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1 GNU Emacs NEWS -- history of user-visible changes. 5 Jan 2000
2 Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
3 See the end for copying conditions.
4
5 Please send Emacs bug reports to bug-gnu-emacs@gnu.org.
6 For older news, see the file ONEWS.
7
8 \f
9 * Installation Changes in Emacs 21.1
10
11 ** `movemail' defaults to supporting POP. You can turn this off using
12 the --without-pop configure option, should that be necessary.
13
14 ** There are new configure options associated with the support for
15 images and toolkit scrollbars. Use the --help option in `configure'
16 to list them.
17
18 ** There is a new configure option `--without-xim' that instructs
19 Emacs to not use X Input Methods (XIM), if they these are available.
20
21 ** There is a new configure option `--disable-largefile' to omit
22 Unix-98-style support for large files if that is available.
23
24 ** You can build a 64-bit Emacs for SPARC/Solaris systems which
25 support 64-bit executables. See etc/MACHINES for instructions.
26 \f
27 * Changes in Emacs 21.1
28
29 ** C-down-mouse-3 is bound differently. Now if the menu bar is not
30 displayed it pops up a menu containing the items which would be on the
31 menu bar. If the menu bar is displayed, it pops up the major mode
32 menu or the Edit menu if there is no major mode menu.
33
34 ** Variable `load-path' is no longer customizable because it contains
35 a version-dependent component.
36
37 ** The <delete> function key is now bound to `delete-char' by default.
38 Note that this takes effect only on window systems. On TTYs, Emacs
39 will receive ASCII 127 when the DEL key is pressed. This
40 character is still bound as before.
41
42 ** Item Save Options on the Options menu allows saving options set
43 using that menu.
44
45 ** New function executable-make-buffer-file-executable-if-script-p is
46 suitable as an after-save-hook as an alternative to executable-chmod.
47
48 ** The most preferred coding-system is now used to save a buffer if
49 buffer-file-coding-system is `undecided' and it is safe for the buffer
50 contents. (The most preferred is set by set-language-environment or
51 by M-x prefer-coding-system.) Thus if you visit an ASCII file and
52 insert a non-ASCII character from your current language environment,
53 the file will be saved silently with the appropriate coding.
54 Previously you would be prompted for a safe coding system.
55
56 ** New variable `inhibit-iso-escape-detection' determines if Emacs'
57 coding system detection algorithm should pay attention to ISO2022's
58 escape sequences. If this variable is non-nil, the algorithm ignores
59 such escape sequences. The default value is nil, and it is
60 recommended not to change it except for the special case that you
61 always want to read any escape code verbatim. If you just want to
62 read a specific file without decoding escape codes, use C-x RET c
63 (`universal-coding-system-argument'). For instance, C-x RET c latin-1
64 RET C-x C-f filename RET.
65
66 ** Variable `default-korean-keyboard' is initialized properly from the
67 environment variable `HANGUL_KEYBOARD_TYPE'.
68
69 ** C-u C-x = provides detailed information about the character at
70 point in a pop-up window.
71
72 ** New command M-x list-charset-chars reads a character set name and
73 displays all characters in that character set.
74
75 ** M-x set-terminal-coding-system (C-x RET t) now allows CCL-based
76 coding systems such as cpXXX and cyrillic-koi8.
77
78 ** M-; now calls comment-dwim which tries to do something clever based
79 on the context.
80
81 ** The function `getenv' is now callable interactively.
82
83 ** The many obsolete language `setup-...-environment' commands have
84 been removed -- use `set-language-environment'.
85
86 ** New user options `display-time-mail-face' and
87 `display-time-use-mail-icon' control the appearance of mode-line mail
88 indicator used by the display-time package. On a suitable display the
89 indicator can be an icon and is mouse-sensitive.
90
91 ** Emacs' auto-save list files are now by default stored in a
92 sub-directory `.emacs.d/auto-save-list/' of the user's home directory.
93 (On MS-DOS, this subdirectory's name is `_emacs.d/auto-save.list/'.)
94 You can customize `auto-save-list-prefix' to change this location.
95
96 ** On window-systems, additional space can be put between text lines
97 on the display using several methods
98
99 - By setting frame parameter `line-spacing' to PIXELS. PIXELS must be
100 a positive integer, and specifies that PIXELS number of pixels should
101 be put below text lines on the affected frame or frames.
102
103 - By setting X resource `lineSpacing', class `LineSpacing'. This is
104 equivalent ot specifying the frame parameter.
105
106 - By specifying `--line-spacing=N' or `-lsp N' on the command line.
107
108 - By setting buffer-local variable `line-spacing'. The meaning is
109 the same, but applies to the a particular buffer only.
110
111 ** The new command `clone-indirect-buffer' can be used to create
112 an indirect buffer that is a twin copy of the current buffer. The
113 command `clone-indirect-buffer-other-window', bound to C-x 4 c,
114 does the same but displays the indirect buffer in another window.
115
116 ** New user options `backup-directory-alist' and
117 `make-backup-file-name-function' control the placement of backups,
118 typically in a single directory or in an invisible sub-directory.
119
120 ** New commands iso-iso2sgml and iso-sgml2iso convert between Latin-1
121 characters and the corresponding SGML (HTML) entities.
122
123 ** Emacs now refuses to load compiled Lisp files which weren't
124 compiled with Emacs. Set `load-dangerous-libraries' to t to change
125 this behavior.
126
127 The reason for this change is an incompatible change in XEmacs' byte
128 compiler. Files compiled with XEmacs can contain byte codes that let
129 Emacs dump core.
130
131 ** New X resources recognized
132
133 *** The X resource `synchronous', class `Synchronous', specifies
134 whether Emacs should run in synchronous mode. Synchronous mode
135 is useful for debugging X problems.
136
137 Example:
138
139 emacs.synchronous: true
140
141 *** The X resource `visualClass, class `VisualClass', specifies the
142 visual Emacs should use. The resource's value should be a string of
143 the form `CLASS-DEPTH', where CLASS is the name of the visual class,
144 and DEPTH is the requested color depth as a decimal number. Valid
145 visual class names are
146
147 TrueColor
148 PseudoColor
149 DirectColor
150 StaticColor
151 GrayScale
152 StaticGray
153
154 Visual class names specified as X resource are case-insensitive, i.e.
155 `pseudocolor', `Pseudocolor' and `PseudoColor' all have the same
156 meaning.
157
158 The program `xdpyinfo' can be used to list the visual classes
159 supported on your display, and which depths they have. If
160 `visualClass' is not specified, Emacs uses the display's default
161 visual.
162
163 Example:
164
165 emacs.visualClass: TrueColor-8
166
167 *** The X resource `privateColormap', class `PrivateColormap',
168 specifies that Emacs should use a private colormap if it is using the
169 default visual, and that visual is of class PseudoColor. Recognized
170 resource values are `true' or `on'.
171
172 Example:
173
174 emacs.privateColormap: true
175
176 ** The menu bar configuration has changed. The new configuration is
177 more CUA-compliant. The most significant change is that Options is
178 now a separate menu-bar item, with Mule and Customize as its submenus.
179
180 ** User-option `show-cursor-in-non-selected-windows' controls how to
181 display the cursor in non-selected windows. If nil, no cursor is
182 shown, if non-nil a hollow box cursor is shown. This option can
183 be customized.
184
185 ** The variable `echo-keystrokes' may now have a floating point value.
186
187 ** C-x 5 1 runs the new command delete-other-frames which deletes
188 all frames except the selected one.
189
190 ** If your init file is compiled (.emacs.elc), `user-init-file' is set
191 to the source name (.emacs.el), if that exists, after loading it.
192
193 ** The help string specified for a menu-item whose definition contains
194 the property `:help HELP' is now displayed under X, on MS-Windows, and
195 MS-DOS, either in the echo area or with tooltips. Many standard menus
196 displayed by Emacs now have help strings.
197
198 ** Highlighting of mouse-sensitive regions is now supported in the
199 MS-DOS version of Emacs.
200
201 ** New user option `read-mail-command' specifies a command to use to
202 read mail from the menu etc.
203
204 ** Hexl contains a new command `hexl-insert-hex-string' which inserts
205 a string of hexadecimal numbers read from the mini-buffer.
206
207 ** Changes in Texinfo mode.
208
209 ** A couple of new key bindings have been added for inserting Texinfo
210 macros
211
212 Key binding Macro
213 -------------------------
214 C-c C-c C-s @strong
215 C-c C-c C-e @emph
216 C-c C-c u @url
217 C-c C-c q @quotation
218 C-c C-c m @email
219
220 ** Changes in Outline mode.
221
222 There is now support for Imenu to index headings. A new command
223 `outline-headers-as-kill' copies the visible headings in the region to
224 the kill ring, e.g. to produce a table of contents.
225
226 ** New command M-x check-parens can be used to find unbalanced paren
227 groups and strings in buffers in Lisp mode (or other modes).
228
229 ** You can now easily create new *Info* buffers using either M-x clone-buffer
230 or C-u m <entry> RET. M-x clone-buffer can also be used on *Help* and
231 several other special buffers.
232
233 ** Emacs can now support 'wheeled' mice (such as the MS IntelliMouse)
234 under XFree86. To enable this, simply put (mwheel-install) in your
235 .emacs file.
236
237 The variables `mwheel-follow-mouse' and `mwheel-scroll-amount'
238 determine where and by how much buffers are scrolled.
239
240 ** Listing buffers with M-x list-buffers (C-x C-b) now shows
241 abbreviated file names. Abbreviations can be customized by changing
242 `directory-abbrev-alist'.
243
244 ** Reading from the mini-buffer now reads from standard input if Emacs
245 is running in batch mode. For example,
246
247 (message "%s" (read t))
248
249 will read a Lisp expression from standard input and print the result
250 to standard output.
251
252 ** Faces and frame parameters.
253
254 There are four new faces `scroll-bar', `border', `cursor' and `mouse'.
255 Setting the frame parameters `scroll-bar-foreground' and
256 `scroll-bar-background' sets foreground and background color of face
257 `scroll-bar' and vice versa. Setting frame parameter `border-color'
258 sets the background color of face `border' and vice versa. Likewise
259 for frame parameters `cursor-color' and face `cursor', and frame
260 parameter `mouse-color' and face `mouse'.
261
262 Changing frame parameter `font' sets font-related attributes of the
263 `default' face and vice versa. Setting frame parameters
264 `foreground-color' or `background-color' sets the colors of the
265 `default' face and vice versa.
266
267 ** New face `menu'.
268
269 The face `menu' can be used to change colors and font of Emacs' menus.
270 Setting the font of LessTif/Motif menus is currently not supported;
271 attempts to set the font are ignored in this case.
272
273 ** New frame parameter `screen-gamma' for gamma correction.
274
275 The new frame parameter `screen-gamma' specifies gamma-correction for
276 colors. Its value may be nil, the default, in which case no gamma
277 correction occurs, or a number > 0, usually a float, that specifies
278 the screen gamma of a frame's display.
279
280 PC monitors usually have a screen gamma of 2.2. smaller values result
281 in darker colors. You might want to try a screen gamma of 1.5 for LCD
282 color displays. The viewing gamma Emacs uses is 0.4545. (1/2.2).
283
284 The X resource name of this parameter is `screenGamma', class
285 `ScreenGamma'.
286
287 ** Emacs has a new redisplay engine.
288
289 The new redisplay handles characters of variable width and height.
290 Italic text can be used without redisplay problems. Fonts containing
291 oversized characters, i.e. characters larger than the logical height
292 of a font can be used. Images of various formats can be displayed in
293 the text.
294
295 ** Emacs has a new face implementation.
296
297 The new faces no longer fundamentally use X font names to specify the
298 font. Instead, each face has several independent attributes--family,
299 height, width, weight and slant--that it may or may not specify.
300 These attributes can be merged from various faces, and then together
301 specify a font.
302
303 Faces are supported on terminals that can display color or fonts.
304 These terminal capabilities are auto-detected. Details can be found
305 under Lisp changes, below.
306
307 ** New default font is Courier 12pt.
308
309 ** When using a windowing terminal, Emacs window now has a cursor of
310 its own. When the window is selected, the cursor is solid; otherwise,
311 it is hollow.
312
313 ** Bitmap areas to the left and right of windows are used to display
314 truncation marks, continuation marks, overlay arrows and alike. The
315 foreground, background, and stipple of these areas can be changed by
316 customizing face `fringe'.
317
318 ** The mode line under X is now drawn with shadows by default. You
319 can change its appearance by modifying the face `modeline'.
320
321 ** LessTif support.
322
323 Emacs now runs with LessTif (see <http://www.lesstif.org>). You will
324 need a version 0.88.1 or later.
325
326 ** Toolkit scroll bars.
327
328 Emacs now uses toolkit scrollbars if available. When configured for
329 LessTif/Motif, it will use that toolkit's scrollbar. Otherwise, when
330 configured for Lucid and Athena widgets, it will use the Xaw3d scroll
331 bar if Xaw3d is available. You can turn off the use of toolkit scroll
332 bars by specifying `--with-toolkit-scroll-bars=no' when configuring
333 Emacs.
334
335 When you encounter problems with the Xaw3d scroll bar, watch out how
336 Xaw3d is compiled on your system. If the Makefile generated from
337 Xaw3d's Imakefile contains a `-DNARROWPROTO' compiler option, and your
338 Emacs system configuration file `s/your-system.h' does not contain a
339 define for NARROWPROTO, you might consider adding it. Take
340 `s/freebsd.h' as an example.
341
342 Alternatively, if you don't have access to the Xaw3d source code, take
343 a look at your system's imake configuration file, for example in the
344 directory `/usr/X11R6/lib/X11/config' (paths are different on
345 different systems). You will find files `*.cf' there. If your
346 system's cf-file contains a line like `#define NeedWidePrototypes NO',
347 add a `#define NARROWPROTO' to your Emacs system configuration file.
348
349 The reason for this is that one Xaw3d function uses `double' or
350 `float' function parameters depending on the setting of NARROWPROTO.
351 This is not a problem when Imakefiles are used because each system's
352 image configuration file contains the necessary information. Since
353 Emacs doesn't use imake, this has do be done manually.
354
355 ** Toggle buttons and radio buttons in menus.
356
357 When compiled with LessTif (or Motif) support, Emacs uses toolkit
358 widgets for radio and toggle buttons in menus. When configured for
359 Lucid, Emacs draws radio buttons and toggle buttons similar to Motif.
360
361 ** Highlighting of trailing whitespace.
362
363 When `show-trailing-whitespace' is non-nil, Emacs displays trailing
364 whitespace in the face `trailing-whitespace'. Trailing whitespace is
365 defined as spaces or tabs at the end of a line. To avoid busy
366 highlighting when entering new text, trailing whitespace is not
367 displayed if point is at the end of the line containing the
368 whitespace.
369
370 ** Busy-cursor.
371
372 Emacs can optionally display a busy-cursor under X. You can turn the
373 display on or off by customizing group `cursor'.
374
375 ** Blinking cursor
376
377 M-x blink-cursor-mode toggles a blinking cursor under X and on
378 terminals having terminal capabilities `vi', `vs', and `ve'. Blinking
379 and related parameters like frequency and delay can be customized in
380 the group `cursor'.
381
382 ** New font-lock support mode `jit-lock-mode'.
383
384 This support mode is roughly equivalent to `lazy-lock' but is
385 generally faster. It supports stealth and deferred fontification.
386 See the documentation of the function `jit-lock-mode' for more
387 details.
388
389 Font-lock uses jit-lock-mode as default support mode, so you don't
390 have to do anything to activate it.
391
392 ** Tabs and variable-width text.
393
394 Tabs are now displayed with stretch properties; the width of a tab is
395 defined as a multiple of the normal character width of a frame, and is
396 independent of the fonts used in the text where the tab appears.
397 Thus, tabs can be used to line up text in different fonts.
398
399 ** Enhancements of the Lucid menu bar
400
401 *** The Lucid menu bar now supports the resource "margin".
402
403 emacs.pane.menubar.margin: 5
404
405 The default margin is 4 which makes the menu bar appear like the
406 LessTif/Motif one.
407
408 *** Arrows that indicate sub-menus are now drawn with shadows, as in
409 LessTif and Motif.
410
411 ** Hscrolling in C code.
412
413 Horizontal scrolling now happens automatically if
414 `automatic-hscrolling' is set (the default). This setting can be
415 customized.
416
417 ** Tool bar support.
418
419 Emacs supports a tool bar at the top of a frame under X. For details
420 how to define a tool bar, see the page describing Lisp-level changes.
421
422 ** Mouse-sensitive mode line.
423
424 Different parts of the mode line under X have been made
425 mouse-sensitive. Moving the mouse to a mouse-sensitive part in the mode
426 line changes the appearance of the mouse pointer to an arrow, and help
427 about available mouse actions is displayed either in the echo area, or
428 in the tooltip window if you have enabled one.
429
430 Currently, the following actions have been defined:
431
432 - Mouse-1 on the buffer name in the mode line switches between two
433 buffers.
434
435 - Mouse-2 on the buffer-name switches to the next buffer, and
436 M-mouse-2 switches to the previous buffer in the buffer list.
437
438 - Mouse-3 on the buffer-name displays a buffer menu.
439
440 - Mouse-2 on the read-only status in the mode line (`%' or `*')
441 toggles the read-only status.
442
443 - Mouse-3 on the mode name display a minor-mode menu.
444
445 ** LessTif/Motif file selection dialog.
446
447 When Emacs is configured to use LessTif or Motif, reading a file name
448 from a menu will pop up a file selection dialog if `use-dialog-box' is
449 non-nil.
450
451 ** Emacs can display faces on TTY frames.
452
453 Emacs automatically detects terminals that are able to display colors.
454 Faces with a weight greater than normal are displayed extra-bright, if
455 the terminal supports it. Faces with a weight less than normal and
456 italic faces are displayed dimmed, if the terminal supports it.
457 Underlined faces are displayed underlined if possible. Other face
458 attributes such as `overline', `strike-through', and `box' are ignored
459 on terminals.
460
461 ** Sound support
462
463 Emacs supports playing sound files on GNU/Linux and FreeBSD (Voxware
464 driver and native BSD driver, a.k.a. Luigi's driver). Currently
465 supported file formats are RIFF-WAVE (*.wav) and Sun Audio (*.au).
466
467 ** A new variable, backup-by-copying-when-privileged-mismatch, gives
468 the highest file uid for which backup-by-copying-when-mismatch will be
469 forced on. The assumption is that uids less than or equal to this
470 value are special uids (root, bin, daemon, etc.--not real system
471 users) and that files owned by these users should not change ownership,
472 even if your system policy allows users other than root to edit them.
473
474 The default is 200; set the variable to nil to disable the feature.
475
476 ** A block cursor can be drawn as wide as the glyph under it under X.
477
478 As an example: if a block cursor is over a tab character, it will be
479 drawn as wide as that tab on the display. To do this, set
480 `x-stretch-cursor' to a non-nil value.
481
482 ** Empty display lines at the end of a buffer may be marked with a
483 bitmap (this is similar to the tilde displayed by vi).
484
485 This behavior is activated by setting the buffer-local variable
486 `indicate-empty-lines' to a non-nil value. The default value of this
487 variable is found in `default-indicate-empty-lines'.
488
489 ** There is a new "aggressive" scrolling method.
490
491 When scrolling up because point is above the window start, if the
492 value of the buffer-local variable `scroll-up-aggessively' is a
493 number, Emacs chooses a new window start so that point ends up that
494 fraction of the window's height from the bottom of the window.
495
496 When scrolling down because point is below the window end, if the
497 value of the buffer-local variable `scroll-down-aggessively' is a
498 number, Emacs chooses a new window start so that point ends up that
499 fraction of the window's height from the top of the window.
500
501 ** The rectangle commands now avoid inserting undesirable spaces,
502 notably at the end of lines.
503
504 All these functions have been rewritten to avoid inserting unwanted
505 spaces, and an optional prefix now allows them to behave the old way.
506
507 There is a new command M-x replace-rectangle.
508
509 ** The new command M-x query-replace-regexp-eval acts like
510 query-replace-regexp, but takes a Lisp expression which is evaluated
511 after each match to get the replacement text.
512
513 ** M-x query-replace recognizes a new command `e' (or `E') that lets
514 you edit the replacement string.
515
516 ** The new command mail-abbrev-complete-alias, bound to `M-TAB', let's
517 you complete mail aliases in the text, analogous to
518 lisp-complete-symbol.
519
520 ** Emacs now resizes mini-windows if appropriate.
521
522 If a message is longer than one line, or minibuffer contents are
523 longer than one line, Emacs now resizes the minibuffer window unless
524 it is on a frame of its own. You can control the maximum minibuffer
525 window size by setting the following variable:
526
527 - User option: max-mini-window-height
528
529 Maximum height for resizing mini-windows. If a float, it specifies a
530 fraction of the mini-window frame's height. If an integer, it
531 specifies a number of lines. If nil, don't resize.
532
533 Default is 0.25.
534
535 ** The command `Info-search' now uses a search history.
536
537 ** Changes to hideshow.el
538
539 Hideshow is now at version 5.x. It uses a new algorithms for block
540 selection and traversal and includes more isearch support.
541
542 *** Generalized block selection and traversal
543
544 A block is now recognized by three things: its start and end regexps
545 (both strings), and a match-data selector (an integer) specifying
546 which sub-expression in the start regexp serves as the place where a
547 `forward-sexp'-like function can operate. Hideshow always adjusts
548 point to this sub-expression before calling `hs-forward-sexp-func'
549 (which for most modes evaluates to `forward-sexp').
550
551 If the match-data selector is not specified, it defaults to zero,
552 i.e., the entire start regexp is valid, w/ no prefix. This is
553 backwards compatible with previous versions of hideshow. Please see
554 the docstring for variable `hs-special-modes-alist' for details.
555
556 *** Isearch support for updating mode line
557
558 During incremental search, if Hideshow minor mode is active, hidden
559 blocks are temporarily shown. The variable `hs-headline' records the
560 line at the beginning of the opened block (preceding the hidden
561 portion of the buffer), and the mode line is refreshed. When a block
562 is re-hidden, the variable is set to nil.
563
564 To show `hs-headline' in the mode line, you may wish to include
565 something like this in your .emacs.
566
567 (add-hook 'hs-minor-mode-hook
568 (lambda ()
569 (add-to-list 'mode-line-format 'hs-headline)))
570
571 ** Changes to Change Log mode and Add-Log functions
572
573 If you invoke `add-change-log-entry' from a backup file, it makes an
574 entry appropriate for the file's parent. This is useful for making
575 log entries by comparing a version with deleted functions.
576
577 New command M-x change-log-merge merges another log into the current
578 buffer, fixing old-style date formats if necessary.
579
580 Change Log mode now adds a file's version number to change log entries
581 if user-option `change-log-version-info-enabled' is non-nil.
582
583 The search for a file's version number is performed based on regular
584 expressions from `change-log-version-number-regexp-list' which can be
585 cutomized. Version numbers are only found in the first 10 percent of
586 a file.
587
588 ** Changes in Font Lock
589
590 *** The new function `font-lock-remove-keywords' can be used to remove
591 font-lock keywords from the current buffer or from a specific major
592 mode.
593
594 ** Comint (subshell) changes
595
596 Comint now includes new features to send commands to running processes
597 and redirect the output to a designated buffer or buffers.
598
599 The command M-x comint-redirect-send-command reads a command and
600 buffer name from the mini-buffer. The command is sent to the current
601 buffer's process, and its output is inserted into the specified buffer.
602
603 The command M-x comint-redirect-send-command-to-process acts like
604 M-x comint-redirect-send-command but additionally reads the name of
605 the buffer whose process should be used from the mini-buffer.
606
607 Packages based on comint.el like shell-mode, and
608 scheme-interaction-mode now highlight user input, and support choosing
609 previous input with mouse-2. To control this feature, see the
610 user-option `comint-highlight-input'.
611
612 ** Changes to Rmail mode
613
614 *** The new user-option rmail-rmail-user-mail-address-regexp can be
615 set to fine tune the identification of of the correspondent when
616 receiving new mail. If it matches the address of the sender, the
617 recipient is taken as correspondent of a mail. If nil, the default,
618 `user-login-name' and `user-mail-address' are used to exclude yourself
619 as correspondent.
620
621 Usually you don't have to set this variable, except if you collect
622 mails sent by you under different user names. Then it should be a
623 regexp matching your mail addresses.
624
625 *** The new user-option rmail-confirm-expunge controls whether and how
626 to ask for confirmation before expunging deleted messages from an
627 Rmail file. You can choose between no confirmation, confirmation
628 with y-or-n-p, or confirmation with yes-or-no-p. Default is to ask
629 for confirmation with yes-or-no-p.
630
631 *** RET is now bound in the Rmail summary to rmail-summary-goto-msg,
632 like `j'.
633
634 *** There is a new user option `rmail-digest-end-regexps' that
635 specifies the regular expressions to detect the line that ends a
636 digest message.
637
638 *** The new user option `rmail-automatic-folder-directives' specifies
639 in which folder to put messages automatically.
640
641 ** Changes to TeX mode
642
643 The default mode has been changed from `plain-tex-mode' to
644 `latex-mode'.
645
646 ** Changes to RefTeX mode
647
648 *** RefTeX has new support for index generation. Index entries can be
649 created with `C-c <', with completion available on index keys.
650 Pressing `C-c /' indexes the word at the cursor with a default
651 macro. `C-c >' compiles all index entries into an alphabetically
652 sorted *Index* buffer which looks like the final index. Entries
653 can be edited from that buffer.
654
655 *** Label and citation key selection now allow to select several
656 items and reference them together (use `m' to mark items, `a' or
657 `A' to use all marked entries).
658
659 *** reftex.el has been split into a number of smaller files to reduce
660 memory use when only a part of RefTeX is being used.
661
662 *** a new command `reftex-view-crossref-from-bibtex' (bound to `C-c &'
663 in BibTeX-mode) can be called in a BibTeX database buffer in order
664 to show locations in LaTeX documents where a particular entry has
665 been cited.
666
667 ** Emacs Lisp mode now allows multiple levels of outline headings.
668 The level of a heading is determined from the number of leading
669 semicolons in a heading line. Toplevel forms starting with a `('
670 in column 1 are always made leaves.
671
672 ** The M-x time-stamp command (most commonly used on write-file-hooks)
673 has the following new features:
674
675 *** The patterns for finding the time stamp and for updating a pattern
676 may match text spanning multiple lines. For example, some people like
677 to have the filename and date on separate lines. The new variable
678 time-stamp-inserts-lines controls the matching for multi-line patterns.
679
680 *** More than one time stamp can be updated in the same file. This
681 feature is useful if you need separate time stamps in a program source
682 file to both include in formatted documentation and insert in the
683 compiled binary. The same time-stamp will be written at each matching
684 pattern. The variable time-stamp-count enables this new feature; it
685 defaults to 1.
686
687 ** Partial Completion mode now completes environment variables in
688 file names.
689
690 ** Tooltips.
691
692 Tooltips are small X windows displaying a help string at the current
693 mouse position. To use them, use the Lisp package `tooltip' which you
694 can access via the user option `tooltip-mode'.
695
696 Tooltips also provides support for GUD debugging. If activated,
697 variable values can be displayed in tooltips by pointing at them with
698 the mouse in source buffers. You can customize various aspects of the
699 tooltip display in the group `tooltip'.
700
701 ** Customize changes
702
703 *** Customize now supports comments about customized items. Use the
704 `State' menu to add comments. Note that customization comments will
705 cause the customizations to fail in earlier versions of Emacs.
706
707 *** The new option `custom-buffer-done-function' says whether to kill
708 Custom buffers when you've done with them or just bury them (the
709 default).
710
711 *** The keyword :set-after in defcustom allows to specify dependencies
712 between custom options. Example:
713
714 (defcustom default-input-method nil
715 "*Default input method for multilingual text (a string).
716 This is the input method activated automatically by the command
717 `toggle-input-method' (\\[toggle-input-method])."
718 :group 'mule
719 :type '(choice (const nil) string)
720 :set-after '(current-language-environment))
721
722 This specifies that default-input-method should be set after
723 current-language-environment even if default-input-method appears
724 first in a custom-set-variables statement.
725
726 ** New features in evaluation commands
727
728 *** The commands to evaluate Lisp expressions, such as C-M-x in Lisp
729 modes, C-j in Lisp Interaction mode, and M-:, now bind the variables
730 print-level, print-length, and debug-on-error based on the
731 customizable variables eval-expression-print-level,
732 eval-expression-print-length, and eval-expression-debug-on-error.
733
734 *** The function `eval-defun' (M-C-x) now loads Edebug and instruments
735 code when called with a prefix argument.
736
737 ** Dired changes
738
739 *** New variable `dired-recursive-deletes' determines if the delete
740 command will delete non-empty directories recursively. The default
741 is, delete only empty directories.
742
743 *** New variable `dired-recursive-copies' determines if the copy
744 command will copy directories recursively. The default is, do not
745 copy directories recursively.
746
747 *** In command `dired-do-shell-command' (usually bound to `!') a `?'
748 in the shell command has a special meaning similar to `*', but with
749 the difference that the command will be run on each file individually.
750
751 *** The new command `dired-find-alternate-file' (usually bound to `a')
752 replaces the Dired buffer with the buffer for an alternate file or
753 directory.
754
755 *** The new command `dired-show-file-type' (usually bound to `w') shows
756 a message in the echo area describing what type of file the point is on.
757 This command invokes the external program `file' do its work, and so
758 will only work on systems with that program, and will be only as
759 accurate or inaccurate as it is.
760
761 *** Dired now properly handles undo changes of adding/removing `-R'
762 from ls switches.
763
764 ** The variable mail-specify-envelope-from controls whether to
765 use the -f option when sending mail.
766
767 ** CC mode changes.
768
769 Note: This release contains changes that might not be compatible with
770 current user setups (although it's believed that these
771 incompatibilities will only show in very uncommon circumstances).
772 However, since the impact is uncertain, these changes may be rolled
773 back depending on user feedback. Therefore there's no forward
774 compatibility guarantee wrt the new features introduced in this
775 release.
776
777 *** c-style-variables-are-local-p now defaults to t.
778 This is an incompatible change that has been made to make the behavior
779 of the style system wrt global variable settings less confusing for
780 non-advanced users. If you know what this variable does you might
781 want to set it to nil in your .emacs, otherwise you probably don't
782 have to bother.
783
784 Defaulting c-style-variables-are-local-p to t avoids the confusing
785 situation that occurs when a user sets some style variables globally
786 and edits both a Java and a non-Java file in the same Emacs session.
787 If the style variables aren't buffer local in this case, loading of
788 the second file will cause the default style (either "gnu" or "java"
789 by default) to override the global settings made by the user.
790
791 *** New initialization procedure for the style system.
792 When the initial style for a buffer is determined by CC Mode (from the
793 variable c-default-style), the global values of style variables now
794 take precedence over the values specified by the chosen style. This
795 is different than the old behavior: previously, the style-specific
796 settings would override the global settings. This change makes it
797 possible to do simple configuration in the intuitive way with
798 Customize or with setq lines in one's .emacs file.
799
800 By default, the global value of every style variable is the new
801 special symbol set-from-style, which causes the value to be taken from
802 the style system. This means that in effect, only an explicit setting
803 of a style variable will cause the "overriding" behavior described
804 above.
805
806 Also note that global settings override style-specific settings *only*
807 when the initial style of a buffer is chosen by a CC Mode major mode
808 function. When a style is chosen in other ways --- for example, by a
809 call like (c-set-style "gnu") in a hook, or via M-x c-set-style ---
810 then the style-specific values take precedence over any global style
811 values. In Lisp terms, global values override style-specific values
812 only when the new second argument to c-set-style is non-nil; see the
813 function documentation for more info.
814
815 The purpose of these changes is to make it easier for users,
816 especially novice users, to do simple customizations with Customize or
817 with setq in their .emacs files. On the other hand, the new system is
818 intended to be compatible with advanced users' customizations as well,
819 such as those that choose styles in hooks or whatnot. This new system
820 is believed to be almost entirely compatible with current
821 configurations, in spite of the changed precedence between style and
822 global variable settings when a buffer's default style is set.
823
824 (Thanks to Eric Eide for clarifying this explanation a bit.)
825
826 **** c-offsets-alist is now a customizable variable.
827 This became possible as a result of the new initialization behavior.
828
829 This variable is treated slightly differently from the other style
830 variables; instead of using the symbol set-from-style, it will be
831 completed with the syntactic symbols it doesn't already contain when
832 the style is first initialized. This means it now defaults to the
833 empty list to make all syntactic elements get their values from the
834 style system.
835
836 **** Compatibility variable to restore the old behavior.
837 In case your configuration doesn't work with this change, you can set
838 c-old-style-variable-behavior to non-nil to get the old behavior back
839 as far as possible.
840
841 *** Improvements to line breaking and text filling.
842 CC Mode now handles this more intelligently and seamlessly wrt the
843 surrounding code, especially inside comments. For details see the new
844 chapter about this in the manual.
845
846 **** New variable to recognize comment line prefix decorations.
847 The variable c-comment-prefix-regexp has been added to properly
848 recognize the line prefix in both block and line comments. It's
849 primarily used to initialize the various paragraph recognition and
850 adaptive filling variables that the text handling functions uses.
851
852 **** New variable c-block-comment-prefix.
853 This is a generalization of the now obsolete variable
854 c-comment-continuation-stars to handle arbitrary strings.
855
856 **** CC Mode now uses adaptive fill mode.
857 This to make it adapt better to the paragraph style inside comments.
858
859 It's also possible to use other adaptive filling packages inside CC
860 Mode, notably Kyle E. Jones' Filladapt mode (http://wonderworks.com/).
861 A new convenience function c-setup-filladapt sets up Filladapt for use
862 inside CC Mode.
863
864 Note though that the 2.12 version of Filladapt lacks a feature that
865 causes it to work suboptimally when c-comment-prefix-regexp can match
866 the empty string (which it commonly does). A patch for that is
867 available from the CC Mode web site (http://www.python.org/emacs/
868 cc-mode/).
869
870 **** It's now possible to selectively turn off auto filling.
871 The variable c-ignore-auto-fill is used to ignore auto fill mode in
872 specific contexts, e.g. in preprocessor directives and in string
873 literals.
874
875 **** New context sensitive line break function c-context-line-break.
876 It works like newline-and-indent in normal code, and adapts the line
877 prefix according to the comment style when used inside comments. If
878 you're normally using newline-and-indent, you might want to switch to
879 this function.
880
881 *** Fixes to IDL mode.
882 It now does a better job in recognizing only the constructs relevant
883 to IDL. E.g. it no longer matches "class" as the beginning of a
884 struct block, but it does match the CORBA 2.3 "valuetype" keyword.
885 Thanks to Eric Eide.
886
887 *** Improvements to the Whitesmith style.
888 It now keeps the style consistently on all levels and both when
889 opening braces hangs and when they don't.
890
891 **** New lineup function c-lineup-whitesmith-in-block.
892
893 *** New lineup functions c-lineup-template-args and c-indent-multi-line-block.
894 See their docstrings for details. c-lineup-template-args does a
895 better job of tracking the brackets used as parens in C++ templates,
896 and is used by default to line up continued template arguments.
897
898 *** c-lineup-comment now preserves alignment with a comment on the
899 previous line. It used to instead preserve comments that started in
900 the column specified by comment-column.
901
902 *** c-lineup-C-comments handles "free form" text comments.
903 In comments with a long delimiter line at the start, the indentation
904 is kept unchanged for lines that start with an empty comment line
905 prefix. This is intended for the type of large block comments that
906 contain documentation with its own formatting. In these you normally
907 don't want CC Mode to change the indentation.
908
909 *** The `c' syntactic symbol is now relative to the comment start
910 instead of the previous line, to make integers usable as lineup
911 arguments.
912
913 *** All lineup functions have gotten docstrings.
914
915 *** More preprocessor directive movement functions.
916 c-down-conditional does the reverse of c-up-conditional.
917 c-up-conditional-with-else and c-down-conditional-with-else are
918 variants of these that also stops at "#else" lines (suggested by Don
919 Provan).
920
921 *** Minor improvements to many movement functions in tricky situations.
922
923 ** Makefile mode changes
924
925 *** The mode now uses the abbrev table `makefile-mode-abbrev-table'.
926
927 *** Conditionals and include statements are now highlighted when
928 Fontlock mode is active.
929
930 ** Isearch changes
931
932 *** Isearch now puts a call to `isearch-resume' in the command history,
933 so that searches can be resumed.
934
935 *** In Isearch mode, M-C-s and M-C-r are now bound like C-s and C-r,
936 respectively, i.e. you can repeat a regexp isearch with the same keys
937 that started the search.
938
939 *** In Isearch mode, mouse-2 in the echo area now yanks the current
940 selection into the search string rather than giving an error.
941
942 *** There is a new lazy highlighting feature in incremental search.
943
944 Lazy highlighting is switched on/off by customizing variable
945 `isearch-lazy-highlight'. When active, all matches for the current
946 search string are highlighted. The current match is highlighted as
947 before using face `isearch' or `region'. All other matches are
948 highlighted using face `isearch-lazy-highlight-face' which defaults to
949 `secondary-selection'.
950
951 The extra highlighting makes it easier to anticipate where the cursor
952 will end up each time you press C-s or C-r to repeat a pending search.
953 Highlighting of these additional matches happens in a deferred fashion
954 using "idle timers," so the cycles needed do not rob isearch of its
955 usual snappy response.
956
957 If `isearch-lazy-highlight-cleanup' is set to t, highlights for
958 matches are automatically cleared when you end the search. If it is
959 set to nil, you can remove the highlights manually with `M-x
960 isearch-lazy-highlight-cleanup'.
961
962 ** Changes in sort.el
963
964 The function sort-numeric-fields interprets numbers starting with `0'
965 as octal and numbers starting with `0x' or `0X' as hexadecimal. The
966 new user-option sort-numberic-base can be used to specify a default
967 numeric base.
968
969 ** Changes to Ange-ftp
970
971 *** Ange-ftp allows you to specify of a port number in remote file
972 names cleanly. It is appended to the host name, separated by a hash
973 sign, e.g. `/foo@bar.org#666:mumble'. (This syntax comes from EFS.)
974
975 *** If the new user-option `ange-ftp-try-passive-mode' is set, passive
976 ftp mode will be used if the ftp client supports that.
977
978 ** Shell script mode changes.
979
980 Shell script mode (sh-script) can now indent scripts for shells
981 derived from sh and rc. The indentation style is customizeable, and
982 sh-script can attempt to "learn" the current buffer's style.
983
984 ** Etags changes.
985
986 *** In DOS, etags looks for file.cgz if it cannot find file.c.
987
988 *** New option --ignore-case-regex is an alternative to --regex. It is now
989 possible to bind a regexp to a language, by prepending the regexp with
990 {lang}, where lang is one of the languages that `etags --help' prints out.
991 This feature is useful especially for regex files, where each line contains
992 a regular expression. The manual contains details.
993
994 *** In C and derived languages, etags creates tags for function
995 declarations when given the --declarations option.
996
997 *** In C++, tags are created for "operator". The tags have the form
998 "operator+", without spaces between the keyword and the operator.
999
1000 *** New language Ada: tags are functions, procedures, packages, tasks, and
1001 types.
1002
1003 *** In Fortran, `procedure' is not tagged.
1004
1005 *** In Java, tags are created for "interface".
1006
1007 *** In Lisp, "(defstruct (foo", "(defun (operator" and similar constructs
1008 are now tagged.
1009
1010 *** In Perl, the --globals option tags global variables. my and local
1011 variables are tagged.
1012
1013 *** New language Python: def and class at the beginning of a line are tags.
1014
1015 *** .ss files are Scheme files, .pdb is Postscript with C syntax, .psw is
1016 for PSWrap.
1017
1018 ** Changes in etags.el
1019
1020 *** The new user-option tags-case-fold-search can be used to make
1021 tags operations case-sensitive or case-insensitive. The default
1022 is to use the same setting as case-fold-search.
1023
1024 *** You can display additional output with M-x tags-apropos by setting
1025 the new variable tags-apropos-additional-actions.
1026
1027 If non-nil, the variable's value should be a list of triples (TITLE
1028 FUNCTION TO-SEARCH). For each triple, M-x tags-apropos processes
1029 TO-SEARCH and lists tags from it. TO-SEARCH should be an alist,
1030 obarray, or symbol. If it is a symbol, the symbol's value is used.
1031
1032 TITLE is a string to use to label the list of tags from TO-SEARCH.
1033
1034 FUNCTION is a function to call when an entry is selected in the Tags
1035 List buffer. It is called with one argument, the selected symbol.
1036
1037 A useful example value for this variable might be something like:
1038
1039 '(("Emacs Lisp" Info-goto-emacs-command-node obarray)
1040 ("Common Lisp" common-lisp-hyperspec common-lisp-hyperspec-obarray)
1041 ("SCWM" scwm-documentation scwm-obarray))
1042
1043 *** The face tags-tag-face can be used to customize the appearance
1044 of tags in the output of M-x tags-apropos.
1045
1046 *** Setting tags-apropos-verbose to a non-nil value displays the
1047 names of tags files in the *Tags List* buffer.
1048
1049 ** Emacs now attempts to determine the initial language environment
1050 and preferred and locale coding systems systematically from the
1051 LC_ALL, LC_CTYPE, and LANG environment variables during startup.
1052
1053 ** New language environments `Polish', `Latin-8' and `Latin-9'.
1054 Latin-8 and Latin-9 correspond respectively to the ISO character sets
1055 8859-14 (Celtic) and 8859-15 (updated Latin-1, with the Euro sign).
1056 There is currently no specific input method support for them.
1057
1058 ** Fortran mode has a new command `fortran-strip-sequence-nos' to
1059 remove text past column 72. The syntax class of `\' in Fortran is now
1060 appropriate for C-style escape sequences in strings.
1061
1062 ** SGML mode's default `sgml-validate-command' is now `nsgmls'.
1063
1064 ** A new command `view-emacs-problems' (C-h P) displays the PROBLEMS file.
