specifier' can be used to temporarily add
412 specifications to specifiers. See the documentation for details.
414 *** The new specifiers `vertical-scrollbar-visible-p' and
415 `horizontal-scrollbar-visible-p' may be used to control scrollbar
416 visibility. Previously, the only way to remove a scrollbar was to set
417 its size to 0. This method is still supported for backward
420 *** The new specifiers `scrollbar-on-left-p' and `scrollbar-on-top-p'
421 may be used to control the position of the vertical and horizontal
422 toolbar. Previously, their position could be changed only through the
425 *** The new draggable vertical dividers between windows may be turned
426 off using the `vertical-divider-always-visible-p' specifier. When
427 this is set to nil, the vertical dividers between windows are shown
428 only when needed, and they are not draggable.
430 Other properties of the vertical dividers may be controlled using
431 `vertical-divider-shadow-thickness', `vertical-divider-line-width' and
432 `vertical-divider-spacing' specifiers, which see.
434 ** Frame focus management changes.
436 *** When the variable focus-follows-mouse is non-nil, `select-frame'
437 no longer permanently selects a different frame. The frame selection
438 is temporary and is reverted when the current command terminates, much
439 like the buffer selected by `set-buffer'. This is the same as in FSF
442 *** The new function `focus-frame' sets the window system focus to
443 FRAME (and selects it), regardless of the value of
444 `focus-follows-mouse'. Doing this is not well behaved, so be
445 absolutely sure that you want this.
447 The code that uses `select-frame' only to get the window manager focus
448 should be changed to use `set-frame-focus' instead, so that they keep
449 working when `focus-follows-mouse' is non-nil.
451 *** The special forms `save-selected-frame' and `with-selected-frame'
452 can now be used to temporarily change selected frame.
454 *** The behavior of `other-frame' command (`C-x 5 o') is unaffected by
457 ** The function `select-window' now has an optional second argument
458 NORECORD which if non-nil inhibits the recording of a buffer change.
460 ** The function `vertical-motion' now correctly handles the second,
461 optional WINDOW argument. A new third argument PIXELS, if non-nil,
462 indicates that the returned motion should be in pixels.
464 ** The new function `vertical-motion-pixels' is similar to
465 vertical-motion but takes as input a vertical motion in pixels.
467 ** The new functions window-text-area-pixel-{width,height,edges} can
468 be used to obtain information about the text-displaying area of a
471 ** The new functions `shrink-window-pixels' and `enlarge-window-pixels'
472 can be used to adjust the size of a window by a pixel amount.
474 ** The new function `window-displayed-text-pixel-height' can be used
475 to determine the height of the text actually displayed in a window.
477 ** The arithmetic comparison functions <, >, =, /= now accept a
478 variable number of arguments.
480 This means that if you want to test whether A < B < C, you can write
481 it as (< A B C) instead of (and (< A B) (< B C)). Likewise,
482 (apply #'> LIST) now tests if LIST is monotonously increasing -- and
485 ** The XEmacs hashtables now have a consistent read/print syntax.
486 This means that a hashtable will be readably printed in a
489 #s(hashtable size 2 data (key1 value1 key2 value2))
491 When XEmacs reads this form, it will create a new hashtable according
492 to description. This allows you to easily dump hashtables to files
493 using `prin1', and read them back in using `read'.
495 If `print-readably' is non-nil, a more relaxed syntax is used; for
498 #<hashtable size 2/13 data (key1 value1 key2 value2) 0x874d>
500 ** It is now possible to build XEmacs with LDAP support.
501 You will need to install a LDAP library first. The following have
503 - LDAP 3.3 from the University of Michigan
504 (get it from <URL:http://www.umich.edu/~dirsvcs/ldap/>)
505 - OpenLDAP 1.0.3 from the OpenLDAP Foundation
506 (get it from <URL:http://www.openldap.org/>)
507 - LDAP SDK 1.0 from Netscape Corp.
508 (get it from <URL:http://developer.netscape.com/>)
510 ** When profiling is in effect, a call-count of all recorded functions
511 is now calculated. This information is stored in
512 `call-count-profile-table', and is utilized by `profile-results' as
513 well as the new command `profile-call-count-results'.
515 ** It is now an error to change the value of a symbol whose name
516 starts with a colon, if it is interned in the standard obarray.
518 However, setting such a symbol to its proper value, which is that
519 symbol itself, is not an error. This is for the sake of programs that
520 support pre-19.12 XEmacs and pre-20 GNU Emacs by explicitly setting
521 these variables to themselves.
523 ** The `concat' function no longer accepts integer arguments.
525 ** The new function `string' concatenates all its argument characters
526 and returns the resulting string. This is consistent with other
527 functions, like `list', `vector', etc.
529 ** The function `temp-directory' is now available to return the
530 directory to store temporary files. On Unix this will be obtained
531 from TMPDIR, defaulting to `/tmp'.
533 ** The function load-average now accepts an optional argument
534 USE-FLOATS. If it is non-nil, the load average values are returned as
535 floating point numbers, rather than as integers to be divided by 100.
537 ** The `make-event' function now supports the TYPE and PLIST
538 arguments, which can be used to create various events from Lisp. See
539 the documentation for details.
541 ** `function-interactive' is a new function that returns the
542 interactive specification of a funcallable object.
544 ** The new `lmessage' function allows printing of a formatted message
545 with a particular label.
547 (lmessage 'progress "Processing... %d" counter)
549 This function is more convenient than `display-message' because it
550 automatically applies `format' to its arguments.
552 ** The new `lwarn' function, analogous to `lmessage', allows printing
553 a formatted warning, with a non-default CLASS or LABEL.
555 ** The new function `split-path' can now be used to explode the
556 components of a colon-separated search path into a list.
558 (split-path "foo:bar")
561 ** Specifiers and symbols whose value is a specifier are now allowed
562 as modeline specifications.
564 ** defcustom now accepts the keyword `:version'. Use this to specify
565 in which version of Emacs a certain variable's default value changed.
568 (defcustom foo-max 34 "*Maximum number of foo's allowed."
573 This information is used to control the customize-changed-options
576 ** The line number tracking in modeline is now efficient, even for
577 very large buffers. This is achieved by caching the line numbers of
578 recent buffer positions, and reusing them. This cache is used only in
579 the buffers where `line-number-mode' is in effect.
581 ** When the new GNU Malloc aka Doug Lea Malloc is available, it will
582 be used. This should result in better performance on Linux systems
585 ** The code XEmacs uses to assemble its various paths into the
586 directory hierarchy has been rewritten to support the package system.
587 Look under "Startup Paths" in the Info documentation for more
590 *** site-lisp is now longer part of the load-path by default.
591 Its use is deprecated, but you can specify --with-site-lisp=yes at the
592 configure command line to get it back.
594 *** `Info-default-directory-list' is now obsolete. If you want to
595 change the path which XEmacs uses to search for info files, set
596 `Info-directory-list' instead.