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 ** XEmacs now locates the early package hierarchy at ~/.xemacs/packages.
38 This has changed from simply ~/.xemacs.
40 ** `delete-key-deletes-forward' now defaults to t.
42 `delete-key-deletes-forward' is the variable that regulates the
43 behaviour of the delete key on the systems that offer both a backspace
44 and a delete key. If set to nil, the key labeled "Delete" will delete
45 backward. If set to non-nil, the "Delete" key will delete forward,
46 except on keyboards where a "Backspace" key is not provided.
48 Unless our implementation has bugs, the only reason why you would want
49 to set `delete-key-deletes-forward' to nil is if you want to use the
50 Delete key to delete backwards, despite the presence (according to
51 Xlib) of a BackSpace key on the keyboard.
53 ** Interactive searching and matching case improvements.
55 Case sensitiveness in searching operations is normally controlled by
56 the variable `case-fold-search' (if non-nil, case is ignored while
57 searching). This mechanism has now been slightly improved for
58 interactive searches: if the search string (or regexp) contains
59 uppercase characters, the searching is forced to be case-sensitive,
62 The new behavior affects all functions performing interactive
63 searches, like `zap-to-char', `list-matching-lines', `tags-search'
64 etc. The incremental search facility has always behaved that way.
66 ** You can now create "indirect buffers", like in GNU Emacs. An
67 indirect buffer shares its text with another buffer ("base buffer"),
68 but has its own major mode, local variables, extents, and narrowing.
69 An indirect buffer has a name of its own, distinct from those of the
70 base buffer and all other buffers. An indirect buffer cannot itself
71 be visiting a file (though its base buffer can be). The base buffer
72 cannot itself be indirect.
74 Use (make-indirect-buffer BASE-BUFFER NAME) to make an indirect buffer
75 named NAME whose base is BASE-BUFFER. If BASE-BUFFER is itself an
76 indirect buffer, its base buffer is used as the base for the new
79 You can make an indirect buffer current, or switch to it in a window,
80 just as you would a non-indirect buffer.
82 The function `buffer-base-buffer' returns a buffer's base buffer or
83 nil, if given an ordinary (non-indirect) buffer. The function
84 `buffer-indirect-children' returns a list of the indirect children of
87 ** User names following the tilde character can now be completed at
88 file name prompts; e.g. `C-x C-f ~hni<TAB>' will complete to
89 `~hniksic/'. To make this operation faster, a cache of user names is
90 maintained internally.
92 The new primitives available for this purpose are functions named
93 `user-name-completion' and `user-name-all-completions'.
95 ** Native widgets can be displayed in buffers.
97 The glyph system has been extended to allow the display of glyphs that
98 are implemented as native window-system widgets. Thus you can embed
99 buttons, scrollbars, combo boxes, edit fields and progress gauges in a
100 buffer. As a side effect subwindow support now works once again.
102 This support is currently only available under MS-Windows.
104 ** X-Face support is now available under MS-Windows
106 If an X-Face libary built under MS-Windows is available then XEmacs
107 will use this at build time.
109 ** The font-menu is now available under MS-Windows
111 ** MS-Windows support for selection is much more robust
113 Generally selection should now do what you would expect under
114 MS-Windows: the middle mouse button will paste your current selection
115 or the clipboard; conversions from different types of selection to the
116 clipboard can be made; the kill-ring and friends will be updated as
119 The only thing selection doesn't do is set the clipboard automatically
120 as this would break the MS-Windows model. If you want this behaviour
121 then set `selection-sets-clipboard' to t
124 * Lisp and internal changes in XEmacs 21.2
125 ==========================================
127 ** Much effort has been invested to make XEmacs Lisp faster:
129 *** Many basic lisp operations are now faster.