1065
1066 ** The Dabbrev package has a new user-option `dabbrev-ignore-regexps'
1067 containing a list of regular expressions. Buffers matching a regular
1068 expression from that list, are not checked.
1069
1070 ** New modes and packages
1071
1072 *** The new package xml.el provides a simple but generic XML
1073 parser. It doesn't parse the DTDs however.
1074
1075 *** The comment operations are now provided by the newcomment.el
1076 package which allows different styles of comment-region and should
1077 be more robust while offering the same functionality.
1078
1079 *** The Ebrowse package implements a C++ class browser and tags
1080 facilities tailored for use with C++. It is documented in a
1081 separate Texinfo file.
1082
1083 *** The PCL-CVS package available by either running M-x cvs-examine
1084 or by visiting a CVS administrative directory (with a prefix argument)
1085 provides an alternative interface to VC-dired for CVS.
1086 It comes with log-view-mode to view RCS and SCCS logs and log-edit-mode
1087 used to enter checkin log messages.
1088
1089 *** The new package called `woman' allows to browse Unix man pages
1090 without invoking external programs.
1091
1092 The command `M-x woman' formats manual pages entirely in Emacs Lisp
1093 and then displays them, like `M-x manual-entry' does. Unlike
1094 `manual-entry', `woman' does not invoke any external programs, so it
1095 is useful on systems such as MS-DOS/MS-Windows where the `man' and
1096 Groff or `troff' commands are not readily available.
1097
1098 The command `M-x woman-find-file' asks for the file name of a man
1099 page, then formats and displays it like `M-x woman' does.
1100
1101 *** The new command M-x re-builder offers a convenient interface for
1102 authoring regular expressions with immediate visual feedback.
1103
1104 The buffer from which the command was called becomes the target for
1105 the regexp editor popping up in a separate window. Matching text in
1106 the target buffer is immediately color marked during the editing.
1107 Each sub-expression of the regexp will show up in a different face so
1108 even complex regexps can be edited and verified on target data in a
1109 single step.
1110
1111 On displays not supporting faces the matches instead blink like
1112 matching parens to make them stand out. On such a setup you will
1113 probably also want to use the sub-expression mode when the regexp
1114 contains such to get feedback about their respective limits.
1115
1116 *** glasses-mode is a minor mode that makes
1117 unreadableIdentifiersLikeThis readable. It works as glasses, without
1118 actually modifying content of a buffer.
1119
1120 *** The package ebnf2ps translates an EBNF to a syntactic chart in
1121 PostScript.
1122
1123 Currently accepts ad-hoc EBNF, ISO EBNF and Bison/Yacc.
1124
1125 The ad-hoc default EBNF syntax has the following elements:
1126
1127 ; comment (until end of line)
1128 A non-terminal
1129 "C" terminal
1130 ?C? special
1131 $A default non-terminal
1132 $"C" default terminal
1133 $?C? default special
1134 A = B. production (A is the header and B the body)
1135 C D sequence (C occurs before D)
1136 C | D alternative (C or D occurs)
1137 A - B exception (A excluding B, B without any non-terminal)
1138 n * A repetition (A repeats n (integer) times)
1139 (C) group (expression C is grouped together)
1140 [C] optional (C may or not occurs)
1141 C+ one or more occurrences of C
1142 {C}+ one or more occurrences of C
1143 {C}* zero or more occurrences of C
1144 {C} zero or more occurrences of C
1145 C / D equivalent to: C {D C}*
1146 {C || D}+ equivalent to: C {D C}*
1147 {C || D}* equivalent to: [C {D C}*]
1148 {C || D} equivalent to: [C {D C}*]
1149
1150 Please, see ebnf2ps documentation for EBNF syntax and how to use it.
1151
1152 *** The package align.el will align columns within a region, using M-x
1153 align. Its mode-specific rules, based on regular expressions,
1154 determine where the columns should be split. In C and C++, for
1155 example, it will align variable names in declaration lists, or the
1156 equal signs of assignments.
1157
1158 *** `paragraph-indent-minor-mode' is a new minor mode supporting
1159 paragraphs in the same style as `paragraph-indent-text-mode'.
1160
1161 *** bs.el is a new package for buffer selection similar to
1162 list-buffers or electric-buffer-list. Use M-x bs-show to display a
1163 buffer menu with this package. You can use M-x bs-customize to
1164 customize the package.
1165
1166 *** find-lisp.el is a package emulating the Unix find command in Lisp.
1167
1168 *** calculator.el is a small calculator package that is intended to
1169 replace desktop calculators such as xcalc and calc.exe. Actually, it
1170 is not too small - it has more features than most desktop calculators,
1171 and can be customized easily to get many more functions. It should
1172 not be confused with "calc" which is a much bigger mathematical tool
1173 which answers different needs.
1174
1175 *** The minor modes cwarn-mode and global-cwarn-mode highlights
1176 suspicious C and C++ constructions. Currently, assignments inside
1177 expressions, semicolon following `if', `for' and `while' (except, of
1178 course, after a `do .. while' statement), and C++ functions with
1179 reference parameters are recognized. The modes require font-lock mode
1180 to be enabled.
1181
1182 *** smerge-mode.el provides `smerge-mode', a simple minor-mode for files
1183 containing diff3-style conflict markers, such as generated by RCS.
1184
1185 *** 5x5.el is a simple puzzle game.
1186
1187 *** hl-line.el provides a minor mode to highlight the current line.
1188
1189 *** ansi-color.el translates ANSI terminal escapes into text-properties.
1190
1191 *** delphi.el provides a major mode for editing the Delphi (Object
1192 Pascal) language.
1193
1194 *** quickurl.el provides a simple method of inserting a URL based on
1195 the text at point.
1196
1197 *** sql.el provides an interface to SQL data bases.
1198
1199 *** fortune.el uses the fortune program to create mail/news signatures.
1200
1201 *** whitespace.el ???
1202
1203 *** PostScript mode (ps-mode) is a new major mode for editing PostScript
1204 files. It offers: interaction with a PostScript interpreter, including
1205 (very basic) error handling; fontification, easily customizable for
1206 interpreter messages; auto-indentation; insertion of EPSF templates and
1207 often used code snippets; viewing of BoundingBox; commenting out /
1208 uncommenting regions; conversion of 8bit characters to PostScript octal
1209 codes. All functionality is accessible through a menu.
1210
1211 *** delim-col helps to prettify columns in a text region or rectangle.
1212
1213 Here is an example of columns:
1214
1215 horse apple bus
1216 dog pineapple car EXTRA
1217 porcupine strawberry airplane
1218
1219 Doing the following settings:
1220
1221 (setq delimit-columns-str-before "[ ")
1222 (setq delimit-columns-str-after " ]")
1223 (setq delimit-columns-str-separator ", ")
1224 (setq delimit-columns-separator "\t")
1225
1226
1227 Selecting the lines above and typing:
1228
1229 M-x delimit-columns-region
1230
1231 It results:
1232
1233 [ horse , apple , bus , ]
1234 [ dog , pineapple , car , EXTRA ]
1235 [ porcupine, strawberry, airplane, ]
1236
1237 delim-col has the following options:
1238
1239 delimit-columns-str-before Specify a string to be inserted
1240 before all columns.
1241
1242 delimit-columns-str-separator Specify a string to be inserted
1243 between each column.
1244
1245 delimit-columns-str-after Specify a string to be inserted
1246 after all columns.
1247
1248 delimit-columns-separator Specify a regexp which separates
1249 each column.
1250
1251 delim-col has the following commands:
1252
1253 delimit-columns-region Prettify all columns in a text region.
1254 delimit-columns-rectangle Prettify all columns in a text rectangle.
1255
1256 *** The package recentf.el maintains a menu for visiting files that
1257 were operated on recently.
1258
1259 M-x recentf-mode RET toggles recentf mode.
1260
1261 M-x customize-variable RET recentf-mode RET can be used to enable
1262 recentf at Emacs startup.
1263
1264 M-x customize-variable RET recentf-menu-filter RET to specify a menu
1265 filter function to change the menu appearance. For example, the recent
1266 file list can be displayed:
1267
1268 - organized by major modes, directories or user defined rules.
1269 - sorted by file pathes, file names, ascending or descending.
1270 - showing pathes relative to the current default-directory
1271
1272 The `recentf-filter-changer' menu filter function allows to
1273 dynamically change the menu appearance.
1274
1275 *** elide-head.el provides a mechanism for eliding boilerplate header
1276 text.
1277
1278 *** footnote.el provides `footnote-mode', a minor mode supporting use
1279 of footnotes. It is intended for use with Message mode, but isn't
1280 specific to Message mode.
1281
1282 *** diff-mode.el provides `diff-mode', a major mode for
1283 viewing/editing context diffs (patches). It is selected for files
1284 with extension `.diff', `.diffs', `.patch' and `.rej'.
1285
1286 *** EUDC, the Emacs Unified Directory Client, provides a common user
1287 interface to access directory servers using different directory
1288 protocols. It has a separate manual.
1289
1290 *** autoconf.el provides a major mode for editing configure.in files
1291 for Autoconf, selected automatically.
1292
1293 *** windmove.el provides moving between windows.
1294
1295 *** crm.el provides a facility to read multiple strings from the
1296 minibuffer with completion.
1297
1298 *** todo-mode.el provides management of TODO lists and integration
1299 with the diary features.
1300
1301 *** autoarg.el provides a feature reported from Twenex Emacs whereby
1302 numeric keys supply prefix args rather than self inserting.
1303
1304 *** The function `turn-off-auto-fill' unconditionally turns off Auto
1305 Fill mode.
1306
1307 ** Withdrawn packages
1308
1309 *** mldrag.el has been removed. mouse.el provides the same
1310 functionality with aliases for the mldrag functions.
1311
1312 *** eval-reg.el has been obsoleted by changes to edebug.el and removed.
1313
1314 *** ph.el has been obsoleted by EUDC and removed.
1315
1316 \f
1317 * Lisp changes made after edition 2.6 of the Emacs Lisp Manual,
1318 (Display-related features are described in a page of their own below.)
1319
1320 ** Function `aset' stores any multibyte character in any string
1321 without signaling "Attempt to change char length of a string". It may
1322 convert a unibyte string to multibyte if necessary.
1323
1324 ** The value of the `help-echo' text property is called as a function
1325 or evaluated, if it is not a string already, to obtain a help string.
1326
1327 ** Function `make-obsolete' now has an optional arg to say when the
1328 function was declared obsolete.
1329
1330 ** Function plist-member is renamed from widget-plist-member (which is
1331 retained as an alias).
1332
1333 ** Easy-menu's :filter now works as in XEmacs.
1334 It takes the unconverted (i.e. XEmacs) form of the menu and the result
1335 is automatically converted to Emacs' form.
1336
1337 ** The new function `window-list' has been defined
1338
1339 - Function: window-list &optional WINDOW MINIBUF ALL-FRAMES
1340
1341 Return a list of windows in canonical order. The parameters WINDOW,
1342 MINIBUF and ALL-FRAMES are defined like for `next-window'.
1343
1344 ** There's a new function `some-window' defined as follows
1345
1346 - Function: some-window PREDICATE &optional MINIBUF ALL-FRAMES DEFAULT
1347
1348 Return a window satisfying PREDICATE.
1349
1350 This function cycles through all visible windows using `walk-windows',
1351 calling PREDICATE on each one. PREDICATE is called with a window as
1352 argument. The first window for which PREDICATE returns a non-nil
1353 value is returned. If no window satisfies PREDICATE, DEFAULT is
1354 returned.
1355
1356 Optional second arg MINIBUF t means count the minibuffer window even
1357 if not active. MINIBUF nil or omitted means count the minibuffer iff
1358 it is active. MINIBUF neither t nor nil means not to count the
1359 minibuffer even if it is active.
1360
1361 Several frames may share a single minibuffer; if the minibuffer
1362 counts, all windows on all frames that share that minibuffer count
1363 too. Therefore, if you are using a separate minibuffer frame
1364 and the minibuffer is active and MINIBUF says it counts,
1365 `walk-windows' includes the windows in the frame from which you
1366 entered the minibuffer, as well as the minibuffer window.
1367
1368 ALL-FRAMES is the optional third argument.
1369 ALL-FRAMES nil or omitted means cycle within the frames as specified above.
1370 ALL-FRAMES = `visible' means include windows on all visible frames.
1371 ALL-FRAMES = 0 means include windows on all visible and iconified frames.
1372 ALL-FRAMES = t means include windows on all frames including invisible frames.
1373 If ALL-FRAMES is a frame, it means include windows on that frame.
1374 Anything else means restrict to the selected frame.
1375
1376 ** The function `single-key-description' now encloses function key
1377 and event names in angle brackets.
1378
1379 ** If the variable `message-truncate-lines' is bound to t around a
1380 call to `message', the echo area will not be resized to display that
1381 message; it will be truncated instead, as it was done in 20.x.
1382 Default value is nil.
1383
1384 ** The user option line-number-display-limit can now be set to nil,
1385 meaning no limit.
1386
1387 ** select-safe-coding-system now also checks the most preferred
1388 coding-system if buffer-file-coding-system is `undecided' and
1389 DEFAULT-CODING-SYSTEM is not specified,
1390
1391 ** The function `subr-arity' provides information on the argument list
1392 of a primitive.
1393
1394 ** The text property `keymap' specifies a key map which overrides the
1395 buffer's local map and the map specified by the `local-map' property.
1396 This is probably what most current uses of `local-map' want, rather
1397 than replacing the local map.
1398
1399 ** The obsolete variables before-change-function and
1400 after-change-function are no longer acted upon and have been removed.
1401
1402 ** The function `apropos-mode' runs the hook `apropos-mode-hook'.
1403
1404 ** `concat' no longer accepts individual integer arguments, as
1405 promised long ago.
1406
1407 \f
1408 * Lisp changes in Emacs 21.1 (see following page for display-related features)
1409
1410 Note that +++ before an item means the Lisp manual has been updated.
1411 --- means that I have decided it does not need to be in the Lisp manual.
1412 When you add a new item, please add it without either +++ or ---
1413 so I will know I still need to look at it -- rms.
1414
1415 *** The functions `find-charset-region' and `find-charset-string' include
1416 `eight-bit-control' and/or `eight-bit-graphic' in the returned list
1417 when it finds 8-bit characters. Previously, it included `ascii' in a
1418 multibyte buffer and `unknown' in a unibyte buffer.
1419
1420 *** The functions `set-buffer-modified', `string-as-multibyte' and
1421 `string-as-unibyte' change the byte sequence of a buffer if it
1422 contains a character from the `eight-bit-control' character set.
1423
1424 *** The handling of multibyte sequences in a multibyte buffer is
1425 changed. Previously, a byte sequence matching the pattern
1426 [\200-\237][\240-\377]+ was interpreted as a single character
1427 regardless of the length of the trailing bytes [\240-\377]+. Thus, if
1428 the sequence was longer than what the leading byte indicated, the
1429 extra trailing bytes were ignored by Lisp functions. Now such extra
1430 bytes are independent 8-bit characters belonging to the charset
1431 eight-bit-graphic.
1432
1433 ** Fontsets are now implemented using char-tables.
1434
1435 A fontset can now be specified for for each independent character, for
1436 a group of characters or for a character set rather than just for a
1437 character set as previously.
1438
1439 *** The arguments of the function `set-fontset-font' are changed.
1440 They are NAME, CHARACTER, FONTNAME, and optional FRAME. The function
1441 modifies fontset NAME to use FONTNAME for CHARACTER.
1442
1443 CHARACTER may be a cons (FROM . TO), where FROM and TO are non-generic
1444 characters. In that case FONTNAME is used for all characters in the
1445 range FROM and TO (inclusive). CHARACTER may be a charset. In that
1446 case FONTNAME is used for all character in the charset.
1447
1448 FONTNAME may be a cons (FAMILY . REGISTRY), where FAMILY is the family
1449 name of a font and REGSITRY is a registry name of a font.
1450
1451 *** Variable x-charset-registry has been deleted. The default charset
1452 registries of character sets are set in the default fontset
1453 "fontset-default".
1454
1455 *** The function `create-fontset-from-fontset-spec' ignores the second
1456 argument STYLE-VARIANT. It never creates style-variant fontsets.
1457
1458 ** The method of composing characters is changed. Now character
1459 composition is done by a special text property `composition' in
1460 buffers and strings.
1461
1462 *** Charset composition is deleted. Emacs never creates a `composite
1463 character' which is an independent character with a unique character
1464 code. Thus the following functions handling `composite characters'
1465 have been deleted: composite-char-component,
1466 composite-char-component-count, composite-char-composition-rule,
1467 composite-char-composition-rule and decompose-composite-char delete.
1468 The variables leading-code-composition and min-composite-char have
1469 also been deleted.
1470
1471 *** Three more glyph reference points are added. They can be used to
1472 specify a composition rule. See the documentation of the variable
1473 `reference-point-alist' for more detail.
1474
1475 *** The function `compose-region' takes new arguments COMPONENTS and
1476 MODIFICATION-FUNC. With COMPONENTS, you can specify not only a
1477 composition rule but also characters to be composed. Such characters
1478 may differ between buffer and string text.
1479
1480 *** The function `compose-string' takes new arguments START, END,
1481 COMPONENTS, and MODIFICATION-FUNC.
1482
1483 *** The function `compose-string' puts text property `composition'
1484 directly on the argument STRING instead of returning a new string.
1485 Likewise, the function `decompose-string' just removes text property
1486 `composition' from STRING.
1487
1488 *** The new function `find-composition' returns information about
1489 a composition at a specified position in a buffer or a string.
1490
1491 *** The function `decompose-composite-char' is now labeled as
1492 obsolete.
1493
1494 ** The new character set `mule-unicode-0100-24ff' is introduced for
1495 Unicode characters of the range U+0100..U+24FF. Currently, this
1496 character set is not used.
1497
1498 ** The new character sets `japanese-jisx0213-1' and
1499 `japanese-jisx0213-2' are introduced for the new Japanese standard JIS
1500 X 0213 Plane 1 and Plane 2.
1501
1502 +++
1503 ** The new character sets `eight-bit-control' and `eight-bit-graphic'
1504 are introduced for 8-bit characters in the ranges 0x80..0x9F and
1505 0xA0..0xFF respectively.
1506
1507 +++
1508 ** If the APPEND argument of `write-region' is an integer, it seeks to
1509 that offset in the file before writing.
1510
1511 ** The function `add-minor-mode' has been added for convenience and
1512 compatibility with XEmacs (and is used internally by define-minor-mode).
1513
1514 ** The function `shell-command' now sets the default directory of the
1515 `*Shell Command Output*' buffer to the default directory of the buffer
1516 from which the command was issued.
1517
1518 ** The functions `query-replace', `query-replace-regexp',
1519 `query-replace-regexp-eval' `map-query-replace-regexp',
1520 `replace-string', `replace-regexp', and `perform-replace' take two
1521 additional optional arguments START and END that specify the region to
1522 operate on.
1523
1524 ** The new function `count-screen-lines' is a more flexible alternative
1525 to `window-buffer-height'.
1526
1527 - Function: count-screen-lines &optional BEG END COUNT-FINAL-NEWLINE WINDOW
1528
1529 Return the number of screen lines in the region between BEG and END.
1530 The number of screen lines may be different from the number of actual
1531 lines, due to line breaking, display table, etc.
1532
1533 Optional arguments BEG and END default to `point-min' and `point-max'
1534 respectively.
1535
1536 If region ends with a newline, ignore it unless optinal third argument
1537 COUNT-FINAL-NEWLINE is non-nil.
1538
1539 The optional fourth argument WINDOW specifies the window used for
1540 obtaining parameters such as width, horizontal scrolling, and so
1541 on. The default is to use the selected window's parameters.
1542
1543 Like `vertical-motion', `count-screen-lines' always uses the current
1544 buffer, regardless of which buffer is displayed in WINDOW. This makes
1545 possible to use `count-screen-lines' in any buffer, whether or not it
1546 is currently displayed in some window.
1547
1548 ** The new function `mapc' is like `mapcar' but doesn't collect the
1549 argument function's results.
1550
1551 ** The functions base64-decode-region and base64-decode-string now
1552 signal an error instead of returning nil if decoding fails.
1553
1554 ** The function sendmail-user-agent-compose now recognizes a `body'
1555 header is the list of headers passed to it.
1556
1557 ** The new function member-ignore-case works like `member', but
1558 ignores differences in case and text representation.
1559
1560 ** The buffer-local variable cursor-type can be used to specify the
1561 cursor to use in windows displaying a buffer. Values are interpreted
1562 as follows:
1563
1564 t use the cursor specified for the frame (default)
1565 nil don't display a cursor
1566 `bar' display a bar cursor with default width
1567 (bar . WIDTH) display a bar cursor with width WIDTH
1568 others display a box cursor.
1569
1570 ** The variable open-paren-in-column-0-is-defun-start controls whether
1571 an open parenthesis in column 0 is considered to be the start of a
1572 defun. If set, the default, it is considered a defun start. If not
1573 set, an open parenthesis in column 0 has no special meaning.
1574
1575 ** The new function `string-to-syntax' can be used to translate syntax
1576 specifications in string form as accepted by `modify-syntax-entry' to
1577 the cons-cell form that is used for the values of the `syntax-table'
1578 text property, and in `font-lock-syntactic-keywords'.
1579
1580 Example:
1581
1582 (string-to-syntax "()")
1583 => (4 . 41)
1584
1585 ** Emacs' reader supports CL read syntax for integers in bases
1586 other than 10.
1587
1588 *** `#BINTEGER' or `#bINTEGER' reads INTEGER in binary (radix 2).
1589 INTEGER optionally contains a sign.
1590
1591 #b1111
1592 => 15
1593 #b-1111
1594 => -15
1595
1596 *** `#OINTEGER' or `#oINTEGER' reads INTEGER in octal (radix 8).
1597
1598 #o666
1599 => 438
1600
1601 *** `#XINTEGER' or `#xINTEGER' reads INTEGER in hexadecimal (radix 16).
1602
1603 #xbeef
1604 => 48815
1605
1606 *** `#RADIXrINTEGER' reads INTEGER in radix RADIX, 2 <= RADIX <= 36.
1607
1608 #2R-111
1609 => -7
1610 #25rah
1611 => 267
1612
1613 ** The function `documentation-property' now evaluates the value of
1614 the given property to obtain a string if it doesn't refer to etc/DOC
1615 and isn't a string.
1616
1617 ** If called for a symbol, the function `documentation' now looks for
1618 a `function-documentation' property of that symbol. If it has a non-nil
1619 value, the documentation is taken from that value. If the value is
1620 not a string, it is evaluated to obtain a string.
1621
1622 +++
1623 ** The last argument of `define-key-after' defaults to t for convenience.
1624
1625 ** The new function `replace-regexp-in-string' replaces all matches
1626 for a regexp in a string.
1627
1628 ** `mouse-position' now runs the abnormal hook
1629 `mouse-position-function'.
1630
1631 ** The function string-to-number now returns a float for numbers
1632 that don't fit into a Lisp integer.
1633
1634 ** The variable keyword-symbols-constants-flag has been removed.
1635 Keywords are now always considered constants.
1636
1637 +++
1638 ** The new function `delete-and-extract-region' deletes text and
1639 returns it.
1640
1641 ** The function `clear-this-command-keys' now also clears the vector
1642 returned by function `recent-keys'.
1643
1644 +++
1645 ** Variables `beginning-of-defun-function' and `end-of-defun-function'
1646 can be used to define handlers for the functions that find defuns.
1647 Major modes can define these locally instead of rebinding M-C-a
1648 etc. if the normal conventions for defuns are not appropriate for the
1649 mode.
1650
1651 +++
1652 ** easy-mmode-define-minor-mode now takes an additional BODY argument
1653 and is renamed `define-minor-mode'.
1654
1655 +++
1656 ** If an abbrev has a hook function which is a symbol, and that symbol
1657 has a non-nil `no-self-insert' property, the return value of the hook
1658 function specifies whether an expansion has been done or not. If it
1659 returns nil, abbrev-expand also returns nil, meaning "no expansion has
1660 been performed."
1661
1662 When abbrev expansion is done by typing a self-inserting character,
1663 and the abbrev has a hook with the `no-self-insert' property, and the
1664 hook function returns non-nil meaning expansion has been done,
1665 then the self-inserting character is not inserted.
1666
1667 +++
1668 ** The function `intern-soft' now accepts a symbol as first argument.
1669 In this case, that exact symbol is looked up in the specified obarray,
1670 and the function's value is nil if it is not found.
1671
1672 +++
1673 ** The new macro `with-syntax-table' can be used to evaluate forms
1674 with the syntax table of the current buffer temporarily set to a
1675 specified table.
1676
1677 (with-syntax-table TABLE &rest BODY)
1678
1679 Evaluate BODY with syntax table of current buffer set to a copy of
1680 TABLE. The current syntax table is saved, BODY is evaluated, and the
1681 saved table is restored, even in case of an abnormal exit. Value is
1682 what BODY returns.
1683
1684 +++
1685 ** Regular expressions now support intervals \{n,m\} as well as
1686 Perl's shy-groups \(?:...\) and non-greedy *? +? and ?? operators.
1687
1688 +++
1689 ** The optional argument BUFFER of function file-local-copy has been
1690 removed since it wasn't used by anything.
1691
1692 +++
1693 ** The file name argument of function `file-locked-p' is now required
1694 instead of being optional.
1695
1696 +++
1697 ** The new built-in error `text-read-only' is signaled when trying to
1698 modify read-only text.
1699
1700 +++
1701 ** New functions and variables for locales.
1702
1703 The new variable `locale-coding-system' specifies how to encode and
1704 decode strings passed to low-level message functions like strerror and
1705 time functions like strftime. The new variables
1706 `system-messages-locale' and `system-time-locale' give the system
1707 locales to be used when invoking these two types of functions.
1708
1709 The new function `set-locale-environment' sets the language
1710 environment, preferred coding system, and locale coding system from
1711 the system locale as specified by the LC_ALL, LC_CTYPE, and LANG
1712 environment variables. Normally, it is invoked during startup and need
1713 not be invoked thereafter. It uses the new variables
1714 `locale-language-names', `locale-charset-language-names', and
1715 `locale-preferred-coding-systems' to make its decisions.
1716
1717 +++
1718 ** syntax tables now understand nested comments.
1719 To declare a comment syntax as allowing nesting, just add an `n'
1720 modifier to either of the characters of the comment end and the comment
1721 start sequences.
1722
1723 +++
1724 ** The function `pixmap-spec-p' has been renamed `bitmap-spec-p'
1725 because `bitmap' is more in line with the usual X terminology.
1726
1727 +++
1728 ** New function `propertize'
1729
1730 The new function `propertize' can be used to conveniently construct
1731 strings with text properties.
1732
1733 - Function: propertize STRING &rest PROPERTIES
1734
1735 Value is a copy of STRING with text properties assigned as specified
1736 by PROPERTIES. PROPERTIES is a sequence of pairs PROPERTY VALUE, with
1737 PROPERTY being the name of a text property and VALUE being the
1738 specified value of that property. Example:
1739
1740 (propertize "foo" 'face 'bold 'read-only t)
1741
1742 +++
1743 ** push and pop macros.
1744
1745 Simple versions of the push and pop macros of Common Lisp
1746 are now defined in Emacs Lisp. These macros allow only symbols
1747 as the place that holds the list to be changed.
1748
1749 (push NEWELT LISTNAME) add NEWELT to the front of LISTNAME's value.
1750 (pop LISTNAME) return first elt of LISTNAME, and remove it
1751 (thus altering the value of LISTNAME).
1752
1753 ** New dolist and dotimes macros.
1754
1755 Simple versions of the dolist and dotimes macros of Common Lisp
1756 are now defined in Emacs Lisp.
1757
1758 (dolist (VAR LIST [RESULT]) BODY...)
1759 Execute body once for each element of LIST,
1760 using the variable VAR to hold the current element.
1761 Then return the value of RESULT, or nil if RESULT is omitted.
1762
1763 (dotimes (VAR COUNT [RESULT]) BODY...)
1764 Execute BODY with VAR bound to successive integers running from 0,
1765 inclusive, to COUNT, exclusive.
1766 Then return the value of RESULT, or nil if RESULT is omitted.
1767
1768 +++
1769 ** Regular expressions now support Posix character classes such
1770 as [:alpha:], [:space:] and so on.
1771
1772 [:digit:] matches 0 through 9
1773 [:cntrl:] matches ASCII control characters
1774 [:xdigit:] matches 0 through 9, a through f and A through F.
1775 [:blank:] matches space and tab only
1776 [:graph:] matches graphic characters--everything except ASCII control chars,
1777 space, and DEL.
1778 [:print:] matches printing characters--everything except ASCII control chars
1779 and DEL.
1780 [:alnum:] matches letters and digits.
1781 (But at present, for multibyte characters,
1782 it matches anything that has word syntax.)
1783 [:alpha:] matches letters.
1784 (But at present, for multibyte characters,
1785 it matches anything that has word syntax.)
1786 [:ascii:] matches ASCII (unibyte) characters.
1787 [:nonascii:] matches non-ASCII (multibyte) characters.
1788 [:lower:] matches anything lower-case.
1789 [:punct:] matches punctuation.
1790 (But at present, for multibyte characters,
1791 it matches anything that has non-word syntax.)
1792 [:space:] matches anything that has whitespace syntax.
1793 [:upper:] matches anything upper-case.
1794 [:word:] matches anything that has word syntax.
1795
1796 +++
1797 ** Emacs now has built-in hash tables.
1798
1799 The following functions are defined for hash tables:
1800
1801 - Function: make-hash-table ARGS
1802
1803 The argument list ARGS consists of keyword/argument pairs. All arguments
1804 are optional. The following arguments are defined:
1805
1806 :test TEST
1807
1808 TEST must be a symbol specifying how to compare keys. Default is `eql'.
1809 Predefined are `eq', `eql' and `equal'. If TEST is not predefined,
1810 it must have been defined with `define-hash-table-test'.
1811
1812 :size SIZE
1813
1814 SIZE must be an integer > 0 giving a hint to the implementation how
1815 many elements will be put in the hash table. Default size is 65.
1816
1817 :rehash-size REHASH-SIZE
1818
1819 REHASH-SIZE specifies by how much to grow a hash table once it becomes
1820 full. If REHASH-SIZE is an integer, add that to the hash table's old
1821 size to get the new size. Otherwise, REHASH-SIZE must be a float >
1822 1.0, and the new size is computed by multiplying REHASH-SIZE with the
1823 old size. Default rehash size is 1.5.
1824
1825 :rehash-threshold THRESHOLD
1826
1827 THRESHOLD must be a float > 0 and <= 1.0 specifying when to resize the
1828 hash table. It is resized when the ratio of (number of entries) /
1829 (size of hash table) is >= THRESHOLD. Default threshold is 0.8.
1830
1831 :weakness WEAK
1832
1833 WEAK must be either nil, one of the symbols `key, `value', or t.
1834 Entries are removed from weak tables during garbage collection if
1835 their key and/or value are not referenced elsewhere outside of the
1836 hash table. Default are non-weak hash tables.
1837
1838 - Function: makehash &optional TEST
1839
1840 Similar to make-hash-table, but only TEST can be specified.
1841
1842 - Function: hash-table-p TABLE
1843
1844 Returns non-nil if TABLE is a hash table object.
1845
1846 - Function: copy-hash-table TABLE
1847
1848 Returns a copy of TABLE. Only the table itself is copied, keys and
1849 values are shared.
1850
1851 - Function: hash-table-count TABLE
1852
1853 Returns the number of entries in TABLE.
1854
1855 - Function: hash-table-rehash-size TABLE
1856
1857 Returns the rehash size of TABLE.
1858
1859 - Function: hash-table-rehash-threshold TABLE
1860
1861 Returns the rehash threshold of TABLE.
1862
1863 - Function: hash-table-rehash-size TABLE
1864
1865 Returns the size of TABLE.
1866
1867 - Function: hash-table-rehash-test TABLE
1868
1869 Returns the test TABLE uses to compare keys.
1870
1871 - Function: hash-table-weakness TABLE
1872
1873 Returns the weakness specified for TABLE.
1874
1875 - Function: clrhash TABLE
1876
1877 Clear TABLE.
1878
1879 - Function: gethash KEY TABLE &optional DEFAULT
1880
1881 Look up KEY in TABLE and return its associated VALUE or DEFAULT if
1882 not found.
1883
1884 - Function: puthash KEY VALUE TABLE
1885
1886 Associate KEY with VALUE in TABLE. If KEY is already associated with
1887 another value, replace the old value with VALUE.
1888
1889 - Function: remhash KEY TABLE
1890
1891 Remove KEY from TABLE if it is there.
1892
1893 - Function: maphash FUNCTION TABLE
1894
1895 Call FUNCTION for all elements in TABLE. FUNCTION must take two
1896 arguments KEY and VALUE.
1897
1898 - Function: sxhash OBJ
1899
1900 Return a hash code for Lisp object OBJ.
1901
1902 - Function: define-hash-table-test NAME TEST-FN HASH-FN
1903
1904 Define a new hash table test named NAME. If NAME is specified as
1905 a test in `make-hash-table', the table created will use TEST-FN for
1906 comparing keys, and HASH-FN to compute hash codes for keys. Test
1907 and hash function are stored as symbol property `hash-table-test'
1908 of NAME with a value of (TEST-FN HASH-FN).
1909
1910 TEST-FN must take two arguments and return non-nil if they are the same.
1911
1912 HASH-FN must take one argument and return an integer that is the hash
1913 code of the argument. The function should use the whole range of
1914 integer values for hash code computation, including negative integers.
1915
1916 Example: The following creates a hash table whose keys are supposed to
1917 be strings that are compared case-insensitively.
1918
1919 (defun case-fold-string= (a b)
1920 (compare-strings a nil nil b nil nil t))
1921
1922 (defun case-fold-string-hash (a)
1923 (sxhash (upcase a)))
1924
1925 (define-hash-table-test 'case-fold 'case-fold-string=
1926 'case-fold-string-hash))
1927
1928 (make-hash-table :test 'case-fold)
1929
1930 +++
1931 ** The Lisp reader handles circular structure.
1932
1933 It now works to use the #N= and #N# constructs to represent
1934 circular structures. For example, #1=(a . #1#) represents
1935 a cons cell which is its own cdr.
1936
1937 +++
1938 ** The Lisp printer handles circular structure.
1939
1940 If you bind print-circle to a non-nil value, the Lisp printer outputs
1941 #N= and #N# constructs to represent circular and shared structure.
1942
1943 +++
1944 ** If the second argument to `move-to-column' is anything but nil or
1945 t, that means replace a tab with spaces if necessary to reach the
1946 specified column, but do not add spaces at the end of the line if it
1947 is too short to reach that column.
1948
1949 +++
1950 ** perform-replace has a new feature: the REPLACEMENTS argument may
1951 now be a cons cell (FUNCTION . DATA). This means to call FUNCTION
1952 after each match to get the replacement text. FUNCTION is called with
1953 two arguments: DATA, and the number of replacements already made.
1954
1955 If the FROM-STRING contains any upper-case letters,
1956 perform-replace also turns off `case-fold-search' temporarily
1957 and inserts the replacement text without altering case in it.
1958
1959 +++
1960 ** The function buffer-size now accepts an optional argument
1961 to specify which buffer to return the size of.
1962
1963 +++
1964 ** The calendar motion commands now run the normal hook
1965 calendar-move-hook after moving point.
1966
1967 +++
1968 ** The new variable small-temporary-file-directory specifies a
1969 directory to use for creating temporary files that are likely to be
1970 small. (Certain Emacs features use this directory.) If
1971 small-temporary-file-directory is nil, they use
1972 temporary-file-directory instead.
1973
1974 +++
1975 ** The variable `inhibit-modification-hooks', if non-nil, inhibits all
1976 the hooks that track changes in the buffer. This affects
1977 `before-change-functions' and `after-change-functions', as well as
1978 hooks attached to text properties and overlay properties.
1979
1980 +++
1981 ** assoc-delete-all is a new function that deletes all the
1982 elements of an alist which have a particular value as the car.
1983
1984 +++
1985 ** make-temp-file provides a more reliable way to create a temporary file.
1986
1987 make-temp-file is used like make-temp-name, except that it actually
1988 creates the file before it returns. This prevents a timing error,
1989 ensuring that no other job can use the same name for a temporary file.
1990
1991 +++
1992 ** New exclusive-open feature in `write-region'
1993
1994 The optional seventh arg is now called MUSTBENEW. If non-nil, it insists
1995 on a check for an existing file with the same name. If MUSTBENEW
1996 is `excl', that means to get an error if the file already exists;
1997 never overwrite. If MUSTBENEW is neither nil nor `excl', that means
1998 ask for confirmation before overwriting, but do go ahead and
1999 overwrite the file if the user gives confirmation.
2000
2001 If the MUSTBENEW argument in `write-region' is `excl',
2002 that means to use a special feature in the `open' system call
2003 to get an error if the file exists at that time.
2004 The error reported is `file-already-exists'.
2005
2006 +++
2007 ** Function `format' now handles text properties.
2008
2009 Text properties of the format string are applied to the result string.
2010 If the result string is longer than the format string, text properties
2011 ending at the end of the format string are extended to the end of the
2012 result string.
2013
2014 Text properties from string arguments are applied to the result
2015 string where arguments appear in the result string.
2016
2017 Example:
2018
2019 (let ((s1 "hello, %s")
2020 (s2 "world"))
2021 (put-text-property 0 (length s1) 'face 'bold s1)
2022 (put-text-property 0 (length s2) 'face 'italic s2)
2023 (format s1 s2))
2024
2025 results in a bold-face string with an italic `world' at the end.
2026
2027 +++
2028 ** Messages can now be displayed with text properties.
2029
2030 Text properties are handled as described above for function `format'.
2031 The following example displays a bold-face message with an italic
2032 argument in it.
2033
2034 (let ((msg "hello, %s!")
2035 (arg "world"))
2036 (put-text-property 0 (length msg) 'face 'bold msg)
2037 (put-text-property 0 (length arg) 'face 'italic arg)
2038 (message msg arg))
2039
2040 +++
2041 ** Sound support
2042
2043 Emacs supports playing sound files on GNU/Linux and the free BSDs
2044 (Voxware driver and native BSD driver, aka as Luigi's driver).
2045
2046 Currently supported file formats are RIFF-WAVE (*.wav) and Sun Audio
2047 (*.au). You must configure Emacs with the option `--with-sound=yes'
2048 to enable sound support.
2049
2050 Sound files can be played by calling (play-sound SOUND). SOUND is a
2051 list of the form `(sound PROPERTY...)'. The function is only defined
2052 when sound support is present for the system on which Emacs runs. The
2053 functions runs `play-sound-functions' with one argument which is the
2054 sound to play, before playing the sound.
2055
2056 The following sound properties are supported:
2057
2058 - `:file FILE'
2059
2060 FILE is a file name. If FILE isn't an absolute name, it will be
2061 searched relative to `data-directory'.
2062
2063 - `:data DATA'
2064
2065 DATA is a string containing sound data. Either :file or :data
2066 may be present, but not both.
2067
2068 - `:volume VOLUME'
2069
2070 VOLUME must be an integer in the range 0..100 or a float in the range
2071 0..1. This property is optional.
2072
2073 Other properties are ignored.
2074
2075 ** `multimedia' is a new Finder keyword and Custom group.
2076
2077 ** keywordp is a new predicate to test efficiently for an object being
2078 a keyword symbol.
2079
2080 ** Changes to garbage collection
2081
2082 *** The function garbage-collect now additionally returns the number
2083 of live and free strings.
2084
2085 *** There is a new variable `strings-consed' holding the number of
2086 strings that have been consed so far.
2087
2088 \f
2089 * Lisp-level Display features added after release 2.6 of the Emacs
2090 Lisp Manual
2091
2092 +++
2093 ** Help strings in menu items are now used to provide `help-echo' text.
2094
2095 ** The function `image-size' can be used to determine the size of an
2096 image.
2097
2098 - Function: image-size SPEC &optional PIXELS FRAME
2099
2100 Return the size of an image as a pair (WIDTH . HEIGHT).
2101
2102 SPEC is an image specification. PIXELS non-nil means return sizes
2103 measured in pixels, otherwise return sizes measured in canonical
2104 character units (fractions of the width/height of the frame's default
2105 font). FRAME is the frame on which the image will be displayed.
2106 FRAME nil or omitted means use the selected frame.
2107
2108 ** The function `find-image' can be used to find a usable image
2109 satisfying one of a list of specifications.
2110
2111 +++
2112 ** The STRING argument of `put-image' and `insert-image' is now
2113 optional.
2114
2115 ** Image specifications may contain the property `:ascent center'.
2116
2117 When this property is specified, the image is vertically centered
2118 around a centerline which would be the vertical center of text drawn
2119 at the position of the image, in the manner specified by the text
2120 properties and overlays that apply to the image.
2121
2122 \f
2123 * New Lisp-level Display features in Emacs 21.1
2124
2125 Note that +++ before an item means the Lisp manual has been updated.
2126 --- means that I have decided it does not need to be in the Lisp manual.
2127 When you add a new item, please add it without either +++ or ---
2128 so I will know I still need to look at it -- rms.
2129
2130 ** The function tty-suppress-bold-inverse-default-colors can be used
2131 to make Emacs avoid displaying text with bold black foreground on TTYs.
2132
2133 Some terminals, notably PC consoles, emulate bold text by displaying
2134 text in brighter colors. On such a console, a bold black foreground
2135 is displayed in a gray color. If this turns out to be hard to read on
2136 your monitor---the problem occurred with the mode line on
2137 laptops---you can instruct Emacs to ignore the text's boldness, and to
2138 just display it black instead.
2139
2140 This situation can't be detected automatically. You will have to put
2141 a line like
2142
2143 (tty-suppress-bold-inverse-default-colors t)
2144
2145 in your `.emacs'.
2146
2147 ** New face implementation.
2148
2149 Emacs faces have been reimplemented from scratch. They don't use XLFD
2150 font names anymore and face merging now works as expected.
2151
2152 +++
2153 *** New faces.
2154
2155 Each face can specify the following display attributes:
2156
2157 1. Font family or fontset alias name.
2158
2159 2. Relative proportionate width, aka character set width or set
2160 width (swidth), e.g. `semi-compressed'.
2161
2162 3. Font height in 1/10pt
2163
2164 4. Font weight, e.g. `bold'.
2165
2166 5. Font slant, e.g. `italic'.
2167
2168 6. Foreground color.
2169
2170 7. Background color.
2171
2172 8. Whether or not characters should be underlined, and in what color.
2173
2174 9. Whether or not characters should be displayed in inverse video.
2175
2176 10. A background stipple, a bitmap.
2177
2178 11. Whether or not characters should be overlined, and in what color.
2179
2180 12. Whether or not characters should be strike-through, and in what
2181 color.
2182
2183 13. Whether or not a box should be drawn around characters, its
2184 color, the width of the box lines, and 3D appearance.
2185
2186 Faces are frame-local by nature because Emacs allows to define the
2187 same named face (face names are symbols) differently for different
2188 frames. Each frame has an alist of face definitions for all named
2189 faces. The value of a named face in such an alist is a Lisp vector
2190 with the symbol `face' in slot 0, and a slot for each each of the face
2191 attributes mentioned above.
2192
2193 There is also a global face alist `face-new-frame-defaults'. Face
2194 definitions from this list are used to initialize faces of newly
2195 created frames.
2196
2197 A face doesn't have to specify all attributes. Those not specified
2198 have a nil value. Faces specifying all attributes are called
2199 `fully-specified'.
2200
2201 +++
2202 *** Face merging.
2203
2204 The display style of a given character in the text is determined by
2205 combining several faces. This process is called `face merging'. Any
2206 aspect of the display style that isn't specified by overlays or text
2207 properties is taken from the `default' face. Since it is made sure
2208 that the default face is always fully-specified, face merging always
2209 results in a fully-specified face.
2210
2211 +++
2212 *** Face realization.
2213
2214 After all face attributes for a character have been determined by
2215 merging faces of that character, that face is `realized'. The
2216 realization process maps face attributes to what is physically
2217 available on the system where Emacs runs. The result is a `realized
2218 face' in form of an internal structure which is stored in the face
2219 cache of the frame on which it was realized.
2220
2221 Face realization is done in the context of the charset of the
2222 character to display because different fonts and encodings are used
2223 for different charsets. In other words, for characters of different
2224 charsets, different realized faces are needed to display them.
2225
2226 Except for composite characters, faces are always realized for a
2227 specific character set and contain a specific font, even if the face
2228 being realized specifies a fontset. The reason is that the result of
2229 the new font selection stage is better than what can be done with
2230 statically defined font name patterns in fontsets.
2231
2232 In unibyte text, Emacs' charsets aren't applicable; function
2233 `char-charset' reports ASCII for all characters, including those >
2234 0x7f. The X registry and encoding of fonts to use is determined from
2235 the variable `face-default-registry' in this case. The variable is
2236 initialized at Emacs startup time from the font the user specified for
2237 Emacs.
2238
2239 Currently all unibyte text, i.e. all buffers with
2240 `enable-multibyte-characters' nil are displayed with fonts of the same
2241 registry and encoding `face-default-registry'. This is consistent
2242 with the fact that languages can also be set globally, only.
2243
2244 ++++
2245 **** Clearing face caches.
2246
2247 The Lisp function `clear-face-cache' can be called to clear face caches
2248 on all frames. If called with a non-nil argument, it will also unload
2249 unused fonts.
2250
2251 +++
2252 *** Font selection.
2253
2254 Font selection tries to find the best available matching font for a
2255 given (charset, face) combination. This is done slightly differently
2256 for faces specifying a fontset, or a font family name.
2257
2258 If the face specifies a fontset name, that fontset determines a
2259 pattern for fonts of the given charset. If the face specifies a font
2260 family, a font pattern is constructed. Charset symbols have a
2261 property `x-charset-registry' for that purpose that maps a charset to
2262 an XLFD registry and encoding in the font pattern constructed.
2263
2264 Available fonts on the system on which Emacs runs are then matched
2265 against the font pattern. The result of font selection is the best
2266 match for the given face attributes in this font list.
2267
2268 Font selection can be influenced by the user.
2269
2270 The user can specify the relative importance he gives the face
2271 attributes width, height, weight, and slant by setting
2272 face-font-selection-order (faces.el) to a list of face attribute
2273 names. The default is (:width :height :weight :slant), and means
2274 that font selection first tries to find a good match for the font
2275 width specified by a face, then---within fonts with that width---tries
2276 to find a best match for the specified font height, etc.
2277
2278 Setting `face-alternative-font-family-alist' allows the user to
2279 specify alternative font families to try if a family specified by a
2280 face doesn't exist.
2281
2282 +++
2283 **** Scalable fonts
2284
2285 Emacs can make use of scalable fonts but doesn't do so by default,
2286 since the use of too many or too big scalable fonts may crash XFree86
2287 servers.
2288
2289 To enable scalable font use, set the variable
2290 `scalable-fonts-allowed'. A value of nil, the default, means never use
2291 scalable fonts. A value of t means any scalable font may be used.
2292 Otherwise, the value must be a list of regular expressions. A
2293 scalable font may then be used if it matches a regular expression from
2294 that list. Example:
2295
2296 (setq scalable-fonts-allowed '("muleindian-2$"))
2297
2298 allows the use of scalable fonts with registry `muleindian-2'.
2299
2300 +++
2301 *** Functions and variables related to font selection.
2302
2303 - Function: x-family-fonts &optional FAMILY FRAME
2304
2305 Return a list of available fonts of family FAMILY on FRAME. If FAMILY
2306 is omitted or nil, list all families. Otherwise, FAMILY must be a
2307 string, possibly containing wildcards `?' and `*'.
2308
2309 If FRAME is omitted or nil, use the selected frame. Each element of
2310 the result is a vector [FAMILY WIDTH POINT-SIZE WEIGHT SLANT FIXED-P
2311 FULL REGISTRY-AND-ENCODING]. FAMILY is the font family name.
2312 POINT-SIZE is the size of the font in 1/10 pt. WIDTH, WEIGHT, and
2313 SLANT are symbols describing the width, weight and slant of the font.
2314 These symbols are the same as for face attributes. FIXED-P is non-nil
2315 if the font is fixed-pitch. FULL is the full name of the font, and
2316 REGISTRY-AND-ENCODING is a string giving the registry and encoding of
2317 the font. The result list is sorted according to the current setting
2318 of the face font sort order.
2319
2320 - Function: x-font-family-list
2321
2322 Return a list of available font families on FRAME. If FRAME is
2323 omitted or nil, use the selected frame. Value is a list of conses
2324 (FAMILY . FIXED-P) where FAMILY is a font family, and FIXED-P is
2325 non-nil if fonts of that family are fixed-pitch.
2326
2327 - Variable: font-list-limit
2328
2329 Limit for font matching. If an integer > 0, font matching functions
2330 won't load more than that number of fonts when searching for a
2331 matching font. The default is currently 100.
2332
2333 +++
2334 *** Setting face attributes.
2335
2336 For the most part, the new face implementation is interface-compatible
2337 with the old one. Old face attribute related functions are now
2338 implemented in terms of the new functions `set-face-attribute' and
2339 `face-attribute'.
2340
2341 Face attributes are identified by their names which are keyword
2342 symbols. All attributes can be set to `unspecified'.
2343
2344 The following attributes are recognized:
2345
2346 `:family'
2347
2348 VALUE must be a string specifying the font family, e.g. ``courier'',
2349 or a fontset alias name. If a font family is specified, wild-cards `*'
2350 and `?' are allowed.
2351
2352 `:width'
2353
2354 VALUE specifies the relative proportionate width of the font to use.
2355 It must be one of the symbols `ultra-condensed', `extra-condensed',
2356 `condensed', `semi-condensed', `normal', `semi-expanded', `expanded',
2357 `extra-expanded', or `ultra-expanded'.
2358
2359 `:height'
2360
2361 VALUE must be an integer specifying the height of the font to use in
2362 1/10 pt.
2363
2364 `:weight'
2365
2366 VALUE specifies the weight of the font to use. It must be one of the
2367 symbols `ultra-bold', `extra-bold', `bold', `semi-bold', `normal',
2368 `semi-light', `light', `extra-light', `ultra-light'.
2369
2370 `:slant'
2371
2372 VALUE specifies the slant of the font to use. It must be one of the
2373 symbols `italic', `oblique', `normal', `reverse-italic', or
2374 `reverse-oblique'.
2375
2376 `:foreground', `:background'
2377
2378 VALUE must be a color name, a string.
2379
2380 `:underline'
2381
2382 VALUE specifies whether characters in FACE should be underlined. If
2383 VALUE is t, underline with foreground color of the face. If VALUE is
2384 a string, underline with that color. If VALUE is nil, explicitly
2385 don't underline.
2386
2387 `:overline'
2388
2389 VALUE specifies whether characters in FACE should be overlined. If
2390 VALUE is t, overline with foreground color of the face. If VALUE is a
2391 string, overline with that color. If VALUE is nil, explicitly don't
2392 overline.
2393
2394 `:strike-through'
2395
2396 VALUE specifies whether characters in FACE should be drawn with a line
2397 striking through them. If VALUE is t, use the foreground color of the
2398 face. If VALUE is a string, strike-through with that color. If VALUE
2399 is nil, explicitly don't strike through.
2400
2401 `:box'
2402
2403 VALUE specifies whether characters in FACE should have a box drawn
2404 around them. If VALUE is nil, explicitly don't draw boxes. If
2405 VALUE is t, draw a box with lines of width 1 in the foreground color
2406 of the face. If VALUE is a string, the string must be a color name,
2407 and the box is drawn in that color with a line width of 1. Otherwise,
2408 VALUE must be a property list of the form `(:line-width WIDTH
2409 :color COLOR :style STYLE)'. If a keyword/value pair is missing from
2410 the property list, a default value will be used for the value, as
2411 specified below. WIDTH specifies the width of the lines to draw; it
2412 defaults to 1. COLOR is the name of the color to draw in, default is
2413 the foreground color of the face for simple boxes, and the background
2414 color of the face for 3D boxes. STYLE specifies whether a 3D box
2415 should be draw. If STYLE is `released-button', draw a box looking
2416 like a released 3D button. If STYLE is `pressed-button' draw a box
2417 that appears like a pressed button. If STYLE is nil, the default if
2418 the property list doesn't contain a style specification, draw a 2D
2419 box.
2420
2421 `:inverse-video'
2422
2423 VALUE specifies whether characters in FACE should be displayed in
2424 inverse video. VALUE must be one of t or nil.
2425
2426 `:stipple'
2427
2428 If VALUE is a string, it must be the name of a file of pixmap data.
2429 The directories listed in the `x-bitmap-file-path' variable are
2430 searched. Alternatively, VALUE may be a list of the form (WIDTH
2431 HEIGHT DATA) where WIDTH and HEIGHT are the size in pixels, and DATA
2432 is a string containing the raw bits of the bitmap. VALUE nil means
2433 explicitly don't use a stipple pattern.
2434
2435 For convenience, attributes `:family', `:width', `:height', `:weight',
2436 and `:slant' may also be set in one step from an X font name:
2437
2438 `:font'
2439
2440 Set font-related face attributes from VALUE. VALUE must be a valid
2441 XLFD font name. If it is a font name pattern, the first matching font
2442 is used--this is for compatibility with the behavior of previous
2443 versions of Emacs.
2444
2445 For compatibility with Emacs 20, keywords `:bold' and `:italic' can
2446 be used to specify that a bold or italic font should be used. VALUE
2447 must be t or nil in that case. A value of `unspecified' is not allowed."
2448
2449 Please see also the documentation of `set-face-attribute' and
2450 `defface'.
2451
2452 *** Face attributes and X resources
2453
2454 The following X resource names can be used to set face attributes
2455 from X resources:
2456
2457 Face attribute X resource class
2458 -----------------------------------------------------------------------
2459 :family attributeFamily . Face.AttributeFamily
2460 :width attributeWidth Face.AttributeWidth
2461 :height attributeHeight Face.AttributeHeight
2462 :weight attributeWeight Face.AttributeWeight
2463 :slant attributeSlant Face.AttributeSlant
2464 foreground attributeForeground Face.AttributeForeground
2465 :background attributeBackground . Face.AttributeBackground
2466 :overline attributeOverline Face.AttributeOverline
2467 :strike-through attributeStrikeThrough Face.AttributeStrikeThrough
2468 :box attributeBox Face.AttributeBox
2469 :underline attributeUnderline Face.AttributeUnderline
2470 :inverse-video attributeInverse Face.AttributeInverse
2471 :stipple attributeStipple Face.AttributeStipple
2472 or attributeBackgroundPixmap
2473 Face.AttributeBackgroundPixmap
2474 :font attributeFont Face.AttributeFont
2475 :bold attributeBold Face.AttributeBold
2476 :italic attributeItalic . Face.AttributeItalic
2477 :font attributeFont Face.AttributeFont
2478
2479 +++
2480 *** Text property `face'.
2481
2482 The value of the `face' text property can now be a single face
2483 specification or a list of such specifications. Each face
2484 specification can be
2485
2486 1. A symbol or string naming a Lisp face.
2487
2488 2. A property list of the form (KEYWORD VALUE ...) where each
2489 KEYWORD is a face attribute name, and VALUE is an appropriate value
2490 for that attribute. Please see the doc string of `set-face-attribute'
2491 for face attribute names.
2492
2493 3. Conses of the form (FOREGROUND-COLOR . COLOR) or
2494 (BACKGROUND-COLOR . COLOR) where COLOR is a color name. This is
2495 for compatibility with previous Emacs versions.
2496
2497 +++
2498 ** Support functions for colors on text-only terminals.
2499
2500 The function `tty-color-define' can be used to define colors for use
2501 on TTY and MSDOS frames. It maps a color name to a color number on
2502 the terminal. Emacs defines a couple of common color mappings by
2503 default. You can get defined colors with a call to
2504 `defined-colors'. The function `tty-color-clear' can be
2505 used to clear the mapping table.
2506
2507 ** Unified support for colors independent of frame type.
2508
2509 The new functions `defined-colors', `color-defined-p', `color-values',
2510 and `display-color-p' work for any type of frame. On frames whose
2511 type is neither x nor w32, these functions transparently map X-style
2512 color specifications to the closest colors supported by the frame
2513 display. Lisp programs should use these new functions instead of the
2514 old `x-defined-colors', `x-color-defined-p', `x-color-values', and
2515 `x-display-color-p'. (The old function names are still available for
2516 compatibility; they are now aliases of the new names.) Lisp programs
2517 should no more look at the value of the variable window-system to
2518 modify their color-related behavior.
2519
2520 The primitives `color-gray-p' and `color-supported-p' also work for
2521 any frame type.
2522
2523 ** Platform-independent functions to describe display capabilities.
2524
2525 The new functions `display-mouse-p', `display-popup-menus-p',
2526 `display-graphic-p', `display-selections-p', `display-screens',
2527 `display-pixel-width', `display-pixel-height', `display-mm-width',
2528 `display-mm-height', `display-backing-store', `display-save-under',
2529 `display-planes', `display-color-cells', `display-visual-class', and
2530 `display-grayscale-p' describe the basic capabilities of a particular
2531 display. Lisp programs should call these functions instead of testing
2532 the value of the variables `window-system' or `system-type', or calling
2533 platform-specific functions such as `x-display-pixel-width'.
2534
2535 +++
2536 ** The minibuffer prompt is now actually inserted in the minibuffer.
2537
2538 This makes it possible to scroll through the prompt, if you want to.
2539
2540 The function minubuffer-prompt-end returns the current position of the
2541 end of the minibuffer prompt, if the minibuffer is current.
2542 Otherwise, it returns zero.
2543
2544 ** New `field' abstraction in buffers.
2545
2546 There is now code to support an abstraction called `fields' in emacs
2547 buffers. A field is a contiguous region of text with the same `field'
2548 text-property.
2549
2550 Many emacs functions, such as forward-word, forward-sentence,
2551 forward-paragraph, beginning-of-line, etc., stop moving when they come
2552 to the boundary between fields; beginning-of-line and end-of-line will
2553 not let the point move past the field boundary, but other movement
2554 commands continue into the next field if repeated. Stopping at field
2555 boundaries can be suppressed programmatically by binding
2556 `inhibit-field-text-motion' to a non-nil value around calls to these
2557 functions.
2558
2559 Now that the minibuffer prompt is inserted into the minibuffer, it is in
2560 a separate field from the user-input part of the buffer, so that common
2561 editing commands treat the user's text separately from the prompt.
2562
2563 The following functions are defined for operating on fields:
2564
2565 - Function: constrain-to-field NEW-POS OLD-POS &optional ESCAPE-FROM-EDGE ONLY-IN-LINE
2566
2567 Return the position closest to NEW-POS that is in the same field as OLD-POS.
2568 A field is a region of text with the same `field' property.
2569 If NEW-POS is nil, then the current point is used instead, and set to the
2570 constrained position if that is is different.
2571
2572 If OLD-POS is at the boundary of two fields, then the allowable
2573 positions for NEW-POS depends on the value of the optional argument
2574 ESCAPE-FROM-EDGE: If ESCAPE-FROM-EDGE is nil, then NEW-POS is
2575 constrained to the field that has the same `field' text-property
2576 as any new characters inserted at OLD-POS, whereas if ESCAPE-FROM-EDGE
2577 is non-nil, NEW-POS is constrained to the union of the two adjacent
2578 fields.
2579
2580 If the optional argument ONLY-IN-LINE is non-nil and constraining
2581 NEW-POS would move it to a different line, NEW-POS is returned
2582 unconstrained. This useful for commands that move by line, like
2583 C-n or C-a, which should generally respect field boundaries
2584 only in the case where they can still move to the right line.
2585
2586 - Function: erase-field &optional POS
2587
2588 Erases the field surrounding POS.
2589 A field is a region of text with the same `field' property.
2590 If POS is nil, the position of the current buffer's point is used.
2591
2592 - Function: field-beginning &optional POS ESCAPE-FROM-EDGE
2593
2594 Return the beginning of the field surrounding POS.
2595 A field is a region of text with the same `field' property.
2596 If POS is nil, the position of the current buffer's point is used.
2597 If ESCAPE-FROM-EDGE is non-nil and POS is already at beginning of an
2598 field, then the beginning of the *previous* field is returned.
2599
2600 - Function: field-end &optional POS ESCAPE-FROM-EDGE
2601
2602 Return the end of the field surrounding POS.
2603 A field is a region of text with the same `field' property.
2604 If POS is nil, the position of the current buffer's point is used.
2605 If ESCAPE-FROM-EDGE is non-nil and POS is already at end of a field,
2606 then the end of the *following* field is returned.
2607
2608 - Function: field-string &optional POS
2609
2610 Return the contents of the field surrounding POS as a string.
2611 A field is a region of text with the same `field' property.
2612 If POS is nil, the position of the current buffer's point is used.
2613
2614 - Function: field-string-no-properties &optional POS
2615
2616 Return the contents of the field around POS, without text-properties.
2617 A field is a region of text with the same `field' property.
2618 If POS is nil, the position of the current buffer's point is used.
2619
2620 +++
2621 ** Image support.
2622
2623 Emacs can now display images. Images are inserted into text by giving
2624 strings or buffer text a `display' text property containing one of
2625 (AREA IMAGE) or IMAGE. The display of the `display' property value
2626 replaces the display of the characters having that property.
2627
2628 If the property value has the form (AREA IMAGE), AREA must be one of
2629 `(margin left-margin)', `(margin right-margin)' or `(margin nil)'. If
2630 AREA is `(margin nil)', IMAGE will be displayed in the text area of a
2631 window, otherwise it will be displayed in the left or right marginal
2632 area.
2633
2634 IMAGE is an image specification.
2635
2636 *** Image specifications
2637
2638 Image specifications are lists of the form `(image PROPS)' where PROPS
2639 is a property list whose keys are keyword symbols. Each
2640 specifications must contain a property `:type TYPE' with TYPE being a
2641 symbol specifying the image type, e.g. `xbm'. Properties not
2642 described below are ignored.
2643
2644 The following is a list of properties all image types share.
2645
2646 `:ascent ASCENT'
2647
2648 ASCENT must be a number in the range 0..100, or the symbol `center'.
2649 If it is a number, it specifies the percentage of the image's height
2650 to use for its ascent.
2651
2652 If not specified, ASCENT defaults to the value 50 which means that the
2653 image will be centered with the base line of the row it appears in.
2654
2655 If ASCENT is `center' the image is vertically centered around a
2656 centerline which is the vertical center of text drawn at the position
2657 of the image, in the manner specified by the text properties and
2658 overlays that apply to the image.
2659
2660 `:margin MARGIN'
2661
2662 MARGIN must be a number >= 0 specifying how many pixels to put as
2663 margin around the image. Default is 0.
2664
2665 `:relief RELIEF'
2666
2667 RELIEF is analogous to the `:relief' attribute of faces. Puts a relief
2668 around an image.
2669
2670 `:algorithm ALGO'
2671
2672 Apply an image algorithm to the image before displaying it. ALGO must
2673 be a symbol specifying the algorithm. Currently only `laplace' is
2674 supported which applies a Laplace edge detection algorithm to an image
2675 which is intended to display images "disabled."
2676
2677 `:heuristic-mask BG'
2678
2679 If BG is not nil, build a clipping mask for the image, so that the
2680 background of a frame is visible behind the image. If BG is t,
2681 determine the background color of the image by looking at the 4
2682 corners of the image, assuming the most frequently occuring color from
2683 the corners is the background color of the image. Otherwise, BG must
2684 be a list `(RED GREEN BLUE)' specifying the color to assume for the
2685 background of the image.
2686
2687 `:file FILE'
2688
2689 Load image from FILE. If FILE is not absolute after expanding it,
2690 search for the image in `data-directory'. Some image types support
2691 building images from data. When this is done, no `:file' property
2692 may be present in the image specification.
2693
2694 `:data DATA'
2695
2696 Get image data from DATA. (As of this writing, this is not yet
2697 supported for image type `postscript'). Either :file or :data may be
2698 present in an image specification, but not both. All image types
2699 support strings as DATA, some types allow additional types of DATA.
2700
2701 *** Supported image types
2702
2703 **** XBM, image type `xbm'.
2704
2705 XBM images don't require an external library. Additional image
2706 properties supported are
2707
2708 `:foreground FG'
2709
2710 FG must be a string specifying the image foreground color. Default
2711 is the frame's foreground.
2712
2713 `:background FG'
2714
2715 BG must be a string specifying the image foreground color. Default is
2716 the frame's background color.
2717
2718 XBM images can be constructed from data instead of file. In this
2719 case, the image specification must contain the following properties
2720 instead of a `:file' property.
2721
2722 `:width WIDTH'
2723
2724 WIDTH specifies the width of the image in pixels.
2725
2726 `:height HEIGHT'
2727
2728 HEIGHT specifies the height of the image in pixels.
2729
2730 `:data DATA'
2731
2732 DATA must be either
2733
2734 1. a string large enough to hold the bitmap data, i.e. it must
2735 have a size >= (WIDTH + 7) / 8 * HEIGHT
2736
2737 2. a bool-vector of size >= WIDTH * HEIGHT
2738
2739 3. a vector of strings or bool-vectors, one for each line of the
2740 bitmap.
2741
2742 4. a string that's an in-memory XBM file. Neither width nor
2743 height may be specified in this case because these are defined
2744 in the file.
2745
2746 **** XPM, image type `xpm'
2747
2748 XPM images require the external library `libXpm', package
2749 `xpm-3.4k.tar.gz', version 3.4k or later. Make sure the library is
2750 found when Emacs is configured by supplying appropriate paths via
2751 `--x-includes' and `--x-libraries'.
2752
2753 Additional image properties supported are:
2754
2755 `:color-symbols SYMBOLS'
2756
2757 SYMBOLS must be a list of pairs (NAME . COLOR), with NAME being the
2758 name of color as it appears in an XPM file, and COLOR being an X color
2759 name.
2760
2761 XPM images can be built from memory instead of files. In that case,
2762 add a `:data' property instead of a `:file' property.
2763
2764 The XPM library uses libz in its implementation so that it is able
2765 to display compressed images.
2766
2767 **** PBM, image type `pbm'
2768
2769 PBM images don't require an external library. Color, gray-scale and
2770 mono images are supported. There are no additional image properties
2771 defined.
2772
2773 **** JPEG, image type `jpeg'
2774
2775 Support for JPEG images requires the external library `libjpeg',
2776 package `jpegsrc.v6a.tar.gz', or later. Additional image properties
2777 are:
2778
2779 **** TIFF, image type `tiff'
2780
2781 Support for TIFF images requires the external library `libtiff',
2782 package `tiff-v3.4-tar.gz', or later. There are no additional image
2783 properties defined.
2784
2785 **** GIF, image type `gif'
2786
2787 Support for GIF images requires the external library `libungif', package
2788 `libungif-4.1.0', or later.
2789
2790 Additional image properties supported are:
2791
2792 `:index INDEX'
2793
2794 INDEX must be an integer >= 0. Load image number INDEX from a
2795 multi-image GIF file. An error is signalled if INDEX is too large.
2796
2797 This could be used to implement limited support for animated GIFs.
2798 For example, the following function displays a multi-image GIF file
2799 at point-min in the current buffer, switching between sub-images
2800 every 0.1 seconds.
2801
2802 (defun show-anim (file max)
2803 "Display multi-image GIF file FILE which contains MAX subimages."
2804 (display-anim (current-buffer) file 0 max t))
2805
2806 (defun display-anim (buffer file idx max first-time)
2807 (when (= idx max)
2808 (setq idx 0))
2809 (let ((img (create-image file nil nil :index idx)))
2810 (save-excursion
2811 (set-buffer buffer)
2812 (goto-char (point-min))
2813 (unless first-time (delete-char 1))
2814 (insert-image img "x"))
2815 (run-with-timer 0.1 nil 'display-anim buffer file (1+ idx) max nil)))
2816
2817 **** PNG, image type `png'
2818
2819 Support for PNG images requires the external library `libpng',
2820 package `libpng-1.0.2.tar.gz', or later. There are no additional image
2821 properties defined.
2822
2823 **** Ghostscript, image type `postscript'.
2824
2825 Additional image properties supported are:
2826
2827 `:pt-width WIDTH'
2828
2829 WIDTH is width of the image in pt (1/72 inch). WIDTH must be an
2830 integer. This is a required property.
2831
2832 `:pt-height HEIGHT'
2833
2834 HEIGHT specifies the height of the image in pt (1/72 inch). HEIGHT
2835 must be a integer. This is an required property.
2836
2837 `:bounding-box BOX'
2838
2839 BOX must be a list or vector of 4 integers giving the bounding box of
2840 the PS image, analogous to the `BoundingBox' comment found in PS
2841 files. This is an required property.
2842
2843 Part of the Ghostscript interface is implemented in Lisp. See
2844 lisp/gs.el.
2845
2846 *** Lisp interface.
2847
2848 The variable `image-types' contains a list of those image types
2849 which are supported in the current configuration.
2850
2851 Images are stored in an image cache and removed from the cache when
2852 they haven't been displayed for `image-cache-eviction-delay seconds.
2853 The function `clear-image-cache' can be used to clear the image cache
2854 manually. Images in the cache are compared with `equal', i.e. all
2855 images with `equal' specifications share the same image.
2856
2857 *** Simplified image API, image.el
2858
2859 The new Lisp package image.el contains functions that simplify image
2860 creation and putting images into text. The function `create-image'
2861 can be used to create images. The macro `defimage' can be used to
2862 define an image based on available image types. The functions
2863 `put-image' and `insert-image' can be used to insert an image into a
2864 buffer.
2865
2866 +++
2867 ** Display margins.
2868
2869 Windows can now have margins which are used for special text
2870 and images.
2871
2872 To give a window margins, either set the buffer-local variables
2873 `left-margin-width' and `right-margin-width', or call
2874 `set-window-margins'. The function `window-margins' can be used to
2875 obtain the current settings. To make `left-margin-width' and
2876 `right-margin-width' take effect, you must set them before displaying
2877 the buffer in a window, or use `set-window-buffer' to force an update
2878 of the display margins.
2879
2880 You can put text in margins by giving it a `display' text property
2881 containing a pair of the form `(LOCATION . VALUE)', where LOCATION is
2882 one of `left-margin' or `right-margin' or nil. VALUE can be either a
2883 string, an image specification or a stretch specification (see later
2884 in this file).
2885
2886 +++
2887 ** Help display
2888
2889 Emacs displays short help messages in the echo area, when the mouse
2890 moves over a tool-bar item or a piece of text that has a text property
2891 `help-echo'. This feature also applies to strings in the mode line
2892 that have a `help-echo' property.
2893
2894 If the value of the `help-echo' property is a function, that function
2895 is called with three arguments WINDOW, OBJECT and POSITION. WINDOW is
2896 the window in which the help was found.
2897
2898 If OBJECT is a buffer, POS is the position in the buffer where the
2899 `help-echo' text property was found.
2900
2901 If OBJECT is an overlay, that overlay has a `help-echo' property, and
2902 POS is the position in the overlay's buffer under the mouse.
2903
2904 If OBJECT is a string (an overlay string or a string displayed with
2905 the `display' property), POS is the position in that string under the
2906 mouse.
2907
2908 If the value of the `help-echo' property is neither a function nor a
2909 string, it is evaluated to obtain a help string.
2910
2911 For tool-bar and menu-bar items, their key definition is used to
2912 determine the help to display. If their definition contains a
2913 property `:help FORM', FORM is evaluated to determine the help string.
2914 For tool-bar items without a help form, the caption of the item is
2915 used as help string.
2916
2917 The hook `show-help-function' can be set to a function that displays
2918 the help string differently. For example, enabling a tooltip window
2919 causes the help display to appear there instead of in the echo area.
2920
2921 +++
2922 ** Vertical fractional scrolling.
2923
2924 The display of text in windows can be scrolled smoothly in pixels.
2925 This is useful, for example, for making parts of large images visible.
2926
2927 The function `window-vscroll' returns the current value of vertical
2928 scrolling, a non-negative fraction of the canonical character height.
2929 The function `set-window-vscroll' can be used to set the vertical
2930 scrolling value. Here is an example of how these function might be
2931 used.
2932
2933 (global-set-key [A-down]
2934 #'(lambda ()
2935 (interactive)
2936 (set-window-vscroll (selected-window)
2937 (+ 0.5 (window-vscroll)))))
2938 (global-set-key [A-up]
2939 #'(lambda ()
2940 (interactive)
2941 (set-window-vscroll (selected-window)
2942 (- (window-vscroll) 0.5)))))
2943
2944 +++
2945 ** New hook `fontification-functions'.
2946
2947 Functions from `fontification-functions' are called from redisplay
2948 when it encounters a region of text that is not yet fontified. This
2949 variable automatically becomes buffer-local when set. Each function
2950 is called with one argument, POS.
2951
2952 At least one of the hook functions should fontify one or more
2953 characters starting at POS in the current buffer. It should mark them
2954 as fontified by giving them a non-nil value of the `fontified' text
2955 property. It may be reasonable for these functions to check for the
2956 `fontified' property and not put it back on, but they do not have to.
2957
2958 +++
2959 ** Tool bar support.
2960
2961 Emacs supports a tool bar at the top of a frame under X. The frame
2962 parameter `tool-bar-lines' (X resource "toolBar", class "ToolBar")
2963 controls how may lines to reserve for the tool bar. A zero value
2964 suppresses the tool bar. If the value is non-zero and
2965 `auto-resize-tool-bars' is non-nil the tool bar's size will be changed
2966 automatically so that all tool bar items are visible.
2967
2968 *** Tool bar item definitions
2969
2970 Tool bar items are defined using `define-key' with a prefix-key
2971 `tool-bar'. For example `(define-key global-map [tool-bar item1] ITEM)'
2972 where ITEM is a list `(menu-item CAPTION BINDING PROPS...)'.
2973
2974 CAPTION is the caption of the item, If it's not a string, it is
2975 evaluated to get a string. The caption is currently not displayed in
2976 the tool bar, but it is displayed if the item doesn't have a `:help'
2977 property (see below).
2978
2979 BINDING is the tool bar item's binding. Tool bar items with keymaps as
2980 binding are currently ignored.
2981
2982 The following properties are recognized:
2983
2984 `:enable FORM'.
2985
2986 FORM is evaluated and specifies whether the tool bar item is enabled
2987 or disabled.
2988
2989 `:visible FORM'
2990
2991 FORM is evaluated and specifies whether the tool bar item is displayed.
2992
2993 `:filter FUNCTION'
2994
2995 FUNCTION is called with one parameter, the same list BINDING in which
2996 FUNCTION is specified as the filter. The value FUNCTION returns is
2997 used instead of BINDING to display this item.
2998
2999 `:button (TYPE SELECTED)'
3000
3001 TYPE must be one of `:radio' or `:toggle'. SELECTED is evaluated
3002 and specifies whether the button is selected (pressed) or not.
3003
3004 `:image IMAGES'
3005
3006 IMAGES is either a single image specification or a vector of four
3007 image specifications. If it is a vector, this table lists the
3008 meaning of each of the four elements:
3009
3010 Index Use when item is
3011 ----------------------------------------
3012 0 enabled and selected
3013 1 enabled and deselected
3014 2 disabled and selected
3015 3 disabled and deselected
3016
3017 If IMAGE is a single image specification, a Laplace edge-detection
3018 algorithm is used on that image to draw the image in disabled state.
3019
3020 `:help HELP-STRING'.
3021
3022 Gives a help string to display for the tool bar item. This help
3023 is displayed when the mouse is moved over the item.
3024
3025 *** Tool-bar-related variables.
3026
3027 If `auto-resize-tool-bar' is non-nil, the tool bar will automatically
3028 resize to show all defined tool bar items. It will never grow larger
3029 than 1/4 of the frame's size.
3030
3031 If `auto-raise-tool-bar-buttons' is non-nil, tool bar buttons will be
3032 raised when the mouse moves over them.
3033
3034 You can add extra space between tool bar items by setting
3035 `tool-bar-button-margin' to a positive integer specifying a number of
3036 pixels. Default is 1.
3037
3038 You can change the shadow thickness of tool bar buttons by setting
3039 `tool-bar-button-relief' to an integer. Default is 3.
3040
3041 *** Tool-bar clicks with modifiers.
3042
3043 You can bind commands to clicks with control, shift, meta etc. on
3044 a tool bar item. If
3045
3046 (define-key global-map [tool-bar shell]
3047 '(menu-item "Shell" shell
3048 :image (image :type xpm :file "shell.xpm")))
3049
3050 is the original tool bar item definition, then
3051
3052 (define-key global-map [tool-bar S-shell] 'some-command)
3053
3054 makes a binding to run `some-command' for a shifted click on the same
3055 item.
3056
3057 ** Mode line changes.
3058
3059 +++
3060 *** Mouse-sensitive mode line.
3061
3062 The mode line can be made mouse-sensitive by displaying strings there
3063 that have a `local-map' text property. There are three ways to display
3064 a string with a `local-map' property in the mode line.
3065
3066 1. The mode line spec contains a variable whose string value has
3067 a `local-map' text property.
3068
3069 2. The mode line spec contains a format specifier (e.g. `%12b'), and
3070 that format specifier has a `local-map' property.
3071
3072 3. The mode line spec contains a list containing `:eval FORM'. FORM
3073 is evaluated. If the result is a string, and that string has a
3074 `local-map' property.
3075
3076 The same mechanism is used to determine the `face' and `help-echo'
3077 properties of strings in the mode line. See `bindings.el' for an
3078 example.
3079
3080 *** If a mode line element has the form `(:eval FORM)', FORM is
3081 evaluated and the result is used as mode line element.
3082
3083 +++
3084 *** You can suppress mode-line display by setting the buffer-local
3085 variable mode-line-format to nil.
3086
3087 +++
3088 *** A headerline can now be displayed at the top of a window.
3089
3090 This mode line's contents are controlled by the new variable
3091 `header-line-format' and `default-header-line-format' which are
3092 completely analogous to `mode-line-format' and
3093 `default-mode-line-format'. A value of nil means don't display a top
3094 line.
3095
3096 The appearance of top mode lines is controlled by the face
3097 `header-line'.
3098
3099 The function `coordinates-in-window-p' returns `header-line' for a
3100 position in the header-line.
3101
3102 +++
3103 ** Text property `display'
3104
3105 The `display' text property is used to insert images into text, and
3106 also control other aspects of how text displays. The value of the
3107 `display' property should be a display specification, as described
3108 below, or a list or vector containing display specifications.
3109
3110 *** Variable width and height spaces
3111
3112 To display a space of fractional width or height, use a display
3113 specification of the form `(LOCATION STRECH)'. If LOCATION is
3114 `(margin left-margin)', the space is displayed in the left marginal
3115 area, if it is `(margin right-margin)', it is displayed in the right
3116 marginal area, and if LOCATION is `(margin nil)' the space is
3117 displayed in the text. In the latter case you can also use the
3118 simpler form STRETCH as property value.
3119
3120 The stretch specification STRETCH itself is a list of the form `(space
3121 PROPS)', where PROPS is a property list which can contain the
3122 properties described below.
3123
3124 The display of the fractional space replaces the display of the
3125 characters having the `display' property.
3126
3127 - :width WIDTH
3128
3129 Specifies that the space width should be WIDTH times the normal
3130 character width. WIDTH can be an integer or floating point number.
3131
3132 - :relative-width FACTOR
3133
3134 Specifies that the width of the stretch should be computed from the
3135 first character in a group of consecutive characters that have the
3136 same `display' property. The computation is done by multiplying the
3137 width of that character by FACTOR.
3138
3139 - :align-to HPOS
3140
3141 Specifies that the space should be wide enough to reach HPOS. The
3142 value HPOS is measured in units of the normal character width.
3143
3144 Exactly one of the above properties should be used.
3145
3146 - :height HEIGHT
3147
3148 Specifies the height of the space, as HEIGHT, measured in terms of the
3149 normal line height.
3150
3151 - :relative-height FACTOR
3152
3153 The height of the space is computed as the product of the height
3154 of the text having the `display' property and FACTOR.
3155
3156 - :ascent ASCENT
3157
3158 Specifies that ASCENT percent of the height of the stretch should be
3159 used for the ascent of the stretch, i.e. for the part above the
3160 baseline. The value of ASCENT must be a non-negative number less or
3161 equal to 100.
3162
3163 You should not use both `:height' and `:relative-height' together.
3164
3165 *** Images
3166
3167 A display specification for an image has the form `(LOCATION
3168 . IMAGE)', where IMAGE is an image specification. The image replaces,
3169 in the display, the characters having this display specification in
3170 their `display' text property. If LOCATION is `(margin left-margin)',
3171 the image will be displayed in the left marginal area, if it is
3172 `(margin right-margin)' it will be displayed in the right marginal
3173 area, and if LOCATION is `(margin nil)' the image will be displayed in
3174 the text. In the latter case you can also use the simpler form IMAGE
3175 as display specification.
3176
3177 *** Other display properties
3178
3179 - :space-width FACTOR
3180
3181 Specifies that space characters in the text having that property
3182 should be displayed FACTOR times as wide as normal; FACTOR must be an
3183 integer or float.
3184
3185 - :height HEIGHT
3186
3187 Display text having this property in a font that is smaller or larger.
3188
3189 If HEIGHT is a list of the form `(+ N)', where N is an integer, that
3190 means to use a font that is N steps larger. If HEIGHT is a list of
3191 the form `(- N)', that means to use a font that is N steps smaller. A
3192 ``step'' is defined by the set of available fonts; each size for which
3193 a font is available counts as a step.
3194
3195 If HEIGHT is a number, that means to use a font that is HEIGHT times
3196 as tall as the frame's default font.
3197
3198 If HEIGHT is a symbol, it is called as a function with the current
3199 height as argument. The function should return the new height to use.
3200
3201 Otherwise, HEIGHT is evaluated to get the new height, with the symbol
3202 `height' bound to the current specified font height.
3203
3204 - :raise FACTOR
3205
3206 FACTOR must be a number, specifying a multiple of the current
3207 font's height. If it is positive, that means to display the characters
3208 raised. If it is negative, that means to display them lower down. The
3209 amount of raising or lowering is computed without taking account of the
3210 `:height' subproperty.
3211
3212 *** Conditional display properties
3213
3214 All display specifications can be conditionalized. If a specification
3215 has the form `(:when CONDITION . SPEC)', the specification SPEC
3216 applies only when CONDITION yields a non-nil value when evaluated.
3217 During evaluattion, point is temporarily set to the end position of
3218 the text having the `display' property.
3219
3220 The normal specification consisting of SPEC only is equivalent to
3221 `(:when t SPEC)'.
3222
3223 +++
3224 ** New menu separator types.
3225
3226 Emacs now supports more than one menu separator type. Menu items with
3227 item names consisting of dashes only (including zero dashes) are
3228 treated like before. In addition, the following item names are used
3229 to specify other menu separator types.
3230
3231 - `--no-line' or `--space', or `--:space', or `--:noLine'
3232
3233 No separator lines are drawn, but a small space is inserted where the
3234 separator occurs.
3235
3236 - `--single-line' or `--:singleLine'
3237
3238 A single line in the menu's foreground color.
3239
3240 - `--double-line' or `--:doubleLine'
3241
3242 A double line in the menu's foreground color.
3243
3244 - `--single-dashed-line' or `--:singleDashedLine'
3245
3246 A single dashed line in the menu's foreground color.
3247
3248 - `--double-dashed-line' or `--:doubleDashedLine'
3249
3250 A double dashed line in the menu's foreground color.
3251
3252 - `--shadow-etched-in' or `--:shadowEtchedIn'
3253
3254 A single line with 3D sunken appearance. This is the the form
3255 displayed for item names consisting of dashes only.