130 This is especially the case when running a Mule-enabled XEmacs.
132 A general overhaul of the lisp engine should produce a speedup of 1.4
133 in a Latin-1 XEmacs, and 2.1 in a Mule XEmacs. These numbers were
134 obtained running `(byte-compile "simple.el")', which should be a
135 pretty typical test of "pure" Lisp.
137 *** Lisp hash tables have been re-implemented. The Common Lisp style
138 hash table interface has been made standard, and moved from cl.el into
139 fast C code (See the section on hash tables in the XEmacs Lisp
140 Reference). A speedup factor of 3 can be expected with code that
141 makes intensive use of hash tables.
143 *** The garbage collector has been tuned, leading to a speedup of
146 *** The family of functions that iterate over lists, like `memq', and
147 `rassq', have been made a little faster (typically 1.3).
149 *** Lisp function calls are faster, by approximately a factor of two.
150 However, defining inline functions (via defsubst) still makes sense
153 *** Finally, a few functions have had dramatic performance
154 improvements. For example, `(last long-list)' is now 30 times faster.
156 Of course, your mileage will vary.
158 Many operations do not see any improvement. Surprisingly, running
159 (font-lock-fontify-buffer) does not use the Lisp engine much at all.
160 Speeding up your favorite slow operation is an excellent project to
161 improve XEmacs. Don't forget to profile!
163 ** XEmacs finally has an automated test suite!
164 Although this is not yet very sophisticated, it is already responsible
165 for several important bug fixes in XEmacs. To try it out, simply use
166 the makefile target `make check' after building XEmacs.
168 ** Hash tables have been reimplemented.
169 As was pointed out above, the standard interface to hash tables is now
170 the Common Lisp interface, as described in Common Lisp, the Language
171 (CLtL2, by Steele). The older interface (functions with names
172 containing the phrase `hashtable') will continue to work, but the
173 preferred interface now has names containing the phrase `hash-table'.
175 Here's the executive overview: create hash tables using
176 make-hash-table, and use gethash, puthash, remhash, maphash and
177 clrhash to manipulate entries in the hash table. See the (updated)
178 Lisp Reference Manual for details.
180 ** Lisp code handles circular lists much more robustly.
181 Many basic lisp functions used to loop forever when given a circular
182 list, expecting you to C-g (quit) out of the loop. Now this is more
183 likely to trigger a `circular-list' error. Printing a circular list
184 now results in something like this:
186 (let ((x (cons 'foo 'foo)))
189 => (foo ... <circular list>)
191 An extra bonus is that checking for circularities is not just
192 friendlier, but actually faster than checking for C-g.
194 ** The new form `ignore-file-errors', similar to `ignore-errors' may
195 be used as a short-hand for condition-case when you wish to ignore
196 file-related error. For example:
198 (ignore-file-errors (delete-file "foo"))
200 ** The arguments to `locate-file' are now much more "lispy". As
201 before, the usage is:
203 (locate-file FILENAME PATH-LIST &optional SUFFIXES MODE)
205 Except that SUFFIXES are now a list of strings instead of a single,
206 colon-separated string. MODE is now a symbol or a list of symbols
207 (symbols `exists', `executable', `writable', and `readable' are
208 supported) instead of an integer code. See the documentation for
211 Of course, the old form is still accepted for backward compatibility.
213 ** `translate-region' has been improved in several ways. Its TABLE
214 argument used to be a 256-character string. In addition to this, it
215 can now also be a vector or a char-table (which is useful for Mule.)