3256
3257 - `--shadow-etched-out' or `--:shadowEtchedOut'
3258
3259 A single line with 3D raised appearance.
3260
3261 - `--shadow-etched-in-dash' or `--:shadowEtchedInDash'
3262
3263 A single dashed line with 3D sunken appearance.
3264
3265 - `--shadow-etched-out-dash' or `--:shadowEtchedOutDash'
3266
3267 A single dashed line with 3D raise appearance.
3268
3269 - `--shadow-double-etched-in' or `--:shadowDoubleEtchedIn'
3270
3271 Two lines with 3D sunken appearance.
3272
3273 - `--shadow-double-etched-out' or `--:shadowDoubleEtchedOut'
3274
3275 Two lines with 3D raised appearance.
3276
3277 - `--shadow-double-etched-in-dash' or `--:shadowDoubleEtchedInDash'
3278
3279 Two dashed lines with 3D sunken appearance.
3280
3281 - `--shadow-double-etched-out-dash' or `--:shadowDoubleEtchedOutDash'
3282
3283 Two dashed lines with 3D raised appearance.
3284
3285 Under LessTif/Motif, the last four separator types are displayed like
3286 the corresponding single-line separators.
3287
3288 +++
3289 ** New frame parameters for scroll bar colors.
3290
3291 The new frame parameters `scroll-bar-foreground' and
3292 `scroll-bar-background' can be used to change scroll bar colors.
3293 Their value must be either a color name, a string, or nil to specify
3294 that scroll bars should use a default color. For toolkit scroll bars,
3295 default colors are toolkit specific. For non-toolkit scroll bars, the
3296 default background is the background color of the frame, and the
3297 default foreground is black.
3298
3299 The X resource name of these parameters are `scrollBarForeground'
3300 (class ScrollBarForeground) and `scrollBarBackground' (class
3301 `ScrollBarBackground').
3302
3303 Setting these parameters overrides toolkit specific X resource
3304 settings for scroll bar colors.
3305
3306 +++
3307 ** You can set `redisplay-dont-pause' to a non-nil value to prevent
3308 display updates from being interrupted when input is pending.
3309
3310 ---
3311 ** Changing a window's width may now change its window start if it
3312 starts on a continuation line. The new window start is computed based
3313 on the window's new width, starting from the start of the continued
3314 line as the start of the screen line with the minimum distance from
3315 the original window start.
3316
3317 ---
3318 ** The variable `hscroll-step' and the functions
3319 `hscroll-point-visible' and `hscroll-window-column' have been removed
3320 now that proper horizontal scrolling is implemented.
3321
3322 +++
3323 ** Windows can now be made fixed-width and/or fixed-height.
3324
3325 A window is fixed-size if its buffer has a buffer-local variable
3326 `window-size-fixed' whose value is not nil. A value of `height' makes
3327 windows fixed-height, a value of `width' makes them fixed-width, any
3328 other non-nil value makes them both fixed-width and fixed-height.
3329
3330 The following code makes all windows displaying the current buffer
3331 fixed-width and fixed-height.
3332
3333 (set (make-local-variable 'window-size-fixed) t)
3334
3335 A call to enlarge-window on a window gives an error if that window is
3336 fixed-width and it is tried to change the window's width, or if the
3337 window is fixed-height, and it is tried to change its height. To
3338 change the size of a fixed-size window, bind `window-size-fixed'
3339 temporarily to nil, for example
3340
3341 (let ((window-size-fixed nil))
3342 (enlarge-window 10))
3343
3344 Likewise, an attempt to split a fixed-height window vertically,
3345 or a fixed-width window horizontally results in a error.
3346
3347 ** The cursor-type frame parameter is now supported on MS-DOS
3348 terminals. When Emacs starts, it by default changes the cursor shape
3349 to a solid box, as it does on Unix. The `cursor-type' frame parameter
3350 overrides this as it does on Unix, except that the bar cursor is
3351 horizontal rather than vertical (since the MS-DOS display doesn't
3352 support a vertical-bar cursor).
3353 ^L
3354 * Emacs 20.7 is a bug-fix release with few user-visible changes
3355
3356 ** It is now possible to use CCL-based coding systems for keyboard
3357 input.
3358
3359 ** ange-ftp now handles FTP security extensions, like Kerberos.
3360
3361 ** Rmail has been extended to recognize more forms of digest messages.
3362
3363 ** Now, most coding systems set in keyboard coding system work not
3364 only for character input, but also in incremental search. The
3365 exceptions are such coding systems that handle 2-byte character sets
3366 (e.g euc-kr, euc-jp) and that use ISO's escape sequence
3367 (e.g. iso-2022-jp). They are ignored in incremental search.
3368
3369 ** Support for Macintosh PowerPC-based machines running GNU/Linux has
3370 been added.
3371
3372 ^L
3373 * Emacs 20.6 is a bug-fix release with one user-visible change
3374
3375 ** Support for ARM-based non-RISCiX machines has been added.
3376
3377 ^L
3378 * Emacs 20.5 is a bug-fix release with no user-visible changes.
3379
3380 ** Not new, but not mentioned before:
3381 M-w when Transient Mark mode is enabled disables the mark.
3382 \f
3383 * Changes in Emacs 20.4
3384
3385 ** Init file may be called .emacs.el.
3386
3387 You can now call the Emacs init file `.emacs.el'.
3388 Formerly the name had to be `.emacs'. If you use the name
3389 `.emacs.el', you can byte-compile the file in the usual way.
3390
3391 If both `.emacs' and `.emacs.el' exist, the latter file
3392 is the one that is used.
3393
3394 ** shell-command, and shell-command-on-region, now return
3395 the exit code of the command (unless it is asynchronous).
3396 Also, you can specify a place to put the error output,
3397 separate from the command's regular output.
3398 Interactively, the variable shell-command-default-error-buffer
3399 says where to put error output; set it to a buffer name.
3400 In calls from Lisp, an optional argument ERROR-BUFFER specifies
3401 the buffer name.
3402
3403 When you specify a non-nil error buffer (or buffer name), any error
3404 output is inserted before point in that buffer, with \f\n to separate
3405 it from the previous batch of error output. The error buffer is not
3406 cleared, so error output from successive commands accumulates there.
3407
3408 ** Setting the default value of enable-multibyte-characters to nil in
3409 the .emacs file, either explicitly using setq-default, or via Custom,
3410 is now essentially equivalent to using --unibyte: all buffers
3411 created during startup will be made unibyte after loading .emacs.
3412
3413 ** C-x C-f now handles the wildcards * and ? in file names. For
3414 example, typing C-x C-f c*.c RET visits all the files whose names
3415 match c*.c. To visit a file whose name contains * or ?, add the
3416 quoting sequence /: to the beginning of the file name.
3417
3418 ** The M-x commands keep-lines, flush-lines and count-matches
3419 now have the same feature as occur and query-replace:
3420 if the pattern contains any upper case letters, then
3421 they never ignore case.
3422
3423 ** The end-of-line format conversion feature previously mentioned
3424 under `* Emacs 20.1 changes for MS-DOS and MS-Windows' actually
3425 applies to all operating systems. Emacs recognizes from the contents
3426 of a file what convention it uses to separate lines--newline, CRLF, or
3427 just CR--and automatically converts the contents to the normal Emacs
3428 convention (using newline to separate lines) for editing. This is a
3429 part of the general feature of coding system conversion.
3430
3431 If you subsequently save the buffer, Emacs converts the text back to
3432 the same format that was used in the file before.
3433
3434 You can turn off end-of-line conversion by setting the variable
3435 `inhibit-eol-conversion' to non-nil, e.g. with Custom in the MULE group.
3436
3437 ** The character set property `prefered-coding-system' has been
3438 renamed to `preferred-coding-system', for the sake of correct spelling.
3439 This is a fairly internal feature, so few programs should be affected.
3440
3441 ** Mode-line display of end-of-line format is changed.
3442 The indication of the end-of-line format of the file visited by a
3443 buffer is now more explicit when that format is not the usual one for
3444 your operating system. For example, the DOS-style end-of-line format
3445 is displayed as "(DOS)" on Unix and GNU/Linux systems. The usual
3446 end-of-line format is still displayed as a single character (colon for
3447 Unix, backslash for DOS and Windows, and forward slash for the Mac).
3448
3449 The values of the variables eol-mnemonic-unix, eol-mnemonic-dos,
3450 eol-mnemonic-mac, and eol-mnemonic-undecided, which are strings,
3451 control what is displayed in the mode line for each end-of-line
3452 format. You can now customize these variables.
3453
3454 ** In the previous version of Emacs, tar-mode didn't work well if a
3455 filename contained non-ASCII characters. Now this is fixed. Such a
3456 filename is decoded by file-name-coding-system if the default value of
3457 enable-multibyte-characters is non-nil.
3458
3459 ** The command temp-buffer-resize-mode toggles a minor mode
3460 in which temporary buffers (such as help buffers) are given
3461 windows just big enough to hold the whole contents.
3462
3463 ** If you use completion.el, you must now run the function
3464 dynamic-completion-mode to enable it. Just loading the file
3465 doesn't have any effect.
3466
3467 ** In Flyspell mode, the default is now to make just one Ispell process,
3468 not one per buffer.
3469
3470 ** If you use iswitchb but do not call (iswitchb-default-keybindings) to
3471 use the default keybindings, you will need to add the following line:
3472 (add-hook 'minibuffer-setup-hook 'iswitchb-minibuffer-setup)
3473
3474 ** Auto-show mode is no longer enabled just by loading auto-show.el.
3475 To control it, set `auto-show-mode' via Custom or use the
3476 `auto-show-mode' command.
3477
3478 ** Handling of X fonts' ascent/descent parameters has been changed to
3479 avoid redisplay problems. As a consequence, compared with previous
3480 versions the line spacing and frame size now differ with some font
3481 choices, typically increasing by a pixel per line. This change
3482 occurred in version 20.3 but was not documented then.
3483
3484 ** If you select the bar cursor style, it uses the frame's
3485 cursor-color, rather than the cursor foreground pixel.
3486
3487 ** In multibyte mode, Rmail decodes incoming MIME messages using the
3488 character set specified in the message. If you want to disable this
3489 feature, set the variable rmail-decode-mime-charset to nil.
3490
3491 ** Not new, but not mentioned previously in NEWS: when you use #! at
3492 the beginning of a file to make it executable and specify an
3493 interpreter program, Emacs looks on the second line for the -*- mode
3494 and variable specification, as well as on the first line.
3495
3496 ** Support for IBM codepage encoding of non-ASCII characters.
3497
3498 The new command M-x codepage-setup creates a special coding system
3499 that can be used to convert text between a specific IBM codepage and
3500 one of the character sets built into Emacs which matches that
3501 codepage. For example, codepage 850 corresponds to Latin-1 character
3502 set, codepage 855 corresponds to Cyrillic-ISO character set, etc.
3503
3504 Windows codepages 1250, 1251 and some others, where Windows deviates
3505 from the corresponding ISO character set, are also supported.
3506
3507 IBM box-drawing characters and other glyphs which don't have
3508 equivalents in the corresponding ISO character set, are converted to
3509 a character defined by dos-unsupported-char-glyph on MS-DOS, and to
3510 `?' on other systems.
3511
3512 IBM codepages are widely used on MS-DOS and MS-Windows, so this
3513 feature is most useful on those platforms, but it can also be used on
3514 Unix.
3515
3516 Emacs compiled for MS-DOS automatically loads the support for the
3517 current codepage when it starts.
3518
3519 ** Mail changes
3520
3521 *** When mail is sent using compose-mail (C-x m), and if
3522 `mail-send-nonascii' is set to the new default value `mime',
3523 appropriate MIME headers are added. The headers are added only if
3524 non-ASCII characters are present in the body of the mail, and no other
3525 MIME headers are already present. For example, the following three
3526 headers are added if the coding system used in the *mail* buffer is
3527 latin-1:
3528
3529 MIME-version: 1.0
3530 Content-type: text/plain; charset=iso-8859-1
3531 Content-Transfer-Encoding: 8bit
3532
3533 *** The new variable default-sendmail-coding-system specifies the
3534 default way to encode outgoing mail. This has higher priority than
3535 default-buffer-file-coding-system but has lower priority than
3536 sendmail-coding-system and the local value of
3537 buffer-file-coding-system.
3538
3539 You should not set this variable manually. Instead, set
3540 sendmail-coding-system to specify a fixed encoding for all outgoing
3541 mail.
3542
3543 *** When you try to send a message that contains non-ASCII characters,
3544 if the coding system specified by those variables doesn't handle them,
3545 Emacs will ask you to select a suitable coding system while showing a
3546 list of possible coding systems.
3547
3548 ** CC Mode changes
3549
3550 *** c-default-style can now take an association list that maps major
3551 modes to style names. When this variable is an alist, Java mode no
3552 longer hardcodes a setting to "java" style. See the variable's
3553 docstring for details.
3554
3555 *** It's now possible to put a list as the offset on a syntactic
3556 symbol. The list is evaluated recursively until a non-nil offset is
3557 found. This is useful to combine several lineup functions to act in a
3558 prioritized order on a single line. However, none of the supplied
3559 lineup functions use this feature currently.
3560
3561 *** New syntactic symbol catch-clause, which is used on the "catch" and
3562 "finally" lines in try-catch constructs in C++ and Java.
3563
3564 *** New cleanup brace-catch-brace on c-cleanup-list, which does for
3565 "catch" lines what brace-elseif-brace does for "else if" lines.
3566
3567 *** The braces of Java anonymous inner classes are treated separately
3568 from the braces of other classes in auto-newline mode. Two new
3569 symbols inexpr-class-open and inexpr-class-close may be used on
3570 c-hanging-braces-alist to control the automatic newlines used for
3571 anonymous classes.
3572
3573 *** Support for the Pike language added, along with new Pike specific
3574 syntactic symbols: inlambda, lambda-intro-cont
3575
3576 *** Support for Java anonymous classes via new syntactic symbol
3577 inexpr-class. New syntactic symbol inexpr-statement for Pike
3578 support and gcc-style statements inside expressions. New lineup
3579 function c-lineup-inexpr-block.
3580
3581 *** New syntactic symbol brace-entry-open which is used in brace lists
3582 (i.e. static initializers) when a list entry starts with an open
3583 brace. These used to be recognized as brace-list-entry's.
3584 c-electric-brace also recognizes brace-entry-open braces
3585 (brace-list-entry's can no longer be electrified).
3586
3587 *** New command c-indent-line-or-region, not bound by default.
3588
3589 *** `#' is only electric when typed in the indentation of a line.
3590
3591 *** Parentheses are now electric (via the new command c-electric-paren)
3592 for auto-reindenting lines when parens are typed.
3593
3594 *** In "gnu" style, inline-open offset is now set to zero.
3595
3596 *** Uniform handling of the inclass syntactic symbol. The indentation
3597 associated with it is now always relative to the class opening brace.
3598 This means that the indentation behavior has changed in some
3599 circumstances, but only if you've put anything besides 0 on the
3600 class-open syntactic symbol (none of the default styles do that).
3601
3602 ** Gnus changes.
3603
3604 *** New functionality for using Gnus as an offline newsreader has been
3605 added. A plethora of new commands and modes have been added. See the
3606 Gnus manual for the full story.
3607
3608 *** The nndraft backend has returned, but works differently than
3609 before. All Message buffers are now also articles in the nndraft
3610 group, which is created automatically.
3611
3612 *** `gnus-alter-header-function' can now be used to alter header
3613 values.
3614
3615 *** `gnus-summary-goto-article' now accept Message-ID's.
3616
3617 *** A new Message command for deleting text in the body of a message
3618 outside the region: `C-c C-v'.
3619
3620 *** You can now post to component group in nnvirtual groups with
3621 `C-u C-c C-c'.
3622
3623 *** `nntp-rlogin-program' -- new variable to ease customization.
3624
3625 *** `C-u C-c C-c' in `gnus-article-edit-mode' will now inhibit
3626 re-highlighting of the article buffer.
3627
3628 *** New element in `gnus-boring-article-headers' -- `long-to'.
3629
3630 *** `M-i' symbolic prefix command. See the section "Symbolic
3631 Prefixes" in the Gnus manual for details.
3632
3633 *** `L' and `I' in the summary buffer now take the symbolic prefix
3634 `a' to add the score rule to the "all.SCORE" file.
3635
3636 *** `gnus-simplify-subject-functions' variable to allow greater
3637 control over simplification.
3638
3639 *** `A T' -- new command for fetching the current thread.
3640
3641 *** `/ T' -- new command for including the current thread in the
3642 limit.
3643
3644 *** `M-RET' is a new Message command for breaking cited text.
3645
3646 *** \\1-expressions are now valid in `nnmail-split-methods'.
3647
3648 *** The `custom-face-lookup' function has been removed.
3649 If you used this function in your initialization files, you must
3650 rewrite them to use `face-spec-set' instead.
3651
3652 *** Cancelling now uses the current select method. Symbolic prefix
3653 `a' forces normal posting method.
3654
3655 *** New command to translate M******** sm*rtq**t*s into proper text
3656 -- `W d'.
3657
3658 *** For easier debugging of nntp, you can set `nntp-record-commands'
3659 to a non-nil value.
3660
3661 *** nntp now uses ~/.authinfo, a .netrc-like file, for controlling
3662 where and how to send AUTHINFO to NNTP servers.
3663
3664 *** A command for editing group parameters from the summary buffer
3665 has been added.
3666
3667 *** A history of where mails have been split is available.
3668
3669 *** A new article date command has been added -- `article-date-iso8601'.
3670
3671 *** Subjects can be simplified when threading by setting
3672 `gnus-score-thread-simplify'.
3673
3674 *** A new function for citing in Message has been added --
3675 `message-cite-original-without-signature'.
3676
3677 *** `article-strip-all-blank-lines' -- new article command.
3678
3679 *** A new Message command to kill to the end of the article has
3680 been added.
3681
3682 *** A minimum adaptive score can be specified by using the
3683 `gnus-adaptive-word-minimum' variable.
3684
3685 *** The "lapsed date" article header can be kept continually
3686 updated by the `gnus-start-date-timer' command.
3687
3688 *** Web listserv archives can be read with the nnlistserv backend.
3689
3690 *** Old dejanews archives can now be read by nnweb.
3691
3692 *** `gnus-posting-styles' has been re-activated.
3693
3694 ** Changes to TeX and LaTeX mode
3695
3696 *** The new variable `tex-start-options-string' can be used to give
3697 options for the TeX run. The default value causes TeX to run in
3698 nonstopmode. For an interactive TeX run set it to nil or "".
3699
3700 *** The command `tex-feed-input' sends input to the Tex Shell. In a
3701 TeX buffer it is bound to the keys C-RET, C-c RET, and C-c C-m (some
3702 of these keys may not work on all systems). For instance, if you run
3703 TeX interactively and if the TeX run stops because of an error, you
3704 can continue it without leaving the TeX buffer by typing C-RET.
3705
3706 *** The Tex Shell Buffer is now in `compilation-shell-minor-mode'.
3707 All error-parsing commands of the Compilation major mode are available
3708 but bound to keys that don't collide with the shell. Thus you can use
3709 the Tex Shell for command line executions like a usual shell.
3710
3711 *** The commands `tex-validate-region' and `tex-validate-buffer' check
3712 the matching of braces and $'s. The errors are listed in a *Occur*
3713 buffer and you can use C-c C-c or mouse-2 to go to a particular
3714 mismatch.
3715
3716 ** Changes to RefTeX mode
3717
3718 *** The table of contents buffer can now also display labels and
3719 file boundaries in addition to sections. Use `l', `i', and `c' keys.
3720
3721 *** Labels derived from context (the section heading) are now
3722 lowercase by default. To make the label legal in LaTeX, latin-1
3723 characters will lose their accent. All Mule characters will be
3724 removed from the label.
3725
3726 *** The automatic display of cross reference information can also use
3727 a window instead of the echo area. See variable `reftex-auto-view-crossref'.
3728
3729 *** kpsewhich can be used by RefTeX to find TeX and BibTeX files. See the
3730 customization group `reftex-finding-files'.
3731
3732 *** The option `reftex-bibfile-ignore-list' has been renamed to
3733 `reftex-bibfile-ignore-regexps' and indeed can be fed with regular
3734 expressions.
3735
3736 *** Multiple Selection buffers are now hidden buffers.
3737
3738 ** New/deleted modes and packages
3739
3740 *** The package snmp-mode.el provides major modes for editing SNMP and
3741 SNMPv2 MIBs. It has entries on `auto-mode-alist'.
3742
3743 *** The package sql.el provides a major mode, M-x sql-mode, for
3744 editing SQL files, and M-x sql-interactive-mode for interacting with
3745 SQL interpreters. It has an entry on `auto-mode-alist'.
3746
3747 *** M-x highlight-changes-mode provides a minor mode displaying buffer
3748 changes with a special face.
3749
3750 *** ispell4.el has been deleted. It got in the way of ispell.el and
3751 this was hard to fix reliably. It has long been obsolete -- use
3752 Ispell 3.1 and ispell.el.
3753 \f
3754 * MS-DOS changes in Emacs 20.4
3755
3756 ** Emacs compiled for MS-DOS now supports MULE features better.
3757 This includes support for display of all ISO 8859-N character sets,
3758 conversion to and from IBM codepage encoding of non-ASCII characters,
3759 and automatic setup of the MULE environment at startup. For details,
3760 check out the section `MS-DOS and MULE' in the manual.
3761
3762 The MS-DOS installation procedure automatically configures and builds
3763 Emacs with input method support if it finds an unpacked Leim
3764 distribution when the config.bat script is run.
3765
3766 ** Formerly, the value of lpr-command did not affect printing on
3767 MS-DOS unless print-region-function was set to nil, but now it
3768 controls whether an external program is invoked or output is written
3769 directly to a printer port. Similarly, in the previous version of
3770 Emacs, the value of ps-lpr-command did not affect PostScript printing
3771 on MS-DOS unless ps-printer-name was set to something other than a
3772 string (eg. t or `pipe'), but now it controls whether an external
3773 program is used. (These changes were made so that configuration of
3774 printing variables would be almost identical across all platforms.)
3775
3776 ** In the previous version of Emacs, PostScript and non-PostScript
3777 output was piped to external programs, but because most print programs
3778 available for MS-DOS and MS-Windows cannot read data from their standard
3779 input, on those systems the data to be output is now written to a
3780 temporary file whose name is passed as the last argument to the external
3781 program.
3782
3783 An exception is made for `print', a standard program on Windows NT,
3784 and `nprint', a standard program on Novell Netware. For both of these
3785 programs, the command line is constructed in the appropriate syntax
3786 automatically, using only the value of printer-name or ps-printer-name
3787 as appropriate--the value of the relevant `-switches' variable is
3788 ignored, as both programs have no useful switches.
3789
3790 ** The value of the variable dos-printer (cf. dos-ps-printer), if it has
3791 a value, overrides the value of printer-name (cf. ps-printer-name), on
3792 MS-DOS and MS-Windows only. This has been true since version 20.3, but
3793 was not documented clearly before.
3794
3795 ** All the Emacs games now work on MS-DOS terminals.
3796 This includes Tetris and Snake.
3797 \f
3798 * Lisp changes in Emacs 20.4
3799
3800 ** New functions line-beginning-position and line-end-position
3801 return the position of the beginning or end of the current line.
3802 They both accept an optional argument, which has the same
3803 meaning as the argument to beginning-of-line or end-of-line.
3804
3805 ** find-file and allied functions now have an optional argument
3806 WILDCARD. If this is non-nil, they do wildcard processing,
3807 and visit all files that match the wildcard pattern.
3808
3809 ** Changes in the file-attributes function.
3810
3811 *** The file size returned by file-attributes may be an integer or a float.
3812 It is an integer if the size fits in a Lisp integer, float otherwise.
3813
3814 *** The inode number returned by file-attributes may be an integer (if
3815 the number fits in a Lisp integer) or a cons cell containing two
3816 integers.
3817
3818 ** The new function directory-files-and-attributes returns a list of
3819 files in a directory and their attributes. It accepts the same
3820 arguments as directory-files and has similar semantics, except that
3821 file names and attributes are returned.
3822
3823 ** The new function file-attributes-lessp is a helper function for
3824 sorting the list generated by directory-files-and-attributes. It
3825 accepts two arguments, each a list of a file name and its atttributes.
3826 It compares the file names of each according to string-lessp and
3827 returns the result.
3828
3829 ** The new function file-expand-wildcards expands a wildcard-pattern
3830 to produce a list of existing files that match the pattern.
3831
3832 ** New functions for base64 conversion:
3833
3834 The function base64-encode-region converts a part of the buffer
3835 into the base64 code used in MIME. base64-decode-region
3836 performs the opposite conversion. Line-breaking is supported
3837 optionally.
3838
3839 Functions base64-encode-string and base64-decode-string do a similar
3840 job on the text in a string. They return the value as a new string.
3841
3842 **
3843 The new function process-running-child-p
3844 will tell you if a subprocess has given control of its
3845 terminal to its own child process.
3846
3847 ** interrupt-process and such functions have a new feature:
3848 when the second argument is `lambda', they send a signal
3849 to the running child of the subshell, if any, but if the shell
3850 itself owns its terminal, no signal is sent.
3851
3852 ** There are new widget types `plist' and `alist' which can
3853 be used for customizing variables whose values are plists or alists.
3854
3855 ** easymenu.el Now understands `:key-sequence' and `:style button'.
3856 :included is an alias for :visible.
3857
3858 easy-menu-add-item now understands the values returned by
3859 easy-menu-remove-item and easy-menu-item-present-p. This can be used
3860 to move or copy menu entries.
3861
3862 ** Multibyte editing changes
3863
3864 *** The definitions of sref and char-bytes are changed. Now, sref is
3865 an alias of aref and char-bytes always returns 1. This change is to
3866 make some Emacs Lisp code which works on 20.2 and earlier also
3867 work on the latest Emacs. Such code uses a combination of sref and
3868 char-bytes in a loop typically as below:
3869 (setq char (sref str idx)
3870 idx (+ idx (char-bytes idx)))
3871 The byte-compiler now warns that this is obsolete.
3872
3873 If you want to know how many bytes a specific multibyte character
3874 (say, CH) occupies in a multibyte buffer, use this code:
3875 (charset-bytes (char-charset ch))
3876
3877 *** In multibyte mode, when you narrow a buffer to some region, and the
3878 region is preceded or followed by non-ASCII codes, inserting or
3879 deleting at the head or the end of the region may signal this error:
3880
3881 Byte combining across boundary of accessible buffer text inhibitted
3882
3883 This is to avoid some bytes being combined together into a character
3884 across the boundary.
3885
3886 *** The functions find-charset-region and find-charset-string include
3887 `unknown' in the returned list in the following cases:
3888 o The current buffer or the target string is unibyte and
3889 contains 8-bit characters.
3890 o The current buffer or the target string is multibyte and
3891 contains invalid characters.
3892
3893 *** The functions decode-coding-region and encode-coding-region remove
3894 text properties of the target region. Ideally, they should correctly
3895 preserve text properties, but for the moment, it's hard. Removing
3896 text properties is better than preserving them in a less-than-correct
3897 way.
3898
3899 *** prefer-coding-system sets EOL conversion of default coding systems.
3900 If the argument to prefer-coding-system specifies a certain type of
3901 end of line conversion, the default coding systems set by
3902 prefer-coding-system will specify that conversion type for end of line.
3903
3904 *** The new function thai-compose-string can be used to properly
3905 compose Thai characters in a string.
3906
3907 ** The primitive `define-prefix-command' now takes an optional third
3908 argument NAME, which should be a string. It supplies the menu name
3909 for the created keymap. Keymaps created in order to be displayed as
3910 menus should always use the third argument.
3911
3912 ** The meanings of optional second arguments for read-char,
3913 read-event, and read-char-exclusive are flipped. Now the second
3914 arguments are INHERIT-INPUT-METHOD. These functions use the current
3915 input method (if any) if and only if INHERIT-INPUT-METHOD is non-nil.
3916
3917 ** The new function clear-this-command-keys empties out the contents
3918 of the vector that (this-command-keys) returns. This is useful in
3919 programs that read passwords, to prevent the passwords from echoing
3920 inadvertently as part of the next command in certain cases.
3921
3922 ** The new macro `with-temp-message' displays a temporary message in
3923 the echo area, while executing some Lisp code. Like `progn', it
3924 returns the value of the last form, but it also restores the previous
3925 echo area contents.
3926
3927 (with-temp-message MESSAGE &rest BODY)
3928
3929 ** The function `require' now takes an optional third argument
3930 NOERROR. If it is non-nil, then there is no error if the
3931 requested feature cannot be loaded.
3932
3933 ** In the function modify-face, an argument of (nil) for the
3934 foreground color, background color or stipple pattern
3935 means to clear out that attribute.
3936
3937 ** The `outer-window-id' frame property of an X frame
3938 gives the window number of the outermost X window for the frame.
3939
3940 ** Temporary buffers made with with-output-to-temp-buffer are now
3941 read-only by default, and normally use the major mode Help mode
3942 unless you put them in some other non-Fundamental mode before the
3943 end of with-output-to-temp-buffer.
3944
3945 ** The new functions gap-position and gap-size return information on
3946 the gap of the current buffer.
3947
3948 ** The new functions position-bytes and byte-to-position provide a way
3949 to convert between character positions and byte positions in the
3950 current buffer.
3951
3952 ** vc.el defines two new macros, `edit-vc-file' and `with-vc-file', to
3953 facilitate working with version-controlled files from Lisp programs.
3954 These macros check out a given file automatically if needed, and check
3955 it back in after any modifications have been made.
3956 \f
3957 * Installation Changes in Emacs 20.3
3958
3959 ** The default value of load-path now includes most subdirectories of
3960 the site-specific directories /usr/local/share/emacs/site-lisp and
3961 /usr/local/share/emacs/VERSION/site-lisp, in addition to those
3962 directories themselves. Both immediate subdirectories and
3963 subdirectories multiple levels down are added to load-path.
3964
3965 Not all subdirectories are included, though. Subdirectories whose
3966 names do not start with a letter or digit are excluded.
3967 Subdirectories named RCS or CVS are excluded. Also, a subdirectory
3968 which contains a file named `.nosearch' is excluded. You can use
3969 these methods to prevent certain subdirectories from being searched.
3970
3971 Emacs finds these subdirectories and adds them to load-path when it
3972 starts up. While it would be cleaner to find the subdirectories each
3973 time Emacs loads a file, that would be much slower.
3974
3975 This feature is an incompatible change. If you have stored some Emacs
3976 Lisp files in a subdirectory of the site-lisp directory specifically
3977 to prevent them from being used, you will need to rename the
3978 subdirectory to start with a non-alphanumeric character, or create a
3979 `.nosearch' file in it, in order to continue to achieve the desired
3980 results.
3981
3982 ** Emacs no longer includes an old version of the C preprocessor from
3983 GCC. This was formerly used to help compile Emacs with C compilers
3984 that had limits on the significant length of an identifier, but in
3985 fact we stopped supporting such compilers some time ago.
3986 \f
3987 * Changes in Emacs 20.3
3988
3989 ** The new command C-x z (repeat) repeats the previous command
3990 including its argument. If you repeat the z afterward,
3991 it repeats the command additional times; thus, you can
3992 perform many repetitions with one keystroke per repetition.
3993
3994 ** Emacs now supports "selective undo" which undoes only within a
3995 specified region. To do this, set point and mark around the desired
3996 region and type C-u C-x u (or C-u C-_). You can then continue undoing
3997 further, within the same region, by repeating the ordinary undo
3998 command C-x u or C-_. This will keep undoing changes that were made
3999 within the region you originally specified, until either all of them
4000 are undone, or it encounters a change which crosses the edge of that
4001 region.
4002
4003 In Transient Mark mode, undoing when a region is active requests
4004 selective undo.
4005
4006 ** If you specify --unibyte when starting Emacs, then all buffers are
4007 unibyte, except when a Lisp program specifically creates a multibyte
4008 buffer. Setting the environment variable EMACS_UNIBYTE has the same
4009 effect. The --no-unibyte option overrides EMACS_UNIBYTE and directs
4010 Emacs to run normally in multibyte mode.
4011
4012 The option --unibyte does not affect the reading of Emacs Lisp files,
4013 though. If you want a Lisp file to be read in unibyte mode, use
4014 -*-unibyte: t;-*- on its first line. That will force Emacs to
4015 load that file in unibyte mode, regardless of how Emacs was started.
4016
4017 ** toggle-enable-multibyte-characters no longer has a key binding and
4018 no longer appears in the menu bar. We've realized that changing the
4019 enable-multibyte-characters variable in an existing buffer is
4020 something that most users not do.
4021
4022 ** You can specify a coding system to use for the next cut or paste
4023 operations through the window system with the command C-x RET X.
4024 The coding system can make a difference for communication with other
4025 applications.
4026
4027 C-x RET x specifies a coding system for all subsequent cutting and
4028 pasting operations.
4029
4030 ** You can specify the printer to use for commands that do printing by
4031 setting the variable `printer-name'. Just what a printer name looks
4032 like depends on your operating system. You can specify a different
4033 printer for the Postscript printing commands by setting
4034 `ps-printer-name'.
4035
4036 ** Emacs now supports on-the-fly spell checking by the means of a
4037 minor mode. It is called M-x flyspell-mode. You don't have to remember
4038 any other special commands to use it, and you will hardly notice it
4039 except when you make a spelling error. Flyspell works by highlighting
4040 incorrect words as soon as they are completed or as soon as the cursor
4041 hits a new word.
4042
4043 Flyspell mode works with whichever dictionary you have selected for
4044 Ispell in Emacs. In TeX mode, it understands TeX syntax so as not
4045 to be confused by TeX commands.
4046
4047 You can correct a misspelled word by editing it into something
4048 correct. You can also correct it, or accept it as correct, by
4049 clicking on the word with Mouse-2; that gives you a pop-up menu
4050 of various alternative replacements and actions.
4051
4052 Flyspell mode also proposes "automatic" corrections. M-TAB replaces
4053 the current misspelled word with a possible correction. If several
4054 corrections are made possible, M-TAB cycles through them in
4055 alphabetical order, or in order of decreasing likelihood if
4056 flyspell-sort-corrections is nil.
4057
4058 Flyspell mode also flags an error when a word is repeated, if
4059 flyspell-mark-duplications-flag is non-nil.
4060
4061 ** Changes in input method usage.
4062
4063 Now you can use arrow keys (right, left, down, up) for selecting among
4064 the alternatives just the same way as you do by C-f, C-b, C-n, and C-p
4065 respectively.
4066
4067 You can use the ENTER key to accept the current conversion.
4068
4069 If you type TAB to display a list of alternatives, you can select one
4070 of the alternatives with Mouse-2.
4071
4072 The meaning of the variable `input-method-verbose-flag' is changed so
4073 that you can set it to t, nil, `default', or `complex-only'.
4074
4075 If the value is nil, extra guidance is never given.
4076
4077 If the value is t, extra guidance is always given.
4078
4079 If the value is `complex-only', extra guidance is always given only
4080 when you are using complex input methods such as chinese-py.
4081
4082 If the value is `default' (this is the default), extra guidance is
4083 given in the following case:
4084 o When you are using a complex input method.
4085 o When you are using a simple input method but not in the minibuffer.
4086
4087 If you are using Emacs through a very slow line, setting
4088 input-method-verbose-flag to nil or to complex-only is a good choice,
4089 and if you are using an input method you are not familiar with,
4090 setting it to t is helpful.
4091
4092 The old command select-input-method is now called set-input-method.
4093
4094 In the language environment "Korean", you can use the following
4095 keys:
4096 Shift-SPC toggle-korean-input-method
4097 C-F9 quail-hangul-switch-symbol-ksc
4098 F9 quail-hangul-switch-hanja
4099 These key bindings are canceled when you switch to another language
4100 environment.
4101
4102 ** The minibuffer history of file names now records the specified file
4103 names, not the entire minibuffer input. For example, if the
4104 minibuffer starts out with /usr/foo/, you might type in /etc/passwd to
4105 get
4106
4107 /usr/foo//etc/passwd
4108
4109 which stands for the file /etc/passwd.
4110
4111 Formerly, this used to put /usr/foo//etc/passwd in the history list.
4112 Now this puts just /etc/passwd in the history list.
4113
4114 ** If you are root, Emacs sets backup-by-copying-when-mismatch to t
4115 at startup, so that saving a file will be sure to preserve
4116 its owner and group.
4117
4118 ** find-func.el can now also find the place of definition of Emacs
4119 Lisp variables in user-loaded libraries.
4120
4121 ** C-x r t (string-rectangle) now deletes the existing rectangle
4122 contents before inserting the specified string on each line.
4123
4124 ** There is a new command delete-whitespace-rectangle
4125 which deletes whitespace starting from a particular column
4126 in all the lines on a rectangle. The column is specified
4127 by the left edge of the rectangle.
4128
4129 ** You can now store a number into a register with C-u NUMBER C-x r n REG,
4130 increment it by INC with C-u INC C-x r + REG (to increment by one, omit
4131 C-u INC), and insert it in the buffer with C-x r g REG. This is useful
4132 for writing keyboard macros.
4133
4134 ** The new command M-x speedbar displays a frame in which directories,
4135 files, and tags can be displayed, manipulated, and jumped to. The
4136 frame defaults to 20 characters in width, and is the same height as
4137 the frame that it was started from. Some major modes define
4138 additional commands for the speedbar, including Rmail, GUD/GDB, and
4139 info.
4140
4141 ** query-replace-regexp is now bound to C-M-%.
4142
4143 ** In Transient Mark mode, when the region is active, M-x
4144 query-replace and the other replace commands now operate on the region
4145 contents only.
4146
4147 ** M-x write-region, when used interactively, now asks for
4148 confirmation before overwriting an existing file. When you call
4149 the function from a Lisp program, a new optional argument CONFIRM
4150 says whether to ask for confirmation in this case.
4151
4152 ** If you use find-file-literally and the file is already visited
4153 non-literally, the command asks you whether to revisit the file
4154 literally. If you say no, it signals an error.
4155
4156 ** Major modes defined with the "derived mode" feature
4157 now use the proper name for the mode hook: WHATEVER-mode-hook.
4158 Formerly they used the name WHATEVER-mode-hooks, but that is
4159 inconsistent with Emacs conventions.
4160
4161 ** shell-command-on-region (and shell-command) reports success or
4162 failure if the command produces no output.
4163
4164 ** Set focus-follows-mouse to nil if your window system or window
4165 manager does not transfer focus to another window when you just move
4166 the mouse.
4167
4168 ** mouse-menu-buffer-maxlen has been renamed to
4169 mouse-buffer-menu-maxlen to be consistent with the other related
4170 function and variable names.
4171
4172 ** The new variable auto-coding-alist specifies coding systems for
4173 reading specific files. This has higher priority than
4174 file-coding-system-alist.
4175
4176 ** If you set the variable unibyte-display-via-language-environment to
4177 t, then Emacs displays non-ASCII characters are displayed by
4178 converting them to the equivalent multibyte characters according to
4179 the current language environment. As a result, they are displayed
4180 according to the current fontset.
4181
4182 ** C-q's handling of codes in the range 0200 through 0377 is changed.
4183
4184 The codes in the range 0200 through 0237 are inserted as one byte of
4185 that code regardless of the values of nonascii-translation-table and
4186 nonascii-insert-offset.
4187
4188 For the codes in the range 0240 through 0377, if
4189 enable-multibyte-characters is non-nil and nonascii-translation-table
4190 nor nonascii-insert-offset can't convert them to valid multibyte
4191 characters, they are converted to Latin-1 characters.
4192
4193 ** If you try to find a file that is not read-accessible, you now get
4194 an error, rather than an empty buffer and a warning.
4195
4196 ** In the minibuffer history commands M-r and M-s, an upper case
4197 letter in the regular expression forces case-sensitive search.
4198
4199 ** In the *Help* buffer, cross-references to commands and variables
4200 are inferred and hyperlinked. Use C-h m in Help mode for the relevant
4201 command keys.
4202
4203 ** M-x apropos-command, with a prefix argument, no longer looks for
4204 user option variables--instead it looks for noninteractive functions.
4205
4206 Meanwhile, the command apropos-variable normally searches for
4207 user option variables; with a prefix argument, it looks at
4208 all variables that have documentation.
4209
4210 ** When you type a long line in the minibuffer, and the minibuffer
4211 shows just one line, automatically scrolling works in a special way
4212 that shows you overlap with the previous line of text. The variable
4213 minibuffer-scroll-overlap controls how many characters of overlap
4214 it should show; the default is 20.
4215
4216 Meanwhile, Resize Minibuffer mode is still available; in that mode,
4217 the minibuffer grows taller (up to a point) as needed to show the whole
4218 of your input.
4219
4220 ** The new command M-x customize-changed-options lets you customize
4221 all the options whose meanings or default values have changed in
4222 recent Emacs versions. You specify a previous Emacs version number as
4223 argument, and the command creates a customization buffer showing all
4224 the customizable options which were changed since that version.
4225 Newly added options are included as well.
4226
4227 If you don't specify a particular version number argument,
4228 then the customization buffer shows all the customizable options
4229 for which Emacs versions of changes are recorded.
4230
4231 This function is also bound to the Changed Options entry in the
4232 Customize menu.
4233
4234 ** When you run M-x grep with a prefix argument, it figures out
4235 the tag around point and puts that into the default grep command.
4236
4237 ** The new command M-* (pop-tag-mark) pops back through a history of
4238 buffer positions from which M-. or other tag-finding commands were
4239 invoked.
4240
4241 ** The new variable comment-padding specifies the number of spaces
4242 that `comment-region' will insert before the actual text of the comment.
4243 The default is 1.
4244
4245 ** In Fortran mode the characters `.', `_' and `$' now have symbol
4246 syntax, not word syntax. Fortran mode now supports `imenu' and has
4247 new commands fortran-join-line (M-^) and fortran-narrow-to-subprogram
4248 (C-x n d). M-q can be used to fill a statement or comment block
4249 sensibly.
4250
4251 ** GUD now supports jdb, the Java debugger, and pdb, the Python debugger.
4252
4253 ** If you set the variable add-log-keep-changes-together to a non-nil
4254 value, the command `C-x 4 a' will automatically notice when you make
4255 two entries in one day for one file, and combine them.
4256
4257 ** You can use the command M-x diary-mail-entries to mail yourself a
4258 reminder about upcoming diary entries. See the documentation string
4259 for a sample shell script for calling this function automatically
4260 every night.
4261
4262 ** Desktop changes
4263
4264 *** All you need to do to enable use of the Desktop package, is to set
4265 the variable desktop-enable to t with Custom.
4266
4267 *** Minor modes are now restored. Which minor modes are restored
4268 and how modes are restored is controlled by `desktop-minor-mode-table'.
4269
4270 ** There is no need to do anything special, now, to enable Gnus to
4271 read and post multi-lingual articles.
4272
4273 ** Outline mode has now support for showing hidden outlines when
4274 doing an isearch. In order for this to happen search-invisible should
4275 be set to open (the default). If an isearch match is inside a hidden
4276 outline the outline is made visible. If you continue pressing C-s and
4277 the match moves outside the formerly invisible outline, the outline is
4278 made invisible again.
4279
4280 ** Mail reading and sending changes
4281
4282 *** The Rmail e command now switches to displaying the whole header of
4283 the message before it lets you edit the message. This is so that any
4284 changes you make in the header will not be lost if you subsequently
4285 toggle.
4286
4287 *** The w command in Rmail, which writes the message body into a file,
4288 now works in the summary buffer as well. (The command to delete the
4289 summary buffer is now Q.) The default file name for the w command, if
4290 the message has no subject, is stored in the variable
4291 rmail-default-body-file.
4292
4293 *** Most of the commands and modes that operate on mail and netnews no
4294 longer depend on the value of mail-header-separator. Instead, they
4295 handle whatever separator the buffer happens to use.
4296
4297 *** If you set mail-signature to a value which is not t, nil, or a string,
4298 it should be an expression. When you send a message, this expression
4299 is evaluated to insert the signature.
4300
4301 *** The new Lisp library feedmail.el (version 8) enhances processing of
4302 outbound email messages. It works in coordination with other email
4303 handling packages (e.g., rmail, VM, gnus) and is responsible for
4304 putting final touches on messages and actually submitting them for
4305 transmission. Users of the emacs program "fakemail" might be
4306 especially interested in trying feedmail.
4307
4308 feedmail is not enabled by default. See comments at the top of
4309 feedmail.el for set-up instructions. Among the bigger features
4310 provided by feedmail are:
4311
4312 **** you can park outgoing messages into a disk-based queue and
4313 stimulate sending some or all of them later (handy for laptop users);
4314 there is also a queue for draft messages
4315
4316 **** you can get one last look at the prepped outbound message and
4317 be prompted for confirmation
4318
4319 **** does smart filling of address headers
4320
4321 **** can generate a MESSAGE-ID: line and a DATE: line; the date can be
4322 the time the message was written or the time it is being sent; this
4323 can make FCC copies more closely resemble copies that recipients get
4324
4325 **** you can specify an arbitrary function for actually transmitting
4326 the message; included in feedmail are interfaces for /bin/[r]mail,
4327 /usr/lib/sendmail, and elisp smtpmail; it's easy to write a new
4328 function for something else (10-20 lines of elisp)
4329
4330 ** Dired changes
4331
4332 *** The Dired function dired-do-toggle, which toggles marked and unmarked
4333 files, is now bound to "t" instead of "T".
4334
4335 *** dired-at-point has been added to ffap.el. It allows one to easily
4336 run Dired on the directory name at point.
4337
4338 *** Dired has a new command: %g. It searches the contents of
4339 files in the directory and marks each file that contains a match
4340 for a specified regexp.
4341
4342 ** VC Changes
4343
4344 *** New option vc-ignore-vc-files lets you turn off version control
4345 conveniently.
4346
4347 *** VC Dired has been completely rewritten. It is now much
4348 faster, especially for CVS, and works very similar to ordinary
4349 Dired.
4350
4351 VC Dired is invoked by typing C-x v d and entering the name of the
4352 directory to display. By default, VC Dired gives you a recursive
4353 listing of all files at or below the given directory which are
4354 currently locked (for CVS, all files not up-to-date are shown).
4355
4356 You can change the listing format by setting vc-dired-recurse to nil,
4357 then it shows only the given directory, and you may also set
4358 vc-dired-terse-display to nil, then it shows all files under version
4359 control plus the names of any subdirectories, so that you can type `i'
4360 on such lines to insert them manually, as in ordinary Dired.
4361
4362 All Dired commands operate normally in VC Dired, except for `v', which
4363 is redefined as the version control prefix. That means you may type
4364 `v l', `v =' etc. to invoke `vc-print-log', `vc-diff' and the like on
4365 the file named in the current Dired buffer line. `v v' invokes
4366 `vc-next-action' on this file, or on all files currently marked.
4367
4368 The new command `v t' (vc-dired-toggle-terse-mode) allows you to
4369 toggle between terse display (only locked files) and full display (all
4370 VC files plus subdirectories). There is also a special command,
4371 `* l', to mark all files currently locked.
4372
4373 Giving a prefix argument to C-x v d now does the same thing as in
4374 ordinary Dired: it allows you to supply additional options for the ls
4375 command in the minibuffer, to fine-tune VC Dired's output.
4376
4377 *** Under CVS, if you merge changes from the repository into a working
4378 file, and CVS detects conflicts, VC now offers to start an ediff
4379 session to resolve them.
4380
4381 Alternatively, you can use the new command `vc-resolve-conflicts' to
4382 resolve conflicts in a file at any time. It works in any buffer that
4383 contains conflict markers as generated by rcsmerge (which is what CVS
4384 uses as well).
4385
4386 *** You can now transfer changes between branches, using the new
4387 command vc-merge (C-x v m). It is implemented for RCS and CVS. When
4388 you invoke it in a buffer under version-control, you can specify
4389 either an entire branch or a pair of versions, and the changes on that
4390 branch or between the two versions are merged into the working file.
4391 If this results in any conflicts, they may be resolved interactively,
4392 using ediff.
4393
4394 ** Changes in Font Lock
4395
4396 *** The face and variable previously known as font-lock-reference-face
4397 are now called font-lock-constant-face to better reflect their typical
4398 use for highlighting constants and labels. (Its face properties are
4399 unchanged.) The variable font-lock-reference-face remains for now for
4400 compatibility reasons, but its value is font-lock-constant-face.
4401
4402 ** Frame name display changes
4403
4404 *** The command set-frame-name lets you set the name of the current
4405 frame. You can use the new command select-frame-by-name to select and
4406 raise a frame; this is mostly useful on character-only terminals, or
4407 when many frames are invisible or iconified.
4408
4409 *** On character-only terminal (not a window system), changing the
4410 frame name is now reflected on the mode line and in the Buffers/Frames
4411 menu.
4412
4413 ** Comint (subshell) changes
4414
4415 *** In Comint modes, the commands to kill, stop or interrupt a
4416 subjob now also kill pending input. This is for compatibility
4417 with ordinary shells, where the signal characters do this.
4418
4419 *** There are new commands in Comint mode.
4420
4421 C-c C-x fetches the "next" line from the input history;
4422 that is, the line after the last line you got.
4423 You can use this command to fetch successive lines, one by one.
4424
4425 C-c SPC accumulates lines of input. More precisely, it arranges to
4426 send the current line together with the following line, when you send
4427 the following line.
4428
4429 C-c C-a if repeated twice consecutively now moves to the process mark,
4430 which separates the pending input from the subprocess output and the
4431 previously sent input.
4432
4433 C-c M-r now runs comint-previous-matching-input-from-input;
4434 it searches for a previous command, using the current pending input
4435 as the search string.
4436
4437 *** New option compilation-scroll-output can be set to scroll
4438 automatically in compilation-mode windows.
4439
4440 ** C mode changes
4441
4442 *** Multiline macros are now handled, both as they affect indentation,
4443 and as recognized syntax. New syntactic symbol cpp-macro-cont is
4444 assigned to second and subsequent lines of a multiline macro
4445 definition.
4446
4447 *** A new style "user" which captures all non-hook-ified
4448 (i.e. top-level) .emacs file variable settings and customizations.
4449 Style "cc-mode" is an alias for "user" and is deprecated. "gnu"
4450 style is still the default however.
4451
4452 *** "java" style now conforms to Sun's JDK coding style.
4453
4454 *** There are new commands c-beginning-of-defun, c-end-of-defun which
4455 are alternatives which you could bind to C-M-a and C-M-e if you prefer
4456 them. They do not have key bindings by default.
4457
4458 *** New and improved implementations of M-a (c-beginning-of-statement)
4459 and M-e (c-end-of-statement).
4460
4461 *** C++ namespace blocks are supported, with new syntactic symbols
4462 namespace-open, namespace-close, and innamespace.
4463
4464 *** File local variable settings of c-file-style and c-file-offsets
4465 makes the style variables local to that buffer only.
4466
4467 *** New indentation functions c-lineup-close-paren,
4468 c-indent-one-line-block, c-lineup-dont-change.
4469
4470 *** Improvements (hopefully!) to the way CC Mode is loaded. You
4471 should now be able to do a (require 'cc-mode) to get the entire
4472 package loaded properly for customization in your .emacs file. A new
4473 variable c-initialize-on-load controls this and is t by default.
4474
4475 ** Changes to hippie-expand.
4476
4477 *** New customization variable `hippie-expand-dabbrev-skip-space'. If
4478 non-nil, trailing spaces may be included in the abbreviation to search for,
4479 which then gives the same behavior as the original `dabbrev-expand'.
4480
4481 *** New customization variable `hippie-expand-dabbrev-as-symbol'. If
4482 non-nil, characters of syntax '_' is considered part of the word when
4483 expanding dynamically.
4484
4485 *** New customization variable `hippie-expand-no-restriction'. If
4486 non-nil, narrowed buffers are widened before they are searched.
4487
4488 *** New customization variable `hippie-expand-only-buffers'. If
4489 non-empty, buffers searched are restricted to the types specified in
4490 this list. Useful for example when constructing new special-purpose
4491 expansion functions with `make-hippie-expand-function'.
4492
4493 *** Text properties of the expansion are no longer copied.
4494
4495 ** Changes in BibTeX mode.
4496
4497 *** Any titleword matching a regexp in the new variable
4498 bibtex-autokey-titleword-ignore (case sensitive) is ignored during
4499 automatic key generation. This replaces variable
4500 bibtex-autokey-titleword-first-ignore, which only checked for matches
4501 against the first word in the title.
4502
4503 *** Autokey generation now uses all words from the title, not just
4504 capitalized words. To avoid conflicts with existing customizations,
4505 bibtex-autokey-titleword-ignore is set up such that words starting with
4506 lowerkey characters will still be ignored. Thus, if you want to use
4507 lowercase words from the title, you will have to overwrite the
4508 bibtex-autokey-titleword-ignore standard setting.
4509
4510 *** Case conversion of names and title words for automatic key
4511 generation is more flexible. Variable bibtex-autokey-preserve-case is
4512 replaced by bibtex-autokey-titleword-case-convert and
4513 bibtex-autokey-name-case-convert.
4514
4515 ** Changes in vcursor.el.
4516
4517 *** Support for character terminals is available: there is a new keymap
4518 and the vcursor will appear as an arrow between buffer text. A
4519 variable `vcursor-interpret-input' allows input from the vcursor to be
4520 entered exactly as if typed. Numerous functions, including
4521 `vcursor-compare-windows', have been rewritten to improve consistency
4522 in the selection of windows and corresponding keymaps.
4523
4524 *** vcursor options can now be altered with M-x customize under the
4525 Editing group once the package is loaded.
4526
4527 *** Loading vcursor now does not define keys by default, as this is
4528 generally a bad side effect. Use M-x customize to set
4529 vcursor-key-bindings to t to restore the old behaviour.
4530
4531 *** vcursor-auto-disable can be `copy', which turns off copying from the
4532 vcursor, but doesn't disable it, after any non-vcursor command.
4533
4534 ** Ispell changes.
4535
4536 *** You can now spell check comments and strings in the current
4537 buffer with M-x ispell-comments-and-strings. Comments and strings
4538 are identified by syntax tables in effect.
4539
4540 *** Generic region skipping implemented.
4541 A single buffer can be broken into a number of regions where text will
4542 and will not be checked. The definitions of the regions can be user
4543 defined. New applications and improvements made available by this
4544 include:
4545
4546 o URLs are automatically skipped
4547 o EMail message checking is vastly improved.
4548
4549 *** Ispell can highlight the erroneous word even on non-window terminals.
4550
4551 ** Changes to RefTeX mode
4552
4553 RefTeX has been updated in order to make it more usable with very
4554 large projects (like a several volume math book). The parser has been
4555 re-written from scratch. To get maximum speed from RefTeX, check the
4556 section `Optimizations' in the manual.
4557
4558 *** New recursive parser.
4559
4560 The old version of RefTeX created a single large buffer containing the
4561 entire multifile document in order to parse the document. The new
4562 recursive parser scans the individual files.
4563
4564 *** Parsing only part of a document.
4565
4566 Reparsing of changed document parts can now be made faster by enabling
4567 partial scans. To use this feature, read the documentation string of
4568 the variable `reftex-enable-partial-scans' and set the variable to t.
4569
4570 (setq reftex-enable-partial-scans t)
4571
4572 *** Storing parsing information in a file.
4573
4574 This can improve startup times considerably. To turn it on, use
4575
4576 (setq reftex-save-parse-info t)
4577
4578 *** Using multiple selection buffers
4579
4580 If the creation of label selection buffers is too slow (this happens
4581 for large documents), you can reuse these buffers by setting
4582
4583 (setq reftex-use-multiple-selection-buffers t)
4584
4585 *** References to external documents.
4586
4587 The LaTeX package `xr' allows to cross-reference labels in external
4588 documents. RefTeX can provide information about the external
4589 documents as well. To use this feature, set up the \externaldocument
4590 macros required by the `xr' package and rescan the document with
4591 RefTeX. The external labels can then be accessed with the `x' key in
4592 the selection buffer provided by `reftex-reference' (bound to `C-c )').
4593 The `x' key also works in the table of contents buffer.
4594
4595 *** Many more labeled LaTeX environments are recognized by default.
4596
4597 The builtin command list now covers all the standard LaTeX commands,
4598 and all of the major packages included in the LaTeX distribution.
4599
4600 Also, RefTeX now understands the \appendix macro and changes
4601 the enumeration of sections in the *toc* buffer accordingly.
4602
4603 *** Mouse support for selection and *toc* buffers
4604
4605 The mouse can now be used to select items in the selection and *toc*
4606 buffers. See also the new option `reftex-highlight-selection'.
4607
4608 *** New keymaps for selection and table of contents modes.
4609
4610 The selection processes for labels and citation keys, and the table of
4611 contents buffer now have their own keymaps: `reftex-select-label-map',
4612 `reftex-select-bib-map', `reftex-toc-map'. The selection processes
4613 have a number of new keys predefined. In particular, TAB lets you
4614 enter a label with completion. Check the on-the-fly help (press `?'
4615 at the selection prompt) or read the Info documentation to find out
4616 more.
4617
4618 *** Support for the varioref package
4619
4620 The `v' key in the label selection buffer toggles \ref versus \vref.
4621
4622 *** New hooks
4623
4624 Three new hooks can be used to redefine the way labels, references,
4625 and citations are created. These hooks are
4626 `reftex-format-label-function', `reftex-format-ref-function',
4627 `reftex-format-cite-function'.
4628
4629 *** Citations outside LaTeX
4630
4631 The command `reftex-citation' may also be used outside LaTeX (e.g. in
4632 a mail buffer). See the Info documentation for details.
4633
4634 *** Short context is no longer fontified.
4635
4636 The short context in the label menu no longer copies the
4637 fontification from the text in the buffer. If you prefer it to be
4638 fontified, use
4639
4640 (setq reftex-refontify-context t)
4641
4642 ** file-cache-minibuffer-complete now accepts a prefix argument.
4643 With a prefix argument, it does not try to do completion of
4644 the file name within its directory; it only checks for other
4645 directories that contain the same file name.
4646
4647 Thus, given the file name Makefile, and assuming that a file
4648 Makefile.in exists in the same directory, ordinary
4649 file-cache-minibuffer-complete will try to complete Makefile to
4650 Makefile.in and will therefore never look for other directories that
4651 have Makefile. A prefix argument tells it not to look for longer
4652 names such as Makefile.in, so that instead it will look for other
4653 directories--just as if the name were already complete in its present
4654 directory.
4655
4656 ** New modes and packages
4657
4658 *** There is a new alternative major mode for Perl, Cperl mode.
4659 It has many more features than Perl mode, and some people prefer
4660 it, but some do not.
4661
4662 *** There is a new major mode, M-x vhdl-mode, for editing files of VHDL
4663 code.
4664
4665 *** M-x which-function-mode enables a minor mode that displays the
4666 current function name continuously in the mode line, as you move
4667 around in a buffer.
4668
4669 Which Function mode is effective in major modes which support Imenu.
4670
4671 *** Gametree is a major mode for editing game analysis trees. The author
4672 uses it for keeping notes about his postal Chess games, but it should
4673 be helpful for other two-player games as well, as long as they have an
4674 established system of notation similar to Chess.
4675
4676 *** The new minor mode checkdoc-minor-mode provides Emacs Lisp
4677 documentation string checking for style and spelling. The style
4678 guidelines are found in the Emacs Lisp programming manual.
4679
4680 *** The net-utils package makes some common networking features
4681 available in Emacs. Some of these functions are wrappers around
4682 system utilities (ping, nslookup, etc); others are implementations of
4683 simple protocols (finger, whois) in Emacs Lisp. There are also
4684 functions to make simple connections to TCP/IP ports for debugging and
4685 the like.
4686
4687 *** highlight-changes-mode is a minor mode that uses colors to
4688 identify recently changed parts of the buffer text.
4689
4690 *** The new package `midnight' lets you specify things to be done
4691 within Emacs at midnight--by default, kill buffers that you have not
4692 used in a considerable time. To use this feature, customize
4693 the user option `midnight-mode' to t.
4694
4695 *** The file generic-x.el defines a number of simple major modes.
4696
4697 apache-generic-mode: For Apache and NCSA httpd configuration files
4698 samba-generic-mode: Samba configuration files
4699 fvwm-generic-mode: For fvwm initialization files
4700 x-resource-generic-mode: For X resource files
4701 hosts-generic-mode: For hosts files (.rhosts, /etc/hosts, etc)
4702 mailagent-rules-generic-mode: For mailagent .rules files
4703 javascript-generic-mode: For JavaScript files
4704 vrml-generic-mode: For VRML files
4705 java-manifest-generic-mode: For Java MANIFEST files
4706 java-properties-generic-mode: For Java property files
4707 mailrc-generic-mode: For .mailrc files
4708
4709 Platform-specific modes:
4710
4711 prototype-generic-mode: For Solaris/Sys V prototype files
4712 pkginfo-generic-mode: For Solaris/Sys V pkginfo files
4713 alias-generic-mode: For C shell alias files
4714 inf-generic-mode: For MS-Windows INF files
4715 ini-generic-mode: For MS-Windows INI files
4716 reg-generic-mode: For MS-Windows Registry files
4717 bat-generic-mode: For MS-Windows BAT scripts
4718 rc-generic-mode: For MS-Windows Resource files
4719 rul-generic-mode: For InstallShield scripts
4720 \f
4721 * Lisp changes in Emacs 20.3 since the Emacs Lisp Manual was published
4722
4723 ** If you want a Lisp file to be read in unibyte mode,
4724 use -*-unibyte: t;-*- on its first line.
4725 That will force Emacs to read that file in unibyte mode.
4726 Otherwise, the file will be loaded and byte-compiled in multibyte mode.
4727
4728 Thus, each lisp file is read in a consistent way regardless of whether
4729 you started Emacs with --unibyte, so that a Lisp program gives
4730 consistent results regardless of how Emacs was started.
4731
4732 ** The new function assoc-default is useful for searching an alist,
4733 and using a default value if the key is not found there. You can
4734 specify a comparison predicate, so this function is useful for
4735 searching comparing a string against an alist of regular expressions.
4736
4737 ** The functions unibyte-char-to-multibyte and
4738 multibyte-char-to-unibyte convert between unibyte and multibyte
4739 character codes, in a way that is appropriate for the current language
4740 environment.
4741
4742 ** The functions read-event, read-char and read-char-exclusive now
4743 take two optional arguments. PROMPT, if non-nil, specifies a prompt
4744 string. SUPPRESS-INPUT-METHOD, if non-nil, says to disable the
4745 current input method for reading this one event.
4746
4747 ** Two new variables print-escape-nonascii and print-escape-multibyte
4748 now control whether to output certain characters as
4749 backslash-sequences. print-escape-nonascii applies to single-byte
4750 non-ASCII characters; print-escape-multibyte applies to multibyte
4751 characters. Both of these variables are used only when printing
4752 in readable fashion (prin1 uses them, princ does not).
4753 \f
4754 * Lisp changes in Emacs 20.3 before the Emacs Lisp Manual was published
4755
4756 ** Compiled Emacs Lisp files made with the modified "MBSK" version
4757 of Emacs 20.2 do not work in Emacs 20.3.
4758
4759 ** Buffer positions are now measured in characters, as they were
4760 in Emacs 19 and before. This means that (forward-char 1)
4761 always increases point by 1.
4762
4763 The function chars-in-region now just subtracts its arguments. It is
4764 considered obsolete. The function char-boundary-p has been deleted.
4765
4766 See below for additional changes relating to multibyte characters.
4767
4768 ** defcustom, defface and defgroup now accept the keyword `:version'.
4769 Use this to specify in which version of Emacs a certain variable's
4770 default value changed. For example,
4771
4772 (defcustom foo-max 34 "*Maximum number of foo's allowed."
4773 :type 'integer
4774 :group 'foo
4775 :version "20.3")
4776
4777 (defgroup foo-group nil "The foo group."
4778 :version "20.3")
4779
4780 If an entire new group is added or the variables in it have the
4781 default values changed, then just add a `:version' to that group. It
4782 is recommended that new packages added to the distribution contain a
4783 `:version' in the top level group.
4784
4785 This information is used to control the customize-changed-options command.
4786
4787 ** It is now an error to change the value of a symbol whose name
4788 starts with a colon--if it is interned in the standard obarray.
4789
4790 However, setting such a symbol to its proper value, which is that
4791 symbol itself, is not an error. This is for the sake of programs that
4792 support previous Emacs versions by explicitly setting these variables
4793 to themselves.
4794
4795 If you set the variable keyword-symbols-constant-flag to nil,
4796 this error is suppressed, and you can set these symbols to any
4797 values whatever.
4798
4799 ** There is a new debugger command, R.
4800 It evaluates an expression like e, but saves the result
4801 in the buffer *Debugger-record*.
4802
4803 ** Frame-local variables.
4804
4805 You can now make a variable local to various frames. To do this, call
4806 the function make-variable-frame-local; this enables frames to have
4807 local bindings for that variable.
4808
4809 These frame-local bindings are actually frame parameters: you create a
4810 frame-local binding in a specific frame by calling
4811 modify-frame-parameters and specifying the variable name as the
4812 parameter name.
4813
4814 Buffer-local bindings take precedence over frame-local bindings.
4815 Thus, if the current buffer has a buffer-local binding, that binding is
4816 active; otherwise, if the selected frame has a frame-local binding,
4817 that binding is active; otherwise, the default binding is active.
4818
4819 It would not be hard to implement window-local bindings, but it is not
4820 clear that this would be very useful; windows tend to come and go in a
4821 very transitory fashion, so that trying to produce any specific effect
4822 through a window-local binding would not be very robust.
4823
4824 ** `sregexq' and `sregex' are two new functions for constructing
4825 "symbolic regular expressions." These are Lisp expressions that, when
4826 evaluated, yield conventional string-based regexps. The symbolic form
4827 makes it easier to construct, read, and maintain complex patterns.
4828 See the documentation in sregex.el.
4829
4830 ** parse-partial-sexp's return value has an additional element which
4831 is used to pass information along if you pass it to another call to
4832 parse-partial-sexp, starting its scan where the first call ended.
4833 The contents of this field are not yet finalized.
4834
4835 ** eval-region now accepts a fourth optional argument READ-FUNCTION.
4836 If it is non-nil, that function is used instead of `read'.
4837
4838 ** unload-feature by default removes the feature's functions from
4839 known hooks to avoid trouble, but a package providing FEATURE can
4840 define a hook FEATURE-unload-hook to be run by unload-feature instead.
4841
4842 ** read-from-minibuffer no longer returns the argument DEFAULT-VALUE
4843 when the user enters empty input. It now returns the null string, as
4844 it did in Emacs 19. The default value is made available in the
4845 history via M-n, but it is not applied here as a default.
4846
4847 The other, more specialized minibuffer-reading functions continue to
4848 return the default value (not the null string) when the user enters
4849 empty input.
4850
4851 ** The new variable read-buffer-function controls which routine to use
4852 for selecting buffers. For example, if you set this variable to
4853 `iswitchb-read-buffer', iswitchb will be used to read buffer names.
4854 Other functions can also be used if they accept the same arguments as
4855 `read-buffer' and return the selected buffer name as a string.
4856
4857 ** The new function read-passwd reads a password from the terminal,
4858 echoing a period for each character typed. It takes three arguments:
4859 a prompt string, a flag which says "read it twice to make sure", and a
4860 default password to use if the user enters nothing.
4861
4862 ** The variable fill-nobreak-predicate gives major modes a way to
4863 specify not to break a line at certain places. Its value is a
4864 function which is called with no arguments, with point located at the
4865 place where a break is being considered. If the function returns
4866 non-nil, then the line won't be broken there.
4867
4868 ** window-end now takes an optional second argument, UPDATE.
4869 If this is non-nil, then the function always returns an accurate
4870 up-to-date value for the buffer position corresponding to the
4871 end of the window, even if this requires computation.
4872
4873 ** other-buffer now takes an optional argument FRAME
4874 which specifies which frame's buffer list to use.
4875 If it is nil, that means use the selected frame's buffer list.
4876
4877 ** The new variable buffer-display-time, always local in every buffer,
4878 holds the value of (current-time) as of the last time that a window
4879 was directed to display this buffer.
4880
4881 ** It is now meaningful to compare two window-configuration objects
4882 with `equal'. Two window-configuration objects are equal if they
4883 describe equivalent arrangements of windows, in the same frame--in
4884 other words, if they would give the same results if passed to
4885 set-window-configuration.
4886
4887 ** compare-window-configurations is a new function that compares two
4888 window configurations loosely. It ignores differences in saved buffer
4889 positions and scrolling, and considers only the structure and sizes of
4890 windows and the choice of buffers to display.
4891
4892 ** The variable minor-mode-overriding-map-alist allows major modes to
4893 override the key bindings of a minor mode. The elements of this alist
4894 look like the elements of minor-mode-map-alist: (VARIABLE . KEYMAP).
4895
4896 If the VARIABLE in an element of minor-mode-overriding-map-alist has a
4897 non-nil value, the paired KEYMAP is active, and totally overrides the
4898 map (if any) specified for the same variable in minor-mode-map-alist.
4899
4900 minor-mode-overriding-map-alist is automatically local in all buffers,
4901 and it is meant to be set by major modes.
4902
4903 ** The function match-string-no-properties is like match-string
4904 except that it discards all text properties from the result.
4905
4906 ** The function load-average now accepts an optional argument
4907 USE-FLOATS. If it is non-nil, the load average values are returned as
4908 floating point numbers, rather than as integers to be divided by 100.
4909
4910 ** The new variable temporary-file-directory specifies the directory
4911 to use for creating temporary files. The default value is determined
4912 in a reasonable way for your operating system; on GNU and Unix systems
4913 it is based on the TMP and TMPDIR environment variables.
4914
4915 ** Menu changes
4916
4917 *** easymenu.el now uses the new menu item format and supports the
4918 keywords :visible and :filter. The existing keyword :keys is now
4919 better supported.
4920
4921 The variable `easy-menu-precalculate-equivalent-keybindings' controls
4922 a new feature which calculates keyboard equivalents for the menu when
4923 you define the menu. The default is t. If you rarely use menus, you
4924 can set the variable to nil to disable this precalculation feature;
4925 then the calculation is done only if you use the menu bar.
4926
4927 *** A new format for menu items is supported.
4928
4929 In a keymap, a key binding that has the format
4930 (STRING . REAL-BINDING) or (STRING HELP-STRING . REAL-BINDING)
4931 defines a menu item. Now a menu item definition may also be a list that
4932 starts with the symbol `menu-item'.
4933
4934 The format is:
4935 (menu-item ITEM-NAME) or
4936 (menu-item ITEM-NAME REAL-BINDING . ITEM-PROPERTY-LIST)
4937 where ITEM-NAME is an expression which evaluates to the menu item
4938 string, and ITEM-PROPERTY-LIST has the form of a property list.
4939 The supported properties include
4940
4941 :enable FORM Evaluate FORM to determine whether the
4942 item is enabled.
4943 :visible FORM Evaluate FORM to determine whether the
4944 item should appear in the menu.
4945 :filter FILTER-FN
4946 FILTER-FN is a function of one argument,
4947 which will be REAL-BINDING.
4948 It should return a binding to use instead.
4949 :keys DESCRIPTION
4950 DESCRIPTION is a string that describes an equivalent keyboard
4951 binding for for REAL-BINDING. DESCRIPTION is expanded with
4952 `substitute-command-keys' before it is used.
4953 :key-sequence KEY-SEQUENCE
4954 KEY-SEQUENCE is a key-sequence for an equivalent
4955 keyboard binding.
4956 :key-sequence nil
4957 This means that the command normally has no
4958 keyboard equivalent.
4959 :help HELP HELP is the extra help string (not currently used).
4960 :button (TYPE . SELECTED)
4961 TYPE is :toggle or :radio.
4962 SELECTED is a form, to be evaluated, and its
4963 value says whether this button is currently selected.
4964
4965 Buttons are at the moment only simulated by prefixes in the menu.
4966 Eventually ordinary X-buttons may be supported.
4967
4968 (menu-item ITEM-NAME) defines unselectable item.
4969
4970 ** New event types
4971
4972 *** The new event type `mouse-wheel' is generated by a wheel on a
4973 mouse (such as the MS Intellimouse). The event contains a delta that
4974 corresponds to the amount and direction that the wheel is rotated,
4975 which is typically used to implement a scroll or zoom. The format is:
4976
4977 (mouse-wheel POSITION DELTA)
4978
4979 where POSITION is a list describing the position of the event in the
4980 same format as a mouse-click event, and DELTA is a signed number
4981 indicating the number of increments by which the wheel was rotated. A
4982 negative DELTA indicates that the wheel was rotated backwards, towards
4983 the user, and a positive DELTA indicates that the wheel was rotated
4984 forward, away from the user.
4985
4986 As of now, this event type is generated only on MS Windows.
4987
4988 *** The new event type `drag-n-drop' is generated when a group of
4989 files is selected in an application outside of Emacs, and then dragged
4990 and dropped onto an Emacs frame. The event contains a list of
4991 filenames that were dragged and dropped, which are then typically
4992 loaded into Emacs. The format is:
4993
4994 (drag-n-drop POSITION FILES)
4995
4996 where POSITION is a list describing the position of the event in the
4997 same format as a mouse-click event, and FILES is the list of filenames
4998 that were dragged and dropped.
4999
5000 As of now, this event type is generated only on MS Windows.
5001
5002 ** Changes relating to multibyte characters.
5003
5004 *** The variable enable-multibyte-characters is now read-only;
5005 any attempt to set it directly signals an error. The only way
5006 to change this value in an existing buffer is with set-buffer-multibyte.
5007
5008 *** In a string constant, `\ ' now stands for "nothing at all". You
5009 can use it to terminate a hex escape which is followed by a character
5010 that could otherwise be read as part of the hex escape.
5011
5012 *** String indices are now measured in characters, as they were
5013 in Emacs 19 and before.
5014
5015 The function chars-in-string has been deleted.
5016 The function concat-chars has been renamed to `string'.
5017
5018 *** The function set-buffer-multibyte sets the flag in the current
5019 buffer that says whether the buffer uses multibyte representation or
5020 unibyte representation. If the argument is nil, it selects unibyte
5021 representation. Otherwise it selects multibyte representation.
5022
5023 This function does not change the contents of the buffer, viewed
5024 as a sequence of bytes. However, it does change the contents
5025 viewed as characters; a sequence of two bytes which is treated as
5026 one character when the buffer uses multibyte representation
5027 will count as two characters using unibyte representation.
5028
5029 This function sets enable-multibyte-characters to record which
5030 representation is in use. It also adjusts various data in the buffer
5031 (including its markers, overlays and text properties) so that they are
5032 consistent with the new representation.
5033
5034 *** string-make-multibyte takes a string and converts it to multibyte
5035 representation. Most of the time, you don't need to care
5036 about the representation, because Emacs converts when necessary;
5037 however, it makes a difference when you compare strings.
5038
5039 The conversion of non-ASCII characters works by adding the value of
5040 nonascii-insert-offset to each character, or by translating them
5041 using the table nonascii-translation-table.
5042
5043 *** string-make-unibyte takes a string and converts it to unibyte
5044 representation. Most of the time, you don't need to care about the
5045 representation, but it makes a difference when you compare strings.
5046
5047 The conversion from multibyte to unibyte representation
5048 loses information; the only time Emacs performs it automatically
5049 is when inserting a multibyte string into a unibyte buffer.
5050
5051 *** string-as-multibyte takes a string, and returns another string
5052 which contains the same bytes, but treats them as multibyte.
5053
5054 *** string-as-unibyte takes a string, and returns another string
5055 which contains the same bytes, but treats them as unibyte.
5056
5057 *** The new function compare-strings lets you compare
5058 portions of two strings. Unibyte strings are converted to multibyte,
5059 so that a unibyte string can match a multibyte string.
5060 You can specify whether to ignore case or not.
5061
5062 *** assoc-ignore-case now uses compare-strings so that
5063 it can treat unibyte and multibyte strings as equal.
5064
5065 *** Regular expression operations and buffer string searches now
5066 convert the search pattern to multibyte or unibyte to accord with the
5067 buffer or string being searched.
5068
5069 One consequence is that you cannot always use \200-\377 inside of
5070 [...] to match all non-ASCII characters. This does still work when
5071 searching or matching a unibyte buffer or string, but not when
5072 searching or matching a multibyte string. Unfortunately, there is no
5073 obvious choice of syntax to use within [...] for that job. But, what
5074 you want is just to match all non-ASCII characters, the regular
5075 expression [^\0-\177] works for it.
5076
5077 *** Structure of coding system changed.
5078
5079 All coding systems (including aliases and subsidiaries) are named
5080 by symbols; the symbol's `coding-system' property is a vector
5081 which defines the coding system. Aliases share the same vector
5082 as the principal name, so that altering the contents of this
5083 vector affects the principal name and its aliases. You can define
5084 your own alias name of a coding system by the function
5085 define-coding-system-alias.
5086
5087 The coding system definition includes a property list of its own. Use
5088 the new functions `coding-system-get' and `coding-system-put' to
5089 access such coding system properties as post-read-conversion,
5090 pre-write-conversion, character-translation-table-for-decode,
5091 character-translation-table-for-encode, mime-charset, and
5092 safe-charsets. For instance, (coding-system-get 'iso-latin-1
5093 'mime-charset) gives the corresponding MIME-charset parameter
5094 `iso-8859-1'.
5095
5096 Among the coding system properties listed above, safe-charsets is new.
5097 The value of this property is a list of character sets which this
5098 coding system can correctly encode and decode. For instance:
5099 (coding-system-get 'iso-latin-1 'safe-charsets) => (ascii latin-iso8859-1)
5100
5101 Here, "correctly encode" means that the encoded character sets can
5102 also be handled safely by systems other than Emacs as far as they
5103 are capable of that coding system. Though, Emacs itself can encode
5104 the other character sets and read it back correctly.
5105
5106 *** The new function select-safe-coding-system can be used to find a
5107 proper coding system for encoding the specified region or string.
5108 This function requires a user interaction.
5109
5110 *** The new functions find-coding-systems-region and
5111 find-coding-systems-string are helper functions used by
5112 select-safe-coding-system. They return a list of all proper coding
5113 systems to encode a text in some region or string. If you don't want
5114 a user interaction, use one of these functions instead of
5115 select-safe-coding-system.
5116
5117 *** The explicit encoding and decoding functions, such as
5118 decode-coding-region and encode-coding-string, now set
5119 last-coding-system-used to reflect the actual way encoding or decoding
5120 was done.
5121
5122 *** The new function detect-coding-with-language-environment can be
5123 used to detect a coding system of text according to priorities of
5124 coding systems used by some specific language environment.
5125
5126 *** The functions detect-coding-region and detect-coding-string always
5127 return a list if the arg HIGHEST is nil. Thus, if only ASCII
5128 characters are found, they now return a list of single element
5129 `undecided' or its subsidiaries.
5130
5131 *** The new functions coding-system-change-eol-conversion and
5132 coding-system-change-text-conversion can be used to get a different
5133 coding system than what specified only in how end-of-line or text is
5134 converted.
5135
5136 *** The new function set-selection-coding-system can be used to set a
5137 coding system for communicating with other X clients.
5138
5139 *** The function `map-char-table' now passes as argument only valid
5140 character codes, plus generic characters that stand for entire
5141 character sets or entire subrows of a character set. In other words,
5142 each time `map-char-table' calls its FUNCTION argument, the key value
5143 either will be a valid individual character code, or will stand for a
5144 range of characters.
5145
5146 *** The new function `char-valid-p' can be used for checking whether a
5147 Lisp object is a valid character code or not.
5148
5149 *** The new function `charset-after' returns a charset of a character
5150 in the current buffer at position POS.
5151
5152 *** Input methods are now implemented using the variable
5153 input-method-function. If this is non-nil, its value should be a
5154 function; then, whenever Emacs reads an input event that is a printing
5155 character with no modifier bits, it calls that function, passing the
5156 event as an argument. Often this function will read more input, first
5157 binding input-method-function to nil.
5158
5159 The return value should be a list of the events resulting from input
5160 method processing. These events will be processed sequentially as
5161 input, before resorting to unread-command-events. Events returned by
5162 the input method function are not passed to the input method function,
5163 not even if they are printing characters with no modifier bits.
5164
5165 The input method function is not called when reading the second and
5166 subsequent events of a key sequence.
5167
5168 *** You can customize any language environment by using
5169 set-language-environment-hook and exit-language-environment-hook.
5170
5171 The hook `exit-language-environment-hook' should be used to undo
5172 customizations that you made with set-language-environment-hook. For
5173 instance, if you set up a special key binding for a specific language
5174 environment by set-language-environment-hook, you should set up
5175 exit-language-environment-hook to restore the normal key binding.
5176 \f
5177 * Changes in Emacs 20.1
5178
5179 ** Emacs has a new facility for customization of its many user
5180 options. It is called M-x customize. With this facility you can look
5181 at the many user options in an organized way; they are grouped into a
5182 tree structure.
5183
5184 M-x customize also knows what sorts of values are legitimate for each
5185 user option and ensures that you don't use invalid values.
5186
5187 With M-x customize, you can set options either for the present Emacs
5188 session or permanently. (Permanent settings are stored automatically
5189 in your .emacs file.)
5190
5191 ** Scroll bars are now on the left side of the window.
5192 You can change this with M-x customize-option scroll-bar-mode.
5193
5194 ** The mode line no longer includes the string `Emacs'.
5195 This makes more space in the mode line for other information.
5196
5197 ** When you select a region with the mouse, it is highlighted
5198 immediately afterward. At that time, if you type the DELETE key, it
5199 kills the region.
5200
5201 The BACKSPACE key, and the ASCII character DEL, do not do this; they
5202 delete the character before point, as usual.
5203
5204 ** In an incremental search the whole current match is highlighted
5205 on terminals which support this. (You can disable this feature
5206 by setting search-highlight to nil.)
5207
5208 ** In the minibuffer, in some cases, you can now use M-n to
5209 insert the default value into the minibuffer as text. In effect,
5210 the default value (if the minibuffer routines know it) is tacked
5211 onto the history "in the future". (The more normal use of the
5212 history list is to use M-p to insert minibuffer input used in the
5213 past.)
5214
5215 ** In Text mode, now only blank lines separate paragraphs.
5216 This makes it possible to get the full benefit of Adaptive Fill mode
5217 in Text mode, and other modes derived from it (such as Mail mode).
5218 TAB in Text mode now runs the command indent-relative; this
5219 makes a practical difference only when you use indented paragraphs.
5220
5221 As a result, the old Indented Text mode is now identical to Text mode,
5222 and is an alias for it.
5223
5224 If you want spaces at the beginning of a line to start a paragraph,
5225 use the new mode, Paragraph Indent Text mode.
5226
5227 ** Scrolling changes
5228
5229 *** Scroll commands to scroll a whole screen now preserve the screen
5230 position of the cursor, if scroll-preserve-screen-position is non-nil.
5231
5232 In this mode, if you scroll several screens back and forth, finishing
5233 on the same screen where you started, the cursor goes back to the line
5234 where it started.
5235
5236 *** If you set scroll-conservatively to a small number, then when you
5237 move point a short distance off the screen, Emacs will scroll the
5238 screen just far enough to bring point back on screen, provided that
5239 does not exceed `scroll-conservatively' lines.
5240
5241 *** The new variable scroll-margin says how close point can come to the
5242 top or bottom of a window. It is a number of screen lines; if point
5243 comes within that many lines of the top or bottom of the window, Emacs
5244 recenters the window.
5245
5246 ** International character set support (MULE)
5247
5248 Emacs now supports a wide variety of international character sets,
5249 including European variants of the Latin alphabet, as well as Chinese,
5250 Devanagari (Hindi and Marathi), Ethiopian, Greek, IPA, Japanese,
5251 Korean, Lao, Russian, Thai, Tibetan, and Vietnamese scripts. These
5252 features have been merged from the modified version of Emacs known as
5253 MULE (for "MULti-lingual Enhancement to GNU Emacs")
5254
5255 Users of these scripts have established many more-or-less standard
5256 coding systems for storing files. Emacs uses a single multibyte
5257 character encoding within Emacs buffers; it can translate from a wide
5258 variety of coding systems when reading a file and can translate back
5259 into any of these coding systems when saving a file.