216 If TABLE a vector or a generic char-table, you can map characters to
217 strings instead of to other characters. For instance:
219 (let ((table (make-char-table 'generic)))
220 (put-char-table ?a "the letter a" table)
221 (put-char-table ?b "" table)
222 (put-char-table ?c ?\n table)
223 (translate-region (point-min) (point-max) table))
225 ** The `keywordp' function now returns non-nil only on symbols
226 interned in the global obarray. For example:
228 (keywordp (intern ":foo" [0]))
230 (keywordp (intern ":foo")) ; The same as (keywordp :foo)
233 This behaviour is compatible with other code which treats symbols
234 beginning with colon as keywords only if they are interned in the
235 global obarray. `keywordp' used to wrongly return t in both cases
238 ** The first argument to `intern-soft' may now also be a symbol, like
239 with `unintern'. If given a symbol, `intern-soft' will look for that
240 exact symbol rather than for any string. This is useful when you want
241 to check whether a specific symbol is interned in an obarray, e.g.:
246 (intern-soft (make-symbol "foo"))
249 ** Functions for decoding base64 encoding are now available; see
250 `base64-encode-region', `base64-encode-string', `base64-decode-region'
251 and `base64-decode-string'.
254 * Changes in XEmacs 21.0
255 ========================
257 ** XEmacs has been unbundled into constituent installable packages.
258 See the Info documentation under "Packages" for more information.
259 See the file `etc/PACKAGES' in the distribution for a partial list of
260 packages available at the time of the 21.0 release.
262 ** XEmacs is now supported under Microsoft Windows 95/98 and Windows
263 NT operating systems. For starters, look at the XEmacs on Windows FAQ
264 at <URL:http://jagor.srce.hr/~hniksic/xemacs-on-windows-faq.txt>. To
265 discuss Windows-specific issues, subscribe to the mailing list at
266 <xemacs-nt-request@xemacs.org>.
268 ** XEmacs will now use `XEmacs' as its application class if it finds
269 any `XEmacs' resources in the resource database. Otherwise, it will
270 continue to use the `Emacs' class.
272 ** The options menu has been ported to Custom.
273 This means that each entry in the options menu acts as if you had customized
274 the corresponding variable by hand. ### WARNING: there is currently no
275 upgrading function to help you port your old options settings to the new
276 format. Consequently, if you want to modify the options for XEmacs 21, you
277 will have to set them all again through the menu, and remove the code loading
278 .xemacs-options from your .emacs.
280 ** When the Zmacs region is active, `M-x query-replace' and the other
281 replace commands now operate on the region contents only.
283 ** XEmacs now is able to choose X visuals and use private colormaps.
284 The '-visual <visualStr>' command line option or the '.EmacsVisual'
285 Xresource controls which visual XEmacs will use, and
286 '-privateColormap' or '.privateColormap' will force XEmacs to create a
287 private colormap for use. The syntax for the visual string is
288 "<visual><bitdepth>" where <visual> is one of 'StaticColor',
289 'TrueColor', 'GrayScale', 'PseudoColor' or 'DirectColor' and
290 <bitdepth> is the appropriate number of bits per pixel. If an invalid
291 or non-supported combination is entered, XEmacs attempts to find a happy
292 medium. The X creation mechanism will then determine if it needs to
293 create a colormap for use, or the presence of the private flags will
294 force it to create it.
296 ** The `imenu' package has been ported to XEmacs and is available as a
299 ** `echo-keystrokes' can now be a floating-point number, so that you
300 can set it to intervals shorter than one second.
302 (setq echo-keystrokes 0.1)
304 ** The new command `center-to-window-line' works like `recenter'
305 (bound to `C-l'), only it does not redisplay the whole display area.
307 ** The M-. command will now first search through exact tags matches,
308 and then through inexact matches, as one would expect.
310 ** The new variable `user-full-name' can be used to customize one's
311 name when using the Emacs mail and news reading facilities.
313 Normally, `user-full-name' is a function that returns the full name of
314 a user or UID, as specified by the system -- for instance,
315 (user-full-name "root") returns something like "Super-User". However,
316 when the function is called without arguments, it will return the
317 value of the `user-full-name' variable. The `user-full-name' variable
318 is initialized using the environment variable NAME and (failing that)
319 the user's system name.
321 The behavior of the `user-full-name' function with an argument
322 specified is unchanged.