5260
5261 Keyboards, even in the countries where these character sets are used,
5262 generally don't have keys for all the characters in them. So Emacs
5263 supports various "input methods", typically one for each script or
5264 language, to make it possible to type them.
5265
5266 The Emacs internal multibyte encoding represents a non-ASCII
5267 character as a sequence of bytes in the range 0200 through 0377.
5268
5269 The new prefix key C-x RET is used for commands that pertain
5270 to multibyte characters, coding systems, and input methods.
5271
5272 You can disable multibyte character support as follows:
5273
5274 (setq-default enable-multibyte-characters nil)
5275
5276 Calling the function standard-display-european turns off multibyte
5277 characters, unless you specify a non-nil value for the second
5278 argument, AUTO. This provides compatibility for people who are
5279 already using standard-display-european to continue using unibyte
5280 characters for their work until they want to change.
5281
5282 *** Input methods
5283
5284 An input method is a kind of character conversion which is designed
5285 specifically for interactive input. In Emacs, typically each language
5286 has its own input method (though sometimes several languages which use
5287 the same characters can share one input method). Some languages
5288 support several input methods.
5289
5290 The simplest kind of input method works by mapping ASCII letters into
5291 another alphabet. This is how the Greek and Russian input methods
5292 work.
5293
5294 A more powerful technique is composition: converting sequences of
5295 characters into one letter. Many European input methods use
5296 composition to produce a single non-ASCII letter from a sequence which
5297 consists of a letter followed by diacritics. For example, a' is one
5298 sequence of two characters that might be converted into a single
5299 letter.
5300
5301 The input methods for syllabic scripts typically use mapping followed
5302 by conversion. The input methods for Thai and Korean work this way.
5303 First, letters are mapped into symbols for particular sounds or tone
5304 marks; then, sequences of these which make up a whole syllable are
5305 mapped into one syllable sign--most often a "composite character".
5306
5307 None of these methods works very well for Chinese and Japanese, so
5308 they are handled specially. First you input a whole word using
5309 phonetic spelling; then, after the word is in the buffer, Emacs
5310 converts it into one or more characters using a large dictionary.
5311
5312 Since there is more than one way to represent a phonetically spelled
5313 word using Chinese characters, Emacs can only guess which one to use;
5314 typically these input methods give you a way to say "guess again" if
5315 the first guess is wrong.
5316
5317 *** The command C-x RET m (toggle-enable-multibyte-characters)
5318 turns multibyte character support on or off for the current buffer.
5319
5320 If multibyte character support is turned off in a buffer, then each
5321 byte is a single character, even codes 0200 through 0377--exactly as
5322 they did in Emacs 19.34. This includes the features for support for
5323 the European characters, ISO Latin-1 and ISO Latin-2.
5324
5325 However, there is no need to turn off multibyte character support to
5326 use ISO Latin-1 or ISO Latin-2; the Emacs multibyte character set
5327 includes all the characters in these character sets, and Emacs can
5328 translate automatically to and from either one.
5329
5330 *** Visiting a file in unibyte mode.
5331
5332 Turning off multibyte character support in the buffer after visiting a
5333 file with multibyte code conversion will display the multibyte
5334 sequences already in the buffer, byte by byte. This is probably not
5335 what you want.
5336
5337 If you want to edit a file of unibyte characters (Latin-1, for
5338 example), you can do it by specifying `no-conversion' as the coding
5339 system when reading the file. This coding system also turns off
5340 multibyte characters in that buffer.
5341
5342 If you turn off multibyte character support entirely, this turns off
5343 character conversion as well.
5344
5345 *** Displaying international characters on X Windows.
5346
5347 A font for X typically displays just one alphabet or script.
5348 Therefore, displaying the entire range of characters Emacs supports
5349 requires using many fonts.
5350
5351 Therefore, Emacs now supports "fontsets". Each fontset is a
5352 collection of fonts, each assigned to a range of character codes.
5353
5354 A fontset has a name, like a font. Individual fonts are defined by
5355 the X server; fontsets are defined within Emacs itself. But once you
5356 have defined a fontset, you can use it in a face or a frame just as
5357 you would use a font.
5358
5359 If a fontset specifies no font for a certain character, or if it
5360 specifies a font that does not exist on your system, then it cannot
5361 display that character. It will display an empty box instead.
5362
5363 The fontset height and width are determined by the ASCII characters
5364 (that is, by the font in the fontset which is used for ASCII
5365 characters). If another font in the fontset has a different height,
5366 or the wrong width, then characters assigned to that font are clipped,
5367 and displayed within a box if highlight-wrong-size-font is non-nil.
5368
5369 *** Defining fontsets.
5370
5371 Emacs does not use any fontset by default. Its default font is still
5372 chosen as in previous versions. You can tell Emacs to use a fontset
5373 with the `-fn' option or the `Font' X resource.
5374
5375 Emacs creates a standard fontset automatically according to the value
5376 of standard-fontset-spec. This fontset's short name is
5377 `fontset-standard'. Bold, italic, and bold-italic variants of the
5378 standard fontset are created automatically.
5379
5380 If you specify a default ASCII font with the `Font' resource or `-fn'
5381 argument, a fontset is generated from it. This works by replacing the
5382 FOUNDARY, FAMILY, ADD_STYLE, and AVERAGE_WIDTH fields of the font name
5383 with `*' then using this to specify a fontset. This fontset's short
5384 name is `fontset-startup'.
5385
5386 Emacs checks resources of the form Fontset-N where N is 0, 1, 2...
5387 The resource value should have this form:
5388 FONTSET-NAME, [CHARSET-NAME:FONT-NAME]...
5389 FONTSET-NAME should have the form of a standard X font name, except:
5390 * most fields should be just the wild card "*".
5391 * the CHARSET_REGISTRY field should be "fontset"
5392 * the CHARSET_ENCODING field can be any nickname of the fontset.
5393 The construct CHARSET-NAME:FONT-NAME can be repeated any number
5394 of times; each time specifies the font for one character set.
5395 CHARSET-NAME should be the name name of a character set, and
5396 FONT-NAME should specify an actual font to use for that character set.
5397
5398 Each of these fontsets has an alias which is made from the
5399 last two font name fields, CHARSET_REGISTRY and CHARSET_ENCODING.
5400 You can refer to the fontset by that alias or by its full name.
5401
5402 For any character sets that you don't mention, Emacs tries to choose a
5403 font by substituting into FONTSET-NAME. For instance, with the
5404 following resource,
5405 Emacs*Fontset-0: -*-fixed-medium-r-normal-*-24-*-*-*-*-*-fontset-24
5406 the font for ASCII is generated as below:
5407 -*-fixed-medium-r-normal-*-24-*-ISO8859-1
5408 Here is the substitution rule:
5409 Change CHARSET_REGISTRY and CHARSET_ENCODING to that of the charset
5410 defined in the variable x-charset-registries. For instance, ASCII has
5411 the entry (ascii . "ISO8859-1") in this variable. Then, reduce
5412 sequences of wild cards -*-...-*- with a single wildcard -*-.
5413 (This is to prevent use of auto-scaled fonts.)
5414
5415 The function which processes the fontset resource value to create the
5416 fontset is called create-fontset-from-fontset-spec. You can also call
5417 that function explicitly to create a fontset.
5418
5419 With the X resource Emacs.Font, you can specify a fontset name just
5420 like an actual font name. But be careful not to specify a fontset
5421 name in a wildcard resource like Emacs*Font--that tries to specify the
5422 fontset for other purposes including menus, and they cannot handle
5423 fontsets.
5424
5425 *** The command M-x set-language-environment sets certain global Emacs
5426 defaults for a particular choice of language.
5427
5428 Selecting a language environment typically specifies a default input
5429 method and which coding systems to recognize automatically when
5430 visiting files. However, it does not try to reread files you have
5431 already visited; the text in those buffers is not affected. The
5432 language environment may also specify a default choice of coding
5433 system for new files that you create.
5434
5435 It makes no difference which buffer is current when you use
5436 set-language-environment, because these defaults apply globally to the
5437 whole Emacs session.
5438
5439 For example, M-x set-language-environment RET Latin-1 RET
5440 chooses the Latin-1 character set. In the .emacs file, you can do this
5441 with (set-language-environment "Latin-1").
5442
5443 *** The command C-x RET f (set-buffer-file-coding-system)
5444 specifies the file coding system for the current buffer. This
5445 specifies what sort of character code translation to do when saving
5446 the file. As an argument, you must specify the name of one of the
5447 coding systems that Emacs supports.
5448
5449 *** The command C-x RET c (universal-coding-system-argument)
5450 lets you specify a coding system when you read or write a file.
5451 This command uses the minibuffer to read a coding system name.
5452 After you exit the minibuffer, the specified coding system
5453 is used for *the immediately following command*.
5454
5455 So if the immediately following command is a command to read or
5456 write a file, it uses the specified coding system for that file.
5457
5458 If the immediately following command does not use the coding system,
5459 then C-x RET c ultimately has no effect.
5460
5461 For example, C-x RET c iso-8859-1 RET C-x C-f temp RET
5462 visits the file `temp' treating it as ISO Latin-1.
5463
5464 *** You can specify the coding system for a file using the -*-
5465 construct. Include `coding: CODINGSYSTEM;' inside the -*-...-*-
5466 to specify use of coding system CODINGSYSTEM. You can also
5467 specify the coding system in a local variable list at the end
5468 of the file.
5469
5470 *** The command C-x RET t (set-terminal-coding-system) specifies
5471 the coding system for terminal output. If you specify a character
5472 code for terminal output, all characters output to the terminal are
5473 translated into that character code.
5474
5475 This feature is useful for certain character-only terminals built in
5476 various countries to support the languages of those countries.
5477
5478 By default, output to the terminal is not translated at all.
5479
5480 *** The command C-x RET k (set-keyboard-coding-system) specifies
5481 the coding system for keyboard input.
5482
5483 Character code translation of keyboard input is useful for terminals
5484 with keys that send non-ASCII graphic characters--for example,
5485 some terminals designed for ISO Latin-1 or subsets of it.
5486
5487 By default, keyboard input is not translated at all.
5488
5489 Character code translation of keyboard input is similar to using an
5490 input method, in that both define sequences of keyboard input that
5491 translate into single characters. However, input methods are designed
5492 to be convenient for interactive use, while the code translations are
5493 designed to work with terminals.
5494
5495 *** The command C-x RET p (set-buffer-process-coding-system)
5496 specifies the coding system for input and output to a subprocess.
5497 This command applies to the current buffer; normally, each subprocess
5498 has its own buffer, and thus you can use this command to specify
5499 translation to and from a particular subprocess by giving the command
5500 in the corresponding buffer.
5501
5502 By default, process input and output are not translated at all.
5503
5504 *** The variable file-name-coding-system specifies the coding system
5505 to use for encoding file names before operating on them.
5506 It is also used for decoding file names obtained from the system.
5507
5508 *** The command C-\ (toggle-input-method) activates or deactivates
5509 an input method. If no input method has been selected before, the
5510 command prompts for you to specify the language and input method you
5511 want to use.
5512
5513 C-u C-\ (select-input-method) lets you switch to a different input
5514 method. C-h C-\ (or C-h I) describes the current input method.
5515
5516 *** Some input methods remap the keyboard to emulate various keyboard
5517 layouts commonly used for particular scripts. How to do this
5518 remapping properly depends on your actual keyboard layout. To specify
5519 which layout your keyboard has, use M-x quail-set-keyboard-layout.
5520
5521 *** The command C-h C (describe-coding-system) displays
5522 the coding systems currently selected for various purposes, plus
5523 related information.
5524
5525 *** The command C-h h (view-hello-file) displays a file called
5526 HELLO, which has examples of text in many languages, using various
5527 scripts.
5528
5529 *** The command C-h L (describe-language-support) displays
5530 information about the support for a particular language.
5531 You specify the language as an argument.
5532
5533 *** The mode line now contains a letter or character that identifies
5534 the coding system used in the visited file. It normally follows the
5535 first dash.
5536
5537 A dash indicates the default state of affairs: no code conversion
5538 (except CRLF => newline if appropriate). `=' means no conversion
5539 whatsoever. The ISO 8859 coding systems are represented by digits
5540 1 through 9. Other coding systems are represented by letters:
5541
5542 A alternativnyj (Russian)
5543 B big5 (Chinese)
5544 C cn-gb-2312 (Chinese)
5545 C iso-2022-cn (Chinese)
5546 D in-is13194-devanagari (Indian languages)
5547 E euc-japan (Japanese)
5548 I iso-2022-cjk or iso-2022-ss2 (Chinese, Japanese, Korean)
5549 J junet (iso-2022-7) or old-jis (iso-2022-jp-1978-irv) (Japanese)
5550 K euc-korea (Korean)
5551 R koi8 (Russian)
5552 Q tibetan
5553 S shift_jis (Japanese)
5554 T lao
5555 T tis620 (Thai)
5556 V viscii or vscii (Vietnamese)
5557 i iso-2022-lock (Chinese, Japanese, Korean)
5558 k iso-2022-kr (Korean)
5559 v viqr (Vietnamese)
5560 z hz (Chinese)
5561
5562 When you are using a character-only terminal (not a window system),
5563 two additional characters appear in between the dash and the file
5564 coding system. These two characters describe the coding system for
5565 keyboard input, and the coding system for terminal output.
5566
5567 *** The new variable rmail-file-coding-system specifies the code
5568 conversion to use for RMAIL files. The default value is nil.
5569
5570 When you read mail with Rmail, each message is decoded automatically
5571 into Emacs' internal format. This has nothing to do with
5572 rmail-file-coding-system. That variable controls reading and writing
5573 Rmail files themselves.
5574
5575 *** The new variable sendmail-coding-system specifies the code
5576 conversion for outgoing mail. The default value is nil.
5577
5578 Actually, there are three different ways of specifying the coding system
5579 for sending mail:
5580
5581 - If you use C-x RET f in the mail buffer, that takes priority.
5582 - Otherwise, if you set sendmail-coding-system non-nil, that specifies it.
5583 - Otherwise, the default coding system for new files is used,
5584 if that is non-nil. That comes from your language environment.
5585 - Otherwise, Latin-1 is used.
5586
5587 *** The command C-h t (help-with-tutorial) accepts a prefix argument
5588 to specify the language for the tutorial file. Currently, English,
5589 Japanese, Korean and Thai are supported. We welcome additional
5590 translations.
5591
5592 ** An easy new way to visit a file with no code or format conversion
5593 of any kind: Use M-x find-file-literally. There is also a command
5594 insert-file-literally which inserts a file into the current buffer
5595 without any conversion.
5596
5597 ** C-q's handling of octal character codes is changed.
5598 You can now specify any number of octal digits.
5599 RET terminates the digits and is discarded;
5600 any other non-digit terminates the digits and is then used as input.
5601
5602 ** There are new commands for looking up Info documentation for
5603 functions, variables and file names used in your programs.
5604
5605 Type M-x info-lookup-symbol to look up a symbol in the buffer at point.
5606 Type M-x info-lookup-file to look up a file in the buffer at point.
5607
5608 Precisely which Info files are used to look it up depends on the major
5609 mode. For example, in C mode, the GNU libc manual is used.
5610
5611 ** M-TAB in most programming language modes now runs the command
5612 complete-symbol. This command performs completion on the symbol name
5613 in the buffer before point.
5614
5615 With a numeric argument, it performs completion based on the set of
5616 symbols documented in the Info files for the programming language that
5617 you are using.
5618
5619 With no argument, it does completion based on the current tags tables,
5620 just like the old binding of M-TAB (complete-tag).
5621
5622 ** File locking works with NFS now.
5623
5624 The lock file for FILENAME is now a symbolic link named .#FILENAME,
5625 in the same directory as FILENAME.
5626
5627 This means that collision detection between two different machines now
5628 works reasonably well; it also means that no file server or directory
5629 can become a bottleneck.
5630
5631 The new method does have drawbacks. It means that collision detection
5632 does not operate when you edit a file in a directory where you cannot
5633 create new files. Collision detection also doesn't operate when the
5634 file server does not support symbolic links. But these conditions are
5635 rare, and the ability to have collision detection while using NFS is
5636 so useful that the change is worth while.
5637
5638 When Emacs or a system crashes, this may leave behind lock files which
5639 are stale. So you may occasionally get warnings about spurious
5640 collisions. When you determine that the collision is spurious, just
5641 tell Emacs to go ahead anyway.
5642
5643 ** If you wish to use Show Paren mode to display matching parentheses,
5644 it is no longer sufficient to load paren.el. Instead you must call
5645 show-paren-mode.
5646
5647 ** If you wish to use Delete Selection mode to replace a highlighted
5648 selection when you insert new text, it is no longer sufficient to load
5649 delsel.el. Instead you must call the function delete-selection-mode.
5650
5651 ** If you wish to use Partial Completion mode to complete partial words
5652 within symbols or filenames, it is no longer sufficient to load
5653 complete.el. Instead you must call the function partial-completion-mode.
5654
5655 ** If you wish to use uniquify to rename buffers for you,
5656 it is no longer sufficient to load uniquify.el. You must also
5657 set uniquify-buffer-name-style to one of the non-nil legitimate values.
5658
5659 ** Changes in View mode.
5660
5661 *** Several new commands are available in View mode.
5662 Do H in view mode for a list of commands.
5663
5664 *** There are two new commands for entering View mode:
5665 view-file-other-frame and view-buffer-other-frame.
5666
5667 *** Exiting View mode does a better job of restoring windows to their
5668 previous state.
5669
5670 *** New customization variable view-scroll-auto-exit. If non-nil,
5671 scrolling past end of buffer makes view mode exit.
5672
5673 *** New customization variable view-exits-all-viewing-windows. If
5674 non-nil, view-mode will at exit restore all windows viewing buffer,
5675 not just the selected window.
5676
5677 *** New customization variable view-read-only. If non-nil, visiting a
5678 read-only file automatically enters View mode, and toggle-read-only
5679 turns View mode on or off.
5680
5681 *** New customization variable view-remove-frame-by-deleting controls
5682 how to remove a not needed frame at view mode exit. If non-nil,
5683 delete the frame, if nil make an icon of it.
5684
5685 ** C-x v l, the command to print a file's version control log,
5686 now positions point at the entry for the file's current branch version.
5687
5688 ** C-x v =, the command to compare a file with the last checked-in version,
5689 has a new feature. If the file is currently not locked, so that it is
5690 presumably identical to the last checked-in version, the command now asks
5691 which version to compare with.
5692
5693 ** When using hideshow.el, incremental search can temporarily show hidden
5694 blocks if a match is inside the block.
5695
5696 The block is hidden again if the search is continued and the next match
5697 is outside the block. By customizing the variable
5698 isearch-hide-immediately you can choose to hide all the temporarily
5699 shown blocks only when exiting from incremental search.
5700
5701 By customizing the variable hs-isearch-open you can choose what kind
5702 of blocks to temporarily show during isearch: comment blocks, code
5703 blocks, all of them or none.
5704
5705 ** The new command C-x 4 0 (kill-buffer-and-window) kills the
5706 current buffer and deletes the selected window. It asks for
5707 confirmation first.
5708
5709 ** C-x C-w, which saves the buffer into a specified file name,
5710 now changes the major mode according to that file name.
5711 However, the mode will not be changed if
5712 (1) a local variables list or the `-*-' line specifies a major mode, or
5713 (2) the current major mode is a "special" mode,
5714 not suitable for ordinary files, or
5715 (3) the new file name does not particularly specify any mode.
5716
5717 This applies to M-x set-visited-file-name as well.
5718
5719 However, if you set change-major-mode-with-file-name to nil, then
5720 these commands do not change the major mode.
5721
5722 ** M-x occur changes.
5723
5724 *** If the argument to M-x occur contains upper case letters,
5725 it performs a case-sensitive search.
5726
5727 *** In the *Occur* buffer made by M-x occur,
5728 if you type g or M-x revert-buffer, this repeats the search
5729 using the same regular expression and the same buffer as before.
5730
5731 ** In Transient Mark mode, the region in any one buffer is highlighted
5732 in just one window at a time. At first, it is highlighted in the
5733 window where you set the mark. The buffer's highlighting remains in
5734 that window unless you select to another window which shows the same
5735 buffer--then the highlighting moves to that window.
5736
5737 ** The feature to suggest key bindings when you use M-x now operates
5738 after the command finishes. The message suggesting key bindings
5739 appears temporarily in the echo area. The previous echo area contents
5740 come back after a few seconds, in case they contain useful information.
5741
5742 ** Each frame now independently records the order for recently
5743 selected buffers, so that the default for C-x b is now based on the
5744 buffers recently selected in the selected frame.
5745
5746 ** Outline mode changes.
5747
5748 *** Outline mode now uses overlays (this is the former noutline.el).
5749
5750 *** Incremental searches skip over invisible text in Outline mode.
5751
5752 ** When a minibuffer window is active but not the selected window, if
5753 you try to use the minibuffer, you used to get a nested minibuffer.
5754 Now, this not only gives an error, it also cancels the minibuffer that
5755 was already active.
5756
5757 The motive for this change is so that beginning users do not
5758 unknowingly move away from minibuffers, leaving them active, and then
5759 get confused by it.
5760
5761 If you want to be able to have recursive minibuffers, you must
5762 set enable-recursive-minibuffers to non-nil.
5763
5764 ** Changes in dynamic abbrevs.
5765
5766 *** Expanding dynamic abbrevs with M-/ is now smarter about case
5767 conversion. If the expansion has mixed case not counting the first
5768 character, and the abbreviation matches the beginning of the expansion
5769 including case, then the expansion is copied verbatim.
5770
5771 The expansion is also copied verbatim if the abbreviation itself has
5772 mixed case. And using SPC M-/ to copy an additional word always
5773 copies it verbatim except when the previous copied word is all caps.
5774
5775 *** The values of `dabbrev-case-replace' and `dabbrev-case-fold-search'
5776 are no longer Lisp expressions. They have simply three possible
5777 values.
5778
5779 `dabbrev-case-replace' has these three values: nil (don't preserve
5780 case), t (do), or `case-replace' (do like M-x query-replace).
5781 `dabbrev-case-fold-search' has these three values: nil (don't ignore
5782 case), t (do), or `case-fold-search' (do like search).
5783
5784 ** Minibuffer history lists are truncated automatically now to a
5785 certain length. The variable history-length specifies how long they
5786 can be. The default value is 30.
5787
5788 ** Changes in Mail mode.
5789
5790 *** The key C-x m no longer runs the `mail' command directly.
5791 Instead, it runs the command `compose-mail', which invokes the mail
5792 composition mechanism you have selected with the variable
5793 `mail-user-agent'. The default choice of user agent is
5794 `sendmail-user-agent', which gives behavior compatible with the old
5795 behavior.
5796
5797 C-x 4 m now runs compose-mail-other-window, and C-x 5 m runs
5798 compose-mail-other-frame.
5799
5800 *** While composing a reply to a mail message, from Rmail, you can use
5801 the command C-c C-r to cite just the region from the message you are
5802 replying to. This copies the text which is the selected region in the
5803 buffer that shows the original message.
5804
5805 *** The command C-c C-i inserts a file at the end of the message,
5806 with separator lines around the contents.
5807
5808 *** The command M-x expand-mail-aliases expands all mail aliases
5809 in suitable mail headers. Emacs automatically extracts mail alias
5810 definitions from your mail alias file (e.g., ~/.mailrc). You do not
5811 need to expand mail aliases yourself before sending mail.
5812
5813 *** New features in the mail-complete command.
5814
5815 **** The mail-complete command now inserts the user's full name,
5816 for local users or if that is known. The variable mail-complete-style
5817 controls the style to use, and whether to do this at all.
5818 Its values are like those of mail-from-style.
5819
5820 **** The variable mail-passwd-command lets you specify a shell command
5821 to run to fetch a set of password-entries that add to the ones in
5822 /etc/passwd.
5823
5824 **** The variable mail-passwd-file now specifies a list of files to read
5825 to get the list of user ids. By default, one file is used:
5826 /etc/passwd.
5827
5828 ** You can "quote" a file name to inhibit special significance of
5829 special syntax, by adding `/:' to the beginning. Thus, if you have a
5830 directory named `/foo:', you can prevent it from being treated as a
5831 reference to a remote host named `foo' by writing it as `/:/foo:'.
5832
5833 Emacs uses this new construct automatically when necessary, such as
5834 when you start it with a working directory whose name might otherwise
5835 be taken to be magic.
5836
5837 ** There is a new command M-x grep-find which uses find to select
5838 files to search through, and grep to scan them. The output is
5839 available in a Compile mode buffer, as with M-x grep.
5840
5841 M-x grep now uses the -e option if the grep program supports that.
5842 (-e prevents problems if the search pattern starts with a dash.)
5843
5844 ** In Dired, the & command now flags for deletion the files whose names
5845 suggest they are probably not needed in the long run.
5846
5847 In Dired, * is now a prefix key for mark-related commands.
5848
5849 new key dired.el binding old key
5850 ------- ---------------- -------
5851 * c dired-change-marks c
5852 * m dired-mark m
5853 * * dired-mark-executables * (binding deleted)
5854 * / dired-mark-directories / (binding deleted)
5855 * @ dired-mark-symlinks @ (binding deleted)
5856 * u dired-unmark u
5857 * DEL dired-unmark-backward DEL
5858 * ? dired-unmark-all-files M-C-?
5859 * ! dired-unmark-all-marks
5860 * % dired-mark-files-regexp % m
5861 * C-n dired-next-marked-file M-}
5862 * C-p dired-prev-marked-file M-{
5863
5864 ** Rmail changes.
5865
5866 *** When Rmail cannot convert your incoming mail into Babyl format, it
5867 saves the new mail in the file RMAILOSE.n, where n is an integer
5868 chosen to make a unique name. This way, Rmail will not keep crashing
5869 each time you run it.
5870
5871 *** In Rmail, the variable rmail-summary-line-count-flag now controls
5872 whether to include the line count in the summary. Non-nil means yes.
5873
5874 *** In Rmail summary buffers, d and C-d (the commands to delete
5875 messages) now take repeat counts as arguments. A negative argument
5876 means to move in the opposite direction.
5877
5878 *** In Rmail, the t command now takes an optional argument which lets
5879 you specify whether to show the message headers in full or pruned.
5880
5881 *** In Rmail, the new command w (rmail-output-body-to-file) writes
5882 just the body of the current message into a file, without the headers.
5883 It takes the file name from the message subject, by default, but you
5884 can edit that file name in the minibuffer before it is actually used
5885 for output.
5886
5887 ** Gnus changes.
5888
5889 *** nntp.el has been totally rewritten in an asynchronous fashion.
5890
5891 *** Article prefetching functionality has been moved up into
5892 Gnus.
5893
5894 *** Scoring can now be performed with logical operators like
5895 `and', `or', `not', and parent redirection.
5896
5897 *** Article washing status can be displayed in the
5898 article mode line.
5899
5900 *** gnus.el has been split into many smaller files.
5901
5902 *** Suppression of duplicate articles based on Message-ID.
5903
5904 (setq gnus-suppress-duplicates t)
5905
5906 *** New variables for specifying what score and adapt files
5907 are to be considered home score and adapt files. See
5908 `gnus-home-score-file' and `gnus-home-adapt-files'.
5909
5910 *** Groups can inherit group parameters from parent topics.
5911
5912 *** Article editing has been revamped and is now usable.
5913
5914 *** Signatures can be recognized in more intelligent fashions.
5915 See `gnus-signature-separator' and `gnus-signature-limit'.
5916
5917 *** Summary pick mode has been made to look more nn-like.
5918 Line numbers are displayed and the `.' command can be
5919 used to pick articles.
5920
5921 *** Commands for moving the .newsrc.eld from one server to
5922 another have been added.
5923
5924 `M-x gnus-change-server'
5925
5926 *** A way to specify that "uninteresting" fields be suppressed when
5927 generating lines in buffers.
5928
5929 *** Several commands in the group buffer can be undone with
5930 `M-C-_'.
5931
5932 *** Scoring can be done on words using the new score type `w'.
5933
5934 *** Adaptive scoring can be done on a Subject word-by-word basis:
5935
5936 (setq gnus-use-adaptive-scoring '(word))
5937
5938 *** Scores can be decayed.
5939
5940 (setq gnus-decay-scores t)
5941
5942 *** Scoring can be performed using a regexp on the Date header. The
5943 Date is normalized to compact ISO 8601 format first.
5944
5945 *** A new command has been added to remove all data on articles from
5946 the native server.
5947
5948 `M-x gnus-group-clear-data-on-native-groups'
5949
5950 *** A new command for reading collections of documents
5951 (nndoc with nnvirtual on top) has been added -- `M-C-d'.
5952
5953 *** Process mark sets can be pushed and popped.
5954
5955 *** A new mail-to-news backend makes it possible to post
5956 even when the NNTP server doesn't allow posting.
5957
5958 *** A new backend for reading searches from Web search engines
5959 (DejaNews, Alta Vista, InReference) has been added.
5960
5961 Use the `G w' command in the group buffer to create such
5962 a group.
5963
5964 *** Groups inside topics can now be sorted using the standard
5965 sorting functions, and each topic can be sorted independently.
5966
5967 See the commands under the `T S' submap.
5968
5969 *** Subsets of the groups can be sorted independently.
5970
5971 See the commands under the `G P' submap.
5972
5973 *** Cached articles can be pulled into the groups.
5974
5975 Use the `Y c' command.
5976
5977 *** Score files are now applied in a more reliable order.
5978
5979 *** Reports on where mail messages end up can be generated.
5980
5981 `M-x nnmail-split-history'
5982
5983 *** More hooks and functions have been added to remove junk
5984 from incoming mail before saving the mail.
5985
5986 See `nnmail-prepare-incoming-header-hook'.
5987
5988 *** The nnml mail backend now understands compressed article files.
5989
5990 *** To enable Gnus to read/post multi-lingual articles, you must execute
5991 the following code, for instance, in your .emacs.
5992
5993 (add-hook 'gnus-startup-hook 'gnus-mule-initialize)
5994
5995 Then, when you start Gnus, it will decode non-ASCII text automatically
5996 and show appropriate characters. (Note: if you are using gnus-mime
5997 from the SEMI package, formerly known as TM, you should NOT add this
5998 hook to gnus-startup-hook; gnus-mime has its own method of handling
5999 this issue.)
6000
6001 Since it is impossible to distinguish all coding systems
6002 automatically, you may need to specify a choice of coding system for a
6003 particular news group. This can be done by:
6004
6005 (gnus-mule-add-group NEWSGROUP 'CODING-SYSTEM)
6006
6007 Here NEWSGROUP should be a string which names a newsgroup or a tree
6008 of newsgroups. If NEWSGROUP is "XXX.YYY", all news groups under
6009 "XXX.YYY" (including "XXX.YYY.ZZZ") will use the specified coding
6010 system. CODING-SYSTEM specifies which coding system to use (for both
6011 for reading and posting).
6012
6013 CODING-SYSTEM can also be a cons cell of the form
6014 (READ-CODING-SYSTEM . POST-CODING-SYSTEM)
6015 Then READ-CODING-SYSTEM is used when you read messages from the
6016 newsgroups, while POST-CODING-SYSTEM is used when you post messages
6017 there.
6018
6019 Emacs knows the right coding systems for certain newsgroups by
6020 default. Here are some of these default settings:
6021
6022 (gnus-mule-add-group "fj" 'iso-2022-7)
6023 (gnus-mule-add-group "alt.chinese.text" 'hz-gb-2312)
6024 (gnus-mule-add-group "alt.hk" 'hz-gb-2312)
6025 (gnus-mule-add-group "alt.chinese.text.big5" 'cn-big5)
6026 (gnus-mule-add-group "soc.culture.vietnamese" '(nil . viqr))
6027
6028 When you reply by mail to an article, these settings are ignored;
6029 the mail is encoded according to sendmail-coding-system, as usual.
6030
6031 ** CC mode changes.
6032
6033 *** If you edit primarily one style of C (or C++, Objective-C, Java)
6034 code, you may want to make the CC Mode style variables have global
6035 values so that you can set them directly in your .emacs file. To do
6036 this, set c-style-variables-are-local-p to nil in your .emacs file.
6037 Note that this only takes effect if you do it *before* cc-mode.el is
6038 loaded.
6039
6040 If you typically edit more than one style of C (or C++, Objective-C,
6041 Java) code in a single Emacs session, you may want to make the CC Mode
6042 style variables have buffer local values. By default, all buffers
6043 share the same style variable settings; to make them buffer local, set
6044 c-style-variables-are-local-p to t in your .emacs file. Note that you
6045 must do this *before* CC Mode is loaded.
6046
6047 *** The new variable c-indentation-style holds the C style name
6048 of the current buffer.
6049
6050 *** The variable c-block-comments-indent-p has been deleted, because
6051 it is no longer necessary. C mode now handles all the supported styles
6052 of block comments, with no need to say which one you will use.
6053
6054 *** There is a new indentation style "python", which specifies the C
6055 style that the Python developers like.
6056
6057 *** There is a new c-cleanup-list option: brace-elseif-brace.
6058 This says to put ...} else if (...) {... on one line,
6059 just as brace-else-brace says to put ...} else {... on one line.
6060
6061 ** VC Changes [new]
6062
6063 ** In vc-retrieve-snapshot (C-x v r), if you don't specify a snapshot
6064 name, it retrieves the *latest* versions of all files in the current
6065 directory and its subdirectories (aside from files already locked).
6066
6067 This feature is useful if your RCS directory is a link to a common
6068 master directory, and you want to pick up changes made by other
6069 developers.
6070
6071 You can do the same thing for an individual file by typing C-u C-x C-q
6072 RET in a buffer visiting that file.
6073
6074 *** VC can now handle files under CVS that are being "watched" by
6075 other developers. Such files are made read-only by CVS. To get a
6076 writable copy, type C-x C-q in a buffer visiting such a file. VC then
6077 calls "cvs edit", which notifies the other developers of it.
6078
6079 *** vc-version-diff (C-u C-x v =) now suggests reasonable defaults for
6080 version numbers, based on the current state of the file.
6081
6082 ** Calendar changes.
6083
6084 A new function, list-holidays, allows you list holidays or subclasses
6085 of holidays for ranges of years. Related menu items allow you do this
6086 for the year of the selected date, or the following/previous years.
6087
6088 ** ps-print changes
6089
6090 There are some new user variables for customizing the page layout.
6091
6092 *** Paper size, paper orientation, columns
6093
6094 The variable `ps-paper-type' determines the size of paper ps-print
6095 formats for; it should contain one of the symbols:
6096 `a4' `a3' `letter' `legal' `letter-small' `tabloid'
6097 `ledger' `statement' `executive' `a4small' `b4' `b5'
6098 It defaults to `letter'.
6099 If you need other sizes, see the variable `ps-page-dimensions-database'.
6100
6101 The variable `ps-landscape-mode' determines the orientation
6102 of the printing on the page. nil, the default, means "portrait" mode,
6103 non-nil means "landscape" mode.
6104
6105 The variable `ps-number-of-columns' must be a positive integer.
6106 It determines the number of columns both in landscape and portrait mode.
6107 It defaults to 1.
6108
6109 *** Horizontal layout
6110
6111 The horizontal layout is determined by the variables
6112 `ps-left-margin', `ps-inter-column', and `ps-right-margin'.
6113 All are measured in points.
6114
6115 *** Vertical layout
6116
6117 The vertical layout is determined by the variables
6118 `ps-bottom-margin', `ps-top-margin', and `ps-header-offset'.
6119 All are measured in points.
6120
6121 *** Headers
6122
6123 If the variable `ps-print-header' is nil, no header is printed. Then
6124 `ps-header-offset' is not relevant and `ps-top-margin' represents the
6125 margin above the text.
6126
6127 If the variable `ps-print-header-frame' is non-nil, a gaudy
6128 framing box is printed around the header.
6129
6130 The contents of the header are determined by `ps-header-lines',
6131 `ps-show-n-of-n', `ps-left-header' and `ps-right-header'.
6132
6133 The height of the header is determined by `ps-header-line-pad',
6134 `ps-header-font-family', `ps-header-title-font-size' and
6135 `ps-header-font-size'.
6136
6137 *** Font managing
6138
6139 The variable `ps-font-family' determines which font family is to be
6140 used for ordinary text. Its value must be a key symbol in the alist
6141 `ps-font-info-database'. You can add other font families by adding
6142 elements to this alist.
6143
6144 The variable `ps-font-size' determines the size of the font
6145 for ordinary text. It defaults to 8.5 points.
6146
6147 ** hideshow changes.
6148
6149 *** now supports hiding of blocks of single line comments (like // for
6150 C++, ; for lisp).
6151
6152 *** Support for java-mode added.
6153
6154 *** When doing `hs-hide-all' it is now possible to also hide the comments
6155 in the file if `hs-hide-comments-when-hiding-all' is set.
6156
6157 *** The new function `hs-hide-initial-comment' hides the the comments at
6158 the beginning of the files. Finally those huge RCS logs don't stay in your
6159 way! This is run by default when entering the `hs-minor-mode'.
6160
6161 *** Now uses overlays instead of `selective-display', so is more
6162 robust and a lot faster.
6163
6164 *** A block beginning can span multiple lines.
6165
6166 *** The new variable `hs-show-hidden-short-form' if t, directs hideshow
6167 to show only the beginning of a block when it is hidden. See the
6168 documentation for more details.
6169
6170 ** Changes in Enriched mode.
6171
6172 *** When you visit a file in enriched-mode, Emacs will make sure it is
6173 filled to the current fill-column. This behavior is now independent
6174 of the size of the window. When you save the file, the fill-column in
6175 use is stored as well, so that the whole buffer need not be refilled
6176 the next time unless the fill-column is different.
6177
6178 *** use-hard-newlines is now a minor mode. When it is enabled, Emacs
6179 distinguishes between hard and soft newlines, and treats hard newlines
6180 as paragraph boundaries. Otherwise all newlines inserted are marked
6181 as soft, and paragraph boundaries are determined solely from the text.
6182
6183 ** Font Lock mode
6184
6185 *** Custom support
6186
6187 The variables font-lock-face-attributes, font-lock-display-type and
6188 font-lock-background-mode are now obsolete; the recommended way to specify the
6189 faces to use for Font Lock mode is with M-x customize-group on the new custom
6190 group font-lock-highlighting-faces. If you set font-lock-face-attributes in
6191 your ~/.emacs file, Font Lock mode will respect its value. However, you should
6192 consider converting from setting that variable to using M-x customize.
6193
6194 You can still use X resources to specify Font Lock face appearances.
6195
6196 *** Maximum decoration
6197
6198 Fontification now uses the maximum level of decoration supported by
6199 default. Previously, fontification used a mode-specific default level
6200 of decoration, which is typically the minimum level of decoration
6201 supported. You can set font-lock-maximum-decoration to nil
6202 to get the old behavior.
6203
6204 *** New support
6205
6206 Support is now provided for Java, Objective-C, AWK and SIMULA modes.
6207
6208 Note that Font Lock mode can be turned on without knowing exactly what modes
6209 support Font Lock mode, via the command global-font-lock-mode.
6210
6211 *** Configurable support
6212
6213 Support for C, C++, Objective-C and Java can be more easily configured for
6214 additional types and classes via the new variables c-font-lock-extra-types,
6215 c++-font-lock-extra-types, objc-font-lock-extra-types and, you guessed it,
6216 java-font-lock-extra-types. These value of each of these variables should be a
6217 list of regexps matching the extra type names. For example, the default value
6218 of c-font-lock-extra-types is ("\\sw+_t") which means fontification follows the
6219 convention that C type names end in _t. This results in slower fontification.
6220
6221 Of course, you can change the variables that specify fontification in whatever
6222 way you wish, typically by adding regexps. However, these new variables make
6223 it easier to make specific and common changes for the fontification of types.
6224
6225 *** Adding highlighting patterns to existing support
6226
6227 You can use the new function font-lock-add-keywords to add your own
6228 highlighting patterns, such as for project-local or user-specific constructs,
6229 for any mode.
6230
6231 For example, to highlight `FIXME:' words in C comments, put:
6232
6233 (font-lock-add-keywords 'c-mode '(("\\<FIXME:" 0 font-lock-warning-face t)))
6234
6235 in your ~/.emacs.
6236
6237 *** New faces
6238
6239 Font Lock now defines two new faces, font-lock-builtin-face and
6240 font-lock-warning-face. These are intended to highlight builtin keywords,
6241 distinct from a language's normal keywords, and objects that should be brought
6242 to user attention, respectively. Various modes now use these new faces.
6243
6244 *** Changes to fast-lock support mode
6245
6246 The fast-lock package, one of the two Font Lock support modes, can now process
6247 cache files silently. You can use the new variable fast-lock-verbose, in the
6248 same way as font-lock-verbose, to control this feature.
6249
6250 *** Changes to lazy-lock support mode
6251
6252 The lazy-lock package, one of the two Font Lock support modes, can now fontify
6253 according to the true syntactic context relative to other lines. You can use
6254 the new variable lazy-lock-defer-contextually to control this feature. If
6255 non-nil, changes to the buffer will cause subsequent lines in the buffer to be
6256 refontified after lazy-lock-defer-time seconds of idle time. If nil, then only
6257 the modified lines will be refontified; this is the same as the previous Lazy
6258 Lock mode behaviour and the behaviour of Font Lock mode.
6259
6260 This feature is useful in modes where strings or comments can span lines.
6261 For example, if a string or comment terminating character is deleted, then if
6262 this feature is enabled subsequent lines in the buffer will be correctly
6263 refontified to reflect their new syntactic context. Previously, only the line
6264 containing the deleted character would be refontified and you would have to use
6265 the command M-g M-g (font-lock-fontify-block) to refontify some lines.
6266
6267 As a consequence of this new feature, two other variables have changed:
6268
6269 Variable `lazy-lock-defer-driven' is renamed `lazy-lock-defer-on-scrolling'.
6270 Variable `lazy-lock-defer-time' can now only be a time, i.e., a number.
6271 Buffer modes for which on-the-fly deferral applies can be specified via the
6272 new variable `lazy-lock-defer-on-the-fly'.
6273
6274 If you set these variables in your ~/.emacs, then you may have to change those
6275 settings.
6276
6277 ** Ada mode changes.
6278
6279 *** There is now better support for using find-file.el with Ada mode.
6280 If you switch between spec and body, the cursor stays in the same
6281 procedure (modulo overloading). If a spec has no body file yet, but
6282 you try to switch to its body file, Ada mode now generates procedure
6283 stubs.
6284
6285 *** There are two new commands:
6286 - `ada-make-local' : invokes gnatmake on the current buffer
6287 - `ada-check-syntax' : check syntax of current buffer.
6288
6289 The user options `ada-compiler-make', `ada-make-options',
6290 `ada-language-version', `ada-compiler-syntax-check', and
6291 `ada-compile-options' are used within these commands.
6292
6293 *** Ada mode can now work with Outline minor mode. The outline level
6294 is calculated from the indenting, not from syntactic constructs.
6295 Outlining does not work if your code is not correctly indented.
6296
6297 *** The new function `ada-gnat-style' converts the buffer to the style of
6298 formatting used in GNAT. It places two blanks after a comment start,
6299 places one blank between a word end and an opening '(', and puts one
6300 space between a comma and the beginning of a word.
6301
6302 ** Scheme mode changes.
6303
6304 *** Scheme mode indentation now uses many of the facilities of Lisp
6305 mode; therefore, the variables to customize it are the variables used
6306 for Lisp mode which have names starting with `lisp-'. The variables
6307 with names starting with `scheme-' which used to do this no longer
6308 have any effect.
6309
6310 If you want to use different indentation for Scheme and Lisp, this is
6311 still possible, but now you must do it by adding a hook to
6312 scheme-mode-hook, which could work by setting the `lisp-' indentation
6313 variables as buffer-local variables.
6314
6315 *** DSSSL mode is a variant of Scheme mode, for editing DSSSL scripts.
6316 Use M-x dsssl-mode.
6317
6318 ** Changes to the emacsclient program
6319
6320 *** If a socket can't be found, and environment variables LOGNAME or
6321 USER are set, emacsclient now looks for a socket based on the UID
6322 associated with the name. That is an emacsclient running as root
6323 can connect to an Emacs server started by a non-root user.
6324
6325 *** The emacsclient program now accepts an option --no-wait which tells
6326 it to return immediately without waiting for you to "finish" the
6327 buffer in Emacs.
6328
6329 *** The new option --alternate-editor allows to specify an editor to
6330 use if Emacs is not running. The environment variable
6331 ALTERNATE_EDITOR can be used for the same effect; the command line
6332 option takes precedence.
6333
6334 ** M-x eldoc-mode enables a minor mode in which the echo area
6335 constantly shows the parameter list for function being called at point
6336 (in Emacs Lisp and Lisp Interaction modes only).
6337
6338 ** C-x n d now runs the new command narrow-to-defun,
6339 which narrows the accessible parts of the buffer to just
6340 the current defun.
6341
6342 ** Emacs now handles the `--' argument in the standard way; all
6343 following arguments are treated as ordinary file names.
6344
6345 ** On MSDOS and Windows, the bookmark file is now called _emacs.bmk,
6346 and the saved desktop file is now called _emacs.desktop (truncated if
6347 necessary).
6348
6349 ** When you kill a buffer that visits a file,
6350 if there are any registers that save positions in the file,
6351 these register values no longer become completely useless.
6352 If you try to go to such a register with C-x j, then you are
6353 asked whether to visit the file again. If you say yes,
6354 it visits the file and then goes to the same position.
6355
6356 ** When you visit a file that changes frequently outside Emacs--for
6357 example, a log of output from a process that continues to run--it may
6358 be useful for Emacs to revert the file without querying you whenever
6359 you visit the file afresh with C-x C-f.
6360
6361 You can request this behavior for certain files by setting the
6362 variable revert-without-query to a list of regular expressions. If a
6363 file's name matches any of these regular expressions, find-file and
6364 revert-buffer revert the buffer without asking for permission--but
6365 only if you have not edited the buffer text yourself.
6366
6367 ** set-default-font has been renamed to set-frame-font
6368 since it applies only to the current frame.
6369
6370 ** In TeX mode, you can use the variable tex-main-file to specify the
6371 file for tex-file to run TeX on. (By default, tex-main-file is nil,
6372 and tex-file runs TeX on the current visited file.)
6373
6374 This is useful when you are editing a document that consists of
6375 multiple files. In each of the included files, you can set up a local
6376 variable list which specifies the top-level file of your document for
6377 tex-main-file. Then tex-file will run TeX on the whole document
6378 instead of just the file you are editing.
6379
6380 ** RefTeX mode
6381
6382 RefTeX mode is a new minor mode with special support for \label, \ref
6383 and \cite macros in LaTeX documents. RefTeX distinguishes labels of
6384 different environments (equation, figure, ...) and has full support for
6385 multifile documents. To use it, select a buffer with a LaTeX document and
6386 turn the mode on with M-x reftex-mode. Here are the main user commands:
6387
6388 C-c ( reftex-label
6389 Creates a label semi-automatically. RefTeX is context sensitive and
6390 knows which kind of label is needed.
6391
6392 C-c ) reftex-reference
6393 Offers in a menu all labels in the document, along with context of the
6394 label definition. The selected label is referenced as \ref{LABEL}.
6395
6396 C-c [ reftex-citation
6397 Prompts for a regular expression and displays a list of matching BibTeX
6398 database entries. The selected entry is cited with a \cite{KEY} macro.
6399
6400 C-c & reftex-view-crossref
6401 Views the cross reference of a \ref or \cite command near point.
6402
6403 C-c = reftex-toc
6404 Shows a table of contents of the (multifile) document. From there you
6405 can quickly jump to every section.
6406
6407 Under X, RefTeX installs a "Ref" menu in the menu bar, with additional
6408 commands. Press `?' to get help when a prompt mentions this feature.
6409 Full documentation and customization examples are in the file
6410 reftex.el. You can use the finder to view the file documentation:
6411 C-h p --> tex --> reftex.el
6412
6413 ** Changes in BibTeX mode.
6414
6415 *** Info documentation is now available.
6416
6417 *** Don't allow parentheses in string constants anymore. This confused
6418 both the BibTeX program and Emacs BibTeX mode.
6419
6420 *** Renamed variable bibtex-mode-user-optional-fields to
6421 bibtex-user-optional-fields.
6422
6423 *** Removed variable bibtex-include-OPTannote
6424 (use bibtex-user-optional-fields instead).
6425
6426 *** New interactive functions to copy and kill fields and complete
6427 entries to the BibTeX kill ring, from where they can be yanked back by
6428 appropriate functions.
6429
6430 *** New interactive functions for repositioning and marking of
6431 entries. They are bound by default to M-C-l and M-C-h.
6432
6433 *** New hook bibtex-clean-entry-hook. It is called after entry has
6434 been cleaned.
6435
6436 *** New variable bibtex-field-delimiters, which replaces variables
6437 bibtex-field-{left|right}-delimiter.
6438
6439 *** New variable bibtex-entry-delimiters to determine how entries
6440 shall be delimited.
6441
6442 *** Allow preinitialization of fields. See documentation of
6443 bibtex-user-optional-fields, bibtex-entry-field-alist, and
6444 bibtex-include-OPTkey for details.
6445
6446 *** Book and InBook entries require either an author or an editor
6447 field. This is now supported by bibtex.el. Alternative fields are
6448 prefixed with `ALT'.
6449
6450 *** New variable bibtex-entry-format, which replaces variable
6451 bibtex-clean-entry-zap-empty-opts and allows specification of many
6452 formatting options performed on cleaning an entry (see variable
6453 documentation).
6454
6455 *** Even more control on how automatic keys are generated. See
6456 documentation of bibtex-generate-autokey for details. Transcriptions
6457 for foreign languages other than German are now handled, too.
6458
6459 *** New boolean user option bibtex-comma-after-last-field to decide if
6460 comma should be inserted at end of last field.
6461
6462 *** New boolean user option bibtex-align-at-equal-sign to determine if
6463 alignment should be made at left side of field contents or at equal
6464 signs. New user options to control entry layout (e.g. indentation).
6465
6466 *** New function bibtex-fill-entry to realign entries.
6467
6468 *** New function bibtex-reformat to reformat region or buffer.
6469
6470 *** New function bibtex-convert-alien to convert a BibTeX database
6471 from alien sources.
6472
6473 *** New function bibtex-complete-key (similar to bibtex-complete-string)
6474 to complete prefix to a key defined in buffer. Mainly useful in
6475 crossref entries.
6476
6477 *** New function bibtex-count-entries to count entries in buffer or
6478 region.
6479
6480 *** Added support for imenu.
6481
6482 *** The function `bibtex-validate' now checks current region instead
6483 of buffer if mark is active. Now it shows all errors of buffer in a
6484 `compilation mode' buffer. You can use the normal commands (e.g.
6485 `next-error') for compilation modes to jump to errors.
6486
6487 *** New variable `bibtex-string-file-path' to determine where the files
6488 from `bibtex-string-files' are searched.
6489
6490 ** Iso Accents mode now supports Latin-3 as an alternative.
6491
6492 ** The command next-error now opens blocks hidden by hideshow.
6493
6494 ** The function using-unix-filesystems has been replaced by the
6495 functions add-untranslated-filesystem and remove-untranslated-filesystem.
6496 Each of these functions takes the name of a drive letter or directory
6497 as an argument.
6498
6499 When a filesystem is added as untranslated, all files on it are read
6500 and written in binary mode (no cr/lf translation is performed).
6501
6502 ** browse-url changes
6503
6504 *** New methods for: Grail (browse-url-generic), MMM (browse-url-mmm),
6505 Lynx in a separate xterm (browse-url-lynx-xterm) or in an Emacs window
6506 (browse-url-lynx-emacs), remote W3 (browse-url-w3-gnudoit), generic
6507 non-remote-controlled browsers (browse-url-generic) and associated
6508 customization variables.
6509
6510 *** New commands `browse-url-of-region' and `browse-url'.
6511
6512 *** URLs marked up with <URL:...> (RFC1738) work if broken across
6513 lines. Browsing methods can be associated with URL regexps
6514 (e.g. mailto: URLs) via `browse-url-browser-function'.
6515
6516 ** Changes in Ediff
6517
6518 *** Clicking Mouse-2 on a brief command description in Ediff control panel
6519 pops up the Info file for this command.
6520
6521 *** There is now a variable, ediff-autostore-merges, which controls whether
6522 the result of a merge is saved in a file. By default, this is done only when
6523 merge is done from a session group (eg, when merging files in two different
6524 directories).
6525
6526 *** Since Emacs 19.31 (this hasn't been announced before), Ediff can compare
6527 and merge groups of files residing in different directories, or revisions of
6528 files in the same directory.
6529
6530 *** Since Emacs 19.31, Ediff can apply multi-file patches interactively.
6531 The patches must be in the context format or GNU unified format. (The bug
6532 related to the GNU format has now been fixed.)
6533
6534 ** Changes in Viper
6535
6536 *** The startup file is now .viper instead of .vip
6537 *** All variable/function names have been changed to start with viper-
6538 instead of vip-.
6539 *** C-\ now simulates the meta-key in all Viper states.
6540 *** C-z in Insert state now escapes to Vi for the duration of the next
6541 Viper command. In Vi and Insert states, C-z behaves as before.
6542 *** C-c \ escapes to Vi for one command if Viper is in Insert or Emacs states.
6543 *** _ is no longer the meta-key in Vi state.
6544 *** The variable viper-insert-state-cursor-color can be used to change cursor
6545 color when Viper is in insert state.
6546 *** If search lands the cursor near the top or the bottom of the window,
6547 Viper pulls the window up or down to expose more context. The variable
6548 viper-adjust-window-after-search controls this behavior.
6549
6550 ** Etags changes.
6551
6552 *** In C, C++, Objective C and Java, Etags tags global variables by
6553 default. The resulting tags files are inflated by 30% on average.
6554 Use --no-globals to turn this feature off. Etags can also tag
6555 variables which are members of structure-like constructs, but it does
6556 not by default. Use --members to turn this feature on.
6557
6558 *** C++ member functions are now recognized as tags.
6559
6560 *** Java is tagged like C++. In addition, "extends" and "implements"
6561 constructs are tagged. Files are recognised by the extension .java.
6562
6563 *** Etags can now handle programs written in Postscript. Files are
6564 recognised by the extensions .ps and .pdb (Postscript with C syntax).
6565 In Postscript, tags are lines that start with a slash.
6566
6567 *** Etags now handles Objective C and Objective C++ code. The usual C and
6568 C++ tags are recognized in these languages; in addition, etags
6569 recognizes special Objective C syntax for classes, class categories,
6570 methods and protocols.
6571
6572 *** Etags also handles Cobol. Files are recognised by the extension
6573 .cobol. The tagged lines are those containing a word that begins in
6574 column 8 and ends in a full stop, i.e. anything that could be a
6575 paragraph name.
6576
6577 *** Regexps in Etags now support intervals, as in ed or grep. The syntax of
6578 an interval is \{M,N\}, and it means to match the preceding expression
6579 at least M times and as many as N times.
6580
6581 ** The format for specifying a custom format for time-stamp to insert
6582 in files has changed slightly.
6583
6584 With the new enhancements to the functionality of format-time-string,
6585 time-stamp-format will change to be eventually compatible with it.
6586 This conversion is being done in two steps to maintain compatibility
6587 with old time-stamp-format values.
6588
6589 In the new scheme, alternate case is signified by the number-sign
6590 (`#') modifier, rather than changing the case of the format character.
6591 This feature is as yet incompletely implemented for compatibility
6592 reasons.
6593
6594 In the old time-stamp-format, all numeric fields defaulted to their
6595 natural width. (With format-time-string, each format has a
6596 fixed-width default.) In this version, you can specify the colon
6597 (`:') modifier to a numeric conversion to mean "give me the historical
6598 time-stamp-format width default." Do not use colon if you are
6599 specifying an explicit width, as in "%02d".
6600
6601 Numbers are no longer truncated to the requested width, except in the
6602 case of "%02y", which continues to give a two-digit year. Digit
6603 truncation probably wasn't being used for anything else anyway.
6604
6605 The new formats will work with old versions of Emacs. New formats are
6606 being recommended now to allow time-stamp-format to change in the
6607 future to be compatible with format-time-string. The new forms being
6608 recommended now will continue to work then.
6609
6610 See the documentation string for the variable time-stamp-format for
6611 details.
6612
6613 ** There are some additional major modes:
6614
6615 dcl-mode, for editing VMS DCL files.
6616 m4-mode, for editing files of m4 input.
6617 meta-mode, for editing MetaFont and MetaPost source files.
6618
6619 ** In Shell mode, the command shell-copy-environment-variable lets you
6620 copy the value of a specified environment variable from the subshell
6621 into Emacs.
6622
6623 ** New Lisp packages include:
6624
6625 *** battery.el displays battery status for laptops.
6626
6627 *** M-x bruce (named after Lenny Bruce) is a program that might
6628 be used for adding some indecent words to your email.
6629
6630 *** M-x crisp-mode enables an emulation for the CRiSP editor.
6631
6632 *** M-x dirtrack arranges for better tracking of directory changes
6633 in shell buffers.
6634
6635 *** The new library elint.el provides for linting of Emacs Lisp code.
6636 See the documentation for `elint-initialize', `elint-current-buffer'
6637 and `elint-defun'.
6638
6639 *** M-x expand-add-abbrevs defines a special kind of abbrev which is
6640 meant for programming constructs. These abbrevs expand like ordinary
6641 ones, when you type SPC, but only at the end of a line and not within
6642 strings or comments.
6643
6644 These abbrevs can act as templates: you can define places within an
6645 abbrev for insertion of additional text. Once you expand the abbrev,
6646 you can then use C-x a p and C-x a n to move back and forth to these
6647 insertion points. Thus you can conveniently insert additional text
6648 at these points.
6649
6650 *** filecache.el remembers the location of files so that you
6651 can visit them by short forms of their names.
6652
6653 *** find-func.el lets you find the definition of the user-loaded
6654 Emacs Lisp function at point.
6655
6656 *** M-x handwrite converts text to a "handwritten" picture.
6657
6658 *** M-x iswitchb-buffer is a command for switching to a buffer, much like
6659 switch-buffer, but it reads the argument in a more helpful way.
6660
6661 *** M-x landmark implements a neural network for landmark learning.
6662
6663 *** M-x locate provides a convenient interface to the `locate' program.
6664
6665 *** M4 mode is a new mode for editing files of m4 input.
6666
6667 *** mantemp.el creates C++ manual template instantiations
6668 from the GCC error messages which indicate which instantiations are needed.
6669
6670 *** mouse-copy.el provides a one-click copy and move feature.
6671 You can drag a region with M-mouse-1, and it is automatically
6672 inserted at point. M-Shift-mouse-1 deletes the text from its
6673 original place after inserting the copy.
6674
6675 *** mouse-drag.el lets you do scrolling by dragging Mouse-2
6676 on the buffer.
6677
6678 You click the mouse and move; that distance either translates into the
6679 velocity to scroll (with mouse-drag-throw) or the distance to scroll
6680 (with mouse-drag-drag). Horizontal scrolling is enabled when needed.
6681
6682 Enable mouse-drag with:
6683 (global-set-key [down-mouse-2] 'mouse-drag-throw)
6684 -or-
6685 (global-set-key [down-mouse-2] 'mouse-drag-drag)
6686
6687 *** mspools.el is useful for determining which mail folders have
6688 mail waiting to be read in them. It works with procmail.
6689
6690 *** Octave mode is a major mode for editing files of input for Octave.
6691 It comes with a facility for communicating with an Octave subprocess.
6692
6693 *** ogonek
6694
6695 The ogonek package provides functions for changing the coding of
6696 Polish diacritic characters in buffers. Codings known from various
6697 platforms are supported such as ISO8859-2, Mazovia, IBM Latin2, and
6698 TeX. For example, you can change the coding from Mazovia to
6699 ISO8859-2. Another example is a change of coding from ISO8859-2 to
6700 prefix notation (in which `/a' stands for the aogonek character, for
6701 instance) and vice versa.
6702
6703 To use this package load it using
6704 M-x load-library [enter] ogonek
6705 Then, you may get an explanation by calling one of
6706 M-x ogonek-jak -- in Polish
6707 M-x ogonek-how -- in English
6708 The info specifies the commands and variables provided as well as the
6709 ways of customization in `.emacs'.
6710
6711 *** Interface to ph.
6712
6713 Emacs provides a client interface to CCSO Nameservers (ph/qi)
6714
6715 The CCSO nameserver is used in many universities to provide directory
6716 services about people. ph.el provides a convenient Emacs interface to
6717 these servers.
6718
6719 *** uce.el is useful for replying to unsolicited commercial email.
6720
6721 *** vcursor.el implements a "virtual cursor" feature.
6722 You can move the virtual cursor with special commands
6723 while the real cursor does not move.
6724
6725 *** webjump.el is a "hot list" package which you can set up
6726 for visiting your favorite web sites.
6727
6728 *** M-x winner-mode is a minor mode which saves window configurations,
6729 so you can move back to other configurations that you have recently used.
6730
6731 ** movemail change
6732
6733 Movemail no longer needs to be installed setuid root in order for POP
6734 mail retrieval to function properly. This is because it no longer
6735 supports the RPOP (reserved-port POP) protocol; instead, it uses the
6736 user's POP password to authenticate to the mail server.
6737
6738 This change was made earlier, but not reported in NEWS before.
6739 \f
6740 * Emacs 20.1 changes for MS-DOS and MS-Windows.
6741
6742 ** Changes in handling MS-DOS/MS-Windows text files.
6743
6744 Emacs handles three different conventions for representing
6745 end-of-line: CRLF for MSDOS, LF for Unix and GNU, and CR (used on the
6746 Macintosh). Emacs determines which convention is used in a specific
6747 file based on the contents of that file (except for certain special
6748 file names), and when it saves the file, it uses the same convention.
6749
6750 To save the file and change the end-of-line convention, you can use
6751 C-x RET f (set-buffer-file-coding-system) to specify a different
6752 coding system for the buffer. Then, when you save the file, the newly
6753 specified coding system will take effect. For example, to save with
6754 LF, specify undecided-unix (or some other ...-unix coding system); to
6755 save with CRLF, specify undecided-dos.
6756 \f
6757 * Lisp Changes in Emacs 20.1
6758
6759 ** Byte-compiled files made with Emacs 20 will, in general, work in
6760 Emacs 19 as well, as long as the source code runs in Emacs 19. And
6761 vice versa: byte-compiled files made with Emacs 19 should also run in
6762 Emacs 20, as long as the program itself works in Emacs 20.
6763
6764 ** Windows-specific functions and variables have been renamed
6765 to start with w32- instead of win32-.
6766
6767 In hacker language, calling something a "win" is a form of praise. We
6768 don't want to praise a non-free Microsoft system, so we don't call it
6769 "win".
6770
6771 ** Basic Lisp changes
6772
6773 *** A symbol whose name starts with a colon now automatically
6774 evaluates to itself. Therefore such a symbol can be used as a constant.
6775
6776 *** The defined purpose of `defconst' has been changed. It should now
6777 be used only for values that should not be changed whether by a program
6778 or by the user.
6779
6780 The actual behavior of defconst has not been changed.
6781
6782 *** There are new macros `when' and `unless'
6783
6784 (when CONDITION BODY...) is short for (if CONDITION (progn BODY...))
6785 (unless CONDITION BODY...) is short for (if CONDITION nil BODY...)
6786
6787 *** Emacs now defines functions caar, cadr, cdar and cddr with their
6788 usual Lisp meanings. For example, caar returns the car of the car of
6789 its argument.
6790
6791 *** equal, when comparing strings, now ignores their text properties.
6792
6793 *** The new function `functionp' tests whether an object is a function.
6794
6795 *** arrayp now returns t for char-tables and bool-vectors.
6796
6797 *** Certain primitives which use characters (as integers) now get an
6798 error if the integer is not a valid character code. These primitives
6799 include insert-char, char-to-string, and the %c construct in the
6800 `format' function.
6801
6802 *** The `require' function now insists on adding a suffix, either .el
6803 or .elc, to the file name. Thus, (require 'foo) will not use a file
6804 whose name is just foo. It insists on foo.el or foo.elc.
6805
6806 *** The `autoload' function, when the file name does not contain
6807 either a directory name or the suffix .el or .elc, insists on
6808 adding one of these suffixes.
6809
6810 *** string-to-number now takes an optional second argument BASE
6811 which specifies the base to use when converting an integer.
6812 If BASE is omitted, base 10 is used.
6813
6814 We have not implemented other radices for floating point numbers,
6815 because that would be much more work and does not seem useful.
6816
6817 *** substring now handles vectors as well as strings.
6818
6819 *** The Common Lisp function eql is no longer defined normally.
6820 You must load the `cl' library to define it.
6821
6822 *** The new macro `with-current-buffer' lets you evaluate an expression
6823 conveniently with a different current buffer. It looks like this:
6824
6825 (with-current-buffer BUFFER BODY-FORMS...)
6826
6827 BUFFER is the expression that says which buffer to use.
6828 BODY-FORMS say what to do in that buffer.
6829
6830 *** The new primitive `save-current-buffer' saves and restores the
6831 choice of current buffer, like `save-excursion', but without saving or
6832 restoring the value of point or the mark. `with-current-buffer'
6833 works using `save-current-buffer'.
6834
6835 *** The new macro `with-temp-file' lets you do some work in a new buffer and
6836 write the output to a specified file. Like `progn', it returns the value
6837 of the last form.
6838
6839 *** The new macro `with-temp-buffer' lets you do some work in a new buffer,
6840 which is discarded after use. Like `progn', it returns the value of the
6841 last form. If you wish to return the buffer contents, use (buffer-string)
6842 as the last form.
6843
6844 *** The new function split-string takes a string, splits it at certain
6845 characters, and returns a list of the substrings in between the
6846 matches.
6847
6848 For example, (split-string "foo bar lose" " +") returns ("foo" "bar" "lose").
6849
6850 *** The new macro with-output-to-string executes some Lisp expressions
6851 with standard-output set up so that all output feeds into a string.
6852 Then it returns that string.
6853
6854 For example, if the current buffer name is `foo',
6855
6856 (with-output-to-string
6857 (princ "The buffer is ")
6858 (princ (buffer-name)))
6859
6860 returns "The buffer is foo".
6861
6862 ** Non-ASCII characters are now supported, if enable-multibyte-characters
6863 is non-nil.
6864
6865 These characters have character codes above 256. When inserted in the
6866 buffer or stored in a string, they are represented as multibyte
6867 characters that occupy several buffer positions each.
6868
6869 *** When enable-multibyte-characters is non-nil, a single character in
6870 a buffer or string can be two or more bytes (as many as four).
6871
6872 Buffers and strings are still made up of unibyte elements;
6873 character positions and string indices are always measured in bytes.
6874 Therefore, moving forward one character can increase the buffer
6875 position by 2, 3 or 4. The function forward-char moves by whole
6876 characters, and therefore is no longer equivalent to
6877 (lambda (n) (goto-char (+ (point) n))).
6878
6879 ASCII characters (codes 0 through 127) are still single bytes, always.
6880 Sequences of byte values 128 through 255 are used to represent
6881 non-ASCII characters. These sequences are called "multibyte
6882 characters".
6883
6884 The first byte of a multibyte character is always in the range 128
6885 through 159 (octal 0200 through 0237). These values are called
6886 "leading codes". The second and subsequent bytes are always in the
6887 range 160 through 255 (octal 0240 through 0377). The first byte, the
6888 leading code, determines how many bytes long the sequence is.
6889
6890 *** The function forward-char moves over characters, and therefore
6891 (forward-char 1) may increase point by more than 1 if it moves over a
6892 multibyte character. Likewise, delete-char always deletes a
6893 character, which may be more than one buffer position.
6894
6895 This means that some Lisp programs, which assume that a character is
6896 always one buffer position, need to be changed.
6897
6898 However, all ASCII characters are always one buffer position.
6899
6900 *** The regexp [\200-\377] no longer matches all non-ASCII characters,
6901 because when enable-multibyte-characters is non-nil, these characters
6902 have codes that are not in the range octal 200 to octal 377. However,
6903 the regexp [^\000-\177] does match all non-ASCII characters,
6904 guaranteed.
6905
6906 *** The function char-boundary-p returns non-nil if position POS is
6907 between two characters in the buffer (not in the middle of a
6908 character).
6909
6910 When the value is non-nil, it says what kind of character follows POS:
6911
6912 0 if POS is at an ASCII character or at the end of range,
6913 1 if POS is before a 2-byte length multi-byte form,
6914 2 if POS is at a head of 3-byte length multi-byte form,
6915 3 if POS is at a head of 4-byte length multi-byte form,
6916 4 if POS is at a head of multi-byte form of a composite character.
6917
6918 *** The function char-bytes returns how many bytes the character CHAR uses.
6919
6920 *** Strings can contain multibyte characters. The function
6921 `length' returns the string length counting bytes, which may be
6922 more than the number of characters.
6923
6924 You can include a multibyte character in a string constant by writing
6925 it literally. You can also represent it with a hex escape,
6926 \xNNNNNNN..., using as many digits as necessary. Any character which
6927 is not a valid hex digit terminates this construct. If you want to
6928 follow it with a character that is a hex digit, write backslash and
6929 newline in between; that will terminate the hex escape.
6930
6931 *** The function concat-chars takes arguments which are characters
6932 and returns a string containing those characters.
6933
6934 *** The function sref access a multibyte character in a string.
6935 (sref STRING INDX) returns the character in STRING at INDEX. INDEX
6936 counts from zero. If INDEX is at a position in the middle of a
6937 character, sref signals an error.
6938
6939 *** The function chars-in-string returns the number of characters
6940 in a string. This is less than the length of the string, if the
6941 string contains multibyte characters (the length counts bytes).
6942
6943 *** The function chars-in-region returns the number of characters
6944 in a region from BEG to END. This is less than (- END BEG) if the
6945 region contains multibyte characters (the length counts bytes).
6946
6947 *** The function string-to-list converts a string to a list of
6948 the characters in it. string-to-vector converts a string
6949 to a vector of the characters in it.
6950
6951 *** The function store-substring alters part of the contents
6952 of a string. You call it as follows:
6953
6954 (store-substring STRING IDX OBJ)
6955
6956 This says to alter STRING, by storing OBJ starting at index IDX in
6957 STRING. OBJ may be either a character or a (smaller) string.
6958 This function really does alter the contents of STRING.
6959 Since it is impossible to change the length of an existing string,
6960 it is an error if OBJ doesn't fit within STRING's actual length.
6961
6962 *** char-width returns the width (in columns) of the character CHAR,
6963 if it were displayed in the current buffer and the selected window.
6964
6965 *** string-width returns the width (in columns) of the text in STRING,
6966 if it were displayed in the current buffer and the selected window.
6967
6968 *** truncate-string-to-width shortens a string, if necessary,
6969 to fit within a certain number of columns. (Of course, it does
6970 not alter the string that you give it; it returns a new string
6971 which contains all or just part of the existing string.)
6972
6973 (truncate-string-to-width STR END-COLUMN &optional START-COLUMN PADDING)
6974
6975 This returns the part of STR up to column END-COLUMN.
6976
6977 The optional argument START-COLUMN specifies the starting column.
6978 If this is non-nil, then the first START-COLUMN columns of the string
6979 are not included in the resulting value.
6980
6981 The optional argument PADDING, if non-nil, is a padding character to be added
6982 at the beginning and end the resulting string, to extend it to exactly
6983 WIDTH columns. If PADDING is nil, that means do not pad; then, if STRING
6984 is narrower than WIDTH, the value is equal to STRING.
6985
6986 If PADDING and START-COLUMN are both non-nil, and if there is no clean
6987 place in STRING that corresponds to START-COLUMN (because one
6988 character extends across that column), then the padding character
6989 PADDING is added one or more times at the beginning of the result
6990 string, so that its columns line up as if it really did start at
6991 column START-COLUMN.
6992
6993 *** When the functions in the list after-change-functions are called,
6994 the third argument is the number of bytes in the pre-change text, not
6995 necessarily the number of characters. It is, in effect, the
6996 difference in buffer position between the beginning and the end of the
6997 changed text, before the change.
6998
6999 *** The characters Emacs uses are classified in various character
7000 sets, each of which has a name which is a symbol. In general there is
7001 one character set for each script, not for each language.
7002
7003 **** The function charsetp tests whether an object is a character set name.
7004
7005 **** The variable charset-list holds a list of character set names.
7006
7007 **** char-charset, given a character code, returns the name of the character
7008 set that the character belongs to. (The value is a symbol.)
7009
7010 **** split-char, given a character code, returns a list containing the
7011 name of the character set, followed by one or two byte-values
7012 which identify the character within that character set.
7013
7014 **** make-char, given a character set name and one or two subsequent
7015 byte-values, constructs a character code. This is roughly the
7016 opposite of split-char.
7017
7018 **** find-charset-region returns a list of the character sets
7019 of all the characters between BEG and END.
7020
7021 **** find-charset-string returns a list of the character sets
7022 of all the characters in a string.
7023
7024 *** Here are the Lisp facilities for working with coding systems
7025 and specifying coding systems.
7026
7027 **** The function coding-system-list returns a list of all coding
7028 system names (symbols). With optional argument t, it returns a list
7029 of all distinct base coding systems, not including variants.
7030 (Variant coding systems are those like latin-1-dos, latin-1-unix
7031 and latin-1-mac which specify the end-of-line conversion as well
7032 as what to do about code conversion.)
7033
7034 **** coding-system-p tests a symbol to see if it is a coding system
7035 name. It returns t if so, nil if not.
7036
7037 **** file-coding-system-alist specifies which coding systems to use
7038 for certain file names. It works like network-coding-system-alist,
7039 except that the PATTERN is matched against the file name.
7040
7041 Each element has the format (PATTERN . VAL), where PATTERN determines
7042 which file names the element applies to. PATTERN should be a regexp
7043 to match against a file name.
7044
7045 VAL is a coding system, a cons cell containing two coding systems, or
7046 a function symbol. If VAL is a coding system, it is used for both
7047 decoding what received from the network stream and encoding what sent
7048 to the network stream. If VAL is a cons cell containing two coding
7049 systems, the car specifies the coding system for decoding, and the cdr
7050 specifies the coding system for encoding.
7051
7052 If VAL is a function symbol, the function must return a coding system
7053 or a cons cell containing two coding systems, which is used as above.
7054
7055 **** The variable network-coding-system-alist specifies
7056 the coding system to use for network sockets.
7057
7058 Each element has the format (PATTERN . VAL), where PATTERN determines
7059 which network sockets the element applies to. PATTERN should be
7060 either a port number or a regular expression matching some network
7061 service names.
7062
7063 VAL is a coding system, a cons cell containing two coding systems, or
7064 a function symbol. If VAL is a coding system, it is used for both
7065 decoding what received from the network stream and encoding what sent
7066 to the network stream. If VAL is a cons cell containing two coding
7067 systems, the car specifies the coding system for decoding, and the cdr
7068 specifies the coding system for encoding.
7069
7070 If VAL is a function symbol, the function must return a coding system
7071 or a cons cell containing two coding systems, which is used as above.
7072
7073 **** process-coding-system-alist specifies which coding systems to use
7074 for certain subprocess. It works like network-coding-system-alist,
7075 except that the PATTERN is matched against the program name used to
7076 start the subprocess.
7077
7078 **** The variable default-process-coding-system specifies the coding
7079 systems to use for subprocess (and net connection) input and output,
7080 when nothing else specifies what to do. The value is a cons cell
7081 (OUTPUT-CODING . INPUT-CODING). OUTPUT-CODING applies to output
7082 to the subprocess, and INPUT-CODING applies to input from it.
7083
7084 **** The variable coding-system-for-write, if non-nil, specifies the
7085 coding system to use for writing a file, or for output to a synchronous
7086 subprocess.
7087
7088 It also applies to any asynchronous subprocess or network connection,
7089 but in a different way: the value of coding-system-for-write when you
7090 start the subprocess or connection affects that subprocess or
7091 connection permanently or until overridden.
7092
7093 The variable coding-system-for-write takes precedence over
7094 file-coding-system-alist, process-coding-system-alist and
7095 network-coding-system-alist, and all other methods of specifying a
7096 coding system for output. But most of the time this variable is nil.
7097 It exists so that Lisp programs can bind it to a specific coding
7098 system for one operation at a time.
7099
7100 **** coding-system-for-read applies similarly to input from
7101 files, subprocesses or network connections.
7102
7103 **** The function process-coding-system tells you what
7104 coding systems(s) an existing subprocess is using.
7105 The value is a cons cell,
7106 (DECODING-CODING-SYSTEM . ENCODING-CODING-SYSTEM)
7107 where DECODING-CODING-SYSTEM is used for decoding output from
7108 the subprocess, and ENCODING-CODING-SYSTEM is used for encoding
7109 input to the subprocess.
7110
7111 **** The function set-process-coding-system can be used to
7112 change the coding systems in use for an existing subprocess.
7113
7114 ** Emacs has a new facility to help users manage the many
7115 customization options. To make a Lisp program work with this facility,
7116 you need to use the new macros defgroup and defcustom.
7117
7118 You use defcustom instead of defvar, for defining a user option
7119 variable. The difference is that you specify two additional pieces of
7120 information (usually): the "type" which says what values are
7121 legitimate, and the "group" which specifies the hierarchy for
7122 customization.
7123
7124 Thus, instead of writing
7125
7126 (defvar foo-blurgoze nil
7127 "*Non-nil means that foo will act very blurgozely.")
7128
7129 you would now write this:
7130
7131 (defcustom foo-blurgoze nil
7132 "*Non-nil means that foo will act very blurgozely."
7133 :type 'boolean
7134 :group foo)
7135
7136 The type `boolean' means that this variable has only
7137 two meaningful states: nil and non-nil. Other type values
7138 describe other possibilities; see the manual for Custom
7139 for a description of them.
7140
7141 The "group" argument is used to specify a group which the option
7142 should belong to. You define a new group like this:
7143
7144 (defgroup ispell nil
7145 "Spell checking using Ispell."
7146 :group 'processes)
7147
7148 The "group" argument in defgroup specifies the parent group. The root
7149 group is called `emacs'; it should not contain any variables itself,
7150 but only other groups. The immediate subgroups of `emacs' correspond
7151 to the keywords used by C-h p. Under these subgroups come
7152 second-level subgroups that belong to individual packages.
7153
7154 Each Emacs package should have its own set of groups. A simple
7155 package should have just one group; a more complex package should
7156 have a hierarchy of its own groups. The sole or root group of a
7157 package should be a subgroup of one or more of the "keyword"
7158 first-level subgroups.
7159
7160 ** New `widget' library for inserting UI components in buffers.
7161
7162 This library, used by the new custom library, is documented in a
7163 separate manual that accompanies Emacs.
7164
7165 ** easy-mmode
7166
7167 The easy-mmode package provides macros and functions that make
7168 developing minor modes easier. Roughly, the programmer has to code
7169 only the functionality of the minor mode. All the rest--toggles,
7170 predicate, and documentation--can be done in one call to the macro
7171 `easy-mmode-define-minor-mode' (see the documentation). See also
7172 `easy-mmode-define-keymap'.
7173
7174 ** Text property changes
7175
7176 *** The `intangible' property now works on overlays as well as on a
7177 text property.
7178
7179 *** The new functions next-char-property-change and
7180 previous-char-property-change scan through the buffer looking for a
7181 place where either a text property or an overlay might change. The
7182 functions take two arguments, POSITION and LIMIT. POSITION is the
7183 starting position for the scan. LIMIT says where to stop the scan.
7184
7185 If no property change is found before LIMIT, the value is LIMIT. If
7186 LIMIT is nil, scan goes to the beginning or end of the accessible part
7187 of the buffer. If no property change is found, the value is the
7188 position of the beginning or end of the buffer.
7189
7190 *** In the `local-map' text property or overlay property, the property
7191 value can now be a symbol whose function definition is a keymap. This
7192 is an alternative to using the keymap itself.
7193
7194 ** Changes in invisibility features
7195
7196 *** Isearch can now temporarily show parts of the buffer which are
7197 hidden by an overlay with a invisible property, when the search match
7198 is inside that portion of the buffer. To enable this the overlay
7199 should have a isearch-open-invisible property which is a function that
7200 would be called having the overlay as an argument, the function should
7201 make the overlay visible.
7202
7203 During incremental search the overlays are shown by modifying the
7204 invisible and intangible properties, if beside this more actions are
7205 needed the overlay should have a isearch-open-invisible-temporary
7206 which is a function. The function is called with 2 arguments: one is
7207 the overlay and the second is nil when it should show the overlay and
7208 t when it should hide it.
7209
7210 *** add-to-invisibility-spec, remove-from-invisibility-spec
7211
7212 Modes that use overlays to hide portions of a buffer should set the
7213 invisible property of the overlay to the mode's name (or another symbol)
7214 and modify the `buffer-invisibility-spec' to include that symbol.
7215 Use `add-to-invisibility-spec' and `remove-from-invisibility-spec' to
7216 manipulate the `buffer-invisibility-spec'.
7217 Here is an example of how to do this:
7218
7219 ;; If we want to display an ellipsis:
7220 (add-to-invisibility-spec '(my-symbol . t))
7221 ;; If you don't want ellipsis:
7222 (add-to-invisibility-spec 'my-symbol)
7223
7224 ...
7225 (overlay-put (make-overlay beginning end) 'invisible 'my-symbol)
7226
7227 ...
7228 ;; When done with the overlays:
7229 (remove-from-invisibility-spec '(my-symbol . t))
7230 ;; Or respectively:
7231 (remove-from-invisibility-spec 'my-symbol)
7232
7233 ** Changes in syntax parsing.
7234
7235 *** The syntax-directed buffer-scan functions (such as
7236 `parse-partial-sexp', `forward-word' and similar functions) can now
7237 obey syntax information specified by text properties, if the variable
7238 `parse-sexp-lookup-properties' is non-nil.
7239
7240 If the value of `parse-sexp-lookup-properties' is nil, the behavior
7241 is as before: the syntax-table of the current buffer is always
7242 used to determine the syntax of the character at the position.
7243
7244 When `parse-sexp-lookup-properties' is non-nil, the syntax of a
7245 character in the buffer is calculated thus:
7246
7247 a) if the `syntax-table' text-property of that character
7248 is a cons, this cons becomes the syntax-type;
7249
7250 Valid values of `syntax-table' text-property are: nil, a valid
7251 syntax-table, and a valid syntax-table element, i.e.,
7252 a cons cell of the form (SYNTAX-CODE . MATCHING-CHAR).
7253
7254 b) if the character's `syntax-table' text-property
7255 is a syntax table, this syntax table is used
7256 (instead of the syntax-table of the current buffer) to
7257 determine the syntax type of the character.
7258
7259 c) otherwise the syntax-type is determined by the syntax-table
7260 of the current buffer.
7261
7262 *** The meaning of \s in regular expressions is also affected by the
7263 value of `parse-sexp-lookup-properties'. The details are the same as
7264 for the syntax-directed buffer-scan functions.
7265
7266 *** There are two new syntax-codes, `!' and `|' (numeric values 14
7267 and 15). A character with a code `!' starts a comment which is ended
7268 only by another character with the same code (unless quoted). A
7269 character with a code `|' starts a string which is ended only by
7270 another character with the same code (unless quoted).
7271
7272 These codes are mainly meant for use as values of the `syntax-table'
7273 text property.
7274
7275 *** The function `parse-partial-sexp' has new semantics for the sixth
7276 arg COMMENTSTOP. If it is `syntax-table', parse stops after the start
7277 of a comment or a string, or after end of a comment or a string.
7278
7279 *** The state-list which the return value from `parse-partial-sexp'
7280 (and can also be used as an argument) now has an optional ninth
7281 element: the character address of the start of last comment or string;
7282 nil if none. The fourth and eighth elements have special values if the
7283 string/comment is started by a "!" or "|" syntax-code.
7284
7285 *** Since new features of `parse-partial-sexp' allow a complete
7286 syntactic parsing, `font-lock' no longer supports
7287 `font-lock-comment-start-regexp'.