324 ** The new command `M-x customize-changed-options' lets you customize
325 all the options whose default values have changed in recent Emacs
326 versions. You specify a previous Emacs version number as argument,
327 and the command creates a customization buffer showing all the
328 customizable options whose default values were changed since that
331 If you don't specify a particular version number argument, then the
332 customization buffer shows all the customizable options for which
333 Emacs versions of changes are recorded.
335 ** The new command `add-log-convert' can be used to convert the
336 old-style (pre-20.3) ChangeLog buffers to new style, for
337 consistency. A reminder: if you wish to revert to old-style
338 ChangeLogs instead, customize the value of `add-log-time-format'
341 ** The new command `zap-up-to-char' is now available. It is similar
342 to `zap-to-char', except that it does not delete the searched-for
343 character. It is not bound to a key by default.
345 ** You can now store a number into a register with `C-u NUMBER C-x r n'
346 REG, increment it by INC with `C-u INC C-x r + REG' (to increment by
347 one, omit C-u INC), and insert it in the buffer with `C-x r g REG'.
348 This is useful for writing keyboard macros.
350 ** The M-: command, when given a prefix argument, will now insert its
351 result to the current buffer.
353 ** The `C-h c' command, when given a prefix argument, will now insert
354 the message into the current buffer.
356 ** Horizontally split windows may now be dragged using the mouse.
357 Because of this, the dividers between vertical windows are always
358 visible. To turn it off, set `vertical-divider-always-visible-p' to
361 ** XEmacs/Mule (internationalization) changes.
363 *** Mule support now works on TTY's. Use `set-terminal-coding-system'
364 and `set-keyboard-coding-system' to specify the coding system of your
365 display and keyboard.
367 *** Egg/SJ3 input method is now officially supported. Quail and
368 Egg/Skk have been available through the generalized Leim since 20.3.
370 *** Localized Japanese menubars are available if XEmacs is built with
371 XFONTSET and either the X11 libraries are built with X_LOCALE defined
372 or the native C libraries support Japanese localization. This has
373 been available since 20.3, only it hasn't been announced before.
375 ** Jamie Zawinski's `gdb-highlight' extension is now distributed with
376 the `debug' package. gdb-highlight makes most objects printed in a
377 gdb buffer be mouse-sensitive: as text shows up in the buffer, it is
378 parsed, and objects which are recognized have context-sensitive
379 commands attached to them. To use it, add the following to `.emacs':
381 (add-hook 'gdb-mode-hook (lambda () (require 'gdb-highlight)))
383 ** The package popper.el is now included in the edit-utils package.
384 It has been greatly enhanced with respect to the one once included
385 with the ilisp package and should work well under XEmacs 21.0.
389 *** Like the old 'gnudoit' program. Gnuclient -batch now can read from stdin.
391 *** Gnuclient -batch no longer breaks off the output at the first LF.
395 *** Multiline macros are now handled, both as they affect indentation,
396 and as recognized syntax. New syntactic symbol cpp-macro-cont is
397 assigned to second and subsequent lines of a multiline macro
400 *** A new style "user" which captures all non-hook-ified
401 (i.e. top-level) .emacs file variable setings and customizations.
402 Style "cc-mode" is an alias for "user" and is deprecated. "gnu" style
403 is still the default however.
405 *** "java" style now conforms to Sun's JDK coding style.
407 *** There are new commands c-beginning-of-defun, c-end-of-defun which
408 are alternatives which you could bind to C-M-a and C-M-e if you prefer
409 them. They do not have key bindings by default.
411 *** New and improved implementations of M-a (c-beginning-of-statement)
412 and M-e (c-end-of-statement).
414 *** C++ namespace blocks are supported, with new syntactic symbols
415 namespace-open, namespace-close, and innamespace.
417 *** File local variable settings of c-file-style and c-file-offsets
418 makes the style variables local to that buffer only.
420 *** New indentation functions c-lineup-close-paren,
421 c-indent-one-line-block, c-lineup-dont-change.
423 *** Improvements (hopefully!) to the way CC Mode is loaded. You
424 should now be able to do a (require 'cc-mode) to get the entire
425 package loaded properly for customization in your .emacs file. A new
426 variable c-initialize-on-load controls this and is t by default.
428 ** In Text mode, now only blank lines separate paragraphs.
429 This makes it possible to get the full benefit of Adaptive Fill mode
430 in Text mode, and other modes derived from it (such as Mail mode).
431 TAB in Text mode now runs the command indent-relative; this makes a
432 practical difference only when you use indented paragraphs.
434 As a result, the old Indented Text mode is now identical to Text mode,
435 and is an alias for it.
437 If you want spaces at the beginning of a line to start a paragraph,
438 use the new mode, Paragraph Indent Text mode.
440 ** Changes to Gnus, the XEmacs newsreader.
442 *** New functionality for using Gnus as an offline newsreader has been
443 added. A plethora of new commands and modes have been added. See the
444 Gnus manual for the full story.
446 *** The nndraft backend has returned, but works differently than
447 before. All Message buffers are now also articles in the nndraft
448 group, which is created automatically.
450 *** `gnus-alter-header-function' can now be used to alter header
453 *** `gnus-summary-goto-article' now accept Message-ID's.
455 *** A new Message command for deleting text in the body of a message
456 outside the region: `C-c C-v'.
458 *** You can now post to component group in nnvirtual groups with
461 *** `nntp-rlogin-program' -- new variable to ease customization.
463 *** `C-u C-c C-c' in `gnus-article-edit-mode' will now inhibit
464 re-highlighting of the article buffer.
466 *** New element in `gnus-boring-article-headers' -- `long-to'.
468 *** `M-i' symbolic prefix command. See the section "Symbolic
469 Prefixes" in the Gnus manual for details.
471 *** `L' and `I' in the summary buffer now take the symbolic prefix
472 `a' to add the score rule to the "all.SCORE" file.
474 *** `gnus-simplify-subject-functions' variable to allow greater
475 control over simplification.
477 *** `A T' -- new command for fetching the current thread.
479 *** `/ T' -- new command for including the current thread in the
482 *** `M-RET' is a new Message command for breaking cited text.
484 *** \\1-expressions are now valid in `nnmail-split-methods'.
486 *** The `custom-face-lookup' function has been removed.
487 If you used this function in your initialization files, you must
488 rewrite them to use `face-spec-set' instead.
490 *** Cancelling now uses the current select method. Symbolic prefix
491 `a' forces normal posting method.
493 *** New command to translate M******** sm*rtq**t*s into proper text
496 *** For easier debugging of nntp, you can set `nntp-record-commands'
499 *** nntp now uses ~/.authinfo, a .netrc-like file, for controlling
500 where and how to send AUTHINFO to NNTP servers.
502 *** A command for editing group parameters from the summary buffer
505 *** A history of where mails have been split is available.
507 *** A new article date command has been added -- `article-date-iso8601'.
509 *** Subjects can be simplified when threading by setting
510 `gnus-score-thread-simplify'.
512 *** A new function for citing in Message has been added --
513 `message-cite-original-without-signature'.
515 *** `article-strip-all-blank-lines' -- new article command.
517 *** A new Message command to kill to the end of the article has
520 *** A minimum adaptive score can be specified by using the
521 `gnus-adaptive-word-minimum' variable.
523 *** The "lapsed date" article header can be kept continually
524 updated by the `gnus-start-date-timer' command.
526 *** Web listserv archives can be read with the nnlistserv backend.
528 *** Old dejanews archives can now be read by nnweb.
530 *** Byte-compilation of user-specs now works under XEmacs.
532 ** The `dir' files are no longer essential for functioning of the Info
533 subsystem. If the `dir' file does not exist in an Info directory, the
534 relevant information will be generated on-the-fly.
536 This behavior can be customized, look for `Info-auto-generate-directory'
537 and `Info-save-auto-generated-dir' in the `info' customization group.
540 * Lisp and internal changes in XEmacs 21.0
541 ==========================================
543 ** It is now possible to build XEmacs with support for 31-bit Lisp
544 integers (normally, Lisp integers are only 28 bits wide on 32-bit
545 machines.) Configure with --use-minimal-tagbits to test. With this
546 change, the maximum buffer size on 32-bit machines is increased from
547 128M to 1G. This setting will be made default in a future XEmacs
550 ** Specifier changes.
552 *** When instantiating a specifier, the window locale now has a higher
553 precedence than the buffer locale. This is because the window locale
554 is more specific than the buffer locale.
556 *** The new macro `let-specifier' can be used to temporarily add
557 specifications to specifiers. See the documentation for details.
559 *** The new specifiers `vertical-scrollbar-visible-p' and
560 `horizontal-scrollbar-visible-p' may be used to control scrollbar
561 visibility. Previously, the only way to remove a scrollbar was to set
562 its size to 0. This method is still supported for backward
565 *** The new specifiers `scrollbar-on-left-p' and `scrollbar-on-top-p'
566 may be used to control the position of the vertical and horizontal
567 toolbar. Previously, their position could be changed only through the
570 *** The new draggable vertical dividers between windows may be turned
571 off using the `vertical-divider-always-visible-p' specifier. When
572 this is set to nil, the vertical dividers between windows are shown
573 only when needed, and they are not draggable.
575 Other properties of the vertical dividers may be controlled using
576 `vertical-divider-shadow-thickness', `vertical-divider-line-width' and
577 `vertical-divider-spacing' specifiers, which see.
579 ** Frame focus management changes.
581 *** When the variable focus-follows-mouse is non-nil, `select-frame'
582 no longer permanently selects a different frame. The frame selection
583 is temporary and is reverted when the current command terminates, much
584 like the buffer selected by `set-buffer'. This is the same as in FSF
587 *** The new function `focus-frame' sets the window system focus to
588 FRAME (and selects it), regardless of the value of
589 `focus-follows-mouse'. Doing this is not well behaved, so be
590 absolutely sure that you want this.
592 The code that uses `select-frame' only to get the window manager focus
593 should be changed to use `set-frame-focus' instead, so that they keep
594 working when `focus-follows-mouse' is non-nil.
596 *** The special forms `save-selected-frame' and `with-selected-frame'
597 can now be used to temporarily change selected frame.
599 *** The behavior of `other-frame' command (`C-x 5 o') is unaffected by
602 ** The function `select-window' now has an optional second argument
603 NORECORD which if non-nil inhibits the recording of a buffer change.
605 ** The function `vertical-motion' now correctly handles the second,
606 optional WINDOW argument. A new third argument PIXELS, if non-nil,
607 indicates that the returned motion should be in pixels.
609 ** The new function `vertical-motion-pixels' is similar to
610 vertical-motion but takes as input a vertical motion in pixels.
612 ** The new functions window-text-area-pixel-{width,height,edges} can
613 be used to obtain information about the text-displaying area of a
616 ** The new functions `shrink-window-pixels' and `enlarge-window-pixels'
617 can be used to adjust the size of a window by a pixel amount.
619 ** The new function `window-displayed-text-pixel-height' can be used
620 to determine the height of the text actually displayed in a window.
622 ** The arithmetic comparison functions <, >, =, /= now accept a
623 variable number of arguments.
625 This means that if you want to test whether A < B < C, you can write
626 it as (< A B C) instead of (and (< A B) (< B C)). Likewise,
627 (apply #'> LIST) now tests if LIST is monotonously increasing -- and
630 ** The XEmacs hashtables now have a consistent read/print syntax.
631 This means that a hashtable will be readably printed in a
634 #s(hashtable size 2 data (key1 value1 key2 value2))
636 When XEmacs reads this form, it will create a new hashtable according
637 to description. This allows you to easily dump hashtables to files
638 using `prin1', and read them back in using `read'.
640 If `print-readably' is non-nil, a more relaxed syntax is used; for
643 #<hashtable size 2/13 data (key1 value1 key2 value2) 0x874d>
645 ** It is now possible to build XEmacs with LDAP support.
646 You will need to install a LDAP library first. The following have
648 - LDAP 3.3 from the University of Michigan
649 (get it from <URL:http://www.umich.edu/~dirsvcs/ldap/>)
650 - OpenLDAP 1.0.3 from the OpenLDAP Foundation
651 (get it from <URL:http://www.openldap.org/>)
652 - LDAP SDK 1.0 from Netscape Corp.
653 (get it from <URL:http://developer.netscape.com/>)
655 ** When profiling is in effect, a call-count of all recorded functions
656 is now calculated. This information is stored in
657 `call-count-profile-table', and is utilized by `profile-results' as
658 well as the new command `profile-call-count-results'.
660 ** It is now an error to change the value of a symbol whose name
661 starts with a colon, if it is interned in the standard obarray.
663 However, setting such a symbol to its proper value, which is that
664 symbol itself, is not an error. This is for the sake of programs that
665 support pre-19.12 XEmacs and pre-20 GNU Emacs by explicitly setting
666 these variables to themselves.
668 ** The `concat' function no longer accepts integer arguments.
670 ** The new function `string' concatenates all its argument characters
671 and returns the resulting string. This is consistent with other
672 functions, like `list', `vector', etc.
674 ** The function `temp-directory' is now available to return the
675 directory to store temporary files. On Unix this will be obtained
676 from TMPDIR, defaulting to `/tmp'.
678 ** The function load-average now accepts an optional argument
679 USE-FLOATS. If it is non-nil, the load average values are returned as
680 floating point numbers, rather than as integers to be divided by 100.
682 ** The `make-event' function now supports the TYPE and PLIST
683 arguments, which can be used to create various events from Lisp. See
684 the documentation for details.
686 ** `function-interactive' is a new function that returns the
687 interactive specification of a funcallable object.
689 ** The new `lmessage' function allows printing of a formatted message
690 with a particular label.
692 (lmessage 'progress "Processing... %d" counter)
694 This function is more convenient than `display-message' because it
695 automatically applies `format' to its arguments.
697 ** The new `lwarn' function, analogous to `lmessage', allows printing
698 a formatted warning, with a non-default CLASS or LABEL.
700 ** The new function `split-path' can now be used to explode the
701 components of a colon-separated search path into a list.
703 (split-path "foo:bar")
706 ** Specifiers and symbols whose value is a specifier are now allowed
707 as modeline specifications.
709 ** defcustom now accepts the keyword `:version'. Use this to specify
710 in which version of Emacs a certain variable's default value changed.
713 (defcustom foo-max 34 "*Maximum number of foo's allowed."
718 This information is used to control the customize-changed-options
721 ** The line number tracking in modeline is now efficient, even for
722 very large buffers. This is achieved by caching the line numbers of
723 recent buffer positions, and reusing them. This cache is used only in
724 the buffers where `line-number-mode' is in effect.
726 ** When the new GNU Malloc aka Doug Lea Malloc is available, it will
727 be used. This should result in better performance on Linux systems
730 ** The code XEmacs uses to assemble its various paths into the
731 directory hierarchy has been rewritten to support the package system.
732 Look under "Startup Paths" in the Info documentation for more
735 *** site-lisp is now longer part of the load-path by default.
736 Its use is deprecated, but you can specify --with-site-lisp=yes at the
737 configure command line to get it back.
739 *** `Info-default-directory-list' is now obsolete. If you want to
740 change the path which XEmacs uses to search for info files, set
741 `Info-directory-list' instead.