7288
7289 ** Changes in face features
7290
7291 *** The face functions are now unconditionally defined in Emacs, even
7292 if it does not support displaying on a device that supports faces.
7293
7294 *** The function face-documentation returns the documentation string
7295 of a face (or nil if it doesn't have one).
7296
7297 *** The function face-bold-p returns t if a face should be bold.
7298 set-face-bold-p sets that flag.
7299
7300 *** The function face-italic-p returns t if a face should be italic.
7301 set-face-italic-p sets that flag.
7302
7303 *** You can now specify foreground and background colors for text
7304 by adding elements of the form (foreground-color . COLOR-NAME)
7305 and (background-color . COLOR-NAME) to the list of faces in
7306 the `face' property (either the character's text property or an
7307 overlay property).
7308
7309 This means that you no longer need to create named faces to use
7310 arbitrary colors in a Lisp package.
7311
7312 ** Changes in file-handling functions
7313
7314 *** File-access primitive functions no longer discard an extra redundant
7315 directory name from the beginning of the file name. In other words,
7316 they no longer do anything special with // or /~. That conversion
7317 is now done only in substitute-in-file-name.
7318
7319 This makes it possible for a Lisp program to open a file whose name
7320 begins with ~.
7321
7322 *** If copy-file is unable to set the date of the output file,
7323 it now signals an error with the condition file-date-error.
7324
7325 *** The inode number returned by file-attributes may be an integer (if
7326 the number fits in a Lisp integer) or a list of integers.
7327
7328 *** insert-file-contents can now read from a special file,
7329 as long as the arguments VISIT and REPLACE are nil.
7330
7331 *** The RAWFILE arg to find-file-noselect, if non-nil, now suppresses
7332 character code conversion as well as other things.
7333
7334 Meanwhile, this feature does work with remote file names
7335 (formerly it did not).
7336
7337 *** Lisp packages which create temporary files should use the TMPDIR
7338 environment variable to decide which directory to put them in.
7339
7340 *** interpreter-mode-alist elements now specify regexps
7341 instead of constant strings.
7342
7343 *** expand-file-name no longer treats `//' or `/~' specially. It used
7344 to delete all the text of a file name up through the first slash of
7345 any `//' or `/~' sequence. Now it passes them straight through.
7346
7347 substitute-in-file-name continues to treat those sequences specially,
7348 in the same way as before.
7349
7350 *** The variable `format-alist' is more general now.
7351 The FROM-FN and TO-FN in a format definition can now be strings
7352 which specify shell commands to use as filters to perform conversion.
7353
7354 *** The new function access-file tries to open a file, and signals an
7355 error if that fails. If the open succeeds, access-file does nothing
7356 else, and returns nil.
7357
7358 *** The function insert-directory now signals an error if the specified
7359 directory cannot be listed.
7360
7361 ** Changes in minibuffer input
7362
7363 *** The functions read-buffer, read-variable, read-command, read-string
7364 read-file-name, read-from-minibuffer and completing-read now take an
7365 additional argument which specifies the default value. If this
7366 argument is non-nil, it should be a string; that string is used in two
7367 ways:
7368
7369 It is returned if the user enters empty input.
7370 It is available through the history command M-n.
7371
7372 *** The functions read-string, read-from-minibuffer,
7373 read-no-blanks-input and completing-read now take an additional
7374 argument INHERIT-INPUT-METHOD. If this is non-nil, then the
7375 minibuffer inherits the current input method and the setting of
7376 enable-multibyte-characters from the previously current buffer.
7377
7378 In an interactive spec, you can use M instead of s to read an
7379 argument in this way.
7380
7381 *** All minibuffer input functions discard text properties
7382 from the text you enter in the minibuffer, unless the variable
7383 minibuffer-allow-text-properties is non-nil.
7384
7385 ** Echo area features
7386
7387 *** Clearing the echo area now runs the normal hook
7388 echo-area-clear-hook. Note that the echo area can be used while the
7389 minibuffer is active; in that case, the minibuffer is still active
7390 after the echo area is cleared.
7391
7392 *** The function current-message returns the message currently displayed
7393 in the echo area, or nil if there is none.
7394
7395 ** Keyboard input features
7396
7397 *** tty-erase-char is a new variable that reports which character was
7398 set up as the terminal's erase character when time Emacs was started.
7399
7400 *** num-nonmacro-input-events is the total number of input events
7401 received so far from the terminal. It does not count those generated
7402 by keyboard macros.
7403
7404 ** Frame-related changes
7405
7406 *** make-frame runs the normal hook before-make-frame-hook just before
7407 creating a frame, and just after creating a frame it runs the abnormal
7408 hook after-make-frame-functions with the new frame as arg.
7409
7410 *** The new hook window-configuration-change-hook is now run every time
7411 the window configuration has changed. The frame whose configuration
7412 has changed is the selected frame when the hook is run.
7413
7414 *** Each frame now independently records the order for recently
7415 selected buffers, in its buffer-list frame parameter, so that the
7416 value of other-buffer is now based on the buffers recently displayed
7417 in the selected frame.
7418
7419 *** The value of the frame parameter vertical-scroll-bars
7420 is now `left', `right' or nil. A non-nil value specifies
7421 which side of the window to put the scroll bars on.
7422
7423 ** X Windows features
7424
7425 *** You can examine X resources for other applications by binding
7426 x-resource-class around a call to x-get-resource. The usual value of
7427 x-resource-class is "Emacs", which is the correct value for Emacs.
7428
7429 *** In menus, checkboxes and radio buttons now actually work.
7430 The menu displays the current status of the box or button.
7431
7432 *** The function x-list-fonts now takes an optional fourth argument
7433 MAXIMUM which sets a limit on how many matching fonts to return.
7434 A smaller value of MAXIMUM makes the function faster.
7435
7436 If the only question is whether *any* font matches the pattern,
7437 it is good to supply 1 for this argument.
7438
7439 ** Subprocess features
7440
7441 *** A reminder: it is no longer necessary for subprocess filter
7442 functions and sentinels to do save-match-data, because Emacs does this
7443 automatically.
7444
7445 *** The new function shell-command-to-string executes a shell command
7446 and returns the output from the command as a string.
7447
7448 *** The new function process-contact returns t for a child process,
7449 and (HOSTNAME SERVICE) for a net connection.
7450
7451 ** An error in running pre-command-hook or post-command-hook
7452 does clear the variable to nil. The documentation was wrong before.
7453
7454 ** In define-key-after, if AFTER is t, the new binding now always goes
7455 at the end of the keymap. If the keymap is a menu, this means it
7456 goes after the other menu items.
7457
7458 ** If you have a program that makes several changes in the same area
7459 of the buffer, you can use the macro combine-after-change-calls
7460 around that Lisp code to make it faster when after-change hooks
7461 are in use.
7462
7463 The macro arranges to call the after-change functions just once for a
7464 series of several changes--if that seems safe.
7465
7466 Don't alter the variables after-change-functions and
7467 after-change-function within the body of a combine-after-change-calls
7468 form.
7469
7470 ** If you define an abbrev (with define-abbrev) whose EXPANSION
7471 is not a string, then the abbrev does not expand in the usual sense,
7472 but its hook is still run.
7473
7474 ** Normally, the Lisp debugger is not used (even if you have enabled it)
7475 for errors that are handled by condition-case.
7476
7477 If you set debug-on-signal to a non-nil value, then the debugger is called
7478 regardless of whether there is a handler for the condition. This is
7479 useful for debugging problems that happen inside of a condition-case.
7480
7481 This mode of operation seems to be unreliable in other ways. Errors that
7482 are normal and ought to be handled, perhaps in timers or process
7483 filters, will instead invoke the debugger. So don't say you weren't
7484 warned.
7485
7486 ** The new variable ring-bell-function lets you specify your own
7487 way for Emacs to "ring the bell".
7488
7489 ** If run-at-time's TIME argument is t, the action is repeated at
7490 integral multiples of REPEAT from the epoch; this is useful for
7491 functions like display-time.
7492
7493 ** You can use the function locate-library to find the precise file
7494 name of a Lisp library. This isn't new, but wasn't documented before.
7495
7496 ** Commands for entering view mode have new optional arguments that
7497 can be used from Lisp. Low-level entrance to and exit from view mode
7498 is done by functions view-mode-enter and view-mode-exit.
7499
7500 ** batch-byte-compile-file now makes Emacs return a nonzero status code
7501 if there is an error in compilation.
7502
7503 ** pop-to-buffer, switch-to-buffer-other-window and
7504 switch-to-buffer-other-frame now accept an additional optional
7505 argument NORECORD, much like switch-to-buffer. If it is non-nil,
7506 they don't put the buffer at the front of the buffer list.
7507
7508 ** If your .emacs file leaves the *scratch* buffer non-empty,
7509 Emacs does not display the startup message, so as to avoid changing
7510 the *scratch* buffer.
7511
7512 ** The new function regexp-opt returns an efficient regexp to match a string.
7513 The arguments are STRINGS and (optionally) PAREN. This function can be used
7514 where regexp matching or searching is intensively used and speed is important,
7515 e.g., in Font Lock mode.
7516
7517 ** The variable buffer-display-count is local to each buffer,
7518 and is incremented each time the buffer is displayed in a window.
7519 It starts at 0 when the buffer is created.
7520
7521 ** The new function compose-mail starts composing a mail message
7522 using the user's chosen mail composition agent (specified with the
7523 variable mail-user-agent). It has variants compose-mail-other-window
7524 and compose-mail-other-frame.
7525
7526 ** The `user-full-name' function now takes an optional parameter which
7527 can either be a number (the UID) or a string (the login name). The
7528 full name of the specified user will be returned.
7529
7530 ** Lisp packages that load files of customizations, or any other sort
7531 of user profile, should obey the variable init-file-user in deciding
7532 where to find it. They should load the profile of the user name found
7533 in that variable. If init-file-user is nil, meaning that the -q
7534 option was used, then Lisp packages should not load the customization
7535 files at all.
7536
7537 ** format-time-string now allows you to specify the field width
7538 and type of padding. This works as in printf: you write the field
7539 width as digits in the middle of a %-construct. If you start
7540 the field width with 0, it means to pad with zeros.
7541
7542 For example, %S normally specifies the number of seconds since the
7543 minute; %03S means to pad this with zeros to 3 positions, %_3S to pad
7544 with spaces to 3 positions. Plain %3S pads with zeros, because that
7545 is how %S normally pads to two positions.
7546
7547 ** thing-at-point now supports a new kind of "thing": url.
7548
7549 ** imenu.el changes.
7550
7551 You can now specify a function to be run when selecting an
7552 item from menu created by imenu.
7553
7554 An example of using this feature: if we define imenu items for the
7555 #include directives in a C file, we can open the included file when we
7556 select one of those items.
7557 \f
7558 * Emacs 19.34 is a bug-fix release with no user-visible changes.
7559 \f
7560 * Changes in Emacs 19.33.
7561
7562 ** Bibtex mode no longer turns on Auto Fill automatically. (No major
7563 mode should do that--it is the user's choice.)
7564
7565 ** The variable normal-auto-fill-function specifies the function to
7566 use for auto-fill-function, if and when Auto Fill is turned on.
7567 Major modes can set this locally to alter how Auto Fill works.
7568 \f
7569 * Editing Changes in Emacs 19.32
7570
7571 ** C-x f with no argument now signals an error.
7572 To set the fill column at the current column, use C-u C-x f.
7573
7574 ** Expanding dynamic abbrevs with M-/ is now smarter about case
7575 conversion. If you type the abbreviation with mixed case, and it
7576 matches the beginning of the expansion including case, then the
7577 expansion is copied verbatim. Using SPC M-/ to copy an additional
7578 word always copies it verbatim except when the previous copied word is
7579 all caps.
7580
7581 ** On a non-windowing terminal, which can display only one Emacs frame
7582 at a time, creating a new frame with C-x 5 2 also selects that frame.
7583
7584 When using a display that can show multiple frames at once, C-x 5 2
7585 does make the frame visible, but does not select it. This is the same
7586 as in previous Emacs versions.
7587
7588 ** You can use C-x 5 2 to create multiple frames on MSDOS, just as on a
7589 non-X terminal on Unix. Of course, only one frame is visible at any
7590 time, since your terminal doesn't have the ability to display multiple
7591 frames.
7592
7593 ** On Windows, set win32-pass-alt-to-system to a non-nil value
7594 if you would like tapping the Alt key to invoke the Windows menu.
7595 This feature is not enabled by default; since the Alt key is also the
7596 Meta key, it is too easy and painful to activate this feature by
7597 accident.
7598
7599 ** The command apply-macro-to-region-lines repeats the last defined
7600 keyboard macro once for each complete line within the current region.
7601 It does this line by line, by moving point to the beginning of that
7602 line and then executing the macro.
7603
7604 This command is not new, but was never documented before.
7605
7606 ** You can now use Mouse-1 to place the region around a string constant
7607 (something surrounded by doublequote characters or other delimiter
7608 characters of like syntax) by double-clicking on one of the delimiting
7609 characters.
7610
7611 ** Font Lock mode
7612
7613 *** Font Lock support modes
7614
7615 Font Lock can be configured to use Fast Lock mode and Lazy Lock mode (see
7616 below) in a flexible way. Rather than adding the appropriate function to the
7617 hook font-lock-mode-hook, you can use the new variable font-lock-support-mode
7618 to control which modes have Fast Lock mode or Lazy Lock mode turned on when
7619 Font Lock mode is enabled.
7620
7621 For example, to use Fast Lock mode when Font Lock mode is turned on, put:
7622
7623 (setq font-lock-support-mode 'fast-lock-mode)
7624
7625 in your ~/.emacs.
7626
7627 *** lazy-lock
7628
7629 The lazy-lock package speeds up Font Lock mode by making fontification occur
7630 only when necessary, such as when a previously unfontified part of the buffer
7631 becomes visible in a window. When you create a buffer with Font Lock mode and
7632 Lazy Lock mode turned on, the buffer is not fontified. When certain events
7633 occur (such as scrolling), Lazy Lock makes sure that the visible parts of the
7634 buffer are fontified. Lazy Lock also defers on-the-fly fontification until
7635 Emacs has been idle for a given amount of time.
7636
7637 To use this package, put in your ~/.emacs:
7638
7639 (setq font-lock-support-mode 'lazy-lock-mode)
7640
7641 To control the package behaviour, see the documentation for `lazy-lock-mode'.
7642
7643 ** Changes in BibTeX mode.
7644
7645 *** For all entries allow spaces and tabs between opening brace or
7646 paren and key.
7647
7648 *** Non-escaped double-quoted characters (as in `Sch"of') are now
7649 supported.
7650
7651 ** Gnus changes.
7652
7653 Gnus, the Emacs news reader, has undergone further rewriting. Many new
7654 commands and variables have been added. There should be no
7655 significant incompatibilities between this Gnus version and the
7656 previously released version, except in the message composition area.
7657
7658 Below is a list of the more user-visible changes. Coding changes
7659 between Gnus 5.1 and 5.2 are more extensive.
7660
7661 *** A new message composition mode is used. All old customization
7662 variables for mail-mode, rnews-reply-mode and gnus-msg are now
7663 obsolete.
7664
7665 *** Gnus is now able to generate "sparse" threads -- threads where
7666 missing articles are represented by empty nodes.
7667
7668 (setq gnus-build-sparse-threads 'some)
7669
7670 *** Outgoing articles are stored on a special archive server.
7671
7672 To disable this: (setq gnus-message-archive-group nil)
7673
7674 *** Partial thread regeneration now happens when articles are
7675 referred.
7676
7677 *** Gnus can make use of GroupLens predictions:
7678
7679 (setq gnus-use-grouplens t)
7680
7681 *** A trn-line tree buffer can be displayed.
7682
7683 (setq gnus-use-trees t)
7684
7685 *** An nn-like pick-and-read minor mode is available for the summary
7686 buffers.
7687
7688 (add-hook 'gnus-summary-mode-hook 'gnus-pick-mode)
7689
7690 *** In binary groups you can use a special binary minor mode:
7691
7692 `M-x gnus-binary-mode'
7693
7694 *** Groups can be grouped in a folding topic hierarchy.
7695
7696 (add-hook 'gnus-group-mode-hook 'gnus-topic-mode)
7697
7698 *** Gnus can re-send and bounce mail.
7699
7700 Use the `S D r' and `S D b'.
7701
7702 *** Groups can now have a score, and bubbling based on entry frequency
7703 is possible.
7704
7705 (add-hook 'gnus-summary-exit-hook 'gnus-summary-bubble-group)
7706
7707 *** Groups can be process-marked, and commands can be performed on
7708 groups of groups.
7709
7710 *** Caching is possible in virtual groups.
7711
7712 *** nndoc now understands all kinds of digests, mail boxes, rnews news
7713 batches, ClariNet briefs collections, and just about everything else.
7714
7715 *** Gnus has a new backend (nnsoup) to create/read SOUP packets.
7716
7717 *** The Gnus cache is much faster.
7718
7719 *** Groups can be sorted according to many criteria.
7720
7721 For instance: (setq gnus-group-sort-function 'gnus-group-sort-by-rank)
7722
7723 *** New group parameters have been introduced to set list-address and
7724 expiration times.
7725
7726 *** All formatting specs allow specifying faces to be used.
7727
7728 *** There are several more commands for setting/removing/acting on
7729 process marked articles on the `M P' submap.
7730
7731 *** The summary buffer can be limited to show parts of the available
7732 articles based on a wide range of criteria. These commands have been
7733 bound to keys on the `/' submap.
7734
7735 *** Articles can be made persistent -- as an alternative to saving
7736 articles with the `*' command.
7737
7738 *** All functions for hiding article elements are now toggles.
7739
7740 *** Article headers can be buttonized.
7741
7742 (add-hook 'gnus-article-display-hook 'gnus-article-add-buttons-to-head)
7743
7744 *** All mail backends support fetching articles by Message-ID.
7745
7746 *** Duplicate mail can now be treated properly. See the
7747 `nnmail-treat-duplicates' variable.
7748
7749 *** All summary mode commands are available directly from the article
7750 buffer.
7751
7752 *** Frames can be part of `gnus-buffer-configuration'.
7753
7754 *** Mail can be re-scanned by a daemonic process.
7755
7756 *** Gnus can make use of NoCeM files to filter spam.
7757
7758 (setq gnus-use-nocem t)
7759
7760 *** Groups can be made permanently visible.
7761
7762 (setq gnus-permanently-visible-groups "^nnml:")
7763
7764 *** Many new hooks have been introduced to make customizing easier.
7765
7766 *** Gnus respects the Mail-Copies-To header.
7767
7768 *** Threads can be gathered by looking at the References header.
7769
7770 (setq gnus-summary-thread-gathering-function
7771 'gnus-gather-threads-by-references)
7772
7773 *** Read articles can be stored in a special backlog buffer to avoid
7774 refetching.
7775
7776 (setq gnus-keep-backlog 50)
7777
7778 *** A clean copy of the current article is always stored in a separate
7779 buffer to allow easier treatment.
7780
7781 *** Gnus can suggest where to save articles. See `gnus-split-methods'.
7782
7783 *** Gnus doesn't have to do as much prompting when saving.
7784
7785 (setq gnus-prompt-before-saving t)
7786
7787 *** gnus-uu can view decoded files asynchronously while fetching
7788 articles.
7789
7790 (setq gnus-uu-grabbed-file-functions 'gnus-uu-grab-view)
7791
7792 *** Filling in the article buffer now works properly on cited text.
7793
7794 *** Hiding cited text adds buttons to toggle hiding, and how much
7795 cited text to hide is now customizable.
7796
7797 (setq gnus-cited-lines-visible 2)
7798
7799 *** Boring headers can be hidden.
7800
7801 (add-hook 'gnus-article-display-hook 'gnus-article-hide-boring-headers)
7802
7803 *** Default scoring values can now be set from the menu bar.
7804
7805 *** Further syntax checking of outgoing articles have been added.
7806
7807 The Gnus manual has been expanded. It explains all these new features
7808 in greater detail.
7809 \f
7810 * Lisp Changes in Emacs 19.32
7811
7812 ** The function set-visited-file-name now accepts an optional
7813 second argument NO-QUERY. If it is non-nil, then the user is not
7814 asked for confirmation in the case where the specified file already
7815 exists.
7816
7817 ** The variable print-length applies to printing vectors and bitvectors,
7818 as well as lists.
7819
7820 ** The new function keymap-parent returns the parent keymap
7821 of a given keymap.
7822
7823 ** The new function set-keymap-parent specifies a new parent for a
7824 given keymap. The arguments are KEYMAP and PARENT. PARENT must be a
7825 keymap or nil.
7826
7827 ** Sometimes menu keymaps use a command name, a symbol, which is really
7828 an automatically generated alias for some other command, the "real"
7829 name. In such a case, you should give that alias symbol a non-nil
7830 menu-alias property. That property tells the menu system to look for
7831 equivalent keys for the real name instead of equivalent keys for the
7832 alias.
7833 \f
7834 * Editing Changes in Emacs 19.31
7835
7836 ** Freedom of the press restricted in the United States.
7837
7838 Emacs has been censored in accord with the Communications Decency Act.
7839 This includes removing some features of the doctor program. That law
7840 was described by its supporters as a ban on pornography, but it bans
7841 far more than that. The Emacs distribution has never contained any
7842 pornography, but parts of it were nonetheless prohibited.
7843
7844 For information on US government censorship of the Internet, and what
7845 you can do to bring back freedom of the press, see the web site
7846 `http://www.vtw.org/'.
7847
7848 ** A note about C mode indentation customization.
7849
7850 The old (Emacs 19.29) ways of specifying a C indentation style
7851 do not normally work in the new implementation of C mode.
7852 It has its own methods of customizing indentation, which are
7853 much more powerful than the old C mode. See the Editing Programs
7854 chapter of the manual for details.
7855
7856 However, you can load the library cc-compat to make the old
7857 customization variables take effect.
7858
7859 ** Marking with the mouse.
7860
7861 When you mark a region with the mouse, the region now remains
7862 highlighted until the next input event, regardless of whether you are
7863 using M-x transient-mark-mode.
7864
7865 ** Improved Windows NT/95 support.
7866
7867 *** Emacs now supports scroll bars on Windows NT and Windows 95.
7868
7869 *** Emacs now supports subprocesses on Windows 95. (Subprocesses used
7870 to work on NT only and not on 95.)
7871
7872 *** There are difficulties with subprocesses, though, due to problems
7873 in Windows, beyond the control of Emacs. They work fine as long as
7874 you run Windows applications. The problems arise when you run a DOS
7875 application in a subprocesses. Since current shells run as DOS
7876 applications, these problems are significant.
7877
7878 If you run a DOS application in a subprocess, then the application is
7879 likely to busy-wait, which means that your machine will be 100% busy.
7880 However, if you don't mind the temporary heavy load, the subprocess
7881 will work OK as long as you tell it to terminate before you start any
7882 other DOS application as a subprocess.
7883
7884 Emacs is unable to terminate or interrupt a DOS subprocess.
7885 You have to do this by providing input directly to the subprocess.
7886
7887 If you run two DOS applications at the same time in two separate
7888 subprocesses, even if one of them is asynchronous, you will probably
7889 have to reboot your machine--until then, it will remain 100% busy.
7890 Windows simply does not cope when one Windows process tries to run two
7891 separate DOS subprocesses. Typing CTL-ALT-DEL and then choosing
7892 Shutdown seems to work although it may take a few minutes.
7893
7894 ** M-x resize-minibuffer-mode.
7895
7896 This command, not previously mentioned in NEWS, toggles a mode in
7897 which the minibuffer window expands to show as many lines as the
7898 minibuffer contains.
7899
7900 ** `title' frame parameter and resource.
7901
7902 The `title' X resource now specifies just the frame title, nothing else.
7903 It does not affect the name used for looking up other X resources.
7904 It works by setting the new `title' frame parameter, which likewise
7905 affects just the displayed title of the frame.
7906
7907 The `name' parameter continues to do what it used to do:
7908 it specifies the frame name for looking up X resources,
7909 and also serves as the default for the displayed title
7910 when the `title' parameter is unspecified or nil.
7911
7912 ** Emacs now uses the X toolkit by default, if you have a new
7913 enough version of X installed (X11R5 or newer).
7914
7915 ** When you compile Emacs with the Motif widget set, Motif handles the
7916 F10 key by activating the menu bar. To avoid confusion, the usual
7917 Emacs binding of F10 is replaced with a no-op when using Motif.
7918
7919 If you want to be able to use F10 in Emacs, you can rebind the Motif
7920 menubar to some other key which you don't use. To do so, add
7921 something like this to your X resources file. This example rebinds
7922 the Motif menu bar activation key to S-F12:
7923
7924 Emacs*defaultVirtualBindings: osfMenuBar : Shift<Key>F12
7925
7926 ** In overwrite mode, DEL now inserts spaces in most cases
7927 to replace the characters it "deletes".
7928
7929 ** The Rmail summary now shows the number of lines in each message.
7930
7931 ** Rmail has a new command M-x unforward-rmail-message, which extracts
7932 a forwarded message from the message that forwarded it. To use it,
7933 select a message which contains a forwarded message and then type the command.
7934 It inserts the forwarded message as a separate Rmail message
7935 immediately after the selected one.
7936
7937 This command also undoes the textual modifications that are standardly
7938 made, as part of forwarding, by Rmail and other mail reader programs.
7939
7940 ** Turning off saving of .saves-... files in your home directory.
7941
7942 Each Emacs session writes a file named .saves-... in your home
7943 directory to record which files M-x recover-session should recover.
7944 If you exit Emacs normally with C-x C-c, it deletes that file. If
7945 Emacs or the operating system crashes, the file remains for M-x
7946 recover-session.
7947
7948 You can turn off the writing of these files by setting
7949 auto-save-list-file-name to nil. If you do this, M-x recover-session
7950 will not work.
7951
7952 Some previous Emacs versions failed to delete these files even on
7953 normal exit. This is fixed now. If you are thinking of turning off
7954 this feature because of past experiences with versions that had this
7955 bug, it would make sense to check whether you still want to do so
7956 now that the bug is fixed.
7957
7958 ** Changes to Version Control (VC)
7959
7960 There is a new variable, vc-follow-symlinks. It indicates what to do
7961 when you visit a link to a file that is under version control.
7962 Editing the file through the link bypasses the version control system,
7963 which is dangerous and probably not what you want.
7964
7965 If this variable is t, VC follows the link and visits the real file,
7966 telling you about it in the echo area. If it is `ask' (the default),
7967 VC asks for confirmation whether it should follow the link. If nil,
7968 the link is visited and a warning displayed.
7969
7970 ** iso-acc.el now lets you specify a choice of language.
7971 Languages include "latin-1" (the default) and "latin-2" (which
7972 is designed for entering ISO Latin-2 characters).
7973
7974 There are also choices for specific human languages such as French and
7975 Portuguese. These are subsets of Latin-1, which differ in that they
7976 enable only the accent characters needed for particular language.
7977 The other accent characters, not needed for the chosen language,
7978 remain normal.
7979
7980 ** Posting articles and sending mail now has M-TAB completion on various
7981 header fields (Newsgroups, To, CC, ...).
7982
7983 Completion in the Newsgroups header depends on the list of groups
7984 known to your news reader. Completion in the Followup-To header
7985 offers those groups which are in the Newsgroups header, since
7986 Followup-To usually just holds one of those.
7987
7988 Completion in fields that hold mail addresses works based on the list
7989 of local users plus your aliases. Additionally, if your site provides
7990 a mail directory or a specific host to use for any unrecognized user
7991 name, you can arrange to query that host for completion also. (See the
7992 documentation of variables `mail-directory-process' and
7993 `mail-directory-stream'.)
7994
7995 ** A greatly extended sgml-mode offers new features such as (to be configured)
7996 skeletons with completing read for tags and attributes, typing named
7997 characters including optionally all 8bit characters, making tags invisible
7998 with optional alternate display text, skipping and deleting tag(pair)s.
7999
8000 Note: since Emacs' syntax feature cannot limit the special meaning of ', " and
8001 - to inside <>, for some texts the result, especially of font locking, may be
8002 wrong (see `sgml-specials' if you get wrong results).
8003
8004 The derived html-mode configures this with tags and attributes more or
8005 less HTML3ish. It also offers optional quick keys like C-c 1 for
8006 headline or C-c u for unordered list (see `html-quick-keys'). Edit /
8007 Text Properties / Face or M-g combinations create tags as applicable.
8008 Outline minor mode is supported and level 1 font-locking tries to
8009 fontify tag contents (which only works when they fit on one line, due
8010 to a limitation in font-lock).
8011
8012 External viewing via browse-url can occur automatically upon saving.
8013
8014 ** M-x imenu-add-to-menubar now adds to the menu bar for the current
8015 buffer only. If you want to put an Imenu item in the menu bar for all
8016 buffers that use a particular major mode, use the mode hook, as in
8017 this example:
8018
8019 (add-hook 'emacs-lisp-mode-hook
8020 '(lambda () (imenu-add-to-menubar "Index")))
8021
8022 ** Changes in BibTeX mode.
8023
8024 *** Field names may now contain digits, hyphens, and underscores.
8025
8026 *** Font Lock mode is now supported.
8027
8028 *** bibtex-make-optional-field is no longer interactive.
8029
8030 *** If bibtex-maintain-sorted-entries is non-nil, inserting new
8031 entries is now done with a faster algorithm. However, inserting
8032 will fail in this case if the buffer contains invalid entries or
8033 isn't in sorted order, so you should finish each entry with C-c C-c
8034 (bibtex-close-entry) after you have inserted or modified it.
8035 The default value of bibtex-maintain-sorted-entries is nil.
8036
8037 *** Function `show-all' is no longer bound to a key, since C-u C-c C-q
8038 does the same job.
8039
8040 *** Entries with quotes inside quote-delimited fields (as `author =
8041 "Stefan Sch{\"o}f"') are now supported.
8042
8043 *** Case in field names doesn't matter anymore when searching for help
8044 text.
8045
8046 ** Font Lock mode
8047
8048 *** Global Font Lock mode
8049
8050 Font Lock mode can be turned on globally, in buffers that support it, by the
8051 new command global-font-lock-mode. You can use the new variable
8052 font-lock-global-modes to control which modes have Font Lock mode automagically
8053 turned on. By default, this variable is set so that Font Lock mode is turned
8054 on globally where the buffer mode supports it.
8055
8056 For example, to automagically turn on Font Lock mode where supported, put:
8057
8058 (global-font-lock-mode t)
8059
8060 in your ~/.emacs.
8061
8062 *** Local Refontification
8063
8064 In Font Lock mode, editing a line automatically refontifies that line only.
8065 However, if your change alters the syntactic context for following lines,
8066 those lines remain incorrectly fontified. To refontify them, use the new
8067 command M-g M-g (font-lock-fontify-block).
8068
8069 In certain major modes, M-g M-g refontifies the entire current function.
8070 (The variable font-lock-mark-block-function controls how to find the
8071 current function.) In other major modes, M-g M-g refontifies 16 lines
8072 above and below point.
8073
8074 With a prefix argument N, M-g M-g refontifies N lines above and below point.
8075
8076 ** Follow mode
8077
8078 Follow mode is a new minor mode combining windows showing the same
8079 buffer into one tall "virtual window". The windows are typically two
8080 side-by-side windows. Follow mode makes them scroll together as if
8081 they were a unit. To use it, go to a frame with just one window,
8082 split it into two side-by-side windows using C-x 3, and then type M-x
8083 follow-mode.
8084
8085 M-x follow-mode turns off Follow mode if it is already enabled.
8086
8087 To display two side-by-side windows and activate Follow mode, use the
8088 command M-x follow-delete-other-windows-and-split.
8089
8090 ** hide-show changes.
8091
8092 The hooks hs-hide-hooks and hs-show-hooks have been renamed
8093 to hs-hide-hook and hs-show-hook, to follow the convention for
8094 normal hooks.
8095
8096 ** Simula mode now has a menu containing the most important commands.
8097 The new command simula-indent-exp is bound to C-M-q.
8098
8099 ** etags can now handle programs written in Erlang. Files are
8100 recognised by the extensions .erl and .hrl. The tagged lines are
8101 those that begin a function, record, or macro.
8102
8103 ** MSDOS Changes
8104
8105 *** It is now possible to compile Emacs with the version 2 of DJGPP.
8106 Compilation with DJGPP version 1 also still works.
8107
8108 *** The documentation of DOS-specific aspects of Emacs was rewritten
8109 and expanded; see the ``MS-DOS'' node in the on-line docs.
8110
8111 *** Emacs now uses ~ for backup file names, not .bak.
8112
8113 *** You can simulate mouse-3 on two-button mice by simultaneously
8114 pressing both mouse buttons.
8115
8116 *** A number of packages and commands which previously failed or had
8117 restricted functionality on MS-DOS, now work. The most important ones
8118 are:
8119
8120 **** Printing (both with `M-x lpr-buffer' and with `ps-print' package)
8121 now works.
8122
8123 **** `Ediff' works (in a single-frame mode).
8124
8125 **** `M-x display-time' can be used on MS-DOS (due to the new
8126 implementation of Emacs timers, see below).
8127
8128 **** `Dired' supports Unix-style shell wildcards.
8129
8130 **** The `c-macro-expand' command now works as on other platforms.
8131
8132 **** `M-x recover-session' works.
8133
8134 **** `M-x list-colors-display' displays all the available colors.
8135
8136 **** The `TPU-EDT' package works.
8137 \f
8138 * Lisp changes in Emacs 19.31.
8139
8140 ** The function using-unix-filesystems on Windows NT and Windows 95
8141 tells Emacs to read and write files assuming that they reside on a
8142 remote Unix filesystem. No CR/LF translation is done on any files in
8143 this case. Invoking using-unix-filesystems with t activates this
8144 behavior, and invoking it with any other value deactivates it.
8145
8146 ** Change in system-type and system-configuration values.
8147
8148 The value of system-type on a Linux-based GNU system is now `lignux',
8149 not `linux'. This means that some programs which use `system-type'
8150 need to be changed. The value of `system-configuration' will also
8151 be different.
8152
8153 It is generally recommended to use `system-configuration' rather
8154 than `system-type'.
8155
8156 See the file LINUX-GNU in this directory for more about this.
8157
8158 ** The functions shell-command and dired-call-process
8159 now run file name handlers for default-directory, if it has them.
8160
8161 ** Undoing the deletion of text now restores the positions of markers
8162 that pointed into or next to the deleted text.
8163
8164 ** Timers created with run-at-time now work internally to Emacs, and
8165 no longer use a separate process. Therefore, they now work more
8166 reliably and can be used for shorter time delays.
8167
8168 The new function run-with-timer is a convenient way to set up a timer
8169 to run a specified amount of time after the present. A call looks
8170 like this:
8171
8172 (run-with-timer SECS REPEAT FUNCTION ARGS...)
8173
8174 SECS says how many seconds should elapse before the timer happens.
8175 It may be an integer or a floating point number. When the timer
8176 becomes ripe, the action is to call FUNCTION with arguments ARGS.
8177
8178 REPEAT gives the interval for repeating the timer (measured in
8179 seconds). It may be an integer or a floating point number. nil or 0
8180 means don't repeat at all--call FUNCTION just once.
8181
8182 *** with-timeout provides an easy way to do something but give
8183 up if too much time passes.
8184
8185 (with-timeout (SECONDS TIMEOUT-FORMS...) BODY...)
8186
8187 This executes BODY, but gives up after SECONDS seconds.
8188 If it gives up, it runs the TIMEOUT-FORMS and returns the value
8189 of the last one of them. Normally it returns the value of the last
8190 form in BODY.
8191
8192 *** You can now arrange to call a function whenever Emacs is idle for
8193 a certain length of time. To do this, call run-with-idle-timer. A
8194 call looks like this:
8195
8196 (run-with-idle-timer SECS REPEAT FUNCTION ARGS...)
8197
8198 SECS says how many seconds of idleness should elapse before the timer
8199 runs. It may be an integer or a floating point number. When the
8200 timer becomes ripe, the action is to call FUNCTION with arguments
8201 ARGS.
8202
8203 Emacs becomes idle whenever it finishes executing a keyboard or mouse
8204 command. It remains idle until it receives another keyboard or mouse
8205 command.
8206
8207 REPEAT, if non-nil, means this timer should be activated again each
8208 time Emacs becomes idle and remains idle for SECS seconds The timer
8209 does not repeat if Emacs *remains* idle; it runs at most once after
8210 each time Emacs becomes idle.
8211
8212 If REPEAT is nil, the timer runs just once, the first time Emacs is
8213 idle for SECS seconds.
8214
8215 *** post-command-idle-hook is now obsolete; you shouldn't use it at
8216 all, because it interferes with the idle timer mechanism. If your
8217 programs use post-command-idle-hook, convert them to use idle timers
8218 instead.
8219
8220 *** y-or-n-p-with-timeout lets you ask a question but give up if
8221 there is no answer within a certain time.
8222
8223 (y-or-n-p-with-timeout PROMPT SECONDS DEFAULT-VALUE)
8224
8225 asks the question PROMPT (just like y-or-n-p). If the user answers
8226 within SECONDS seconds, it returns the answer that the user gave.
8227 Otherwise it gives up after SECONDS seconds, and returns DEFAULT-VALUE.
8228
8229 ** Minor change to `encode-time': you can now pass more than seven
8230 arguments. If you do that, the first six arguments have the usual
8231 meaning, the last argument is interpreted as the time zone, and the
8232 arguments in between are ignored.
8233
8234 This means that it works to use the list returned by `decode-time' as
8235 the list of arguments for `encode-time'.
8236
8237 ** The default value of load-path now includes the directory
8238 /usr/local/share/emacs/VERSION/site-lisp In addition to
8239 /usr/local/share/emacs/site-lisp. You can use this new directory for
8240 site-specific Lisp packages that belong with a particular Emacs
8241 version.
8242
8243 It is not unusual for a Lisp package that works well in one Emacs
8244 version to cause trouble in another. Sometimes packages need updating
8245 for incompatible changes; sometimes they look at internal data that
8246 has changed; sometimes the package has been installed in Emacs itself
8247 and the installed version should be used. Whatever the reason for the
8248 problem, this new feature makes it easier to solve.
8249
8250 ** When your program contains a fixed file name (like .completions or
8251 .abbrev.defs), the file name usually needs to be different on operating
8252 systems with limited file name syntax.
8253
8254 Now you can avoid ad-hoc conditionals by using the function
8255 convert-standard-filename to convert the file name to a proper form
8256 for each operating system. Here is an example of use, from the file
8257 completions.el:
8258
8259 (defvar save-completions-file-name
8260 (convert-standard-filename "~/.completions")
8261 "*The filename to save completions to.")
8262
8263 This sets the variable save-completions-file-name to a value that
8264 depends on the operating system, because the definition of
8265 convert-standard-filename depends on the operating system. On
8266 Unix-like systems, it returns the specified file name unchanged. On
8267 MS-DOS, it adapts the name to fit the limitations of that system.
8268
8269 ** The interactive spec N now returns the numeric prefix argument
8270 rather than the raw prefix argument. (It still reads a number using the
8271 minibuffer if there is no prefix argument at all.)
8272
8273 ** When a process is deleted, this no longer disconnects the process
8274 marker from its buffer position.
8275
8276 ** The variable garbage-collection-messages now controls whether
8277 Emacs displays a message at the beginning and end of garbage collection.
8278 The default is nil, meaning there are no messages.
8279
8280 ** The variable debug-ignored-errors specifies certain kinds of errors
8281 that should not enter the debugger. Its value is a list of error
8282 condition symbols and/or regular expressions. If the error has any
8283 of the condition symbols listed, or if any of the regular expressions
8284 matches the error message, then that error does not enter the debugger,
8285 regardless of the value of debug-on-error.
8286
8287 This variable is initialized to match certain common but uninteresting
8288 errors that happen often during editing.
8289
8290 ** The new function error-message-string converts an error datum
8291 into its error message. The error datum is what condition-case
8292 puts into the variable, to describe the error that happened.
8293
8294 ** Anything that changes which buffer appears in a given window
8295 now runs the window-scroll-functions for that window.
8296
8297 ** The new function get-buffer-window-list returns a list of windows displaying
8298 a buffer. The function is called with the buffer (a buffer object or a buffer
8299 name) and two optional arguments specifying the minibuffer windows and frames
8300 to search. Therefore this function takes optional args like next-window etc.,
8301 and not get-buffer-window.
8302
8303 ** buffer-substring now runs the hook buffer-access-fontify-functions,
8304 calling each function with two arguments--the range of the buffer
8305 being accessed. buffer-substring-no-properties does not call them.
8306
8307 If you use this feature, you should set the variable
8308 buffer-access-fontified-property to a non-nil symbol, which is a
8309 property name. Then, if all the characters in the buffer range have a
8310 non-nil value for that property, the buffer-access-fontify-functions
8311 are not called. When called, these functions should put a non-nil
8312 property on the text that they fontify, so that they won't get called
8313 over and over for the same text.
8314
8315 ** Changes in lisp-mnt.el
8316
8317 *** The lisp-mnt package can now recognize file headers that are written
8318 in the formats used by the `what' command and the RCS `ident' command:
8319
8320 ;; @(#) HEADER: text
8321 ;; $HEADER: text $
8322
8323 in addition to the normal
8324
8325 ;; HEADER: text
8326
8327 *** The commands lm-verify and lm-synopsis are now interactive. lm-verify
8328 checks that the library file has proper sections and headers, and
8329 lm-synopsis extracts first line "synopsis'"information.
8330 \f
8331 * For older news, see the file ONEWS.
8332
8333 ----------------------------------------------------------------------
8334 Copyright information:
8335
8336 Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
8337
8338 Permission is granted to anyone to make or distribute verbatim copies
8339 of this document as received, in any medium, provided that the
8340 copyright notice and this permission notice are preserved,
8341 thus giving the recipient permission to redistribute in turn.
8342
8343 Permission is granted to distribute modified versions
8344 of this document, or of portions of it,
8345 under the above conditions, provided also that they
8346 carry prominent notices stating who last changed them.
8347 \f
8348 Local variables:
8349 mode: outline
8350 paragraph-separate: "[ \f]*$"
8351 end: