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1GNU Emacs NEWS -- history of user-visible changes. 23 Jan 1999
2Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
3See the end for copying conditions.
4
5Please send Emacs bug reports to bug-gnu-emacs@gnu.org.
6For older news, see the file ONEWS.
7
8\f
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9* Installation Changes in Emacs 21.1
10
11** `movemail' defaults to supporting POP. You can turn this off using
12the --without-pop configure option, should that be necessary.
13\f
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14* Changes in Emacs 21.1
15
16** Faces and frame parameters.
17
18There are four new faces `scroll-bar', `border', `cursor' and `mouse'.
19Setting the frame parameters `scroll-bar-foreground' and
20`scroll-bar-background' sets foreground and background color of face
21`scroll-bar' and vice versa. Setting frame parameter `border-color'
22sets the background color of face `border' and vice versa. Likewise
23for frame parameters `cursor-color' and face `cursor', and frame
24parameter `mouse-color' and face `mouse'.
25
26Changing frame parameter `font' sets font-related attributes of the
27`default' face and vice versa. Setting frame parameters
28`foreground-color' or `background-color' sets the colors of the
29`default' face and vice versa.
30
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31** New face `menu'.
32
33The face `menu' can be used to change colors and font of Emacs' menus.
34Setting the font of LessTif/Motif menus is currently not supported;
35attempts to set the font are ignored in this case.
36
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37** New frame parameter `screen-gamma' for gamma correction.
38
39The new frame parameter `screen-gamma' specifies gamma-correction for
40colors. Its value may be nil, the default, in which case no gamma
41correction occurs, or a number > 0, usually a float, that specifies
42the screen gamma of a frame's display.
43
44PC monitors usually have a screen gamma of 2.2. smaller values result
45in darker colors. You might want to try a screen gamma of 1.5 for LCD
46color displays. The viewing gamma Emacs uses is 0.4545. (1/2.2).
47
48The X resource name of this parameter is `screenGamma', class
49`ScreenGamma'.
50
51** Emacs has a new redisplay engine.
52
53The new redisplay handles characters of variable width and height.
54Italic text can be used without redisplay problems. Fonts containing
55oversized characters, i.e. characters larger than the logical height
56of a font can be used. Images of various formats can be displayed in
57the text.
58
59** Emacs has a new face implementation.
60
61The new faces no longer fundamentally use X font names to specify the
62font. Instead, each face has several independent attributes--family,
63height, width, weight and slant--that it may or may not specify.
64These attributes can be merged from various faces, and then together
65specify a font.
66
67Faces are supported on terminals that can display color or fonts.
68These terminal capabilities are auto-detected. Details can be found
69under Lisp changes, below.
70
71** New default font is Courier 12pt.
72
73** When using a windowing terminal, Emacs window now has a cursor of
74its own. When the window is selected, the cursor is solid; otherwise,
75it is hollow.
76
77** Bitmap areas to the left and right of windows are used to display
78truncation marks, continuation marks, overlay arrows and alike. The
79foreground, background, and stipple of these areas can be changed by
80customizing face `fringe'.
81
82** The mode line under X is now drawn with shadows by default. You
83can change its appearance by modifying the face `modeline'.
84
85** LessTif support.
86
87Emacs now runs with LessTif (see <http://www.lesstif.org>). You will
88need a version 0.88.1 or later.
89
90** Toolkit scroll bars.
91
92Emacs now uses toolkit scrollbars if available. When configured for
93LessTif/Motif, it will use that toolkit's scrollbar. Otherwise, when
94configured for Lucid and Athena widgets, it will use the Xaw3d scroll
95bar if Xaw3d is available. You can turn off the use of toolkit scroll
96bars by specifying `--with-toolkit-scroll-bars=no' when configuring
97Emacs.
98
99When you encounter problems with the Xaw3d scroll bar, watch out how
100Xaw3d is compiled on your system. If the Makefile generated from
101Xaw3d's Imakefile contains a `-DNARROWPROTO' compiler option, and your
102Emacs system configuration file `s/your-system.h' does not contain a
103define for NARROWPROTO, you might consider adding it. Take
104`s/freebsd.h' as an example.
105
106Alternatively, if you don't have access to the Xaw3d source code, take
107a look at your system's imake configuration file, for example in the
108directory `/usr/X11R6/lib/X11/config' (paths are different on
109different systems). You will find files `*.cf' there. If your
110system's cf-file contains a line like `#define NeedWidePrototypes NO',
111add a `#define NARROWPROTO' to your Emacs system configuration file.
112
113The reason for this is that one Xaw3d function uses `double' or
114`float' function parameters depending on the setting of NARROWPROTO.
115This is not a problem when Imakefiles are used because each system's
116image configuration file contains the necessary information. Since
117Emacs doesn't use imake, this has do be done manually.
118
119** Toggle buttons and radio buttons in menus.
120
121When compiled with LessTif (or Motif) support, Emacs uses toolkit
122widgets for radio and toggle buttons in menus. When configured for
123Lucid, Emacs draws radio buttons and toggle buttons similar to Motif.
124
125** Highlighting of trailing whitespace.
126
127When `show-trailing-whitespace' is non-nil, Emacs displays trailing
128whitespace in the face `trailing-whitespace'. Trailing whitespace is
129defined as spaces or tabs at the end of a line. To avoid busy
130highlighting when entering new text, trailing whitespace is not
131displayed if point is at the end of the line containing the
132whitespace.
133
134** Busy-cursor.
135
136Emacs can optionally display a busy-cursor under X. You can turn the
137display on or off by customizing group `cursor'.
138
139** Blinking cursor
140
141M-x blink-cursor-mode toggles a blinking cursor under X and on
142terminals having terminal capabilities `vi', `vs', and `ve'. Blinking
143and related parameters like frequency and delay can be customized in
144the group `cursor'.
145
146** New font-lock support mode `jit-lock-mode'.
147
148This support mode is roughly equivalent to `lazy-lock' but is
149generally faster. It supports stealth and deferred fontification.
150See the documentation of the function `jit-lock-mode' for more
151details.
152
153Font-lock uses jit-lock-mode as default support mode, so you don't
154have to do anything to activate it.
155
156** Tabs and variable-width text.
157
158Tabs are now displayed with stretch properties; the width of a tab is
159defined as a multiple of the normal character width of a frame, and is
160independent of the fonts used in the text where the tab appears.
161Thus, tabs can be used to line up text in different fonts.
162
163** Enhancements of the Lucid menu bar
164
165*** The Lucid menu bar now supports the resource "margin".
166
167 emacs.pane.menubar.margin: 5
168
169The default margin is 4 which makes the menu bar appear like the Motif
170one.
171
172*** Arrows that indicate sub-menus are now drawn with shadows, like in
173Motif.
174
175** Hscrolling in C code.
176
177Horizontal scrolling now happens automatically.
178
179** Tool bar support.
180
181Emacs supports a tool bar at the top of a frame under X. For details
182how to define a tool bar, see the page describing Lisp-level changes.
183
184** Mouse-sensitive mode line.
185
186Different parts of the mode line under X have been made
187mouse-sensitive. Moving the mouse to a mouse-sensitive part in the mode
188line changes the appearance of the mouse pointer to an arrow, and help
189about available mouse actions is displayed either in the echo area, or
190in the tooltip window if you have enabled one.
191
192Currently, the following actions have been defined:
193
194- Mouse-1 on the buffer name in the mode line switches between two
195buffers.
196
197- Mouse-2 on the buffer-name switches to the next buffer, and
198M-mouse-2 switches to the previous buffer in the buffer list.
199
200- Mouse-3 on the buffer-name displays a buffer menu.
201
202- Mouse-1 on the read-only status in the mode line (`%' or `*')
203toggles the read-only status.
204
205- Mouse-3 on the mode name display a minor-mode menu.
206
207** LessTif/Motif file selection dialog.
208
209When Emacs is configured to use LessTif or Motif, reading a file name
210from a menu will pop up a file selection dialog if `use-dialogs' is
211non-nil.
212
213** Emacs can display faces on TTY frames.
214
215Emacs automatically detects terminals that are able to display colors.
216Faces with a weight greater than normal are displayed extra-bright, if
217the terminal supports it. Faces with a weight less than normal and
218italic faces are displayed dimmed, if the terminal supports it.
219Underlined faces are displayed underlined if possible. Other face
220attributes like overlines, strike-throught, box are ignored.
221
222** Sound support
223
224Emacs supports playing sound files on GNU/Linux and the free BSDs
225(Voxware driver and native BSD driver, aka as Luigi's driver).
226Currently supported file formats are RIFF-WAVE (*.wav) and Sun Audio
227(*.au). You must configure Emacs with the option `--with-sound=yes'
228to enable sound support.
229
230** A new variable, backup-by-copying-when-privileged-mismatch, gives
231the highest file uid for which backup-by-copying-when-mismatch will be
232forced on. The assumption is that uids less than or equal to this
233value are special uids (root, bin, daemon, etc.--not real system
234users) and that files owned by these users should not change ownership,
235even if your system policy allows users other than root to edit them.
236
237The default is 200; set the variable to nil to disable the feature.
238
239** A block cursor can be drawn as wide as the glyph under it under X.
240
241As an example: if a block cursor is over a tab character, it will be
242drawn as wide as that tab on the display. To do this, set
243`x-stretch-cursor' to a non-nil value.
244
245** Empty display lines at the end of a buffer may be marked with a
246bitmap (this is similar to the tilde displayed by vi).
247
248This behavior is activated by setting the buffer-local variable
249`indicate-empty-lines' to a non-nil value. The default value of this
250variable is found in `default-indicate-empty-lines'.
251
252** There is a new "aggressive" scrolling method.
253
254When scrolling up because point is above the window start, if the
255value of the buffer-local variable `scroll-up-aggessively' is a
256number, Emacs chooses a new window start so that point ends up that
257fraction of the window's height from the bottom of the window.
258
259When scrolling down because point is below the window end, if the
260value of the buffer-local variable `scroll-down-aggessively' is a
261number, Emacs chooses a new window start so that point ends up that
262fraction of the window's height from the top of the window.
263
264** The rectangle commands now avoid inserting undesirable spaces,
265notably at the end of lines.
266
267All these functions have been rewritten to avoid inserting unwanted
268spaces, and an optional prefix now allows them to behave the old way.
269
270** The new command M-x query-replace-regexp-eval acts like
271query-replace-regexp, but takes a Lisp expression which is evaluated
272after each match to get the replacement text.
273
274** Emacs now resizes mini-windows if appropriate.
275
276If a message is longer than one line, or mini-buffer contents are
277longer than one line, Emacs now resizes the mini-window unless it is
278on a frame of its own. You can control the maximum mini-window size
279by setting the following variable:
280
281- User option: max-mini-window-height
282
283Maximum height for resizing mini-windows. If a float, it specifies a
284fraction of the mini-window frame's height. If an integer, it
285specifies a number of lines. If nil, don't resize.
286
287Default is 0.25.
288
289** Changes to RefTeX mode
290
291*** RefTeX has new support for index generation. Index entries can be
292 created with `C-c <', with completion available on index keys.
293 Pressing `C-c /' indexes the word at the cursor with a default
294 macro. `C-c >' compiles all index entries into an alphabetically
295 sorted *Index* buffer which looks like the final index. Entries
296 can be edited from that buffer.
297
298*** Label and citation key selection now allow to select several
299 items and reference them together (use `m' to mark items, `a' or
300 `A' to use all marked entries).
301
302*** reftex.el has been split into a number of smaller files to reduce
303 memory use when only a part of RefTeX is being used.
304
305*** a new command `reftex-view-crossref-from-bibtex' (bound to `C-c &'
306 in BibTeX-mode) can be called in a BibTeX database buffer in order
307 to show locations in LaTeX documents where a particular entry has
308 been cited.
309
310** The M-x time-stamp command (most commonly used on write-file-hooks)
311has the following new features:
312
313*** The patterns for finding the time stamp and for updating a pattern
314may match text spanning multiple lines. For example, some people like
315to have the filename and date on separate lines. The new variable
316time-stamp-inserts-lines controls the matching for multi-line patterns.
317
318*** More than one time stamp can be updated in the same file. This
319feature is useful if you need separate time stamps in a program source
320file to both include in formatted documentation and insert in the
321compiled binary. The same time-stamp will be written at each matching
322pattern. The variable time-stamp-count enables this new feature; it
323defaults to 1.
324
325** Tooltips.
326
327Tooltips are small X windows displaying a help string at the current
328mouse position. To use them, use the Lisp package `tooltip' which you
329can access via the user option `tooltip-mode'.
330
331Tooltips also provides support for GUD debugging. If activated,
332variable values can be displayed in tooltips by pointing at them with
333the mouse in source buffers. You can customize various aspects of the
334tooltip display in the group `tooltip'.
335
336** Customize changes
337
338*** Customize now supports comments about customized items. Use the
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339`State' menu to add comments. Note that customization comments will
340cause the customizations to fail in earlier versions of Emacs.
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341
342*** The new option `custom-buffer-done-function' says whether to kill
343Custom buffers when you've done with them or just bury them (the
344default).
345
346** New features in evaluation commands
347
348The commands to evaluate Lisp expressions, such as C-M-x in Lisp
349modes, C-j in Lisp Interaction mode, and M-:, now bind the variables
350print-level, print-length, and debug-on-error based on the
351customizable variables eval-expression-print-level,
352eval-expression-print-length, and eval-expression-debug-on-error.
353
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354** Dired changes
355
356*** New variable `dired-recursive-deletes' determines if the delete
357command will delete non-empty directories recursively. The default
358is, delete only empty directories.
359
360*** New variable `dired-recursive-copies' determines if the copy
361command will copy directories recursively. The default is, do not
362copy directories recursively.
363
364** The variable mail-specify-envelope-from controls whether to
365use the -f option when sending mail.
366
367** In Isearch mode, mouse-2 in the echo area now yanks the current
368selection into the search string rather than giving an error.
369
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370** Ange-ftp allows you to specify of a port number in remote file
371names cleanly. It is appended to the host name, separated by a hash
372sign, e.g. `/foo@bar.org#666:mumble'. (This syntax comes from EFS.)
373
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374** Shell script mode changes.
375
376Shell script mode (sh-script) can now indent scripts for shells
377derived from sh and rc. The indentation style is customizeable, and
378sh-script can attempt to "learn" the current buffer's style.
379
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380** Emacs now attempts to determine the initial language environment
381and preferred and locale coding systems systematically from the
382LC_ALL, LC_CTYPE, and LANG environment variables during startup.
383
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384** New language environments `Latin-8' and `Latin-9'.
385These correspond respectively to the ISO character sets 8859-14
386(Celtic) and 8859-15 (updated Latin-1, with the Euro sign). There is
387currently no specific input method support for them.
388
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389** New modes and packages
390
391*** 5x5.el is a simple puzzle game.
392
393*** hl-line.el provides a minor mode to highlight the current line.
394
395*** ansi-color.el translates ANSI terminal escapes into text-properties.
396
397*** delphi.el provides a major mode for editing the Delphi (Object
398Pascal) language.
399
400*** quickurl.el provides a simple method of inserting a URL based on
401the text at point.
402
403*** sql.el provides an interface to SQL data bases.
404
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405*** fortune.el uses the fortune program to create mail/news signatures.
406
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407*** whitespace.el ???
408
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409*** PostScript mode (ps-mode) is a new major mode for editing PostScript
410files. It offers: interaction with a PostScript interpreter, including
411(very basic) error handling; fontification, easily customizable for
412interpreter messages; auto-indentation; insertion of EPSF templates and
413often used code snippets; viewing of BoundingBox; commenting out /
414uncommenting regions; conversion of 8bit characters to PostScript octal
415codes. All functionality is accessible through a menu.
416
417*** delim-col helps to prettify columns in a text region or rectangle.
418
419Here is an example of columns:
420
421horse apple bus
422dog pineapple car EXTRA
423porcupine strawberry airplane
424
425Doing the following settings:
426
427 (setq delimit-columns-str-before "[ ")
428 (setq delimit-columns-str-after " ]")
429 (setq delimit-columns-str-separator ", ")
430 (setq delimit-columns-separator "\t")
431
432
433Selecting the lines above and typing:
434
435 M-x delimit-columns-region
436
437It results:
438
439[ horse , apple , bus , ]
440[ dog , pineapple , car , EXTRA ]
441[ porcupine, strawberry, airplane, ]
442
443delim-col has the following options:
444
445 delimit-columns-str-before Specify a string to be inserted
446 before all columns.
447
448 delimit-columns-str-separator Specify a string to be inserted
449 between each column.
450
451 delimit-columns-str-after Specify a string to be inserted
452 after all columns.
453
454 delimit-columns-separator Specify a regexp which separates
455 each column.
456
457delim-col has the following commands:
458
459 delimit-columns-region Prettify all columns in a text region.
460 delimit-columns-rectangle Prettify all columns in a text rectangle.
461
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462*** The package recentf.el maintains a menu for visiting files that
463were operated on recently. When enabled, a new "Open Recent" submenu
464is displayed in the "Files" menu.
465
466The recent files list is automatically saved across Emacs sessions.
467
468To enable/disable recentf use M-x recentf-mode.
469
470To enable recentf at Emacs startup use
471M-x customize-variable RET recentf-mode RET.
472
473To change the number of recent files displayed and others options use
474M-x customize-group RET recentf RET.
475
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476*** elide-head.el provides a mechanism for eliding boilerplate header
477text.
478
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479** Withdrawn packages
480
481*** mldrag.el has been removed. mouse.el provides the same
482functionality with aliases for the mldrag functions.
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483
484*** eval-reg.el has been obsoleted by changes to edebug.el.
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485
486** Not new, but not mentioned before:
487M-w when Transient Mark mode is enabled disables the mark.
488
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489\f
490* Lisp changes in Emacs 21.1 (see following page for display-related features)
491
492Note that +++ before an item means the Lisp manual has been updated.
493--- means that I have decided it does not need to be in the Lisp manual.
494When you add a new item, please add it without either +++ or ---
495so I will know I still need to look at it -- rms.
496
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497** New functions and variables for locales.
498
499The new variable `locale-coding-system' specifies how to encode and
500decode strings passed to low-level message functions like strerror and
501time functions like strftime. The new variables `messages-locale' and
502`time-locale' give the system locales to be used during the next
503invocations of these two types of functions; the new variables
504`previous-messages-locale' and `previous-time-locale' give the locales
505most recently used.
506
507The new function `set-locale-environment' sets the language
508environment, preferred coding system, and locale coding system from
509the system locale as specified by the LC_ALL, LC_CTYPE, and LANG
510environment variables. It is normally invoked during startup. It
511uses the new variables `locale-language-names',
512`locale-charset-language-names', and `locale-preferred-coding-systems'
513to make its decisions.
514
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515** syntax tables now understand nested comments.
516To declare a comment syntax as allowing nesting, just add an `n'
517modifier to either of the characters of the comment end and the comment
518start sequences.
519
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520** The function `pixmap-spec-p' has been renamed `bitmap-spec-p'
521because `bitmap' is more in line with the usual X terminology.
522
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523** New function `propertize'
524
525The new function `propertize' can be used to conveniently construct
526strings with text properties.
527
528- Function: propertize STRING &rest PROPERTIES
529
530Value is a copy of STRING with text properties assigned as specified
531by PROPERTIES. PROPERTIES is a sequence of pairs PROPERTY VALUE, with
532PROPERTY being the name of a text property and VALUE being the
533specified value of that property. Example:
534
535 (propertize "foo" 'face 'bold 'read-only t)
536
537+++
538** push and pop macros.
539
540A simple version of the push and pop macros of Common Lisp
541is now defined in Emacs Lisp. These macros allow only symbols
542as the place that holds the list to be changed.
543
544(push NEWELT LISTNAME) add NEWELT to the front of LISTNAME's value.
545(pop LISTNAME) return first elt of LISTNAME, and remove it
546 (thus altering the value of LISTNAME).
547
548+++
549** Regular expressions now support Posix character classes such
550as [:alpha:], [:space:] and so on.
551
552[:digit:] matches 0 through 9
553[:cntrl:] matches ASCII control characters
554[:xdigit:] matches 0 through 9, a through f and A through F.
555[:blank:] matches space and tab only
556[:graph:] matches graphic characters--everything except ASCII control chars,
557 space, and DEL.
558[:print:] matches printing characters--everything except ASCII control chars
559 and DEL.
560[:alnum:] matches letters and digits.
561 (But at present, for multibyte characters,
562 it matches anything that has word syntax.)
563[:alpha:] matches letters.
564 (But at present, for multibyte characters,
565 it matches anything that has word syntax.)
566[:ascii:] matches ASCII (unibyte) characters.
567[:nonascii:] matches non-ASCII (multibyte) characters.
568[:lower:] matches anything lower-case.
569[:punct:] matches punctuation.
570 (But at present, for multibyte characters,
571 it matches anything that has non-word syntax.)
572[:space:] matches anything that has whitespace syntax.
573[:upper:] matches anything upper-case.
574[:word:] matches anything that has word syntax.
575
576+++
577** Emacs now has built-in hash tables.
578
579The following functions are defined for hash tables:
580
581- Function: make-hash-table ARGS
582
583The argument list ARGS consists of keyword/argument pairs. All arguments
584are optional. The following arguments are defined:
585
586:test TEST
587
588TEST must be a symbol specifying how to compare keys. Default is `eql'.
589Predefined are `eq', `eql' and `equal'. If TEST is not predefined,
590it must have been defined with `define-hash-table-test'.
591
592:size SIZE
593
594SIZE must be an integer > 0 giving a hint to the implementation how
595many elements will be put in the hash table. Default size is 65.
596
597:rehash-size REHASH-SIZE
598
599REHASH-SIZE specifies by how much to grow a hash table once it becomes
600full. If REHASH-SIZE is an integer, add that to the hash table's old
601size to get the new size. Otherwise, REHASH-SIZE must be a float >
6021.0, and the new size is computed by multiplying REHASH-SIZE with the
603old size. Default rehash size is 1.5.
604
605:rehash-threshold THRESHOLD
606
607THRESHOLD must be a float > 0 and <= 1.0 specifying when to resize the
608hash table. It is resized when the ratio of (number of entries) /
609(size of hash table) is >= THRESHOLD. Default threshold is 0.8.
610
611:weakness WEAK
612
613WEAK must be either nil, one of the symbols `key, `value', or t.
614Entries are removed from weak tables during garbage collection if
615their key and/or value are not referenced elsewhere outside of the
616hash table. Default are non-weak hash tables.
617
618- Function: makehash &optional TEST
619
620Similar to make-hash-table, but only TEST can be specified.
621
622- Function: hash-table-p TABLE
623
624Returns non-nil if TABLE is a hash table object.
625
626- Function: copy-hash-table TABLE
627
628Returns a copy of TABLE. Only the table itself is copied, keys and
629values are shared.
630
631- Function: hash-table-count TABLE
632
633Returns the number of entries in TABLE.
634
635- Function: hash-table-rehash-size TABLE
636
637Returns the rehash size of TABLE.
638
639- Function: hash-table-rehash-threshold TABLE
640
641Returns the rehash threshold of TABLE.
642
643- Function: hash-table-rehash-size TABLE
644
645Returns the size of TABLE.
646
647- Function: hash-table-rehash-test TABLE
648
649Returns the test TABLE uses to compare keys.
650
651- Function: hash-table-weakness TABLE
652
653Returns the weakness specified for TABLE.
654
655- Function: clrhash TABLE
656
657Clear TABLE.
658
659- Function: gethash KEY TABLE &optional DEFAULT
660
661Look up KEY in TABLE and return its associated VALUE or DEFAULT if
662not found.
663
664- Function: puthash KEY VALUE TABLE
665
666Associate KEY with VALUE in TABLE. If KEY is already associated with
667another value, replace the old value with VALUE.
668
669- Function: remhash KEY TABLE
670
671Remove KEY from TABLE if it is there.
672
673- Function: maphash FUNCTION TABLE
674
675Call FUNCTION for all elements in TABLE. FUNCTION must take two
676arguments KEY and VALUE.
677
678- Function: sxhash OBJ
679
680Return a hash code for Lisp object OBJ.
681
682- Function: define-hash-table-test NAME TEST-FN HASH-FN
683
684Define a new hash table test named NAME. If NAME is specified as
685a test in `make-hash-table', the table created will use TEST-FN for
686comparing keys, and HASH-FN to compute hash codes for keys. Test
687and hash function are stored as symbol property `hash-table-test'
688of NAME with a value of (TEST-FN HASH-FN).
689
690TEST-FN must take two arguments and return non-nil if they are the same.
691
692HASH-FN must take one argument and return an integer that is the hash
693code of the argument. The function should use the whole range of
694integer values for hash code computation, including negative integers.
695
696Example: The following creates a hash table whose keys are supposed to
697be strings that are compared case-insensitively.
698
699 (defun case-fold-string= (a b)
700 (compare-strings a nil nil b nil nil t))
701
702 (defun case-fold-string-hash (a)
703 (sxhash (upcase a)))
704
705 (define-hash-table-test 'case-fold 'case-fold-string=
706 'case-fold-string-hash))
707
708 (make-hash-table :test 'case-fold)
709
710+++
711** The Lisp reader handles circular structure.
712
713It now works to use the #N= and #N# constructs to represent
714circular structures. For example, #1=(a . #1#) represents
715a cons cell which is its own cdr.
716
717+++
718** The Lisp printer handles circular structure.
719
720If you bind print-circle to a non-nil value, the Lisp printer outputs
721#N= and #N# constructs to represent circular and shared structure.
722
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723+++
724** If the second argument to `move-to-column' is anything but nil or
725t, that means replace a tab with spaces if necessary to reach the
726specified column, but do not add spaces at the end of the line if it
727is too short to reach that column.
728
729+++
730** perform-replace has a new feature: the REPLACEMENTS argument may
731now be a cons cell (FUNCTION . DATA). This means to call FUNCTION
732after each match to get the replacement text. FUNCTION is called with
733two arguments: DATA, and the number of replacements already made.
734
735If the FROM-STRING contains any upper-case letters,
736perform-replace also turns off `case-fold-search' temporarily
737and inserts the replacement text without altering case in it.
738
739+++
740** The function buffer-size now accepts an optional argument
741to specify which buffer to return the size of.
742
743+++
744** The calendar motion commands now run the normal hook
745calendar-move-hook after moving point.
746
747+++
748** The new variable small-temporary-file-directory specifies a
749directory to use for creating temporary files that are likely to be
750small. (Certain Emacs features use this directory.) If
751small-temporary-file-directory is nil, they use
752temporary-file-directory instead.
753
754+++
755** The variable `inhibit-modification-hooks', if non-nil, inhibits all
756the hooks that track changes in the buffer. This affects
757`before-change-functions' and `after-change-functions', as well as
758hooks attached to text properties and overlay properties.
759
760+++
761** assoc-delete-all is a new function that deletes all the
762elements of an alist which have a particular value as the car.
763
764+++
765** make-temp-file provides a more reliable way to create a temporary file.
766
767make-temp-file is used like make-temp-name, except that it actually
768creates the file before it returns. This prevents a timing error,
769ensuring that no other job can use the same name for a temporary file.
770
771+++
772** New exclusive-open feature in `write-region'
773
774The optional seventh arg is now called MUSTBENEW. If non-nil, it insists
775on a check for an existing file with the same name. If MUSTBENEW
776is `excl', that means to get an error if the file already exists;
777never overwrite. If MUSTBENEW is neither nil nor `excl', that means
778ask for confirmation before overwriting, but do go ahead and
779overwrite the file if the user gives confirmation.
780
781If the MUSTBENEW argument in `write-region' is `excl',
782that means to use a special feature in the `open' system call
783to get an error if the file exists at that time.
784The error reported is `file-already-exists'.
785
786+++
787** Function `format' now handles text properties.
788
789Text properties of the format string are applied to the result string.
790If the result string is longer than the format string, text properties
791ending at the end of the format string are extended to the end of the
792result string.
793
794Text properties from string arguments are applied to the result
795string where arguments appear in the result string.
796
797Example:
798
799 (let ((s1 "hello, %s")
800 (s2 "world"))
801 (put-text-property 0 (length s1) 'face 'bold s1)
802 (put-text-property 0 (length s2) 'face 'italic s2)
b246b1f6 803 (format s1 s2))
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804
805results in a bold-face string with an italic `world' at the end.
806
807+++
808** Messages can now be displayed with text properties.
809
810Text properties are handled as described above for function `format'.
811The following example displays a bold-face message with an italic
812argument in it.
813
814 (let ((msg "hello, %s!")
815 (arg "world"))
816 (put-text-property 0 (length msg) 'face 'bold msg)
817 (put-text-property 0 (length arg) 'face 'italic arg)
818 (message msg arg))
819
820+++
821** Sound support
822
823Emacs supports playing sound files on GNU/Linux and the free BSDs
824(Voxware driver and native BSD driver, aka as Luigi's driver).
825
826Currently supported file formats are RIFF-WAVE (*.wav) and Sun Audio
827(*.au). You must configure Emacs with the option `--with-sound=yes'
828to enable sound support.
829
830Sound files can be played by calling (play-sound SOUND). SOUND is a
831list of the form `(sound PROPERTY...)'. The function is only defined
832when sound support is present for the system on which Emacs runs. The
833functions runs `play-sound-functions' with one argument which is the
834sound to play, before playing the sound.
835
836The following sound properties are supported:
837
838- `:file FILE'
839
840FILE is a file name. If FILE isn't an absolute name, it will be
841searched relative to `data-directory'.
842
843- `:volume VOLUME'
844
845VOLUME must be an integer in the range 0..100 or a float in the range
8460..1. This property is optional.
847
848Other properties are ignored.
849
850** `multimedia' is a new Finder keyword and Custom group.
851\f
852* New Lisp-level Display features in Emacs 21.1
853
854Note that +++ before an item means the Lisp manual has been updated.
855--- means that I have decided it does not need to be in the Lisp manual.
856When you add a new item, please add it without either +++ or ---
857so I will know I still need to look at it -- rms.
858
859** New face implementation.
860
861Emacs faces have been reimplemented from scratch. They don't use XLFD
862font names anymore and face merging now works as expected.
863
864+++
865*** New faces.
866
867Each face can specify the following display attributes:
868
869 1. Font family or fontset alias name.
870
871 2. Relative proportionate width, aka character set width or set
872 width (swidth), e.g. `semi-compressed'.
873
874 3. Font height in 1/10pt
875
876 4. Font weight, e.g. `bold'.
877
878 5. Font slant, e.g. `italic'.
879
880 6. Foreground color.
881
882 7. Background color.
883
884 8. Whether or not characters should be underlined, and in what color.
885
886 9. Whether or not characters should be displayed in inverse video.
887
888 10. A background stipple, a bitmap.
889
890 11. Whether or not characters should be overlined, and in what color.
891
892 12. Whether or not characters should be strike-through, and in what
893 color.
894
895 13. Whether or not a box should be drawn around characters, its
896 color, the width of the box lines, and 3D appearance.
897
898Faces are frame-local by nature because Emacs allows to define the
899same named face (face names are symbols) differently for different
900frames. Each frame has an alist of face definitions for all named
901faces. The value of a named face in such an alist is a Lisp vector
902with the symbol `face' in slot 0, and a slot for each each of the face
903attributes mentioned above.
904
905There is also a global face alist `face-new-frame-defaults'. Face
906definitions from this list are used to initialize faces of newly
907created frames.
908
909A face doesn't have to specify all attributes. Those not specified
910have a nil value. Faces specifying all attributes are called
911`fully-specified'.
912
913+++
914*** Face merging.
915
916The display style of a given character in the text is determined by
917combining several faces. This process is called `face merging'. Any
918aspect of the display style that isn't specified by overlays or text
919properties is taken from the `default' face. Since it is made sure
920that the default face is always fully-specified, face merging always
921results in a fully-specified face.
922
923+++
924*** Face realization.
925
926After all face attributes for a character have been determined by
927merging faces of that character, that face is `realized'. The
928realization process maps face attributes to what is physically
929available on the system where Emacs runs. The result is a `realized
930face' in form of an internal structure which is stored in the face
931cache of the frame on which it was realized.
932
933Face realization is done in the context of the charset of the
934character to display because different fonts and encodings are used
935for different charsets. In other words, for characters of different
936charsets, different realized faces are needed to display them.
937
938Except for composite characters, faces are always realized for a
939specific character set and contain a specific font, even if the face
940being realized specifies a fontset. The reason is that the result of
941the new font selection stage is better than what can be done with
942statically defined font name patterns in fontsets.
943
944In unibyte text, Emacs' charsets aren't applicable; function
945`char-charset' reports ASCII for all characters, including those >
9460x7f. The X registry and encoding of fonts to use is determined from
947the variable `face-default-registry' in this case. The variable is
948initialized at Emacs startup time from the font the user specified for
949Emacs.
950
951Currently all unibyte text, i.e. all buffers with
952`enable-multibyte-characters' nil are displayed with fonts of the same
953registry and encoding `face-default-registry'. This is consistent
954with the fact that languages can also be set globally, only.
955
956++++
957**** Clearing face caches.
958
959The Lisp function `clear-face-cache' can be called to clear face caches
960on all frames. If called with a non-nil argument, it will also unload
961unused fonts.
962
963+++
964*** Font selection.
965
966Font selection tries to find the best available matching font for a
967given (charset, face) combination. This is done slightly differently
968for faces specifying a fontset, or a font family name.
969
970If the face specifies a fontset name, that fontset determines a
971pattern for fonts of the given charset. If the face specifies a font
972family, a font pattern is constructed. Charset symbols have a
973property `x-charset-registry' for that purpose that maps a charset to
974an XLFD registry and encoding in the font pattern constructed.
975
976Available fonts on the system on which Emacs runs are then matched
977against the font pattern. The result of font selection is the best
978match for the given face attributes in this font list.
979
980Font selection can be influenced by the user.
981
982The user can specify the relative importance he gives the face
983attributes width, height, weight, and slant by setting
984face-font-selection-order (faces.el) to a list of face attribute
985names. The default is (:width :height :weight :slant), and means
986that font selection first tries to find a good match for the font
987width specified by a face, then---within fonts with that width---tries
988to find a best match for the specified font height, etc.
989
990Setting `face-alternative-font-family-alist' allows the user to
991specify alternative font families to try if a family specified by a
992face doesn't exist.
993
994+++
995**** Scalable fonts
996
997Emacs can make use of scalable fonts but doesn't do so by default,
998since the use of too many or too big scalable fonts may crash XFree86
999servers.
1000
1001To enable scalable font use, set the variable
b246b1f6 1002`scalable-fonts-allowed'. A value of nil, the default, means never use
a933dad1
DL
1003scalable fonts. A value of t means any scalable font may be used.
1004Otherwise, the value must be a list of regular expressions. A
1005scalable font may then be used if it matches a regular expression from
1006that list. Example:
1007
1008 (setq scalable-fonts-allowed '("muleindian-2$"))
1009
1010allows the use of scalable fonts with registry `muleindian-2'.
1011
1012+++
1013*** Functions and variables related to font selection.
1014
1015- Function: x-family-fonts &optional FAMILY FRAME
1016
1017Return a list of available fonts of family FAMILY on FRAME. If FAMILY
1018is omitted or nil, list all families. Otherwise, FAMILY must be a
1019string, possibly containing wildcards `?' and `*'.
1020
1021If FRAME is omitted or nil, use the selected frame. Each element of
1022the result is a vector [FAMILY WIDTH POINT-SIZE WEIGHT SLANT FIXED-P
1023FULL REGISTRY-AND-ENCODING]. FAMILY is the font family name.
1024POINT-SIZE is the size of the font in 1/10 pt. WIDTH, WEIGHT, and
1025SLANT are symbols describing the width, weight and slant of the font.
1026These symbols are the same as for face attributes. FIXED-P is non-nil
1027if the font is fixed-pitch. FULL is the full name of the font, and
1028REGISTRY-AND-ENCODING is a string giving the registry and encoding of
1029the font. The result list is sorted according to the current setting
1030of the face font sort order.
1031
1032- Function: x-font-family-list
1033
1034Return a list of available font families on FRAME. If FRAME is
1035omitted or nil, use the selected frame. Value is a list of conses
1036(FAMILY . FIXED-P) where FAMILY is a font family, and FIXED-P is
1037non-nil if fonts of that family are fixed-pitch.
1038
1039- Variable: font-list-limit
1040
1041Limit for font matching. If an integer > 0, font matching functions
1042won't load more than that number of fonts when searching for a
1043matching font. The default is currently 100.
1044
1045+++
1046*** Setting face attributes.
1047
1048For the most part, the new face implementation is interface-compatible
1049with the old one. Old face attribute related functions are now
1050implemented in terms of the new functions `set-face-attribute' and
1051`face-attribute'.
1052
1053Face attributes are identified by their names which are keyword
1054symbols. All attributes can be set to `unspecified'.
1055
1056The following attributes are recognized:
1057
1058`:family'
1059
1060VALUE must be a string specifying the font family, e.g. ``courier'',
1061or a fontset alias name. If a font family is specified, wild-cards `*'
1062and `?' are allowed.
1063
1064`:width'
1065
1066VALUE specifies the relative proportionate width of the font to use.
1067It must be one of the symbols `ultra-condensed', `extra-condensed',
1068`condensed', `semi-condensed', `normal', `semi-expanded', `expanded',
1069`extra-expanded', or `ultra-expanded'.
1070
1071`:height'
1072
1073VALUE must be an integer specifying the height of the font to use in
10741/10 pt.
1075
1076`:weight'
1077
1078VALUE specifies the weight of the font to use. It must be one of the
1079symbols `ultra-bold', `extra-bold', `bold', `semi-bold', `normal',
1080`semi-light', `light', `extra-light', `ultra-light'.
1081
1082`:slant'
1083
1084VALUE specifies the slant of the font to use. It must be one of the
1085symbols `italic', `oblique', `normal', `reverse-italic', or
1086`reverse-oblique'.
1087
1088`:foreground', `:background'
1089
1090VALUE must be a color name, a string.
1091
1092`:underline'
1093
1094VALUE specifies whether characters in FACE should be underlined. If
1095VALUE is t, underline with foreground color of the face. If VALUE is
1096a string, underline with that color. If VALUE is nil, explicitly
1097don't underline.
1098
1099`:overline'
1100
1101VALUE specifies whether characters in FACE should be overlined. If
1102VALUE is t, overline with foreground color of the face. If VALUE is a
1103string, overline with that color. If VALUE is nil, explicitly don't
1104overline.
1105
1106`:strike-through'
1107
1108VALUE specifies whether characters in FACE should be drawn with a line
1109striking through them. If VALUE is t, use the foreground color of the
1110face. If VALUE is a string, strike-through with that color. If VALUE
1111is nil, explicitly don't strike through.
1112
1113`:box'
1114
1115VALUE specifies whether characters in FACE should have a box drawn
1116around them. If VALUE is nil, explicitly don't draw boxes. If
1117VALUE is t, draw a box with lines of width 1 in the foreground color
1118of the face. If VALUE is a string, the string must be a color name,
1119and the box is drawn in that color with a line width of 1. Otherwise,
1120VALUE must be a property list of the form `(:line-width WIDTH
1121:color COLOR :style STYLE)'. If a keyword/value pair is missing from
1122the property list, a default value will be used for the value, as
1123specified below. WIDTH specifies the width of the lines to draw; it
1124defaults to 1. COLOR is the name of the color to draw in, default is
1125the foreground color of the face for simple boxes, and the background
1126color of the face for 3D boxes. STYLE specifies whether a 3D box
1127should be draw. If STYLE is `released-button', draw a box looking
1128like a released 3D button. If STYLE is `pressed-button' draw a box
1129that appears like a pressed button. If STYLE is nil, the default if
1130the property list doesn't contain a style specification, draw a 2D
1131box.
1132
1133`:inverse-video'
1134
1135VALUE specifies whether characters in FACE should be displayed in
1136inverse video. VALUE must be one of t or nil.
1137
1138`:stipple'
1139
1140If VALUE is a string, it must be the name of a file of pixmap data.
1141The directories listed in the `x-bitmap-file-path' variable are
1142searched. Alternatively, VALUE may be a list of the form (WIDTH
1143HEIGHT DATA) where WIDTH and HEIGHT are the size in pixels, and DATA
1144is a string containing the raw bits of the bitmap. VALUE nil means
1145explicitly don't use a stipple pattern.
1146
1147For convenience, attributes `:family', `:width', `:height', `:weight',
1148and `:slant' may also be set in one step from an X font name:
1149
1150`:font'
1151
1152Set font-related face attributes from VALUE. VALUE must be a valid
1153XLFD font name. If it is a font name pattern, the first matching font
1154is used--this is for compatibility with the behavior of previous
1155versions of Emacs.
1156
1157For compatibility with Emacs 20, keywords `:bold' and `:italic' can
1158be used to specify that a bold or italic font should be used. VALUE
1159must be t or nil in that case. A value of `unspecified' is not allowed."
1160
1161Please see also the documentation of `set-face-attribute' and
1162`defface'.
1163
1164*** Face attributes and X resources
1165
1166The following X resource names can be used to set face attributes
1167from X resources:
1168
1169 Face attribute X resource class
1170-----------------------------------------------------------------------
1171 :family attributeFamily . Face.AttributeFamily
1172 :width attributeWidth Face.AttributeWidth
1173 :height attributeHeight Face.AttributeHeight
1174 :weight attributeWeight Face.AttributeWeight
1175 :slant attributeSlant Face.AttributeSlant
1176 foreground attributeForeground Face.AttributeForeground
1177 :background attributeBackground . Face.AttributeBackground
1178 :overline attributeOverline Face.AttributeOverline
1179 :strike-through attributeStrikeThrough Face.AttributeStrikeThrough
1180 :box attributeBox Face.AttributeBox
1181 :underline attributeUnderline Face.AttributeUnderline
1182 :inverse-video attributeInverse Face.AttributeInverse
1183 :stipple attributeStipple Face.AttributeStipple
1184 or attributeBackgroundPixmap
1185 Face.AttributeBackgroundPixmap
1186 :font attributeFont Face.AttributeFont
1187 :bold attributeBold Face.AttributeBold
1188 :italic attributeItalic . Face.AttributeItalic
1189 :font attributeFont Face.AttributeFont
1190
1191+++
1192*** Text property `face'.
1193
1194The value of the `face' text property can now be a single face
1195specification or a list of such specifications. Each face
1196specification can be
1197
11981. A symbol or string naming a Lisp face.
1199
12002. A property list of the form (KEYWORD VALUE ...) where each
1201 KEYWORD is a face attribute name, and VALUE is an appropriate value
1202 for that attribute. Please see the doc string of `set-face-attribute'
1203 for face attribute names.
1204
12053. Conses of the form (FOREGROUND-COLOR . COLOR) or
1206 (BACKGROUND-COLOR . COLOR) where COLOR is a color name. This is
1207 for compatibility with previous Emacs versions.
1208
1209+++
1210** Support functions for colors on text-only terminals.
1211
1212The function `face-register-tty-color' can be used to define colors
1213for use on TTY frames. It maps a color name to a color number on the
1214terminal. Emacs defines a couple of default color mappings by
1215default. You can get defined colors with a call to
1216`tty-defined-colors'. The function `face-clear-tty-colors' can be
1217used to clear the mapping table.
1218
1219+++
1220** The minibuffer prompt is now actually inserted in the minibuffer.
a933dad1 1221
463cac2d 1222This makes it possible to scroll through the prompt, if you want to.
a933dad1
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1223
1224The function minubuffer-prompt-end returns the current position of the
1225end of the minibuffer prompt, if the minibuffer is current.
1226Otherwise, it returns zero.
1227
463cac2d
GM
1228** New `field' abstraction in buffers.
1229
1230There is now code to support an abstraction called `fields' in emacs
1231buffers. A field is a contiguous region of text with the same `field'
1232text-property.
1233
1234Certain functions, such as forward-word, forward-sentence,
1235forward-paragraph, beginning-of-line, etc., stop moving when they come
1236to the boundary between fields (beginning-of-line and end-of-line will
1237not let the point move past the field boundary, but other movement
1238commands continue into the next field if repeated).
1239
1240The new function constrain-to-field may be used to achieve similar
1241behavior; other new field functions include field-beginning, field-end,
1242erase-field, and field-string.
1243
1244Now that the minibuffer prompt is inserted into the minibuffer, it is in
1245a separate field from the user-input part of the buffer, so that many
1246editing commands treat the user's text separately from the prompt.
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1247
1248+++
1249** Image support.
1250
1251Emacs can now display images. Images are inserted into text by giving
1252strings or buffer text a `display' text property containing one of
1253(AREA IMAGE) or IMAGE. The display of the `display' property value
1254replaces the display of the characters having that property.
1255
1256If the property value has the form (AREA IMAGE), AREA must be one of
1257`(margin left-margin)', `(margin right-margin)' or `(margin nil)'. If
1258AREA is `(margin nil)', IMAGE will be displayed in the text area of a
1259window, otherwise it will be displayed in the left or right marginal
1260area.
1261
1262IMAGE is an image specification.
1263
1264*** Image specifications
1265
1266Image specifications are lists of the form `(image PROPS)' where PROPS
1267is a property list whose keys are keyword symbols. Each
1268specifications must contain a property `:type TYPE' with TYPE being a
1269symbol specifying the image type, e.g. `xbm'.
1270
1271The following is a list of properties all image types share.
1272
1273`:ascent ASCENT'
1274
1275ASCENT must be a number in the range 0..100, and specifies the percentage
1276of the image's height to use for its ascent. Default is 50.
1277
1278`:margin MARGIN'
1279
1280MARGIN must be a number >= 0 specifying how many pixels to put as
1281margin around the image. Default is 0.
1282
1283`:relief RELIEF'
1284
1285RELIEF is analogous to the `:relief' attribute of faces. Puts a relief
1286around an image.
1287
1288`:algorithm ALGO'
1289
1290Apply an image algorithm to the image before displaying it. ALGO must
1291be a symbol specifying the algorithm. Currently only `laplace' is
1292supported which applies a Laplace edge detection algorithm to an image
1293which is intended to display images "disabled."
1294
1295`:heuristic-mask BG'
1296
1297If BG is not nil, build a clipping mask for the image, so that the
1298background of a frame is visible behind the image. If BG is t,
1299determine the background color of the image by looking at the 4
1300corners of the image, assuming the most frequently occuring color from
1301the corners is the background color of the image. Otherwise, BG must
1302be a list `(RED GREEN BLUE)' specifying the color to assume for the
1303background of the image.
1304
1305`:file FILE'
1306
1307Load image from FILE. If FILE is not absolute after expanding it,
1308search for the image in `data-directory'. Some image types support
1309building images from data. When this is done, no `:file' property
1310may be present in the image specification.
1311
1312
1313*** Supported image types
1314
b246b1f6 1315**** XBM, image type `xbm'.
a933dad1
DL
1316
1317XBM images don't require an external library. Additional image
1318properties supported are
1319
1320`:foreground FG'
1321
1322FG must be a string specifying the image foreground color. Default
1323is the frame's foreground.
1324
1325`:background FG'
1326
1327BG must be a string specifying the image foreground color. Default is
1328the frame's background color.
1329
1330XBM images can be constructed from data instead of file. In this
1331case, the image specification must contain the following properties
1332instead of a `:file' property.
1333
1334`:width WIDTH'
1335
1336WIDTH specifies the width of the image in pixels.
1337
1338`:height HEIGHT'
1339
1340HEIGHT specifies the height of the image in pixels.
1341
1342`:data DATA'
1343
1344DATA must be either
1345
1346 1. a string large enough to hold the bitmap data, i.e. it must
1347 have a size >= (WIDTH + 7) / 8 * HEIGHT
1348
1349 2. a bool-vector of size >= WIDTH * HEIGHT
1350
1351 3. a vector of strings or bool-vectors, one for each line of the
1352 bitmap.
1353
1354**** XPM, image type `xpm'
1355
1356XPM images require the external library `libXpm', package
1357`xpm-3.4k.tar.gz', version 3.4k or later. Make sure the library is
1358found when Emacs is configured by supplying appropriate paths via
1359`--x-includes' and `--x-libraries'.
1360
1361Additional image properties supported are:
1362
1363`:color-symbols SYMBOLS'
1364
1365SYMBOLS must be a list of pairs (NAME . COLOR), with NAME being the
1366name of color as it appears in an XPM file, and COLOR being an X color
1367name.
1368
1369XPM images can be built from memory instead of files. In that case,
1370add a `:data' property instead of a `:file' property.
1371
1372`:data DATA'
1373
1374DATA must be a string containing an XPM image. The contents of the
1375string are of the same format as that of XPM files.
1376
1377The XPM library uses libz in its implementation so that it is able
1378to display compressed images.
1379
1380**** PBM, image type `pbm'
1381
1382PBM images don't require an external library. Color, gray-scale and
1383mono images are supported. There are no additional image properties
1384defined.
1385
1386**** JPEG, image type `jpeg'
1387
1388Support for JPEG images requires the external library `libjpeg',
1389package `jpegsrc.v6a.tar.gz', or later. There are no additional image
1390properties defined.
1391
1392**** TIFF, image type `tiff'
1393
1394Support for TIFF images requires the external library `libtiff',
1395package `tiff-v3.4-tar.gz', or later. There are no additional image
1396properties defined.
1397
1398**** GIF, image type `gif'
1399
1400Support for GIF images requires the external library `libungif', package
1401`libungif-4.1.0', or later.
1402
1403Additional image properties supported are:
1404
1405`:index INDEX'
1406
1407INDEX must be an integer >= 0. Load image number INDEX from a
1408multi-image GIF file. An error is signalled if INDEX is too large.
1409
1410This could be used to implement limited support for animated GIFs.
1411For example, the following function displays a multi-image GIF file
1412at point-min in the current buffer, switching between sub-images
1413every 0.1 seconds.
1414
1415(defun show-anim (file max)
1416 "Display multi-image GIF file FILE which contains MAX subimages."
1417 (display-anim (current-buffer) file 0 max t))
1418
1419(defun display-anim (buffer file idx max first-time)
1420 (when (= idx max)
1421 (setq idx 0))
1422 (let ((img (create-image file nil :index idx)))
1423 (save-excursion
1424 (set-buffer buffer)
1425 (goto-char (point-min))
1426 (unless first-time (delete-char 1))
1427 (insert-image img "x"))
1428 (run-with-timer 0.1 nil 'display-anim buffer file (1+ idx) max nil)))
1429
1430**** PNG, image type `png'
1431
1432Support for PNG images requires the external library `libpng',
1433package `libpng-1.0.2.tar.gz', or later. There are no additional image
1434properties defined.
1435
1436**** Ghostscript, image type `postscript'.
1437
1438Additional image properties supported are:
1439
1440`:pt-width WIDTH'
1441
1442WIDTH is width of the image in pt (1/72 inch). WIDTH must be an
b246b1f6 1443integer. This is a required property.
a933dad1
DL
1444
1445`:pt-height HEIGHT'
1446
1447HEIGHT specifies the height of the image in pt (1/72 inch). HEIGHT
b246b1f6 1448must be a integer. This is an required property.
a933dad1
DL
1449
1450`:bounding-box BOX'
1451
1452BOX must be a list or vector of 4 integers giving the bounding box of
1453the PS image, analogous to the `BoundingBox' comment found in PS
1454files. This is an required property.
1455
1456Part of the Ghostscript interface is implemented in Lisp. See
1457lisp/gs.el.
1458
1459*** Lisp interface.
1460
1461The variable `image-types' contains a list of those image types
1462which are supported in the current configuration.
1463
1464Images are stored in an image cache and removed from the cache when
1465they haven't been displayed for `image-cache-eviction-delay seconds.
1466The function `clear-image-cache' can be used to clear the image cache
1467manually.
1468
1469*** Simplified image API, image.el
1470
1471The new Lisp package image.el contains functions that simplify image
1472creation and putting images into text. The function `create-image'
1473can be used to create images. The macro `defimage' can be used to
1474define an image based on available image types. The functions
1475`put-image' and `insert-image' can be used to insert an image into a
1476buffer.
1477
1478+++
1479** Display margins.
1480
1481Windows can now have margins which are used for special text
1482and images.
1483
1484To give a window margins, either set the buffer-local variables
1485`left-margin-width' and `right-margin-width', or call
1486`set-window-margins'. The function `window-margins' can be used to
1487obtain the current settings. To make `left-margin-width' and
1488`right-margin-width' take effect, you must set them before displaying
1489the buffer in a window, or use `set-window-buffer' to force an update
1490of the display margins.
1491
1492You can put text in margins by giving it a `display' text property
1493containing a pair of the form `(LOCATION . VALUE)', where LOCATION is
1494one of `left-margin' or `right-margin' or nil. VALUE can be either a
1495string, an image specification or a stretch specification (see later
1496in this file).
1497
1498+++
1499** Help display
1500
1501Emacs displays short help messages in the echo area, when the mouse
1502moves over a tool-bar item or a piece of text that has a text property
1503`help-echo'. This feature also applies to strings in the mode line
1504that have a `help-echo' property.
1505
1506The value of the `help-echo' property must be a string. For tool-bar
1507items, their key definition is used to determine the help to display.
1508If their definition contains a property `:help FORM', FORM is
1509evaluated to determine the help string. Otherwise, the caption of the
1510tool-bar item is used.
1511
1512The hook `show-help-function' can be set to a function that displays
1513help differently. For example, enabling a tooltip window causes the
1514help display to appear there instead of in the echo area.
1515
1516+++
1517** Vertical fractional scrolling.
1518
1519The display of text in windows can be scrolled smoothly in pixels.
1520This is useful, for example, for making parts of large images visible.
1521
1522The function `window-vscroll' returns the current value of vertical
1523scrolling, a non-negative fraction of the canonical character height.
1524The function `set-window-vscroll' can be used to set the vertical
1525scrolling value. Here is an example of how these function might be
1526used.
1527
1528 (global-set-key [A-down]
1529 #'(lambda ()
1530 (interactive)
1531 (set-window-vscroll (selected-window)
1532 (+ 0.5 (window-vscroll)))))
1533 (global-set-key [A-up]
1534 #'(lambda ()
1535 (interactive)
1536 (set-window-vscroll (selected-window)
1537 (- (window-vscroll) 0.5)))))
1538
1539+++
1540** New hook `fontification-functions'.
1541
1542Functions from `fontification-functions' are called from redisplay
1543when it encounters a region of text that is not yet fontified. This
1544variable automatically becomes buffer-local when set. Each function
1545is called with one argument, POS.
1546
1547At least one of the hook functions should fontify one or more
1548characters starting at POS in the current buffer. It should mark them
1549as fontified by giving them a non-nil value of the `fontified' text
1550property. It may be reasonable for these functions to check for the
1551`fontified' property and not put it back on, but they do not have to.
1552
1553+++
1554** Tool bar support.
1555
1556Emacs supports a tool bar at the top of a frame under X. The frame
1557parameter `tool-bar-lines' (X resource "toolBar", class "ToolBar")
1558controls how may lines to reserve for the tool bar. A zero value
1559suppresses the tool bar. If the value is non-zero and
1560`auto-resize-tool-bars' is non-nil the tool bar's size will be changed
1561automatically so that all tool bar items are visible.
1562
1563*** Tool bar item definitions
1564
1565Tool bar items are defined using `define-key' with a prefix-key
1566`tool-bar'. For example `(define-key global-map [tool-bar item1] ITEM)'
1567where ITEM is a list `(menu-item CAPTION BINDING PROPS...)'.
1568
1569CAPTION is the caption of the item, If it's not a string, it is
1570evaluated to get a string. The caption is currently not displayed in
1571the tool bar, but it is displayed if the item doesn't have a `:help'
1572property (see below).
1573
1574BINDING is the tool bar item's binding. Tool bar items with keymaps as
1575binding are currently ignored.
1576
1577The following properties are recognized:
1578
1579`:enable FORM'.
1580
1581FORM is evaluated and specifies whether the tool bar item is enabled
1582or disabled.
1583
1584`:visible FORM'
1585
1586FORM is evaluated and specifies whether the tool bar item is displayed.
1587
1588`:filter FUNCTION'
1589
1590FUNCTION is called with one parameter, the same list BINDING in which
1591FUNCTION is specified as the filter. The value FUNCTION returns is
1592used instead of BINDING to display this item.
1593
1594`:button (TYPE SELECTED)'
1595
1596TYPE must be one of `:radio' or `:toggle'. SELECTED is evaluated
1597and specifies whether the button is selected (pressed) or not.
1598
1599`:image IMAGES'
1600
1601IMAGES is either a single image specification or a vector of four
1602image specifications. If it is a vector, this table lists the
1603meaning of each of the four elements:
1604
1605 Index Use when item is
1606 ----------------------------------------
1607 0 enabled and selected
1608 1 enabled and deselected
1609 2 disabled and selected
1610 3 disabled and deselected
1611
1612`:help HELP-STRING'.
1613
1614Gives a help string to display for the tool bar item. This help
1615is displayed when the mouse is moved over the item.
1616
1617*** Tool-bar-related variables.
1618
1619If `auto-resize-tool-bar' is non-nil, the tool bar will automatically
1620resize to show all defined tool bar items. It will never grow larger
1621than 1/4 of the frame's size.
1622
1623If `auto-raise-tool-bar-buttons' is non-nil, tool bar buttons will be
1624raised when the mouse moves over them.
1625
1626You can add extra space between tool bar items by setting
1627`tool-bar-button-margin' to a positive integer specifying a number of
1628pixels. Default is 1.
1629
1630You can change the shadow thickness of tool bar buttons by setting
1631`tool-bar-button-relief' to an integer. Default is 3.
1632
1633*** Tool-bar clicks with modifiers.
1634
1635You can bind commands to clicks with control, shift, meta etc. on
1636a tool bar item. If
1637
1638 (define-key global-map [tool-bar shell]
1639 '(menu-item "Shell" shell
1640 :image (image :type xpm :file "shell.xpm")))
1641
1642is the original tool bar item definition, then
1643
1644 (define-key global-map [tool-bar S-shell] 'some-command)
1645
1646makes a binding to run `some-command' for a shifted click on the same
1647item.
1648
1649** Mode line changes.
1650
1651+++
1652*** Mouse-sensitive mode line.
1653
1654The mode line can be made mouse-sensitive by displaying strings there
1655that have a `local-map' text property. There are three ways to display
1656a string with a `local-map' property in the mode line.
1657
16581. The mode line spec contains a variable whose string value has
1659a `local-map' text property.
1660
16612. The mode line spec contains a format specifier (e.g. `%12b'), and
1662that format specifier has a `local-map' property.
1663
16643. The mode line spec contains a list containing `:eval FORM'. FORM
1665is evaluated. If the result is a string, and that string has a
1666`local-map' property.
1667
1668The same mechanism is used to determine the `face' and `help-echo'
1669properties of strings in the mode line. See `bindings.el' for an
1670example.
1671
1672+++
1673*** You can suppress mode-line display by setting the buffer-local
1674variable mode-line-format to nil.
1675
1676+++
1677*** A headerline can now be displayed at the top of a window.
1678
1679This mode line's contents are controlled by the new variable
1680`header-line-format' and `default-header-line-format' which are
1681completely analogous to `mode-line-format' and
1682`default-mode-line-format'. A value of nil means don't display a top
1683line.
1684
1685The appearance of top mode lines is controlled by the face
1686`header-line'.
1687
1688The function `coordinates-in-window-p' returns `header-line' for a
1689position in the header-line.
1690
1691+++
1692** Text property `display'
1693
1694The `display' text property is used to insert images into text, and
1695also control other aspects of how text displays. The value of the
1696`display' property should be a display specification, as described
1697below, or a list or vector containing display specifications.
1698
1699*** Variable width and height spaces
1700
1701To display a space of fractional width or height, use a display
1702specification of the form `(LOCATION STRECH)'. If LOCATION is
1703`(margin left-margin)', the space is displayed in the left marginal
1704area, if it is `(margin right-margin)', it is displayed in the right
1705marginal area, and if LOCATION is `(margin nil)' the space is
1706displayed in the text. In the latter case you can also use the
1707simpler form STRETCH as property value.
1708
1709The stretch specification STRETCH itself is a list of the form `(space
1710PROPS)', where PROPS is a property list which can contain the
1711properties described below.
1712
1713The display of the fractional space replaces the display of the
1714characters having the `display' property.
1715
1716- :width WIDTH
1717
1718Specifies that the space width should be WIDTH times the normal
1719character width. WIDTH can be an integer or floating point number.
1720
1721- :relative-width FACTOR
1722
1723Specifies that the width of the stretch should be computed from the
1724first character in a group of consecutive characters that have the
1725same `display' property. The computation is done by multiplying the
1726width of that character by FACTOR.
1727
1728- :align-to HPOS
1729
1730Specifies that the space should be wide enough to reach HPOS. The
1731value HPOS is measured in units of the normal character width.
1732
1733Exactly one of the above properties should be used.
1734
1735- :height HEIGHT
1736
1737Specifies the height of the space, as HEIGHT, measured in terms of the
1738normal line height.
1739
1740- :relative-height FACTOR
1741
1742The height of the space is computed as the product of the height
1743of the text having the `display' property and FACTOR.
1744
1745- :ascent ASCENT
1746
1747Specifies that ASCENT percent of the height of the stretch should be
1748used for the ascent of the stretch, i.e. for the part above the
1749baseline. The value of ASCENT must be a non-negative number less or
1750equal to 100.
1751
1752You should not use both `:height' and `:relative-height' together.
1753
1754*** Images
1755
1756A display specification for an image has the form `(LOCATION
1757. IMAGE)', where IMAGE is an image specification. The image replaces,
1758in the display, the characters having this display specification in
1759their `display' text property. If LOCATION is `(margin left-margin)',
1760the image will be displayed in the left marginal area, if it is
1761`(margin right-margin)' it will be displayed in the right marginal
1762area, and if LOCATION is `(margin nil)' the image will be displayed in
1763the text. In the latter case you can also use the simpler form IMAGE
1764as display specification.
1765
1766*** Other display properties
1767
1768- :space-width FACTOR
1769
1770Specifies that space characters in the text having that property
1771should be displayed FACTOR times as wide as normal; FACTOR must be an
1772integer or float.
1773
1774- :height HEIGHT
1775
1776Display text having this property in a font that is smaller or larger.
1777
1778If HEIGHT is a list of the form `(+ N)', where N is an integer, that
1779means to use a font that is N steps larger. If HEIGHT is a list of
1780the form `(- N)', that means to use a font that is N steps smaller. A
1781``step'' is defined by the set of available fonts; each size for which
1782a font is available counts as a step.
1783
1784If HEIGHT is a number, that means to use a font that is HEIGHT times
1785as tall as the frame's default font.
1786
1787If HEIGHT is a symbol, it is called as a function with the current
1788height as argument. The function should return the new height to use.
1789
1790Otherwise, HEIGHT is evaluated to get the new height, with the symbol
1791`height' bound to the current specified font height.
1792
1793- :raise FACTOR
1794
1795FACTOR must be a number, specifying a multiple of the current
1796font's height. If it is positive, that means to display the characters
1797raised. If it is negative, that means to display them lower down. The
1798amount of raising or lowering is computed without taking account of the
1799`:height' subproperty.
1800
1801*** Conditional display properties
1802
1803All display specifications can be conditionalized. If a specification
1804has the form `(:when CONDITION . SPEC)', the specification SPEC
1805applies only when CONDITION yields a non-nil value when evaluated.
1806During evaluattion, point is temporarily set to the end position of
1807the text having the `display' property.
1808
1809The normal specification consisting of SPEC only is equivalent to
1810`(:when t SPEC)'.
1811
1812+++
1813** New menu separator types.
1814
1815Emacs now supports more than one menu separator type. Menu items with
1816item names consisting of dashes only (including zero dashes) are
1817treated like before. In addition, the following item names are used
1818to specify other menu separator types.
1819
1820- `--no-line' or `--space', or `--:space', or `--:noLine'
1821
1822No separator lines are drawn, but a small space is inserted where the
1823separator occurs.
1824
1825- `--single-line' or `--:singleLine'
1826
1827A single line in the menu's foreground color.
1828
1829- `--double-line' or `--:doubleLine'
1830
1831A double line in the menu's foreground color.
1832
1833- `--single-dashed-line' or `--:singleDashedLine'
1834
1835A single dashed line in the menu's foreground color.
1836
1837- `--double-dashed-line' or `--:doubleDashedLine'
1838
1839A double dashed line in the menu's foreground color.
1840
1841- `--shadow-etched-in' or `--:shadowEtchedIn'
1842
1843A single line with 3D sunken appearance. This is the the form
1844displayed for item names consisting of dashes only.
1845
1846- `--shadow-etched-out' or `--:shadowEtchedOut'
1847
1848A single line with 3D raised appearance.
1849
1850- `--shadow-etched-in-dash' or `--:shadowEtchedInDash'
1851
1852A single dashed line with 3D sunken appearance.
1853
1854- `--shadow-etched-out-dash' or `--:shadowEtchedOutDash'
1855
1856A single dashed line with 3D raise appearance.
1857
1858- `--shadow-double-etched-in' or `--:shadowDoubleEtchedIn'
1859
1860Two lines with 3D sunken appearance.
1861
1862- `--shadow-double-etched-out' or `--:shadowDoubleEtchedOut'
1863
1864Two lines with 3D raised appearance.
1865
1866- `--shadow-double-etched-in-dash' or `--:shadowDoubleEtchedInDash'
1867
1868Two dashed lines with 3D sunken appearance.
1869
1870- `--shadow-double-etched-out-dash' or `--:shadowDoubleEtchedOutDash'
1871
1872Two dashed lines with 3D raised appearance.
1873
1874Under LessTif/Motif, the last four separator types are displayed like
1875the corresponding single-line separators.
1876
1877+++
1878** New frame parameters for scroll bar colors.
1879
1880The new frame parameters `scroll-bar-foreground' and
1881`scroll-bar-background' can be used to change scroll bar colors.
1882Their value must be either a color name, a string, or nil to specify
1883that scroll bars should use a default color. For toolkit scroll bars,
1884default colors are toolkit specific. For non-toolkit scroll bars, the
1885default background is the background color of the frame, and the
1886default foreground is black.
1887
1888The X resource name of these parameters are `scrollBarForeground'
1889(class ScrollBarForeground) and `scrollBarBackground' (class
1890`ScrollBarBackground').
1891
1892Setting these parameters overrides toolkit specific X resource
1893settings for scroll bar colors.
1894
1895+++
1896** You can set `redisplay-dont-pause' to a non-nil value to prevent
1897display updates from being interrupted when input is pending.
1898
1899---
1900** Changing a window's width may now change its window start if it
1901starts on a continuation line. The new window start is computed based
1902on the window's new width, starting from the start of the continued
1903line as the start of the screen line with the minimum distance from
1904the original window start.
1905
1906---
1907** The variable `hscroll-step' and the functions
1908`hscroll-point-visible' and `hscroll-window-column' have been removed
1909now that proper horizontal scrolling is implemented.
1910
1911+++
1912** Windows can now be made fixed-width and/or fixed-height.
1913
1914A window is fixed-size if its buffer has a buffer-local variable
1915`window-size-fixed' whose value is not nil. A value of `height' makes
1916windows fixed-height, a value of `width' makes them fixed-width, any
1917other non-nil value makes them both fixed-width and fixed-height.
1918
1919The following code makes all windows displaying the current buffer
1920fixed-width and fixed-height.
1921
1922 (set (make-local-variable 'window-size-fixed) t)
1923
1924A call to enlarge-window on a window gives an error if that window is
1925fixed-width and it is tried to change the window's width, or if the
1926window is fixed-height, and it is tried to change its height. To
1927change the size of a fixed-size window, bind `window-size-fixed'
1928temporarily to nil, for example
1929
1930 (let ((window-size-fixed nil))
1931 (enlarge-window 10))
1932
1933Likewise, an attempt to split a fixed-height window vertically,
1934or a fixed-width window horizontally results in a error.
1935\f
1936* Changes in Emacs 20.4
1937
1938** Init file may be called .emacs.el.
1939
1940You can now call the Emacs init file `.emacs.el'.
1941Formerly the name had to be `.emacs'. If you use the name
1942`.emacs.el', you can byte-compile the file in the usual way.
1943
1944If both `.emacs' and `.emacs.el' exist, the latter file
1945is the one that is used.
1946
1947** shell-command, and shell-command-on-region, now return
1948the exit code of the command (unless it is asynchronous).
1949Also, you can specify a place to put the error output,
1950separate from the command's regular output.
1951Interactively, the variable shell-command-default-error-buffer
1952says where to put error output; set it to a buffer name.
1953In calls from Lisp, an optional argument ERROR-BUFFER specifies
1954the buffer name.
1955
1956When you specify a non-nil error buffer (or buffer name), any error
1957output is inserted before point in that buffer, with \f\n to separate
1958it from the previous batch of error output. The error buffer is not
1959cleared, so error output from successive commands accumulates there.
1960
1961** Setting the default value of enable-multibyte-characters to nil in
1962the .emacs file, either explicitly using setq-default, or via Custom,
1963is now essentially equivalent to using --unibyte: all buffers
1964created during startup will be made unibyte after loading .emacs.
1965
1966** C-x C-f now handles the wildcards * and ? in file names. For
1967example, typing C-x C-f c*.c RET visits all the files whose names
1968match c*.c. To visit a file whose name contains * or ?, add the
1969quoting sequence /: to the beginning of the file name.
1970
1971** The M-x commands keep-lines, flush-lines and count-matches
1972now have the same feature as occur and query-replace:
1973if the pattern contains any upper case letters, then
1974they never ignore case.
1975
1976** The end-of-line format conversion feature previously mentioned
1977under `* Emacs 20.1 changes for MS-DOS and MS-Windows' actually
1978applies to all operating systems. Emacs recognizes from the contents
1979of a file what convention it uses to separate lines--newline, CRLF, or
1980just CR--and automatically converts the contents to the normal Emacs
1981convention (using newline to separate lines) for editing. This is a
1982part of the general feature of coding system conversion.
1983
1984If you subsequently save the buffer, Emacs converts the text back to
1985the same format that was used in the file before.
1986
1987You can turn off end-of-line conversion by setting the variable
1988`inhibit-eol-conversion' to non-nil, e.g. with Custom in the MULE group.
1989
1990** The character set property `prefered-coding-system' has been
1991renamed to `preferred-coding-system', for the sake of correct spelling.
1992This is a fairly internal feature, so few programs should be affected.
1993
1994** Mode-line display of end-of-line format is changed.
1995The indication of the end-of-line format of the file visited by a
1996buffer is now more explicit when that format is not the usual one for
1997your operating system. For example, the DOS-style end-of-line format
1998is displayed as "(DOS)" on Unix and GNU/Linux systems. The usual
1999end-of-line format is still displayed as a single character (colon for
2000Unix, backslash for DOS and Windows, and forward slash for the Mac).
2001
2002The values of the variables eol-mnemonic-unix, eol-mnemonic-dos,
2003eol-mnemonic-mac, and eol-mnemonic-undecided, which are strings,
2004control what is displayed in the mode line for each end-of-line
2005format. You can now customize these variables.
2006
2007** In the previous version of Emacs, tar-mode didn't work well if a
2008filename contained non-ASCII characters. Now this is fixed. Such a
2009filename is decoded by file-name-coding-system if the default value of
2010enable-multibyte-characters is non-nil.
2011
2012** The command temp-buffer-resize-mode toggles a minor mode
2013in which temporary buffers (such as help buffers) are given
2014windows just big enough to hold the whole contents.
2015
2016** If you use completion.el, you must now run the function
2017dynamic-completion-mode to enable it. Just loading the file
2018doesn't have any effect.
2019
2020** In Flyspell mode, the default is now to make just one Ispell process,
2021not one per buffer.
2022
2023** If you use iswitchb but do not call (iswitchb-default-keybindings) to
2024use the default keybindings, you will need to add the following line:
2025 (add-hook 'minibuffer-setup-hook 'iswitchb-minibuffer-setup)
2026
2027** Auto-show mode is no longer enabled just by loading auto-show.el.
2028To control it, set `auto-show-mode' via Custom or use the
2029`auto-show-mode' command.
2030
2031** Handling of X fonts' ascent/descent parameters has been changed to
2032avoid redisplay problems. As a consequence, compared with previous
2033versions the line spacing and frame size now differ with some font
2034choices, typically increasing by a pixel per line. This change
2035occurred in version 20.3 but was not documented then.
2036
2037** If you select the bar cursor style, it uses the frame's
2038cursor-color, rather than the cursor foreground pixel.
2039
2040** In multibyte mode, Rmail decodes incoming MIME messages using the
2041character set specified in the message. If you want to disable this
2042feature, set the variable rmail-decode-mime-charset to nil.
2043
2044** Not new, but not mentioned previously in NEWS: when you use #! at
2045the beginning of a file to make it executable and specify an
2046interpreter program, Emacs looks on the second line for the -*- mode
2047and variable specification, as well as on the first line.
2048
2049** Support for IBM codepage encoding of non-ASCII characters.
2050
2051The new command M-x codepage-setup creates a special coding system
2052that can be used to convert text between a specific IBM codepage and
2053one of the character sets built into Emacs which matches that
2054codepage. For example, codepage 850 corresponds to Latin-1 character
2055set, codepage 855 corresponds to Cyrillic-ISO character set, etc.
2056
2057Windows codepages 1250, 1251 and some others, where Windows deviates
2058from the corresponding ISO character set, are also supported.
2059
2060IBM box-drawing characters and other glyphs which don't have
2061equivalents in the corresponding ISO character set, are converted to
2062a character defined by dos-unsupported-char-glyph on MS-DOS, and to
2063`?' on other systems.
2064
2065IBM codepages are widely used on MS-DOS and MS-Windows, so this
2066feature is most useful on those platforms, but it can also be used on
2067Unix.
2068
2069Emacs compiled for MS-DOS automatically loads the support for the
2070current codepage when it starts.
2071
2072** Mail changes
2073
2074*** The new variable default-sendmail-coding-system specifies the
2075default way to encode outgoing mail. This has higher priority than
2076default-buffer-file-coding-system but has lower priority than
2077sendmail-coding-system and the local value of
2078buffer-file-coding-system.
2079
2080You should not set this variable manually. Instead, set
2081sendmail-coding-system to specify a fixed encoding for all outgoing
2082mail.
2083
2084*** When you try to send a message that contains non-ASCII characters,
2085if the coding system specified by those variables doesn't handle them,
2086Emacs will ask you to select a suitable coding system while showing a
2087list of possible coding systems.
2088
2089** CC Mode changes
2090
2091*** c-default-style can now take an association list that maps major
2092modes to style names. When this variable is an alist, Java mode no
2093longer hardcodes a setting to "java" style. See the variable's
2094docstring for details.
2095
2096*** It's now possible to put a list as the offset on a syntactic
2097symbol. The list is evaluated recursively until a non-nil offset is
2098found. This is useful to combine several lineup functions to act in a
2099prioritized order on a single line. However, none of the supplied
2100lineup functions use this feature currently.
2101
2102*** New syntactic symbol catch-clause, which is used on the "catch" and
2103"finally" lines in try-catch constructs in C++ and Java.
2104
2105*** New cleanup brace-catch-brace on c-cleanup-list, which does for
2106"catch" lines what brace-elseif-brace does for "else if" lines.
2107
2108*** The braces of Java anonymous inner classes are treated separately
2109from the braces of other classes in auto-newline mode. Two new
2110symbols inexpr-class-open and inexpr-class-close may be used on
2111c-hanging-braces-alist to control the automatic newlines used for
2112anonymous classes.
2113
2114*** Support for the Pike language added, along with new Pike specific
2115syntactic symbols: inlambda, lambda-intro-cont
2116
2117*** Support for Java anonymous classes via new syntactic symbol
2118inexpr-class. New syntactic symbol inexpr-statement for Pike
2119support and gcc-style statements inside expressions. New lineup
2120function c-lineup-inexpr-block.
2121
2122*** New syntactic symbol brace-entry-open which is used in brace lists
2123(i.e. static initializers) when a list entry starts with an open
2124brace. These used to be recognized as brace-list-entry's.
2125c-electric-brace also recognizes brace-entry-open braces
2126(brace-list-entry's can no longer be electrified).
2127
2128*** New command c-indent-line-or-region, not bound by default.
2129
2130*** `#' is only electric when typed in the indentation of a line.
2131
2132*** Parentheses are now electric (via the new command c-electric-paren)
2133for auto-reindenting lines when parens are typed.
2134
2135*** In "gnu" style, inline-open offset is now set to zero.
2136
2137*** Uniform handling of the inclass syntactic symbol. The indentation
2138associated with it is now always relative to the class opening brace.
2139This means that the indentation behavior has changed in some
2140circumstances, but only if you've put anything besides 0 on the
2141class-open syntactic symbol (none of the default styles do that).
2142
2143** Gnus changes.
2144
2145*** New functionality for using Gnus as an offline newsreader has been
2146added. A plethora of new commands and modes have been added. See the
2147Gnus manual for the full story.
2148
2149*** The nndraft backend has returned, but works differently than
2150before. All Message buffers are now also articles in the nndraft
2151group, which is created automatically.
2152
2153*** `gnus-alter-header-function' can now be used to alter header
2154values.
2155
2156*** `gnus-summary-goto-article' now accept Message-ID's.
2157
2158*** A new Message command for deleting text in the body of a message
2159outside the region: `C-c C-v'.
2160
2161*** You can now post to component group in nnvirtual groups with
2162`C-u C-c C-c'.
2163
2164*** `nntp-rlogin-program' -- new variable to ease customization.
2165
2166*** `C-u C-c C-c' in `gnus-article-edit-mode' will now inhibit
2167re-highlighting of the article buffer.
2168
2169*** New element in `gnus-boring-article-headers' -- `long-to'.
2170
2171*** `M-i' symbolic prefix command. See the section "Symbolic
2172Prefixes" in the Gnus manual for details.
2173
2174*** `L' and `I' in the summary buffer now take the symbolic prefix
2175`a' to add the score rule to the "all.SCORE" file.
2176
2177*** `gnus-simplify-subject-functions' variable to allow greater
2178control over simplification.
2179
2180*** `A T' -- new command for fetching the current thread.
2181
2182*** `/ T' -- new command for including the current thread in the
2183limit.
2184
2185*** `M-RET' is a new Message command for breaking cited text.
2186
2187*** \\1-expressions are now valid in `nnmail-split-methods'.
2188
2189*** The `custom-face-lookup' function has been removed.
2190If you used this function in your initialization files, you must
2191rewrite them to use `face-spec-set' instead.
2192
2193*** Cancelling now uses the current select method. Symbolic prefix
2194`a' forces normal posting method.
2195
2196*** New command to translate M******** sm*rtq**t*s into proper text
2197-- `W d'.
2198
2199*** For easier debugging of nntp, you can set `nntp-record-commands'
2200to a non-nil value.
2201
2202*** nntp now uses ~/.authinfo, a .netrc-like file, for controlling
2203where and how to send AUTHINFO to NNTP servers.
2204
2205*** A command for editing group parameters from the summary buffer
2206has been added.
2207
2208*** A history of where mails have been split is available.
2209
2210*** A new article date command has been added -- `article-date-iso8601'.
2211
2212*** Subjects can be simplified when threading by setting
2213`gnus-score-thread-simplify'.
2214
2215*** A new function for citing in Message has been added --
2216`message-cite-original-without-signature'.
2217
2218*** `article-strip-all-blank-lines' -- new article command.
2219
2220*** A new Message command to kill to the end of the article has
2221been added.
2222
2223*** A minimum adaptive score can be specified by using the
2224`gnus-adaptive-word-minimum' variable.
2225
2226*** The "lapsed date" article header can be kept continually
2227updated by the `gnus-start-date-timer' command.
2228
2229*** Web listserv archives can be read with the nnlistserv backend.
2230
2231*** Old dejanews archives can now be read by nnweb.
2232
2233*** `gnus-posting-styles' has been re-activated.
2234
2235** Changes to TeX and LaTeX mode
2236
2237*** The new variable `tex-start-options-string' can be used to give
2238options for the TeX run. The default value causes TeX to run in
2239nonstopmode. For an interactive TeX run set it to nil or "".
2240
2241*** The command `tex-feed-input' sends input to the Tex Shell. In a
2242TeX buffer it is bound to the keys C-RET, C-c RET, and C-c C-m (some
2243of these keys may not work on all systems). For instance, if you run
2244TeX interactively and if the TeX run stops because of an error, you
2245can continue it without leaving the TeX buffer by typing C-RET.
2246
2247*** The Tex Shell Buffer is now in `compilation-shell-minor-mode'.
2248All error-parsing commands of the Compilation major mode are available
2249but bound to keys that don't collide with the shell. Thus you can use
2250the Tex Shell for command line executions like a usual shell.
2251
2252*** The commands `tex-validate-region' and `tex-validate-buffer' check
2253the matching of braces and $'s. The errors are listed in a *Occur*
2254buffer and you can use C-c C-c or mouse-2 to go to a particular
2255mismatch.
2256
2257** Changes to RefTeX mode
2258
2259*** The table of contents buffer can now also display labels and
2260file boundaries in addition to sections. Use `l', `i', and `c' keys.
2261
2262*** Labels derived from context (the section heading) are now
2263lowercase by default. To make the label legal in LaTeX, latin-1
2264characters will lose their accent. All Mule characters will be
2265removed from the label.
2266
2267*** The automatic display of cross reference information can also use
2268a window instead of the echo area. See variable `reftex-auto-view-crossref'.
2269
2270*** kpsewhich can be used by RefTeX to find TeX and BibTeX files. See the
2271customization group `reftex-finding-files'.
2272
2273*** The option `reftex-bibfile-ignore-list' has been renamed to
2274`reftex-bibfile-ignore-regexps' and indeed can be fed with regular
2275expressions.
2276
2277*** Multiple Selection buffers are now hidden buffers.
2278
2279** New/deleted modes and packages
2280
2281*** The package snmp-mode.el provides major modes for editing SNMP and
2282SNMPv2 MIBs. It has entries on `auto-mode-alist'.
2283
2284*** The package sql.el provides a major mode, M-x sql-mode, for
2285editing SQL files, and M-x sql-interactive-mode for interacting with
2286SQL interpreters. It has an entry on `auto-mode-alist'.
2287
2288*** M-x highlight-changes-mode provides a minor mode displaying buffer
2289changes with a special face.
2290
2291*** ispell4.el has been deleted. It got in the way of ispell.el and
2292this was hard to fix reliably. It has long been obsolete -- use
2293Ispell 3.1 and ispell.el.
2294\f
2295* MS-DOS changes in Emacs 20.4
2296
2297** Emacs compiled for MS-DOS now supports MULE features better.
2298This includes support for display of all ISO 8859-N character sets,
2299conversion to and from IBM codepage encoding of non-ASCII characters,
2300and automatic setup of the MULE environment at startup. For details,
2301check out the section `MS-DOS and MULE' in the manual.
2302
2303The MS-DOS installation procedure automatically configures and builds
2304Emacs with input method support if it finds an unpacked Leim
2305distribution when the config.bat script is run.
2306
2307** Formerly, the value of lpr-command did not affect printing on
2308MS-DOS unless print-region-function was set to nil, but now it
2309controls whether an external program is invoked or output is written
2310directly to a printer port. Similarly, in the previous version of
2311Emacs, the value of ps-lpr-command did not affect PostScript printing
2312on MS-DOS unless ps-printer-name was set to something other than a
2313string (eg. t or `pipe'), but now it controls whether an external
2314program is used. (These changes were made so that configuration of
2315printing variables would be almost identical across all platforms.)
2316
2317** In the previous version of Emacs, PostScript and non-PostScript
2318output was piped to external programs, but because most print programs
2319available for MS-DOS and MS-Windows cannot read data from their standard
2320input, on those systems the data to be output is now written to a
2321temporary file whose name is passed as the last argument to the external
2322program.
2323
2324An exception is made for `print', a standard program on Windows NT,
2325and `nprint', a standard program on Novell Netware. For both of these
2326programs, the command line is constructed in the appropriate syntax
2327automatically, using only the value of printer-name or ps-printer-name
2328as appropriate--the value of the relevant `-switches' variable is
2329ignored, as both programs have no useful switches.
2330
2331** The value of the variable dos-printer (cf. dos-ps-printer), if it has
2332a value, overrides the value of printer-name (cf. ps-printer-name), on
2333MS-DOS and MS-Windows only. This has been true since version 20.3, but
2334was not documented clearly before.
2335
2336** All the Emacs games now work on MS-DOS terminals.
2337This includes Tetris and Snake.
2338\f
2339* Lisp changes in Emacs 20.4
2340
2341** New functions line-beginning-position and line-end-position
2342return the position of the beginning or end of the current line.
2343They both accept an optional argument, which has the same
2344meaning as the argument to beginning-of-line or end-of-line.
2345
2346** find-file and allied functions now have an optional argument
2347WILDCARD. If this is non-nil, they do wildcard processing,
2348and visit all files that match the wildcard pattern.
2349
2350** Changes in the file-attributes function.
2351
2352*** The file size returned by file-attributes may be an integer or a float.
2353It is an integer if the size fits in a Lisp integer, float otherwise.
2354
2355*** The inode number returned by file-attributes may be an integer (if
2356the number fits in a Lisp integer) or a cons cell containing two
2357integers.
2358
2359** The new function directory-files-and-attributes returns a list of
2360files in a directory and their attributes. It accepts the same
2361arguments as directory-files and has similar semantics, except that
2362file names and attributes are returned.
2363
2364** The new function file-attributes-lessp is a helper function for
2365sorting the list generated by directory-files-and-attributes. It
2366accepts two arguments, each a list of a file name and its atttributes.
2367It compares the file names of each according to string-lessp and
2368returns the result.
2369
2370** The new function file-expand-wildcards expands a wildcard-pattern
2371to produce a list of existing files that match the pattern.
2372
2373** New functions for base64 conversion:
2374
2375The function base64-encode-region converts a part of the buffer
2376into the base64 code used in MIME. base64-decode-region
2377performs the opposite conversion. Line-breaking is supported
2378optionally.
2379
2380Functions base64-encode-string and base64-decode-string do a similar
2381job on the text in a string. They return the value as a new string.
2382
2383**
2384The new function process-running-child-p
2385will tell you if a subprocess has given control of its
2386terminal to its own child process.
2387
2388** interrupt-process and such functions have a new feature:
2389when the second argument is `lambda', they send a signal
2390to the running child of the subshell, if any, but if the shell
2391itself owns its terminal, no signal is sent.
2392
2393** There are new widget types `plist' and `alist' which can
2394be used for customizing variables whose values are plists or alists.
2395
2396** easymenu.el Now understands `:key-sequence' and `:style button'.
2397:included is an alias for :visible.
2398
2399easy-menu-add-item now understands the values returned by
2400easy-menu-remove-item and easy-menu-item-present-p. This can be used
2401to move or copy menu entries.
2402
2403** Multibyte editing changes
2404
2405*** The definitions of sref and char-bytes are changed. Now, sref is
2406an alias of aref and char-bytes always returns 1. This change is to
2407make some Emacs Lisp code which works on 20.2 and earlier also
2408work on the latest Emacs. Such code uses a combination of sref and
2409char-bytes in a loop typically as below:
2410 (setq char (sref str idx)
2411 idx (+ idx (char-bytes idx)))
2412The byte-compiler now warns that this is obsolete.
2413
2414If you want to know how many bytes a specific multibyte character
2415(say, CH) occupies in a multibyte buffer, use this code:
2416 (charset-bytes (char-charset ch))
2417
2418*** In multibyte mode, when you narrow a buffer to some region, and the
2419region is preceded or followed by non-ASCII codes, inserting or
2420deleting at the head or the end of the region may signal this error:
2421
2422 Byte combining across boundary of accessible buffer text inhibitted
2423
2424This is to avoid some bytes being combined together into a character
2425across the boundary.
2426
2427*** The functions find-charset-region and find-charset-string include
2428`unknown' in the returned list in the following cases:
2429 o The current buffer or the target string is unibyte and
2430 contains 8-bit characters.
2431 o The current buffer or the target string is multibyte and
2432 contains invalid characters.
2433
2434*** The functions decode-coding-region and encode-coding-region remove
2435text properties of the target region. Ideally, they should correctly
2436preserve text properties, but for the moment, it's hard. Removing
2437text properties is better than preserving them in a less-than-correct
2438way.
2439
2440*** prefer-coding-system sets EOL conversion of default coding systems.
2441If the argument to prefer-coding-system specifies a certain type of
2442end of line conversion, the default coding systems set by
2443prefer-coding-system will specify that conversion type for end of line.
2444
2445*** The new function thai-compose-string can be used to properly
2446compose Thai characters in a string.
2447
2448** The primitive `define-prefix-command' now takes an optional third
2449argument NAME, which should be a string. It supplies the menu name
2450for the created keymap. Keymaps created in order to be displayed as
2451menus should always use the third argument.
2452
2453** The meanings of optional second arguments for read-char,
2454read-event, and read-char-exclusive are flipped. Now the second
2455arguments are INHERIT-INPUT-METHOD. These functions use the current
2456input method (if any) if and only if INHERIT-INPUT-METHOD is non-nil.
2457
2458** The new function clear-this-command-keys empties out the contents
2459of the vector that (this-command-keys) returns. This is useful in
2460programs that read passwords, to prevent the passwords from echoing
2461inadvertently as part of the next command in certain cases.
2462
2463** The new macro `with-temp-message' displays a temporary message in
2464the echo area, while executing some Lisp code. Like `progn', it
2465returns the value of the last form, but it also restores the previous
2466echo area contents.
2467
2468 (with-temp-message MESSAGE &rest BODY)
2469
2470** The function `require' now takes an optional third argument
2471NOERROR. If it is non-nil, then there is no error if the
2472requested feature cannot be loaded.
2473
2474** In the function modify-face, an argument of (nil) for the
2475foreground color, background color or stipple pattern
2476means to clear out that attribute.
2477
2478** The `outer-window-id' frame property of an X frame
2479gives the window number of the outermost X window for the frame.
2480
2481** Temporary buffers made with with-output-to-temp-buffer are now
2482read-only by default, and normally use the major mode Help mode
2483unless you put them in some other non-Fundamental mode before the
2484end of with-output-to-temp-buffer.
2485
2486** The new functions gap-position and gap-size return information on
2487the gap of the current buffer.
2488
2489** The new functions position-bytes and byte-to-position provide a way
2490to convert between character positions and byte positions in the
2491current buffer.
2492
2493** vc.el defines two new macros, `edit-vc-file' and `with-vc-file', to
2494facilitate working with version-controlled files from Lisp programs.
2495These macros check out a given file automatically if needed, and check
2496it back in after any modifications have been made.
2497\f
2498* Installation Changes in Emacs 20.3
2499
2500** The default value of load-path now includes most subdirectories of
2501the site-specific directories /usr/local/share/emacs/site-lisp and
2502/usr/local/share/emacs/VERSION/site-lisp, in addition to those
2503directories themselves. Both immediate subdirectories and
2504subdirectories multiple levels down are added to load-path.
2505
2506Not all subdirectories are included, though. Subdirectories whose
2507names do not start with a letter or digit are excluded.
2508Subdirectories named RCS or CVS are excluded. Also, a subdirectory
2509which contains a file named `.nosearch' is excluded. You can use
2510these methods to prevent certain subdirectories from being searched.
2511
2512Emacs finds these subdirectories and adds them to load-path when it
2513starts up. While it would be cleaner to find the subdirectories each
2514time Emacs loads a file, that would be much slower.
2515
2516This feature is an incompatible change. If you have stored some Emacs
2517Lisp files in a subdirectory of the site-lisp directory specifically
2518to prevent them from being used, you will need to rename the
2519subdirectory to start with a non-alphanumeric character, or create a
2520`.nosearch' file in it, in order to continue to achieve the desired
2521results.
2522
2523** Emacs no longer includes an old version of the C preprocessor from
2524GCC. This was formerly used to help compile Emacs with C compilers
2525that had limits on the significant length of an identifier, but in
2526fact we stopped supporting such compilers some time ago.
2527\f
2528* Changes in Emacs 20.3
2529
2530** The new command C-x z (repeat) repeats the previous command
2531including its argument. If you repeat the z afterward,
2532it repeats the command additional times; thus, you can
2533perform many repetitions with one keystroke per repetition.
2534
2535** Emacs now supports "selective undo" which undoes only within a
2536specified region. To do this, set point and mark around the desired
2537region and type C-u C-x u (or C-u C-_). You can then continue undoing
2538further, within the same region, by repeating the ordinary undo
2539command C-x u or C-_. This will keep undoing changes that were made
2540within the region you originally specified, until either all of them
2541are undone, or it encounters a change which crosses the edge of that
2542region.
2543
2544In Transient Mark mode, undoing when a region is active requests
2545selective undo.
2546
2547** If you specify --unibyte when starting Emacs, then all buffers are
2548unibyte, except when a Lisp program specifically creates a multibyte
2549buffer. Setting the environment variable EMACS_UNIBYTE has the same
2550effect. The --no-unibyte option overrides EMACS_UNIBYTE and directs
2551Emacs to run normally in multibyte mode.
2552
2553The option --unibyte does not affect the reading of Emacs Lisp files,
2554though. If you want a Lisp file to be read in unibyte mode, use
2555-*-unibyte: t;-*- on its first line. That will force Emacs to
2556load that file in unibyte mode, regardless of how Emacs was started.
2557
2558** toggle-enable-multibyte-characters no longer has a key binding and
2559no longer appears in the menu bar. We've realized that changing the
2560enable-multibyte-characters variable in an existing buffer is
2561something that most users not do.
2562
2563** You can specify a coding system to use for the next cut or paste
2564operations through the window system with the command C-x RET X.
2565The coding system can make a difference for communication with other
2566applications.
2567
2568C-x RET x specifies a coding system for all subsequent cutting and
2569pasting operations.
2570
2571** You can specify the printer to use for commands that do printing by
2572setting the variable `printer-name'. Just what a printer name looks
2573like depends on your operating system. You can specify a different
2574printer for the Postscript printing commands by setting
2575`ps-printer-name'.
2576
2577** Emacs now supports on-the-fly spell checking by the means of a
2578minor mode. It is called M-x flyspell-mode. You don't have to remember
2579any other special commands to use it, and you will hardly notice it
2580except when you make a spelling error. Flyspell works by highlighting
2581incorrect words as soon as they are completed or as soon as the cursor
2582hits a new word.
2583
2584Flyspell mode works with whichever dictionary you have selected for
2585Ispell in Emacs. In TeX mode, it understands TeX syntax so as not
2586to be confused by TeX commands.
2587
2588You can correct a misspelled word by editing it into something
2589correct. You can also correct it, or accept it as correct, by
2590clicking on the word with Mouse-2; that gives you a pop-up menu
2591of various alternative replacements and actions.
2592
2593Flyspell mode also proposes "automatic" corrections. M-TAB replaces
2594the current misspelled word with a possible correction. If several
2595corrections are made possible, M-TAB cycles through them in
2596alphabetical order, or in order of decreasing likelihood if
2597flyspell-sort-corrections is nil.
2598
2599Flyspell mode also flags an error when a word is repeated, if
2600flyspell-mark-duplications-flag is non-nil.
2601
2602** Changes in input method usage.
2603
2604Now you can use arrow keys (right, left, down, up) for selecting among
2605the alternatives just the same way as you do by C-f, C-b, C-n, and C-p
2606respectively.
2607
2608You can use the ENTER key to accept the current conversion.
2609
2610If you type TAB to display a list of alternatives, you can select one
2611of the alternatives with Mouse-2.
2612
2613The meaning of the variable `input-method-verbose-flag' is changed so
2614that you can set it to t, nil, `default', or `complex-only'.
2615
2616 If the value is nil, extra guidance is never given.
2617
2618 If the value is t, extra guidance is always given.
2619
2620 If the value is `complex-only', extra guidance is always given only
2621 when you are using complex input methods such as chinese-py.
2622
2623 If the value is `default' (this is the default), extra guidance is
2624 given in the following case:
2625 o When you are using a complex input method.
2626 o When you are using a simple input method but not in the minibuffer.
2627
2628If you are using Emacs through a very slow line, setting
2629input-method-verbose-flag to nil or to complex-only is a good choice,
2630and if you are using an input method you are not familiar with,
2631setting it to t is helpful.
2632
2633The old command select-input-method is now called set-input-method.
2634
2635In the language environment "Korean", you can use the following
2636keys:
2637 Shift-SPC toggle-korean-input-method
2638 C-F9 quail-hangul-switch-symbol-ksc
2639 F9 quail-hangul-switch-hanja
2640These key bindings are canceled when you switch to another language
2641environment.
2642
2643** The minibuffer history of file names now records the specified file
2644names, not the entire minibuffer input. For example, if the
2645minibuffer starts out with /usr/foo/, you might type in /etc/passwd to
2646get
2647
2648 /usr/foo//etc/passwd
2649
2650which stands for the file /etc/passwd.
2651
2652Formerly, this used to put /usr/foo//etc/passwd in the history list.
2653Now this puts just /etc/passwd in the history list.
2654
2655** If you are root, Emacs sets backup-by-copying-when-mismatch to t
2656at startup, so that saving a file will be sure to preserve
2657its owner and group.
2658
2659** find-func.el can now also find the place of definition of Emacs
2660Lisp variables in user-loaded libraries.
2661
2662** C-x r t (string-rectangle) now deletes the existing rectangle
2663contents before inserting the specified string on each line.
2664
2665** There is a new command delete-whitespace-rectangle
2666which deletes whitespace starting from a particular column
2667in all the lines on a rectangle. The column is specified
2668by the left edge of the rectangle.
2669
2670** You can now store a number into a register with C-u NUMBER C-x r n REG,
2671increment it by INC with C-u INC C-x r + REG (to increment by one, omit
2672C-u INC), and insert it in the buffer with C-x r g REG. This is useful
2673for writing keyboard macros.
2674
2675** The new command M-x speedbar displays a frame in which directories,
2676files, and tags can be displayed, manipulated, and jumped to. The
2677frame defaults to 20 characters in width, and is the same height as
2678the frame that it was started from. Some major modes define
2679additional commands for the speedbar, including Rmail, GUD/GDB, and
2680info.
2681
2682** query-replace-regexp is now bound to C-M-%.
2683
2684** In Transient Mark mode, when the region is active, M-x
2685query-replace and the other replace commands now operate on the region
2686contents only.
2687
2688** M-x write-region, when used interactively, now asks for
2689confirmation before overwriting an existing file. When you call
2690the function from a Lisp program, a new optional argument CONFIRM
2691says whether to ask for confirmation in this case.
2692
2693** If you use find-file-literally and the file is already visited
2694non-literally, the command asks you whether to revisit the file
2695literally. If you say no, it signals an error.
2696
2697** Major modes defined with the "derived mode" feature
2698now use the proper name for the mode hook: WHATEVER-mode-hook.
2699Formerly they used the name WHATEVER-mode-hooks, but that is
2700inconsistent with Emacs conventions.
2701
2702** shell-command-on-region (and shell-command) reports success or
2703failure if the command produces no output.
2704
2705** Set focus-follows-mouse to nil if your window system or window
2706manager does not transfer focus to another window when you just move
2707the mouse.
2708
2709** mouse-menu-buffer-maxlen has been renamed to
2710mouse-buffer-menu-maxlen to be consistent with the other related
2711function and variable names.
2712
2713** The new variable auto-coding-alist specifies coding systems for
2714reading specific files. This has higher priority than
2715file-coding-system-alist.
2716
2717** If you set the variable unibyte-display-via-language-environment to
2718t, then Emacs displays non-ASCII characters are displayed by
2719converting them to the equivalent multibyte characters according to
2720the current language environment. As a result, they are displayed
2721according to the current fontset.
2722
2723** C-q's handling of codes in the range 0200 through 0377 is changed.
2724
2725The codes in the range 0200 through 0237 are inserted as one byte of
2726that code regardless of the values of nonascii-translation-table and
2727nonascii-insert-offset.
2728
2729For the codes in the range 0240 through 0377, if
2730enable-multibyte-characters is non-nil and nonascii-translation-table
2731nor nonascii-insert-offset can't convert them to valid multibyte
2732characters, they are converted to Latin-1 characters.
2733
2734** If you try to find a file that is not read-accessible, you now get
2735an error, rather than an empty buffer and a warning.
2736
2737** In the minibuffer history commands M-r and M-s, an upper case
2738letter in the regular expression forces case-sensitive search.
2739
2740** In the *Help* buffer, cross-references to commands and variables
2741are inferred and hyperlinked. Use C-h m in Help mode for the relevant
2742command keys.
2743
2744** M-x apropos-command, with a prefix argument, no longer looks for
2745user option variables--instead it looks for noninteractive functions.
2746
2747Meanwhile, the command apropos-variable normally searches for
2748user option variables; with a prefix argument, it looks at
2749all variables that have documentation.
2750
2751** When you type a long line in the minibuffer, and the minibuffer
2752shows just one line, automatically scrolling works in a special way
2753that shows you overlap with the previous line of text. The variable
2754minibuffer-scroll-overlap controls how many characters of overlap
2755it should show; the default is 20.
2756
2757Meanwhile, Resize Minibuffer mode is still available; in that mode,
2758the minibuffer grows taller (up to a point) as needed to show the whole
2759of your input.
2760
2761** The new command M-x customize-changed-options lets you customize
2762all the options whose meanings or default values have changed in
2763recent Emacs versions. You specify a previous Emacs version number as
2764argument, and the command creates a customization buffer showing all
2765the customizable options which were changed since that version.
2766Newly added options are included as well.
2767
2768If you don't specify a particular version number argument,
2769then the customization buffer shows all the customizable options
2770for which Emacs versions of changes are recorded.
2771
2772This function is also bound to the Changed Options entry in the
2773Customize menu.
2774
2775** When you run M-x grep with a prefix argument, it figures out
2776the tag around point and puts that into the default grep command.
2777
2778** The new command M-* (pop-tag-mark) pops back through a history of
2779buffer positions from which M-. or other tag-finding commands were
2780invoked.
2781
2782** The new variable comment-padding specifies the number of spaces
2783that `comment-region' will insert before the actual text of the comment.
2784The default is 1.
2785
2786** In Fortran mode the characters `.', `_' and `$' now have symbol
2787syntax, not word syntax. Fortran mode now supports `imenu' and has
2788new commands fortran-join-line (M-^) and fortran-narrow-to-subprogram
2789(C-x n d). M-q can be used to fill a statement or comment block
2790sensibly.
2791
2792** GUD now supports jdb, the Java debugger, and pdb, the Python debugger.
2793
2794** If you set the variable add-log-keep-changes-together to a non-nil
2795value, the command `C-x 4 a' will automatically notice when you make
2796two entries in one day for one file, and combine them.
2797
2798** You can use the command M-x diary-mail-entries to mail yourself a
2799reminder about upcoming diary entries. See the documentation string
2800for a sample shell script for calling this function automatically
2801every night.
2802
2803** All you need to do, to enable use of the Desktop package, is to set
2804the variable desktop-enable to t with Custom.
2805
2806** There is no need to do anything special, now, to enable Gnus to
2807read and post multi-lingual articles.
2808
2809** Outline mode has now support for showing hidden outlines when
2810doing an isearch. In order for this to happen search-invisible should
2811be set to open (the default). If an isearch match is inside a hidden
2812outline the outline is made visible. If you continue pressing C-s and
2813the match moves outside the formerly invisible outline, the outline is
2814made invisible again.
2815
2816** Mail reading and sending changes
2817
2818*** The Rmail e command now switches to displaying the whole header of
2819the message before it lets you edit the message. This is so that any
2820changes you make in the header will not be lost if you subsequently
2821toggle.
2822
2823*** The w command in Rmail, which writes the message body into a file,
2824now works in the summary buffer as well. (The command to delete the
2825summary buffer is now Q.) The default file name for the w command, if
2826the message has no subject, is stored in the variable
2827rmail-default-body-file.
2828
2829*** Most of the commands and modes that operate on mail and netnews no
2830longer depend on the value of mail-header-separator. Instead, they
2831handle whatever separator the buffer happens to use.
2832
2833*** If you set mail-signature to a value which is not t, nil, or a string,
2834it should be an expression. When you send a message, this expression
2835is evaluated to insert the signature.
2836
2837*** The new Lisp library feedmail.el (version 8) enhances processing of
2838outbound email messages. It works in coordination with other email
2839handling packages (e.g., rmail, VM, gnus) and is responsible for
2840putting final touches on messages and actually submitting them for
2841transmission. Users of the emacs program "fakemail" might be
2842especially interested in trying feedmail.
2843
2844feedmail is not enabled by default. See comments at the top of
2845feedmail.el for set-up instructions. Among the bigger features
2846provided by feedmail are:
2847
2848**** you can park outgoing messages into a disk-based queue and
2849stimulate sending some or all of them later (handy for laptop users);
2850there is also a queue for draft messages
2851
2852**** you can get one last look at the prepped outbound message and
2853be prompted for confirmation
2854
2855**** does smart filling of address headers
2856
2857**** can generate a MESSAGE-ID: line and a DATE: line; the date can be
2858the time the message was written or the time it is being sent; this
2859can make FCC copies more closely resemble copies that recipients get
2860
2861**** you can specify an arbitrary function for actually transmitting
2862the message; included in feedmail are interfaces for /bin/[r]mail,
2863/usr/lib/sendmail, and elisp smtpmail; it's easy to write a new
2864function for something else (10-20 lines of elisp)
2865
2866** Dired changes
2867
2868*** The Dired function dired-do-toggle, which toggles marked and unmarked
2869files, is now bound to "t" instead of "T".
2870
2871*** dired-at-point has been added to ffap.el. It allows one to easily
2872run Dired on the directory name at point.
2873
2874*** Dired has a new command: %g. It searches the contents of
2875files in the directory and marks each file that contains a match
2876for a specified regexp.
2877
2878** VC Changes
2879
2880*** New option vc-ignore-vc-files lets you turn off version control
2881conveniently.
2882
2883*** VC Dired has been completely rewritten. It is now much
2884faster, especially for CVS, and works very similar to ordinary
2885Dired.
2886
2887VC Dired is invoked by typing C-x v d and entering the name of the
2888directory to display. By default, VC Dired gives you a recursive
2889listing of all files at or below the given directory which are
2890currently locked (for CVS, all files not up-to-date are shown).
2891
2892You can change the listing format by setting vc-dired-recurse to nil,
2893then it shows only the given directory, and you may also set
2894vc-dired-terse-display to nil, then it shows all files under version
2895control plus the names of any subdirectories, so that you can type `i'
2896on such lines to insert them manually, as in ordinary Dired.
2897
2898All Dired commands operate normally in VC Dired, except for `v', which
2899is redefined as the version control prefix. That means you may type
2900`v l', `v =' etc. to invoke `vc-print-log', `vc-diff' and the like on
2901the file named in the current Dired buffer line. `v v' invokes
2902`vc-next-action' on this file, or on all files currently marked.
2903
2904The new command `v t' (vc-dired-toggle-terse-mode) allows you to
2905toggle between terse display (only locked files) and full display (all
2906VC files plus subdirectories). There is also a special command,
2907`* l', to mark all files currently locked.
2908
2909Giving a prefix argument to C-x v d now does the same thing as in
2910ordinary Dired: it allows you to supply additional options for the ls
2911command in the minibuffer, to fine-tune VC Dired's output.
2912
2913*** Under CVS, if you merge changes from the repository into a working
2914file, and CVS detects conflicts, VC now offers to start an ediff
2915session to resolve them.
2916
2917Alternatively, you can use the new command `vc-resolve-conflicts' to
2918resolve conflicts in a file at any time. It works in any buffer that
2919contains conflict markers as generated by rcsmerge (which is what CVS
2920uses as well).
2921
2922*** You can now transfer changes between branches, using the new
2923command vc-merge (C-x v m). It is implemented for RCS and CVS. When
2924you invoke it in a buffer under version-control, you can specify
2925either an entire branch or a pair of versions, and the changes on that
2926branch or between the two versions are merged into the working file.
2927If this results in any conflicts, they may be resolved interactively,
2928using ediff.
2929
2930** Changes in Font Lock
2931
2932*** The face and variable previously known as font-lock-reference-face
2933are now called font-lock-constant-face to better reflect their typical
2934use for highlighting constants and labels. (Its face properties are
2935unchanged.) The variable font-lock-reference-face remains for now for
2936compatibility reasons, but its value is font-lock-constant-face.
2937
2938** Frame name display changes
2939
2940*** The command set-frame-name lets you set the name of the current
2941frame. You can use the new command select-frame-by-name to select and
2942raise a frame; this is mostly useful on character-only terminals, or
2943when many frames are invisible or iconified.
2944
2945*** On character-only terminal (not a window system), changing the
2946frame name is now reflected on the mode line and in the Buffers/Frames
2947menu.
2948
2949** Comint (subshell) changes
2950
2951*** In Comint modes, the commands to kill, stop or interrupt a
2952subjob now also kill pending input. This is for compatibility
2953with ordinary shells, where the signal characters do this.
2954
2955*** There are new commands in Comint mode.
2956
2957C-c C-x fetches the "next" line from the input history;
2958that is, the line after the last line you got.
2959You can use this command to fetch successive lines, one by one.
2960
2961C-c SPC accumulates lines of input. More precisely, it arranges to
2962send the current line together with the following line, when you send
2963the following line.
2964
2965C-c C-a if repeated twice consecutively now moves to the process mark,
2966which separates the pending input from the subprocess output and the
2967previously sent input.
2968
2969C-c M-r now runs comint-previous-matching-input-from-input;
2970it searches for a previous command, using the current pending input
2971as the search string.
2972
2973*** New option compilation-scroll-output can be set to scroll
2974automatically in compilation-mode windows.
2975
2976** C mode changes
2977
2978*** Multiline macros are now handled, both as they affect indentation,
2979and as recognized syntax. New syntactic symbol cpp-macro-cont is
2980assigned to second and subsequent lines of a multiline macro
2981definition.
2982
2983*** A new style "user" which captures all non-hook-ified
2984(i.e. top-level) .emacs file variable settings and customizations.
2985Style "cc-mode" is an alias for "user" and is deprecated. "gnu"
2986style is still the default however.
2987
2988*** "java" style now conforms to Sun's JDK coding style.
2989
2990*** There are new commands c-beginning-of-defun, c-end-of-defun which
2991are alternatives which you could bind to C-M-a and C-M-e if you prefer
2992them. They do not have key bindings by default.
2993
2994*** New and improved implementations of M-a (c-beginning-of-statement)
2995and M-e (c-end-of-statement).
2996
2997*** C++ namespace blocks are supported, with new syntactic symbols
2998namespace-open, namespace-close, and innamespace.
2999
3000*** File local variable settings of c-file-style and c-file-offsets
3001makes the style variables local to that buffer only.
3002
3003*** New indentation functions c-lineup-close-paren,
3004c-indent-one-line-block, c-lineup-dont-change.
3005
3006*** Improvements (hopefully!) to the way CC Mode is loaded. You
3007should now be able to do a (require 'cc-mode) to get the entire
3008package loaded properly for customization in your .emacs file. A new
3009variable c-initialize-on-load controls this and is t by default.
3010
3011** Changes to hippie-expand.
3012
3013*** New customization variable `hippie-expand-dabbrev-skip-space'. If
3014non-nil, trailing spaces may be included in the abbreviation to search for,
3015which then gives the same behavior as the original `dabbrev-expand'.
3016
3017*** New customization variable `hippie-expand-dabbrev-as-symbol'. If
3018non-nil, characters of syntax '_' is considered part of the word when
3019expanding dynamically.
3020
3021*** New customization variable `hippie-expand-no-restriction'. If
3022non-nil, narrowed buffers are widened before they are searched.
3023
3024*** New customization variable `hippie-expand-only-buffers'. If
3025non-empty, buffers searched are restricted to the types specified in
3026this list. Useful for example when constructing new special-purpose
3027expansion functions with `make-hippie-expand-function'.
3028
3029*** Text properties of the expansion are no longer copied.
3030
3031** Changes in BibTeX mode.
3032
3033*** Any titleword matching a regexp in the new variable
3034bibtex-autokey-titleword-ignore (case sensitive) is ignored during
3035automatic key generation. This replaces variable
3036bibtex-autokey-titleword-first-ignore, which only checked for matches
3037against the first word in the title.
3038
3039*** Autokey generation now uses all words from the title, not just
3040capitalized words. To avoid conflicts with existing customizations,
3041bibtex-autokey-titleword-ignore is set up such that words starting with
3042lowerkey characters will still be ignored. Thus, if you want to use
3043lowercase words from the title, you will have to overwrite the
3044bibtex-autokey-titleword-ignore standard setting.
3045
3046*** Case conversion of names and title words for automatic key
3047generation is more flexible. Variable bibtex-autokey-preserve-case is
3048replaced by bibtex-autokey-titleword-case-convert and
3049bibtex-autokey-name-case-convert.
3050
3051** Changes in vcursor.el.
3052
3053*** Support for character terminals is available: there is a new keymap
3054and the vcursor will appear as an arrow between buffer text. A
3055variable `vcursor-interpret-input' allows input from the vcursor to be
3056entered exactly as if typed. Numerous functions, including
3057`vcursor-compare-windows', have been rewritten to improve consistency
3058in the selection of windows and corresponding keymaps.
3059
3060*** vcursor options can now be altered with M-x customize under the
3061Editing group once the package is loaded.
3062
3063*** Loading vcursor now does not define keys by default, as this is
3064generally a bad side effect. Use M-x customize to set
3065vcursor-key-bindings to t to restore the old behaviour.
3066
3067*** vcursor-auto-disable can be `copy', which turns off copying from the
3068vcursor, but doesn't disable it, after any non-vcursor command.
3069
3070** Ispell changes.
3071
3072*** You can now spell check comments and strings in the current
3073buffer with M-x ispell-comments-and-strings. Comments and strings
3074are identified by syntax tables in effect.
3075
3076*** Generic region skipping implemented.
3077A single buffer can be broken into a number of regions where text will
3078and will not be checked. The definitions of the regions can be user
3079defined. New applications and improvements made available by this
3080include:
3081
3082 o URLs are automatically skipped
3083 o EMail message checking is vastly improved.
3084
3085*** Ispell can highlight the erroneous word even on non-window terminals.
3086
3087** Changes to RefTeX mode
3088
3089RefTeX has been updated in order to make it more usable with very
3090large projects (like a several volume math book). The parser has been
3091re-written from scratch. To get maximum speed from RefTeX, check the
3092section `Optimizations' in the manual.
3093
3094*** New recursive parser.
3095
3096The old version of RefTeX created a single large buffer containing the
3097entire multifile document in order to parse the document. The new
3098recursive parser scans the individual files.
3099
3100*** Parsing only part of a document.
3101
3102Reparsing of changed document parts can now be made faster by enabling
3103partial scans. To use this feature, read the documentation string of
3104the variable `reftex-enable-partial-scans' and set the variable to t.
3105
3106 (setq reftex-enable-partial-scans t)
3107
3108*** Storing parsing information in a file.
3109
3110This can improve startup times considerably. To turn it on, use
3111
3112 (setq reftex-save-parse-info t)
3113
3114*** Using multiple selection buffers
3115
3116If the creation of label selection buffers is too slow (this happens
3117for large documents), you can reuse these buffers by setting
3118
3119 (setq reftex-use-multiple-selection-buffers t)
3120
3121*** References to external documents.
3122
3123The LaTeX package `xr' allows to cross-reference labels in external
3124documents. RefTeX can provide information about the external
3125documents as well. To use this feature, set up the \externaldocument
3126macros required by the `xr' package and rescan the document with
3127RefTeX. The external labels can then be accessed with the `x' key in
3128the selection buffer provided by `reftex-reference' (bound to `C-c )').
3129The `x' key also works in the table of contents buffer.
3130
3131*** Many more labeled LaTeX environments are recognized by default.
3132
3133The builtin command list now covers all the standard LaTeX commands,
3134and all of the major packages included in the LaTeX distribution.
3135
3136Also, RefTeX now understands the \appendix macro and changes
3137the enumeration of sections in the *toc* buffer accordingly.
3138
3139*** Mouse support for selection and *toc* buffers
3140
3141The mouse can now be used to select items in the selection and *toc*
3142buffers. See also the new option `reftex-highlight-selection'.
3143
3144*** New keymaps for selection and table of contents modes.
3145
3146The selection processes for labels and citation keys, and the table of
3147contents buffer now have their own keymaps: `reftex-select-label-map',
3148`reftex-select-bib-map', `reftex-toc-map'. The selection processes
3149have a number of new keys predefined. In particular, TAB lets you
3150enter a label with completion. Check the on-the-fly help (press `?'
3151at the selection prompt) or read the Info documentation to find out
3152more.
3153
3154*** Support for the varioref package
3155
3156The `v' key in the label selection buffer toggles \ref versus \vref.
3157
3158*** New hooks
3159
3160Three new hooks can be used to redefine the way labels, references,
3161and citations are created. These hooks are
3162`reftex-format-label-function', `reftex-format-ref-function',
3163`reftex-format-cite-function'.
3164
3165*** Citations outside LaTeX
3166
3167The command `reftex-citation' may also be used outside LaTeX (e.g. in
3168a mail buffer). See the Info documentation for details.
3169
3170*** Short context is no longer fontified.
3171
3172The short context in the label menu no longer copies the
3173fontification from the text in the buffer. If you prefer it to be
3174fontified, use
3175
3176 (setq reftex-refontify-context t)
3177
3178** file-cache-minibuffer-complete now accepts a prefix argument.
3179With a prefix argument, it does not try to do completion of
3180the file name within its directory; it only checks for other
3181directories that contain the same file name.
3182
3183Thus, given the file name Makefile, and assuming that a file
3184Makefile.in exists in the same directory, ordinary
3185file-cache-minibuffer-complete will try to complete Makefile to
3186Makefile.in and will therefore never look for other directories that
3187have Makefile. A prefix argument tells it not to look for longer
3188names such as Makefile.in, so that instead it will look for other
3189directories--just as if the name were already complete in its present
3190directory.
3191
3192** New modes and packages
3193
3194*** There is a new alternative major mode for Perl, Cperl mode.
3195It has many more features than Perl mode, and some people prefer
3196it, but some do not.
3197
3198*** There is a new major mode, M-x vhdl-mode, for editing files of VHDL
3199code.
3200
3201*** M-x which-function-mode enables a minor mode that displays the
3202current function name continuously in the mode line, as you move
3203around in a buffer.
3204
3205Which Function mode is effective in major modes which support Imenu.
3206
3207*** Gametree is a major mode for editing game analysis trees. The author
3208uses it for keeping notes about his postal Chess games, but it should
3209be helpful for other two-player games as well, as long as they have an
3210established system of notation similar to Chess.
3211
3212*** The new minor mode checkdoc-minor-mode provides Emacs Lisp
3213documentation string checking for style and spelling. The style
3214guidelines are found in the Emacs Lisp programming manual.
3215
3216*** The net-utils package makes some common networking features
3217available in Emacs. Some of these functions are wrappers around
3218system utilities (ping, nslookup, etc); others are implementations of
3219simple protocols (finger, whois) in Emacs Lisp. There are also
3220functions to make simple connections to TCP/IP ports for debugging and
3221the like.
3222
3223*** highlight-changes-mode is a minor mode that uses colors to
3224identify recently changed parts of the buffer text.
3225
3226*** The new package `midnight' lets you specify things to be done
3227within Emacs at midnight--by default, kill buffers that you have not
3228used in a considerable time. To use this feature, customize
3229the user option `midnight-mode' to t.
3230
3231*** The file generic-x.el defines a number of simple major modes.
3232
3233 apache-generic-mode: For Apache and NCSA httpd configuration files
3234 samba-generic-mode: Samba configuration files
3235 fvwm-generic-mode: For fvwm initialization files
3236 x-resource-generic-mode: For X resource files
3237 hosts-generic-mode: For hosts files (.rhosts, /etc/hosts, etc)
3238 mailagent-rules-generic-mode: For mailagent .rules files
3239 javascript-generic-mode: For JavaScript files
3240 vrml-generic-mode: For VRML files
3241 java-manifest-generic-mode: For Java MANIFEST files
3242 java-properties-generic-mode: For Java property files
3243 mailrc-generic-mode: For .mailrc files
3244
3245 Platform-specific modes:
3246
3247 prototype-generic-mode: For Solaris/Sys V prototype files
3248 pkginfo-generic-mode: For Solaris/Sys V pkginfo files
3249 alias-generic-mode: For C shell alias files
3250 inf-generic-mode: For MS-Windows INF files
3251 ini-generic-mode: For MS-Windows INI files
3252 reg-generic-mode: For MS-Windows Registry files
3253 bat-generic-mode: For MS-Windows BAT scripts
3254 rc-generic-mode: For MS-Windows Resource files
3255 rul-generic-mode: For InstallShield scripts
3256\f
3257* Lisp changes in Emacs 20.3 since the Emacs Lisp Manual was published
3258
3259** If you want a Lisp file to be read in unibyte mode,
3260use -*-unibyte: t;-*- on its first line.
3261That will force Emacs to read that file in unibyte mode.
3262Otherwise, the file will be loaded and byte-compiled in multibyte mode.
3263
3264Thus, each lisp file is read in a consistent way regardless of whether
3265you started Emacs with --unibyte, so that a Lisp program gives
3266consistent results regardless of how Emacs was started.
3267
3268** The new function assoc-default is useful for searching an alist,
3269and using a default value if the key is not found there. You can
3270specify a comparison predicate, so this function is useful for
3271searching comparing a string against an alist of regular expressions.
3272
3273** The functions unibyte-char-to-multibyte and
3274multibyte-char-to-unibyte convert between unibyte and multibyte
3275character codes, in a way that is appropriate for the current language
3276environment.
3277
3278** The functions read-event, read-char and read-char-exclusive now
3279take two optional arguments. PROMPT, if non-nil, specifies a prompt
3280string. SUPPRESS-INPUT-METHOD, if non-nil, says to disable the
3281current input method for reading this one event.
3282
3283** Two new variables print-escape-nonascii and print-escape-multibyte
3284now control whether to output certain characters as
3285backslash-sequences. print-escape-nonascii applies to single-byte
3286non-ASCII characters; print-escape-multibyte applies to multibyte
3287characters. Both of these variables are used only when printing
3288in readable fashion (prin1 uses them, princ does not).
3289\f
3290* Lisp changes in Emacs 20.3 before the Emacs Lisp Manual was published
3291
3292** Compiled Emacs Lisp files made with the modified "MBSK" version
3293of Emacs 20.2 do not work in Emacs 20.3.
3294
3295** Buffer positions are now measured in characters, as they were
3296in Emacs 19 and before. This means that (forward-char 1)
3297always increases point by 1.
3298
3299The function chars-in-region now just subtracts its arguments. It is
3300considered obsolete. The function char-boundary-p has been deleted.
3301
3302See below for additional changes relating to multibyte characters.
3303
3304** defcustom, defface and defgroup now accept the keyword `:version'.
3305Use this to specify in which version of Emacs a certain variable's
3306default value changed. For example,
3307
3308 (defcustom foo-max 34 "*Maximum number of foo's allowed."
3309 :type 'integer
3310 :group 'foo
3311 :version "20.3")
3312
3313 (defgroup foo-group nil "The foo group."
3314 :version "20.3")
3315
3316If an entire new group is added or the variables in it have the
3317default values changed, then just add a `:version' to that group. It
3318is recommended that new packages added to the distribution contain a
3319`:version' in the top level group.
3320
3321This information is used to control the customize-changed-options command.
3322
3323** It is now an error to change the value of a symbol whose name
3324starts with a colon--if it is interned in the standard obarray.
3325
3326However, setting such a symbol to its proper value, which is that
3327symbol itself, is not an error. This is for the sake of programs that
3328support previous Emacs versions by explicitly setting these variables
3329to themselves.
3330
3331If you set the variable keyword-symbols-constant-flag to nil,
3332this error is suppressed, and you can set these symbols to any
3333values whatever.
3334
3335** There is a new debugger command, R.
3336It evaluates an expression like e, but saves the result
3337in the buffer *Debugger-record*.
3338
3339** Frame-local variables.
3340
3341You can now make a variable local to various frames. To do this, call
3342the function make-variable-frame-local; this enables frames to have
3343local bindings for that variable.
3344
3345These frame-local bindings are actually frame parameters: you create a
3346frame-local binding in a specific frame by calling
3347modify-frame-parameters and specifying the variable name as the
3348parameter name.
3349
3350Buffer-local bindings take precedence over frame-local bindings.
3351Thus, if the current buffer has a buffer-local binding, that binding is
3352active; otherwise, if the selected frame has a frame-local binding,
3353that binding is active; otherwise, the default binding is active.
3354
3355It would not be hard to implement window-local bindings, but it is not
3356clear that this would be very useful; windows tend to come and go in a
3357very transitory fashion, so that trying to produce any specific effect
3358through a window-local binding would not be very robust.
3359
3360** `sregexq' and `sregex' are two new functions for constructing
3361"symbolic regular expressions." These are Lisp expressions that, when
3362evaluated, yield conventional string-based regexps. The symbolic form
3363makes it easier to construct, read, and maintain complex patterns.
3364See the documentation in sregex.el.
3365
3366** parse-partial-sexp's return value has an additional element which
3367is used to pass information along if you pass it to another call to
3368parse-partial-sexp, starting its scan where the first call ended.
3369The contents of this field are not yet finalized.
3370
3371** eval-region now accepts a fourth optional argument READ-FUNCTION.
3372If it is non-nil, that function is used instead of `read'.
3373
3374** unload-feature by default removes the feature's functions from
3375known hooks to avoid trouble, but a package providing FEATURE can
3376define a hook FEATURE-unload-hook to be run by unload-feature instead.
3377
3378** read-from-minibuffer no longer returns the argument DEFAULT-VALUE
3379when the user enters empty input. It now returns the null string, as
3380it did in Emacs 19. The default value is made available in the
3381history via M-n, but it is not applied here as a default.
3382
3383The other, more specialized minibuffer-reading functions continue to
3384return the default value (not the null string) when the user enters
3385empty input.
3386
3387** The new variable read-buffer-function controls which routine to use
3388for selecting buffers. For example, if you set this variable to
3389`iswitchb-read-buffer', iswitchb will be used to read buffer names.
3390Other functions can also be used if they accept the same arguments as
3391`read-buffer' and return the selected buffer name as a string.
3392
3393** The new function read-passwd reads a password from the terminal,
3394echoing a period for each character typed. It takes three arguments:
3395a prompt string, a flag which says "read it twice to make sure", and a
3396default password to use if the user enters nothing.
3397
3398** The variable fill-nobreak-predicate gives major modes a way to
3399specify not to break a line at certain places. Its value is a
3400function which is called with no arguments, with point located at the
3401place where a break is being considered. If the function returns
3402non-nil, then the line won't be broken there.
3403
3404** window-end now takes an optional second argument, UPDATE.
3405If this is non-nil, then the function always returns an accurate
3406up-to-date value for the buffer position corresponding to the
3407end of the window, even if this requires computation.
3408
3409** other-buffer now takes an optional argument FRAME
3410which specifies which frame's buffer list to use.
3411If it is nil, that means use the selected frame's buffer list.
3412
3413** The new variable buffer-display-time, always local in every buffer,
3414holds the value of (current-time) as of the last time that a window
3415was directed to display this buffer.
3416
3417** It is now meaningful to compare two window-configuration objects
3418with `equal'. Two window-configuration objects are equal if they
3419describe equivalent arrangements of windows, in the same frame--in
3420other words, if they would give the same results if passed to
3421set-window-configuration.
3422
3423** compare-window-configurations is a new function that compares two
3424window configurations loosely. It ignores differences in saved buffer
3425positions and scrolling, and considers only the structure and sizes of
3426windows and the choice of buffers to display.
3427
3428** The variable minor-mode-overriding-map-alist allows major modes to
3429override the key bindings of a minor mode. The elements of this alist
3430look like the elements of minor-mode-map-alist: (VARIABLE . KEYMAP).
3431
3432If the VARIABLE in an element of minor-mode-overriding-map-alist has a
3433non-nil value, the paired KEYMAP is active, and totally overrides the
3434map (if any) specified for the same variable in minor-mode-map-alist.
3435
3436minor-mode-overriding-map-alist is automatically local in all buffers,
3437and it is meant to be set by major modes.
3438
3439** The function match-string-no-properties is like match-string
3440except that it discards all text properties from the result.
3441
3442** The function load-average now accepts an optional argument
3443USE-FLOATS. If it is non-nil, the load average values are returned as
3444floating point numbers, rather than as integers to be divided by 100.
3445
3446** The new variable temporary-file-directory specifies the directory
3447to use for creating temporary files. The default value is determined
3448in a reasonable way for your operating system; on GNU and Unix systems
3449it is based on the TMP and TMPDIR environment variables.
3450
3451** Menu changes
3452
3453*** easymenu.el now uses the new menu item format and supports the
3454keywords :visible and :filter. The existing keyword :keys is now
3455better supported.
3456
3457The variable `easy-menu-precalculate-equivalent-keybindings' controls
3458a new feature which calculates keyboard equivalents for the menu when
3459you define the menu. The default is t. If you rarely use menus, you
3460can set the variable to nil to disable this precalculation feature;
3461then the calculation is done only if you use the menu bar.
3462
3463*** A new format for menu items is supported.
3464
3465In a keymap, a key binding that has the format
3466 (STRING . REAL-BINDING) or (STRING HELP-STRING . REAL-BINDING)
3467defines a menu item. Now a menu item definition may also be a list that
3468starts with the symbol `menu-item'.
3469
3470The format is:
3471 (menu-item ITEM-NAME) or
3472 (menu-item ITEM-NAME REAL-BINDING . ITEM-PROPERTY-LIST)
3473where ITEM-NAME is an expression which evaluates to the menu item
3474string, and ITEM-PROPERTY-LIST has the form of a property list.
3475The supported properties include
3476
3477:enable FORM Evaluate FORM to determine whether the
3478 item is enabled.
3479:visible FORM Evaluate FORM to determine whether the
3480 item should appear in the menu.
3481:filter FILTER-FN
3482 FILTER-FN is a function of one argument,
3483 which will be REAL-BINDING.
3484 It should return a binding to use instead.
3485:keys DESCRIPTION
3486 DESCRIPTION is a string that describes an equivalent keyboard
3487 binding for for REAL-BINDING. DESCRIPTION is expanded with
3488 `substitute-command-keys' before it is used.
3489:key-sequence KEY-SEQUENCE
3490 KEY-SEQUENCE is a key-sequence for an equivalent
3491 keyboard binding.
3492:key-sequence nil
3493 This means that the command normally has no
3494 keyboard equivalent.
3495:help HELP HELP is the extra help string (not currently used).
3496:button (TYPE . SELECTED)
3497 TYPE is :toggle or :radio.
3498 SELECTED is a form, to be evaluated, and its
3499 value says whether this button is currently selected.
3500
3501Buttons are at the moment only simulated by prefixes in the menu.
3502Eventually ordinary X-buttons may be supported.
3503
3504(menu-item ITEM-NAME) defines unselectable item.
3505
3506** New event types
3507
3508*** The new event type `mouse-wheel' is generated by a wheel on a
3509mouse (such as the MS Intellimouse). The event contains a delta that
3510corresponds to the amount and direction that the wheel is rotated,
3511which is typically used to implement a scroll or zoom. The format is:
3512
3513 (mouse-wheel POSITION DELTA)
3514
3515where POSITION is a list describing the position of the event in the
3516same format as a mouse-click event, and DELTA is a signed number
3517indicating the number of increments by which the wheel was rotated. A
3518negative DELTA indicates that the wheel was rotated backwards, towards
3519the user, and a positive DELTA indicates that the wheel was rotated
3520forward, away from the user.
3521
3522As of now, this event type is generated only on MS Windows.
3523
3524*** The new event type `drag-n-drop' is generated when a group of
3525files is selected in an application outside of Emacs, and then dragged
3526and dropped onto an Emacs frame. The event contains a list of
3527filenames that were dragged and dropped, which are then typically
3528loaded into Emacs. The format is:
3529
3530 (drag-n-drop POSITION FILES)
3531
3532where POSITION is a list describing the position of the event in the
3533same format as a mouse-click event, and FILES is the list of filenames
3534that were dragged and dropped.
3535
3536As of now, this event type is generated only on MS Windows.
3537
3538** Changes relating to multibyte characters.
3539
3540*** The variable enable-multibyte-characters is now read-only;
3541any attempt to set it directly signals an error. The only way
3542to change this value in an existing buffer is with set-buffer-multibyte.
3543
3544*** In a string constant, `\ ' now stands for "nothing at all". You
3545can use it to terminate a hex escape which is followed by a character
3546that could otherwise be read as part of the hex escape.
3547
3548*** String indices are now measured in characters, as they were
3549in Emacs 19 and before.
3550
3551The function chars-in-string has been deleted.
3552The function concat-chars has been renamed to `string'.
3553
3554*** The function set-buffer-multibyte sets the flag in the current
3555buffer that says whether the buffer uses multibyte representation or
3556unibyte representation. If the argument is nil, it selects unibyte
3557representation. Otherwise it selects multibyte representation.
3558
3559This function does not change the contents of the buffer, viewed
3560as a sequence of bytes. However, it does change the contents
3561viewed as characters; a sequence of two bytes which is treated as
3562one character when the buffer uses multibyte representation
3563will count as two characters using unibyte representation.
3564
3565This function sets enable-multibyte-characters to record which
3566representation is in use. It also adjusts various data in the buffer
3567(including its markers, overlays and text properties) so that they are
3568consistent with the new representation.
3569
3570*** string-make-multibyte takes a string and converts it to multibyte
3571representation. Most of the time, you don't need to care
3572about the representation, because Emacs converts when necessary;
3573however, it makes a difference when you compare strings.
3574
3575The conversion of non-ASCII characters works by adding the value of
3576nonascii-insert-offset to each character, or by translating them
3577using the table nonascii-translation-table.
3578
3579*** string-make-unibyte takes a string and converts it to unibyte
3580representation. Most of the time, you don't need to care about the
3581representation, but it makes a difference when you compare strings.
3582
3583The conversion from multibyte to unibyte representation
3584loses information; the only time Emacs performs it automatically
3585is when inserting a multibyte string into a unibyte buffer.
3586
3587*** string-as-multibyte takes a string, and returns another string
3588which contains the same bytes, but treats them as multibyte.
3589
3590*** string-as-unibyte takes a string, and returns another string
3591which contains the same bytes, but treats them as unibyte.
3592
3593*** The new function compare-strings lets you compare
3594portions of two strings. Unibyte strings are converted to multibyte,
3595so that a unibyte string can match a multibyte string.
3596You can specify whether to ignore case or not.
3597
3598*** assoc-ignore-case now uses compare-strings so that
3599it can treat unibyte and multibyte strings as equal.
3600
3601*** Regular expression operations and buffer string searches now
3602convert the search pattern to multibyte or unibyte to accord with the
3603buffer or string being searched.
3604
3605One consequence is that you cannot always use \200-\377 inside of
3606[...] to match all non-ASCII characters. This does still work when
3607searching or matching a unibyte buffer or string, but not when
3608searching or matching a multibyte string. Unfortunately, there is no
3609obvious choice of syntax to use within [...] for that job. But, what
3610you want is just to match all non-ASCII characters, the regular
3611expression [^\0-\177] works for it.
3612
3613*** Structure of coding system changed.
3614
3615All coding systems (including aliases and subsidiaries) are named
3616by symbols; the symbol's `coding-system' property is a vector
3617which defines the coding system. Aliases share the same vector
3618as the principal name, so that altering the contents of this
3619vector affects the principal name and its aliases. You can define
3620your own alias name of a coding system by the function
3621define-coding-system-alias.
3622
3623The coding system definition includes a property list of its own. Use
3624the new functions `coding-system-get' and `coding-system-put' to
3625access such coding system properties as post-read-conversion,
3626pre-write-conversion, character-translation-table-for-decode,
3627character-translation-table-for-encode, mime-charset, and
3628safe-charsets. For instance, (coding-system-get 'iso-latin-1
3629'mime-charset) gives the corresponding MIME-charset parameter
3630`iso-8859-1'.
3631
3632Among the coding system properties listed above, safe-charsets is new.
3633The value of this property is a list of character sets which this
3634coding system can correctly encode and decode. For instance:
3635(coding-system-get 'iso-latin-1 'safe-charsets) => (ascii latin-iso8859-1)
3636
3637Here, "correctly encode" means that the encoded character sets can
3638also be handled safely by systems other than Emacs as far as they
3639are capable of that coding system. Though, Emacs itself can encode
3640the other character sets and read it back correctly.
3641
3642*** The new function select-safe-coding-system can be used to find a
3643proper coding system for encoding the specified region or string.
3644This function requires a user interaction.
3645
3646*** The new functions find-coding-systems-region and
3647find-coding-systems-string are helper functions used by
3648select-safe-coding-system. They return a list of all proper coding
3649systems to encode a text in some region or string. If you don't want
3650a user interaction, use one of these functions instead of
3651select-safe-coding-system.
3652
3653*** The explicit encoding and decoding functions, such as
3654decode-coding-region and encode-coding-string, now set
3655last-coding-system-used to reflect the actual way encoding or decoding
3656was done.
3657
3658*** The new function detect-coding-with-language-environment can be
3659used to detect a coding system of text according to priorities of
3660coding systems used by some specific language environment.
3661
3662*** The functions detect-coding-region and detect-coding-string always
3663return a list if the arg HIGHEST is nil. Thus, if only ASCII
3664characters are found, they now return a list of single element
3665`undecided' or its subsidiaries.
3666
3667*** The new functions coding-system-change-eol-conversion and
3668coding-system-change-text-conversion can be used to get a different
3669coding system than what specified only in how end-of-line or text is
3670converted.
3671
3672*** The new function set-selection-coding-system can be used to set a
3673coding system for communicating with other X clients.
3674
3675*** The function `map-char-table' now passes as argument only valid
3676character codes, plus generic characters that stand for entire
3677character sets or entire subrows of a character set. In other words,
3678each time `map-char-table' calls its FUNCTION argument, the key value
3679either will be a valid individual character code, or will stand for a
3680range of characters.
3681
3682*** The new function `char-valid-p' can be used for checking whether a
3683Lisp object is a valid character code or not.
3684
3685*** The new function `charset-after' returns a charset of a character
3686in the current buffer at position POS.
3687
3688*** Input methods are now implemented using the variable
3689input-method-function. If this is non-nil, its value should be a
3690function; then, whenever Emacs reads an input event that is a printing
3691character with no modifier bits, it calls that function, passing the
3692event as an argument. Often this function will read more input, first
3693binding input-method-function to nil.
3694
3695The return value should be a list of the events resulting from input
3696method processing. These events will be processed sequentially as
3697input, before resorting to unread-command-events. Events returned by
3698the input method function are not passed to the input method function,
3699not even if they are printing characters with no modifier bits.
3700
3701The input method function is not called when reading the second and
3702subsequent events of a key sequence.
3703
3704*** You can customize any language environment by using
3705set-language-environment-hook and exit-language-environment-hook.
3706
3707The hook `exit-language-environment-hook' should be used to undo
3708customizations that you made with set-language-environment-hook. For
3709instance, if you set up a special key binding for a specific language
3710environment by set-language-environment-hook, you should set up
3711exit-language-environment-hook to restore the normal key binding.
3712\f
3713* Changes in Emacs 20.1
3714
3715** Emacs has a new facility for customization of its many user
3716options. It is called M-x customize. With this facility you can look
3717at the many user options in an organized way; they are grouped into a
3718tree structure.
3719
3720M-x customize also knows what sorts of values are legitimate for each
3721user option and ensures that you don't use invalid values.
3722
3723With M-x customize, you can set options either for the present Emacs
3724session or permanently. (Permanent settings are stored automatically
3725in your .emacs file.)
3726
3727** Scroll bars are now on the left side of the window.
3728You can change this with M-x customize-option scroll-bar-mode.
3729
3730** The mode line no longer includes the string `Emacs'.
3731This makes more space in the mode line for other information.
3732
3733** When you select a region with the mouse, it is highlighted
3734immediately afterward. At that time, if you type the DELETE key, it
3735kills the region.
3736
3737The BACKSPACE key, and the ASCII character DEL, do not do this; they
3738delete the character before point, as usual.
3739
3740** In an incremental search the whole current match is highlighted
3741on terminals which support this. (You can disable this feature
3742by setting search-highlight to nil.)
3743
3744** In the minibuffer, in some cases, you can now use M-n to
3745insert the default value into the minibuffer as text. In effect,
3746the default value (if the minibuffer routines know it) is tacked
3747onto the history "in the future". (The more normal use of the
3748history list is to use M-p to insert minibuffer input used in the
3749past.)
3750
3751** In Text mode, now only blank lines separate paragraphs.
3752This makes it possible to get the full benefit of Adaptive Fill mode
3753in Text mode, and other modes derived from it (such as Mail mode).
3754TAB in Text mode now runs the command indent-relative; this
3755makes a practical difference only when you use indented paragraphs.
3756
3757As a result, the old Indented Text mode is now identical to Text mode,
3758and is an alias for it.
3759
3760If you want spaces at the beginning of a line to start a paragraph,
3761use the new mode, Paragraph Indent Text mode.
3762
3763** Scrolling changes
3764
3765*** Scroll commands to scroll a whole screen now preserve the screen
3766position of the cursor, if scroll-preserve-screen-position is non-nil.
3767
3768In this mode, if you scroll several screens back and forth, finishing
3769on the same screen where you started, the cursor goes back to the line
3770where it started.
3771
3772*** If you set scroll-conservatively to a small number, then when you
3773move point a short distance off the screen, Emacs will scroll the
3774screen just far enough to bring point back on screen, provided that
3775does not exceed `scroll-conservatively' lines.
3776
3777*** The new variable scroll-margin says how close point can come to the
3778top or bottom of a window. It is a number of screen lines; if point
3779comes within that many lines of the top or bottom of the window, Emacs
3780recenters the window.
3781
3782** International character set support (MULE)
3783
3784Emacs now supports a wide variety of international character sets,
3785including European variants of the Latin alphabet, as well as Chinese,
3786Devanagari (Hindi and Marathi), Ethiopian, Greek, IPA, Japanese,
3787Korean, Lao, Russian, Thai, Tibetan, and Vietnamese scripts. These
3788features have been merged from the modified version of Emacs known as
3789MULE (for "MULti-lingual Enhancement to GNU Emacs")
3790
3791Users of these scripts have established many more-or-less standard
3792coding systems for storing files. Emacs uses a single multibyte
3793character encoding within Emacs buffers; it can translate from a wide
3794variety of coding systems when reading a file and can translate back
3795into any of these coding systems when saving a file.
3796
3797Keyboards, even in the countries where these character sets are used,
3798generally don't have keys for all the characters in them. So Emacs
3799supports various "input methods", typically one for each script or
3800language, to make it possible to type them.
3801
3802The Emacs internal multibyte encoding represents a non-ASCII
3803character as a sequence of bytes in the range 0200 through 0377.
3804
3805The new prefix key C-x RET is used for commands that pertain
3806to multibyte characters, coding systems, and input methods.
3807
3808You can disable multibyte character support as follows:
3809
3810 (setq-default enable-multibyte-characters nil)
3811
3812Calling the function standard-display-european turns off multibyte
3813characters, unless you specify a non-nil value for the second
3814argument, AUTO. This provides compatibility for people who are
3815already using standard-display-european to continue using unibyte
3816characters for their work until they want to change.
3817
3818*** Input methods
3819
3820An input method is a kind of character conversion which is designed
3821specifically for interactive input. In Emacs, typically each language
3822has its own input method (though sometimes several languages which use
3823the same characters can share one input method). Some languages
3824support several input methods.
3825
3826The simplest kind of input method works by mapping ASCII letters into
3827another alphabet. This is how the Greek and Russian input methods
3828work.
3829
3830A more powerful technique is composition: converting sequences of
3831characters into one letter. Many European input methods use
3832composition to produce a single non-ASCII letter from a sequence which
3833consists of a letter followed by diacritics. For example, a' is one
3834sequence of two characters that might be converted into a single
3835letter.
3836
3837The input methods for syllabic scripts typically use mapping followed
3838by conversion. The input methods for Thai and Korean work this way.
3839First, letters are mapped into symbols for particular sounds or tone
3840marks; then, sequences of these which make up a whole syllable are
3841mapped into one syllable sign--most often a "composite character".
3842
3843None of these methods works very well for Chinese and Japanese, so
3844they are handled specially. First you input a whole word using
3845phonetic spelling; then, after the word is in the buffer, Emacs
3846converts it into one or more characters using a large dictionary.
3847
3848Since there is more than one way to represent a phonetically spelled
3849word using Chinese characters, Emacs can only guess which one to use;
3850typically these input methods give you a way to say "guess again" if
3851the first guess is wrong.
3852
3853*** The command C-x RET m (toggle-enable-multibyte-characters)
3854turns multibyte character support on or off for the current buffer.
3855
3856If multibyte character support is turned off in a buffer, then each
3857byte is a single character, even codes 0200 through 0377--exactly as
3858they did in Emacs 19.34. This includes the features for support for
3859the European characters, ISO Latin-1 and ISO Latin-2.
3860
3861However, there is no need to turn off multibyte character support to
3862use ISO Latin-1 or ISO Latin-2; the Emacs multibyte character set
3863includes all the characters in these character sets, and Emacs can
3864translate automatically to and from either one.
3865
3866*** Visiting a file in unibyte mode.
3867
3868Turning off multibyte character support in the buffer after visiting a
3869file with multibyte code conversion will display the multibyte
3870sequences already in the buffer, byte by byte. This is probably not
3871what you want.
3872
3873If you want to edit a file of unibyte characters (Latin-1, for
3874example), you can do it by specifying `no-conversion' as the coding
3875system when reading the file. This coding system also turns off
3876multibyte characters in that buffer.
3877
3878If you turn off multibyte character support entirely, this turns off
3879character conversion as well.
3880
3881*** Displaying international characters on X Windows.
3882
3883A font for X typically displays just one alphabet or script.
3884Therefore, displaying the entire range of characters Emacs supports
3885requires using many fonts.
3886
3887Therefore, Emacs now supports "fontsets". Each fontset is a
3888collection of fonts, each assigned to a range of character codes.
3889
3890A fontset has a name, like a font. Individual fonts are defined by
3891the X server; fontsets are defined within Emacs itself. But once you
3892have defined a fontset, you can use it in a face or a frame just as
3893you would use a font.
3894
3895If a fontset specifies no font for a certain character, or if it
3896specifies a font that does not exist on your system, then it cannot
3897display that character. It will display an empty box instead.
3898
3899The fontset height and width are determined by the ASCII characters
3900(that is, by the font in the fontset which is used for ASCII
3901characters). If another font in the fontset has a different height,
3902or the wrong width, then characters assigned to that font are clipped,
3903and displayed within a box if highlight-wrong-size-font is non-nil.
3904
3905*** Defining fontsets.
3906
3907Emacs does not use any fontset by default. Its default font is still
3908chosen as in previous versions. You can tell Emacs to use a fontset
3909with the `-fn' option or the `Font' X resource.
3910
3911Emacs creates a standard fontset automatically according to the value
3912of standard-fontset-spec. This fontset's short name is
3913`fontset-standard'. Bold, italic, and bold-italic variants of the
3914standard fontset are created automatically.
3915
3916If you specify a default ASCII font with the `Font' resource or `-fn'
3917argument, a fontset is generated from it. This works by replacing the
3918FOUNDARY, FAMILY, ADD_STYLE, and AVERAGE_WIDTH fields of the font name
3919with `*' then using this to specify a fontset. This fontset's short
3920name is `fontset-startup'.
3921
3922Emacs checks resources of the form Fontset-N where N is 0, 1, 2...
3923The resource value should have this form:
3924 FONTSET-NAME, [CHARSET-NAME:FONT-NAME]...
3925FONTSET-NAME should have the form of a standard X font name, except:
3926 * most fields should be just the wild card "*".
3927 * the CHARSET_REGISTRY field should be "fontset"
3928 * the CHARSET_ENCODING field can be any nickname of the fontset.
3929The construct CHARSET-NAME:FONT-NAME can be repeated any number
3930of times; each time specifies the font for one character set.
3931CHARSET-NAME should be the name name of a character set, and
3932FONT-NAME should specify an actual font to use for that character set.
3933
3934Each of these fontsets has an alias which is made from the
3935last two font name fields, CHARSET_REGISTRY and CHARSET_ENCODING.
3936You can refer to the fontset by that alias or by its full name.
3937
3938For any character sets that you don't mention, Emacs tries to choose a
3939font by substituting into FONTSET-NAME. For instance, with the
3940following resource,
3941 Emacs*Fontset-0: -*-fixed-medium-r-normal-*-24-*-*-*-*-*-fontset-24
3942the font for ASCII is generated as below:
3943 -*-fixed-medium-r-normal-*-24-*-ISO8859-1
3944Here is the substitution rule:
3945 Change CHARSET_REGISTRY and CHARSET_ENCODING to that of the charset
3946 defined in the variable x-charset-registries. For instance, ASCII has
3947 the entry (ascii . "ISO8859-1") in this variable. Then, reduce
3948 sequences of wild cards -*-...-*- with a single wildcard -*-.
3949 (This is to prevent use of auto-scaled fonts.)
3950
3951The function which processes the fontset resource value to create the
3952fontset is called create-fontset-from-fontset-spec. You can also call
3953that function explicitly to create a fontset.
3954
3955With the X resource Emacs.Font, you can specify a fontset name just
3956like an actual font name. But be careful not to specify a fontset
3957name in a wildcard resource like Emacs*Font--that tries to specify the
3958fontset for other purposes including menus, and they cannot handle
3959fontsets.
3960
3961*** The command M-x set-language-environment sets certain global Emacs
3962defaults for a particular choice of language.
3963
3964Selecting a language environment typically specifies a default input
3965method and which coding systems to recognize automatically when
3966visiting files. However, it does not try to reread files you have
3967already visited; the text in those buffers is not affected. The
3968language environment may also specify a default choice of coding
3969system for new files that you create.
3970
3971It makes no difference which buffer is current when you use
3972set-language-environment, because these defaults apply globally to the
3973whole Emacs session.
3974
3975For example, M-x set-language-environment RET Latin-1 RET
3976chooses the Latin-1 character set. In the .emacs file, you can do this
3977with (set-language-environment "Latin-1").
3978
3979*** The command C-x RET f (set-buffer-file-coding-system)
3980specifies the file coding system for the current buffer. This
3981specifies what sort of character code translation to do when saving
3982the file. As an argument, you must specify the name of one of the
3983coding systems that Emacs supports.
3984
3985*** The command C-x RET c (universal-coding-system-argument)
3986lets you specify a coding system when you read or write a file.
3987This command uses the minibuffer to read a coding system name.
3988After you exit the minibuffer, the specified coding system
3989is used for *the immediately following command*.
3990
3991So if the immediately following command is a command to read or
3992write a file, it uses the specified coding system for that file.
3993
3994If the immediately following command does not use the coding system,
3995then C-x RET c ultimately has no effect.
3996
3997For example, C-x RET c iso-8859-1 RET C-x C-f temp RET
3998visits the file `temp' treating it as ISO Latin-1.
3999
4000*** You can specify the coding system for a file using the -*-
4001construct. Include `coding: CODINGSYSTEM;' inside the -*-...-*-
4002to specify use of coding system CODINGSYSTEM. You can also
4003specify the coding system in a local variable list at the end
4004of the file.
4005
4006*** The command C-x RET t (set-terminal-coding-system) specifies
4007the coding system for terminal output. If you specify a character
4008code for terminal output, all characters output to the terminal are
4009translated into that character code.
4010
4011This feature is useful for certain character-only terminals built in
4012various countries to support the languages of those countries.
4013
4014By default, output to the terminal is not translated at all.
4015
4016*** The command C-x RET k (set-keyboard-coding-system) specifies
4017the coding system for keyboard input.
4018
4019Character code translation of keyboard input is useful for terminals
4020with keys that send non-ASCII graphic characters--for example,
4021some terminals designed for ISO Latin-1 or subsets of it.
4022
4023By default, keyboard input is not translated at all.
4024
4025Character code translation of keyboard input is similar to using an
4026input method, in that both define sequences of keyboard input that
4027translate into single characters. However, input methods are designed
4028to be convenient for interactive use, while the code translations are
4029designed to work with terminals.
4030
4031*** The command C-x RET p (set-buffer-process-coding-system)
4032specifies the coding system for input and output to a subprocess.
4033This command applies to the current buffer; normally, each subprocess
4034has its own buffer, and thus you can use this command to specify
4035translation to and from a particular subprocess by giving the command
4036in the corresponding buffer.
4037
4038By default, process input and output are not translated at all.
4039
4040*** The variable file-name-coding-system specifies the coding system
4041to use for encoding file names before operating on them.
4042It is also used for decoding file names obtained from the system.
4043
4044*** The command C-\ (toggle-input-method) activates or deactivates
4045an input method. If no input method has been selected before, the
4046command prompts for you to specify the language and input method you
4047want to use.
4048
4049C-u C-\ (select-input-method) lets you switch to a different input
4050method. C-h C-\ (or C-h I) describes the current input method.
4051
4052*** Some input methods remap the keyboard to emulate various keyboard
4053layouts commonly used for particular scripts. How to do this
4054remapping properly depends on your actual keyboard layout. To specify
4055which layout your keyboard has, use M-x quail-set-keyboard-layout.
4056
4057*** The command C-h C (describe-coding-system) displays
4058the coding systems currently selected for various purposes, plus
4059related information.
4060
4061*** The command C-h h (view-hello-file) displays a file called
4062HELLO, which has examples of text in many languages, using various
4063scripts.
4064
4065*** The command C-h L (describe-language-support) displays
4066information about the support for a particular language.
4067You specify the language as an argument.
4068
4069*** The mode line now contains a letter or character that identifies
4070the coding system used in the visited file. It normally follows the
4071first dash.
4072
4073A dash indicates the default state of affairs: no code conversion
4074(except CRLF => newline if appropriate). `=' means no conversion
4075whatsoever. The ISO 8859 coding systems are represented by digits
40761 through 9. Other coding systems are represented by letters:
4077
4078 A alternativnyj (Russian)
4079 B big5 (Chinese)
4080 C cn-gb-2312 (Chinese)
4081 C iso-2022-cn (Chinese)
4082 D in-is13194-devanagari (Indian languages)
4083 E euc-japan (Japanese)
4084 I iso-2022-cjk or iso-2022-ss2 (Chinese, Japanese, Korean)
4085 J junet (iso-2022-7) or old-jis (iso-2022-jp-1978-irv) (Japanese)
4086 K euc-korea (Korean)
4087 R koi8 (Russian)
4088 Q tibetan
4089 S shift_jis (Japanese)
4090 T lao
4091 T tis620 (Thai)
4092 V viscii or vscii (Vietnamese)
4093 i iso-2022-lock (Chinese, Japanese, Korean)
4094 k iso-2022-kr (Korean)
4095 v viqr (Vietnamese)
4096 z hz (Chinese)
4097
4098When you are using a character-only terminal (not a window system),
4099two additional characters appear in between the dash and the file
4100coding system. These two characters describe the coding system for
4101keyboard input, and the coding system for terminal output.
4102
4103*** The new variable rmail-file-coding-system specifies the code
4104conversion to use for RMAIL files. The default value is nil.
4105
4106When you read mail with Rmail, each message is decoded automatically
4107into Emacs' internal format. This has nothing to do with
4108rmail-file-coding-system. That variable controls reading and writing
4109Rmail files themselves.
4110
4111*** The new variable sendmail-coding-system specifies the code
4112conversion for outgoing mail. The default value is nil.
4113
4114Actually, there are three different ways of specifying the coding system
4115for sending mail:
4116
4117- If you use C-x RET f in the mail buffer, that takes priority.
4118- Otherwise, if you set sendmail-coding-system non-nil, that specifies it.
4119- Otherwise, the default coding system for new files is used,
4120 if that is non-nil. That comes from your language environment.
4121- Otherwise, Latin-1 is used.
4122
4123*** The command C-h t (help-with-tutorial) accepts a prefix argument
4124to specify the language for the tutorial file. Currently, English,
4125Japanese, Korean and Thai are supported. We welcome additional
4126translations.
4127
4128** An easy new way to visit a file with no code or format conversion
4129of any kind: Use M-x find-file-literally. There is also a command
4130insert-file-literally which inserts a file into the current buffer
4131without any conversion.
4132
4133** C-q's handling of octal character codes is changed.
4134You can now specify any number of octal digits.
4135RET terminates the digits and is discarded;
4136any other non-digit terminates the digits and is then used as input.
4137
4138** There are new commands for looking up Info documentation for
4139functions, variables and file names used in your programs.
4140
4141Type M-x info-lookup-symbol to look up a symbol in the buffer at point.
4142Type M-x info-lookup-file to look up a file in the buffer at point.
4143
4144Precisely which Info files are used to look it up depends on the major
4145mode. For example, in C mode, the GNU libc manual is used.
4146
4147** M-TAB in most programming language modes now runs the command
4148complete-symbol. This command performs completion on the symbol name
4149in the buffer before point.
4150
4151With a numeric argument, it performs completion based on the set of
4152symbols documented in the Info files for the programming language that
4153you are using.
4154
4155With no argument, it does completion based on the current tags tables,
4156just like the old binding of M-TAB (complete-tag).
4157
4158** File locking works with NFS now.
4159
4160The lock file for FILENAME is now a symbolic link named .#FILENAME,
4161in the same directory as FILENAME.
4162
4163This means that collision detection between two different machines now
4164works reasonably well; it also means that no file server or directory
4165can become a bottleneck.
4166
4167The new method does have drawbacks. It means that collision detection
4168does not operate when you edit a file in a directory where you cannot
4169create new files. Collision detection also doesn't operate when the
4170file server does not support symbolic links. But these conditions are
4171rare, and the ability to have collision detection while using NFS is
4172so useful that the change is worth while.
4173
4174When Emacs or a system crashes, this may leave behind lock files which
4175are stale. So you may occasionally get warnings about spurious
4176collisions. When you determine that the collision is spurious, just
4177tell Emacs to go ahead anyway.
4178
4179** If you wish to use Show Paren mode to display matching parentheses,
4180it is no longer sufficient to load paren.el. Instead you must call
4181show-paren-mode.
4182
4183** If you wish to use Delete Selection mode to replace a highlighted
4184selection when you insert new text, it is no longer sufficient to load
4185delsel.el. Instead you must call the function delete-selection-mode.
4186
4187** If you wish to use Partial Completion mode to complete partial words
4188within symbols or filenames, it is no longer sufficient to load
4189complete.el. Instead you must call the function partial-completion-mode.
4190
4191** If you wish to use uniquify to rename buffers for you,
4192it is no longer sufficient to load uniquify.el. You must also
4193set uniquify-buffer-name-style to one of the non-nil legitimate values.
4194
4195** Changes in View mode.
4196
4197*** Several new commands are available in View mode.
4198Do H in view mode for a list of commands.
4199
4200*** There are two new commands for entering View mode:
4201view-file-other-frame and view-buffer-other-frame.
4202
4203*** Exiting View mode does a better job of restoring windows to their
4204previous state.
4205
4206*** New customization variable view-scroll-auto-exit. If non-nil,
4207scrolling past end of buffer makes view mode exit.
4208
4209*** New customization variable view-exits-all-viewing-windows. If
4210non-nil, view-mode will at exit restore all windows viewing buffer,
4211not just the selected window.
4212
4213*** New customization variable view-read-only. If non-nil, visiting a
4214read-only file automatically enters View mode, and toggle-read-only
4215turns View mode on or off.
4216
4217*** New customization variable view-remove-frame-by-deleting controls
4218how to remove a not needed frame at view mode exit. If non-nil,
4219delete the frame, if nil make an icon of it.
4220
4221** C-x v l, the command to print a file's version control log,
4222now positions point at the entry for the file's current branch version.
4223
4224** C-x v =, the command to compare a file with the last checked-in version,
4225has a new feature. If the file is currently not locked, so that it is
4226presumably identical to the last checked-in version, the command now asks
4227which version to compare with.
4228
4229** When using hideshow.el, incremental search can temporarily show hidden
4230blocks if a match is inside the block.
4231
4232The block is hidden again if the search is continued and the next match
4233is outside the block. By customizing the variable
4234isearch-hide-immediately you can choose to hide all the temporarily
4235shown blocks only when exiting from incremental search.
4236
4237By customizing the variable hs-isearch-open you can choose what kind
4238of blocks to temporarily show during isearch: comment blocks, code
4239blocks, all of them or none.
4240
4241** The new command C-x 4 0 (kill-buffer-and-window) kills the
4242current buffer and deletes the selected window. It asks for
4243confirmation first.
4244
4245** C-x C-w, which saves the buffer into a specified file name,
4246now changes the major mode according to that file name.
4247However, the mode will not be changed if
4248(1) a local variables list or the `-*-' line specifies a major mode, or
4249(2) the current major mode is a "special" mode,
4250 not suitable for ordinary files, or
4251(3) the new file name does not particularly specify any mode.
4252
4253This applies to M-x set-visited-file-name as well.
4254
4255However, if you set change-major-mode-with-file-name to nil, then
4256these commands do not change the major mode.
4257
4258** M-x occur changes.
4259
4260*** If the argument to M-x occur contains upper case letters,
4261it performs a case-sensitive search.
4262
4263*** In the *Occur* buffer made by M-x occur,
4264if you type g or M-x revert-buffer, this repeats the search
4265using the same regular expression and the same buffer as before.
4266
4267** In Transient Mark mode, the region in any one buffer is highlighted
4268in just one window at a time. At first, it is highlighted in the
4269window where you set the mark. The buffer's highlighting remains in
4270that window unless you select to another window which shows the same
4271buffer--then the highlighting moves to that window.
4272
4273** The feature to suggest key bindings when you use M-x now operates
4274after the command finishes. The message suggesting key bindings
4275appears temporarily in the echo area. The previous echo area contents
4276come back after a few seconds, in case they contain useful information.
4277
4278** Each frame now independently records the order for recently
4279selected buffers, so that the default for C-x b is now based on the
4280buffers recently selected in the selected frame.
4281
4282** Outline mode changes.
4283
4284*** Outline mode now uses overlays (this is the former noutline.el).
4285
4286*** Incremental searches skip over invisible text in Outline mode.
4287
4288** When a minibuffer window is active but not the selected window, if
4289you try to use the minibuffer, you used to get a nested minibuffer.
4290Now, this not only gives an error, it also cancels the minibuffer that
4291was already active.
4292
4293The motive for this change is so that beginning users do not
4294unknowingly move away from minibuffers, leaving them active, and then
4295get confused by it.
4296
4297If you want to be able to have recursive minibuffers, you must
4298set enable-recursive-minibuffers to non-nil.
4299
4300** Changes in dynamic abbrevs.
4301
4302*** Expanding dynamic abbrevs with M-/ is now smarter about case
4303conversion. If the expansion has mixed case not counting the first
4304character, and the abbreviation matches the beginning of the expansion
4305including case, then the expansion is copied verbatim.
4306
4307The expansion is also copied verbatim if the abbreviation itself has
4308mixed case. And using SPC M-/ to copy an additional word always
4309copies it verbatim except when the previous copied word is all caps.
4310
4311*** The values of `dabbrev-case-replace' and `dabbrev-case-fold-search'
4312are no longer Lisp expressions. They have simply three possible
4313values.
4314
4315`dabbrev-case-replace' has these three values: nil (don't preserve
4316case), t (do), or `case-replace' (do like M-x query-replace).
4317`dabbrev-case-fold-search' has these three values: nil (don't ignore
4318case), t (do), or `case-fold-search' (do like search).
4319
4320** Minibuffer history lists are truncated automatically now to a
4321certain length. The variable history-length specifies how long they
4322can be. The default value is 30.
4323
4324** Changes in Mail mode.
4325
4326*** The key C-x m no longer runs the `mail' command directly.
4327Instead, it runs the command `compose-mail', which invokes the mail
4328composition mechanism you have selected with the variable
4329`mail-user-agent'. The default choice of user agent is
4330`sendmail-user-agent', which gives behavior compatible with the old
4331behavior.
4332
4333C-x 4 m now runs compose-mail-other-window, and C-x 5 m runs
4334compose-mail-other-frame.
4335
4336*** While composing a reply to a mail message, from Rmail, you can use
4337the command C-c C-r to cite just the region from the message you are
4338replying to. This copies the text which is the selected region in the
4339buffer that shows the original message.
4340
4341*** The command C-c C-i inserts a file at the end of the message,
4342with separator lines around the contents.
4343
4344*** The command M-x expand-mail-aliases expands all mail aliases
4345in suitable mail headers. Emacs automatically extracts mail alias
4346definitions from your mail alias file (e.g., ~/.mailrc). You do not
4347need to expand mail aliases yourself before sending mail.
4348
4349*** New features in the mail-complete command.
4350
4351**** The mail-complete command now inserts the user's full name,
4352for local users or if that is known. The variable mail-complete-style
4353controls the style to use, and whether to do this at all.
4354Its values are like those of mail-from-style.
4355
4356**** The variable mail-passwd-command lets you specify a shell command
4357to run to fetch a set of password-entries that add to the ones in
4358/etc/passwd.
4359
4360**** The variable mail-passwd-file now specifies a list of files to read
4361to get the list of user ids. By default, one file is used:
4362/etc/passwd.
4363
4364** You can "quote" a file name to inhibit special significance of
4365special syntax, by adding `/:' to the beginning. Thus, if you have a
4366directory named `/foo:', you can prevent it from being treated as a
4367reference to a remote host named `foo' by writing it as `/:/foo:'.
4368
4369Emacs uses this new construct automatically when necessary, such as
4370when you start it with a working directory whose name might otherwise
4371be taken to be magic.
4372
4373** There is a new command M-x grep-find which uses find to select
4374files to search through, and grep to scan them. The output is
4375available in a Compile mode buffer, as with M-x grep.
4376
4377M-x grep now uses the -e option if the grep program supports that.
4378(-e prevents problems if the search pattern starts with a dash.)
4379
4380** In Dired, the & command now flags for deletion the files whose names
4381suggest they are probably not needed in the long run.
4382
4383In Dired, * is now a prefix key for mark-related commands.
4384
4385new key dired.el binding old key
4386------- ---------------- -------
4387 * c dired-change-marks c
4388 * m dired-mark m
4389 * * dired-mark-executables * (binding deleted)
4390 * / dired-mark-directories / (binding deleted)
4391 * @ dired-mark-symlinks @ (binding deleted)
4392 * u dired-unmark u
4393 * DEL dired-unmark-backward DEL
4394 * ? dired-unmark-all-files M-C-?
4395 * ! dired-unmark-all-marks
4396 * % dired-mark-files-regexp % m
4397 * C-n dired-next-marked-file M-}
4398 * C-p dired-prev-marked-file M-{
4399
4400** Rmail changes.
4401
4402*** When Rmail cannot convert your incoming mail into Babyl format, it
4403saves the new mail in the file RMAILOSE.n, where n is an integer
4404chosen to make a unique name. This way, Rmail will not keep crashing
4405each time you run it.
4406
4407*** In Rmail, the variable rmail-summary-line-count-flag now controls
4408whether to include the line count in the summary. Non-nil means yes.
4409
4410*** In Rmail summary buffers, d and C-d (the commands to delete
4411messages) now take repeat counts as arguments. A negative argument
4412means to move in the opposite direction.
4413
4414*** In Rmail, the t command now takes an optional argument which lets
4415you specify whether to show the message headers in full or pruned.
4416
4417*** In Rmail, the new command w (rmail-output-body-to-file) writes
4418just the body of the current message into a file, without the headers.
4419It takes the file name from the message subject, by default, but you
4420can edit that file name in the minibuffer before it is actually used
4421for output.
4422
4423** Gnus changes.
4424
4425*** nntp.el has been totally rewritten in an asynchronous fashion.
4426
4427*** Article prefetching functionality has been moved up into
4428Gnus.
4429
4430*** Scoring can now be performed with logical operators like
4431`and', `or', `not', and parent redirection.
4432
4433*** Article washing status can be displayed in the
4434article mode line.
4435
4436*** gnus.el has been split into many smaller files.
4437
4438*** Suppression of duplicate articles based on Message-ID.
4439
4440(setq gnus-suppress-duplicates t)
4441
4442*** New variables for specifying what score and adapt files
4443are to be considered home score and adapt files. See
4444`gnus-home-score-file' and `gnus-home-adapt-files'.
4445
4446*** Groups can inherit group parameters from parent topics.
4447
4448*** Article editing has been revamped and is now usable.
4449
4450*** Signatures can be recognized in more intelligent fashions.
4451See `gnus-signature-separator' and `gnus-signature-limit'.
4452
4453*** Summary pick mode has been made to look more nn-like.
4454Line numbers are displayed and the `.' command can be
4455used to pick articles.
4456
4457*** Commands for moving the .newsrc.eld from one server to
4458another have been added.
4459
4460 `M-x gnus-change-server'
4461
4462*** A way to specify that "uninteresting" fields be suppressed when
4463generating lines in buffers.
4464
4465*** Several commands in the group buffer can be undone with
4466`M-C-_'.
4467
4468*** Scoring can be done on words using the new score type `w'.
4469
4470*** Adaptive scoring can be done on a Subject word-by-word basis:
4471
4472 (setq gnus-use-adaptive-scoring '(word))
4473
4474*** Scores can be decayed.
4475
4476 (setq gnus-decay-scores t)
4477
4478*** Scoring can be performed using a regexp on the Date header. The
4479Date is normalized to compact ISO 8601 format first.
4480
4481*** A new command has been added to remove all data on articles from
4482the native server.
4483
4484 `M-x gnus-group-clear-data-on-native-groups'
4485
4486*** A new command for reading collections of documents
4487(nndoc with nnvirtual on top) has been added -- `M-C-d'.
4488
4489*** Process mark sets can be pushed and popped.
4490
4491*** A new mail-to-news backend makes it possible to post
4492even when the NNTP server doesn't allow posting.
4493
4494*** A new backend for reading searches from Web search engines
4495(DejaNews, Alta Vista, InReference) has been added.
4496
4497 Use the `G w' command in the group buffer to create such
4498 a group.
4499
4500*** Groups inside topics can now be sorted using the standard
4501sorting functions, and each topic can be sorted independently.
4502
4503 See the commands under the `T S' submap.
4504
4505*** Subsets of the groups can be sorted independently.
4506
4507 See the commands under the `G P' submap.
4508
4509*** Cached articles can be pulled into the groups.
4510
4511 Use the `Y c' command.
4512
4513*** Score files are now applied in a more reliable order.
4514
4515*** Reports on where mail messages end up can be generated.
4516
4517 `M-x nnmail-split-history'
4518
4519*** More hooks and functions have been added to remove junk
4520from incoming mail before saving the mail.
4521
4522 See `nnmail-prepare-incoming-header-hook'.
4523
4524*** The nnml mail backend now understands compressed article files.
4525
4526*** To enable Gnus to read/post multi-lingual articles, you must execute
4527the following code, for instance, in your .emacs.
4528
4529 (add-hook 'gnus-startup-hook 'gnus-mule-initialize)
4530
4531Then, when you start Gnus, it will decode non-ASCII text automatically
4532and show appropriate characters. (Note: if you are using gnus-mime
4533from the SEMI package, formerly known as TM, you should NOT add this
4534hook to gnus-startup-hook; gnus-mime has its own method of handling
4535this issue.)
4536
4537Since it is impossible to distinguish all coding systems
4538automatically, you may need to specify a choice of coding system for a
4539particular news group. This can be done by:
4540
4541 (gnus-mule-add-group NEWSGROUP 'CODING-SYSTEM)
4542
4543Here NEWSGROUP should be a string which names a newsgroup or a tree
4544of newsgroups. If NEWSGROUP is "XXX.YYY", all news groups under
4545"XXX.YYY" (including "XXX.YYY.ZZZ") will use the specified coding
4546system. CODING-SYSTEM specifies which coding system to use (for both
4547for reading and posting).
4548
4549CODING-SYSTEM can also be a cons cell of the form
4550 (READ-CODING-SYSTEM . POST-CODING-SYSTEM)
4551Then READ-CODING-SYSTEM is used when you read messages from the
4552newsgroups, while POST-CODING-SYSTEM is used when you post messages
4553there.
4554
4555Emacs knows the right coding systems for certain newsgroups by
4556default. Here are some of these default settings:
4557
4558 (gnus-mule-add-group "fj" 'iso-2022-7)
4559 (gnus-mule-add-group "alt.chinese.text" 'hz-gb-2312)
4560 (gnus-mule-add-group "alt.hk" 'hz-gb-2312)
4561 (gnus-mule-add-group "alt.chinese.text.big5" 'cn-big5)
4562 (gnus-mule-add-group "soc.culture.vietnamese" '(nil . viqr))
4563
4564When you reply by mail to an article, these settings are ignored;
4565the mail is encoded according to sendmail-coding-system, as usual.
4566
4567** CC mode changes.
4568
4569*** If you edit primarily one style of C (or C++, Objective-C, Java)
4570code, you may want to make the CC Mode style variables have global
4571values so that you can set them directly in your .emacs file. To do
4572this, set c-style-variables-are-local-p to nil in your .emacs file.
4573Note that this only takes effect if you do it *before* cc-mode.el is
4574loaded.
4575
4576If you typically edit more than one style of C (or C++, Objective-C,
4577Java) code in a single Emacs session, you may want to make the CC Mode
4578style variables have buffer local values. By default, all buffers
4579share the same style variable settings; to make them buffer local, set
4580c-style-variables-are-local-p to t in your .emacs file. Note that you
4581must do this *before* CC Mode is loaded.
4582
4583*** The new variable c-indentation-style holds the C style name
4584of the current buffer.
4585
4586*** The variable c-block-comments-indent-p has been deleted, because
4587it is no longer necessary. C mode now handles all the supported styles
4588of block comments, with no need to say which one you will use.
4589
4590*** There is a new indentation style "python", which specifies the C
4591style that the Python developers like.
4592
4593*** There is a new c-cleanup-list option: brace-elseif-brace.
4594This says to put ...} else if (...) {... on one line,
4595just as brace-else-brace says to put ...} else {... on one line.
4596
4597** VC Changes [new]
4598
4599** In vc-retrieve-snapshot (C-x v r), if you don't specify a snapshot
4600name, it retrieves the *latest* versions of all files in the current
4601directory and its subdirectories (aside from files already locked).
4602
4603This feature is useful if your RCS directory is a link to a common
4604master directory, and you want to pick up changes made by other
4605developers.
4606
4607You can do the same thing for an individual file by typing C-u C-x C-q
4608RET in a buffer visiting that file.
4609
4610*** VC can now handle files under CVS that are being "watched" by
4611other developers. Such files are made read-only by CVS. To get a
4612writable copy, type C-x C-q in a buffer visiting such a file. VC then
4613calls "cvs edit", which notifies the other developers of it.
4614
4615*** vc-version-diff (C-u C-x v =) now suggests reasonable defaults for
4616version numbers, based on the current state of the file.
4617
4618** Calendar changes.
4619
4620A new function, list-holidays, allows you list holidays or subclasses
4621of holidays for ranges of years. Related menu items allow you do this
4622for the year of the selected date, or the following/previous years.
4623
4624** ps-print changes
4625
4626There are some new user variables for customizing the page layout.
4627
4628*** Paper size, paper orientation, columns
4629
4630The variable `ps-paper-type' determines the size of paper ps-print
4631formats for; it should contain one of the symbols:
4632`a4' `a3' `letter' `legal' `letter-small' `tabloid'
4633`ledger' `statement' `executive' `a4small' `b4' `b5'
4634It defaults to `letter'.
4635If you need other sizes, see the variable `ps-page-dimensions-database'.
4636
4637The variable `ps-landscape-mode' determines the orientation
4638of the printing on the page. nil, the default, means "portrait" mode,
4639non-nil means "landscape" mode.
4640
4641The variable `ps-number-of-columns' must be a positive integer.
4642It determines the number of columns both in landscape and portrait mode.
4643It defaults to 1.
4644
4645*** Horizontal layout
4646
4647The horizontal layout is determined by the variables
4648`ps-left-margin', `ps-inter-column', and `ps-right-margin'.
4649All are measured in points.
4650
4651*** Vertical layout
4652
4653The vertical layout is determined by the variables
4654`ps-bottom-margin', `ps-top-margin', and `ps-header-offset'.
4655All are measured in points.
4656
4657*** Headers
4658
4659If the variable `ps-print-header' is nil, no header is printed. Then
4660`ps-header-offset' is not relevant and `ps-top-margin' represents the
4661margin above the text.
4662
4663If the variable `ps-print-header-frame' is non-nil, a gaudy
4664framing box is printed around the header.
4665
4666The contents of the header are determined by `ps-header-lines',
4667`ps-show-n-of-n', `ps-left-header' and `ps-right-header'.
4668
4669The height of the header is determined by `ps-header-line-pad',
4670`ps-header-font-family', `ps-header-title-font-size' and
4671`ps-header-font-size'.
4672
4673*** Font managing
4674
4675The variable `ps-font-family' determines which font family is to be
4676used for ordinary text. Its value must be a key symbol in the alist
4677`ps-font-info-database'. You can add other font families by adding
4678elements to this alist.
4679
4680The variable `ps-font-size' determines the size of the font
4681for ordinary text. It defaults to 8.5 points.
4682
4683** hideshow changes.
4684
4685*** now supports hiding of blocks of single line comments (like // for
4686C++, ; for lisp).
4687
4688*** Support for java-mode added.
4689
4690*** When doing `hs-hide-all' it is now possible to also hide the comments
4691in the file if `hs-hide-comments-when-hiding-all' is set.
4692
4693*** The new function `hs-hide-initial-comment' hides the the comments at
4694the beginning of the files. Finally those huge RCS logs don't stay in your
4695way! This is run by default when entering the `hs-minor-mode'.
4696
4697*** Now uses overlays instead of `selective-display', so is more
4698robust and a lot faster.
4699
4700*** A block beginning can span multiple lines.
4701
4702*** The new variable `hs-show-hidden-short-form' if t, directs hideshow
4703to show only the beginning of a block when it is hidden. See the
4704documentation for more details.
4705
4706** Changes in Enriched mode.
4707
4708*** When you visit a file in enriched-mode, Emacs will make sure it is
4709filled to the current fill-column. This behavior is now independent
4710of the size of the window. When you save the file, the fill-column in
4711use is stored as well, so that the whole buffer need not be refilled
4712the next time unless the fill-column is different.
4713
4714*** use-hard-newlines is now a minor mode. When it is enabled, Emacs
4715distinguishes between hard and soft newlines, and treats hard newlines
4716as paragraph boundaries. Otherwise all newlines inserted are marked
4717as soft, and paragraph boundaries are determined solely from the text.
4718
4719** Font Lock mode
4720
4721*** Custom support
4722
4723The variables font-lock-face-attributes, font-lock-display-type and
4724font-lock-background-mode are now obsolete; the recommended way to specify the
4725faces to use for Font Lock mode is with M-x customize-group on the new custom
4726group font-lock-highlighting-faces. If you set font-lock-face-attributes in
4727your ~/.emacs file, Font Lock mode will respect its value. However, you should
4728consider converting from setting that variable to using M-x customize.
4729
4730You can still use X resources to specify Font Lock face appearances.
4731
4732*** Maximum decoration
4733
4734Fontification now uses the maximum level of decoration supported by
4735default. Previously, fontification used a mode-specific default level
4736of decoration, which is typically the minimum level of decoration
4737supported. You can set font-lock-maximum-decoration to nil
4738to get the old behavior.
4739
4740*** New support
4741
4742Support is now provided for Java, Objective-C, AWK and SIMULA modes.
4743
4744Note that Font Lock mode can be turned on without knowing exactly what modes
4745support Font Lock mode, via the command global-font-lock-mode.
4746
4747*** Configurable support
4748
4749Support for C, C++, Objective-C and Java can be more easily configured for
4750additional types and classes via the new variables c-font-lock-extra-types,
4751c++-font-lock-extra-types, objc-font-lock-extra-types and, you guessed it,
4752java-font-lock-extra-types. These value of each of these variables should be a
4753list of regexps matching the extra type names. For example, the default value
4754of c-font-lock-extra-types is ("\\sw+_t") which means fontification follows the
4755convention that C type names end in _t. This results in slower fontification.
4756
4757Of course, you can change the variables that specify fontification in whatever
4758way you wish, typically by adding regexps. However, these new variables make
4759it easier to make specific and common changes for the fontification of types.
4760
4761*** Adding highlighting patterns to existing support
4762
4763You can use the new function font-lock-add-keywords to add your own
4764highlighting patterns, such as for project-local or user-specific constructs,
4765for any mode.
4766
4767For example, to highlight `FIXME:' words in C comments, put:
4768
4769 (font-lock-add-keywords 'c-mode '(("\\<FIXME:" 0 font-lock-warning-face t)))
4770
4771in your ~/.emacs.
4772
4773*** New faces
4774
4775Font Lock now defines two new faces, font-lock-builtin-face and
4776font-lock-warning-face. These are intended to highlight builtin keywords,
4777distinct from a language's normal keywords, and objects that should be brought
4778to user attention, respectively. Various modes now use these new faces.
4779
4780*** Changes to fast-lock support mode
4781
4782The fast-lock package, one of the two Font Lock support modes, can now process
4783cache files silently. You can use the new variable fast-lock-verbose, in the
4784same way as font-lock-verbose, to control this feature.
4785
4786*** Changes to lazy-lock support mode
4787
4788The lazy-lock package, one of the two Font Lock support modes, can now fontify
4789according to the true syntactic context relative to other lines. You can use
4790the new variable lazy-lock-defer-contextually to control this feature. If
4791non-nil, changes to the buffer will cause subsequent lines in the buffer to be
4792refontified after lazy-lock-defer-time seconds of idle time. If nil, then only
4793the modified lines will be refontified; this is the same as the previous Lazy
4794Lock mode behaviour and the behaviour of Font Lock mode.
4795
4796This feature is useful in modes where strings or comments can span lines.
4797For example, if a string or comment terminating character is deleted, then if
4798this feature is enabled subsequent lines in the buffer will be correctly
4799refontified to reflect their new syntactic context. Previously, only the line
4800containing the deleted character would be refontified and you would have to use
4801the command M-g M-g (font-lock-fontify-block) to refontify some lines.
4802
4803As a consequence of this new feature, two other variables have changed:
4804
4805Variable `lazy-lock-defer-driven' is renamed `lazy-lock-defer-on-scrolling'.
4806Variable `lazy-lock-defer-time' can now only be a time, i.e., a number.
4807Buffer modes for which on-the-fly deferral applies can be specified via the
4808new variable `lazy-lock-defer-on-the-fly'.
4809
4810If you set these variables in your ~/.emacs, then you may have to change those
4811settings.
4812
4813** Ada mode changes.
4814
4815*** There is now better support for using find-file.el with Ada mode.
4816If you switch between spec and body, the cursor stays in the same
4817procedure (modulo overloading). If a spec has no body file yet, but
4818you try to switch to its body file, Ada mode now generates procedure
4819stubs.
4820
4821*** There are two new commands:
4822 - `ada-make-local' : invokes gnatmake on the current buffer
4823 - `ada-check-syntax' : check syntax of current buffer.
4824
4825The user options `ada-compiler-make', `ada-make-options',
4826`ada-language-version', `ada-compiler-syntax-check', and
4827`ada-compile-options' are used within these commands.
4828
4829*** Ada mode can now work with Outline minor mode. The outline level
4830is calculated from the indenting, not from syntactic constructs.
4831Outlining does not work if your code is not correctly indented.
4832
4833*** The new function `ada-gnat-style' converts the buffer to the style of
4834formatting used in GNAT. It places two blanks after a comment start,
4835places one blank between a word end and an opening '(', and puts one
4836space between a comma and the beginning of a word.
4837
4838** Scheme mode changes.
4839
4840*** Scheme mode indentation now uses many of the facilities of Lisp
4841mode; therefore, the variables to customize it are the variables used
4842for Lisp mode which have names starting with `lisp-'. The variables
4843with names starting with `scheme-' which used to do this no longer
4844have any effect.
4845
4846If you want to use different indentation for Scheme and Lisp, this is
4847still possible, but now you must do it by adding a hook to
4848scheme-mode-hook, which could work by setting the `lisp-' indentation
4849variables as buffer-local variables.
4850
4851*** DSSSL mode is a variant of Scheme mode, for editing DSSSL scripts.
4852Use M-x dsssl-mode.
4853
4854** The emacsclient program now accepts an option --no-wait which tells
4855it to return immediately without waiting for you to "finish" the
4856buffer in Emacs.
4857
4858** M-x eldoc-mode enables a minor mode in which the echo area
4859constantly shows the parameter list for function being called at point
4860(in Emacs Lisp and Lisp Interaction modes only).
4861
4862** C-x n d now runs the new command narrow-to-defun,
4863which narrows the accessible parts of the buffer to just
4864the current defun.
4865
4866** Emacs now handles the `--' argument in the standard way; all
4867following arguments are treated as ordinary file names.
4868
4869** On MSDOS and Windows, the bookmark file is now called _emacs.bmk,
4870and the saved desktop file is now called _emacs.desktop (truncated if
4871necessary).
4872
4873** When you kill a buffer that visits a file,
4874if there are any registers that save positions in the file,
4875these register values no longer become completely useless.
4876If you try to go to such a register with C-x j, then you are
4877asked whether to visit the file again. If you say yes,
4878it visits the file and then goes to the same position.
4879
4880** When you visit a file that changes frequently outside Emacs--for
4881example, a log of output from a process that continues to run--it may
4882be useful for Emacs to revert the file without querying you whenever
4883you visit the file afresh with C-x C-f.
4884
4885You can request this behavior for certain files by setting the
4886variable revert-without-query to a list of regular expressions. If a
4887file's name matches any of these regular expressions, find-file and
4888revert-buffer revert the buffer without asking for permission--but
4889only if you have not edited the buffer text yourself.
4890
4891** set-default-font has been renamed to set-frame-font
4892since it applies only to the current frame.
4893
4894** In TeX mode, you can use the variable tex-main-file to specify the
4895file for tex-file to run TeX on. (By default, tex-main-file is nil,
4896and tex-file runs TeX on the current visited file.)
4897
4898This is useful when you are editing a document that consists of
4899multiple files. In each of the included files, you can set up a local
4900variable list which specifies the top-level file of your document for
4901tex-main-file. Then tex-file will run TeX on the whole document
4902instead of just the file you are editing.
4903
4904** RefTeX mode
4905
4906RefTeX mode is a new minor mode with special support for \label, \ref
4907and \cite macros in LaTeX documents. RefTeX distinguishes labels of
4908different environments (equation, figure, ...) and has full support for
4909multifile documents. To use it, select a buffer with a LaTeX document and
4910turn the mode on with M-x reftex-mode. Here are the main user commands:
4911
4912C-c ( reftex-label
4913 Creates a label semi-automatically. RefTeX is context sensitive and
4914 knows which kind of label is needed.
4915
4916C-c ) reftex-reference
4917 Offers in a menu all labels in the document, along with context of the
4918 label definition. The selected label is referenced as \ref{LABEL}.
4919
4920C-c [ reftex-citation
4921 Prompts for a regular expression and displays a list of matching BibTeX
4922 database entries. The selected entry is cited with a \cite{KEY} macro.
4923
4924C-c & reftex-view-crossref
4925 Views the cross reference of a \ref or \cite command near point.
4926
4927C-c = reftex-toc
4928 Shows a table of contents of the (multifile) document. From there you
4929 can quickly jump to every section.
4930
4931Under X, RefTeX installs a "Ref" menu in the menu bar, with additional
4932commands. Press `?' to get help when a prompt mentions this feature.
4933Full documentation and customization examples are in the file
4934reftex.el. You can use the finder to view the file documentation:
4935C-h p --> tex --> reftex.el
4936
4937** Changes in BibTeX mode.
4938
4939*** Info documentation is now available.
4940
4941*** Don't allow parentheses in string constants anymore. This confused
4942both the BibTeX program and Emacs BibTeX mode.
4943
4944*** Renamed variable bibtex-mode-user-optional-fields to
4945bibtex-user-optional-fields.
4946
4947*** Removed variable bibtex-include-OPTannote
4948(use bibtex-user-optional-fields instead).
4949
4950*** New interactive functions to copy and kill fields and complete
4951entries to the BibTeX kill ring, from where they can be yanked back by
4952appropriate functions.
4953
4954*** New interactive functions for repositioning and marking of
4955entries. They are bound by default to M-C-l and M-C-h.
4956
4957*** New hook bibtex-clean-entry-hook. It is called after entry has
4958been cleaned.
4959
4960*** New variable bibtex-field-delimiters, which replaces variables
4961bibtex-field-{left|right}-delimiter.
4962
4963*** New variable bibtex-entry-delimiters to determine how entries
4964shall be delimited.
4965
4966*** Allow preinitialization of fields. See documentation of
4967bibtex-user-optional-fields, bibtex-entry-field-alist, and
4968bibtex-include-OPTkey for details.
4969
4970*** Book and InBook entries require either an author or an editor
4971field. This is now supported by bibtex.el. Alternative fields are
4972prefixed with `ALT'.
4973
4974*** New variable bibtex-entry-format, which replaces variable
4975bibtex-clean-entry-zap-empty-opts and allows specification of many
4976formatting options performed on cleaning an entry (see variable
4977documentation).
4978
4979*** Even more control on how automatic keys are generated. See
4980documentation of bibtex-generate-autokey for details. Transcriptions
4981for foreign languages other than German are now handled, too.
4982
4983*** New boolean user option bibtex-comma-after-last-field to decide if
4984comma should be inserted at end of last field.
4985
4986*** New boolean user option bibtex-align-at-equal-sign to determine if
4987alignment should be made at left side of field contents or at equal
4988signs. New user options to control entry layout (e.g. indentation).
4989
4990*** New function bibtex-fill-entry to realign entries.
4991
4992*** New function bibtex-reformat to reformat region or buffer.
4993
4994*** New function bibtex-convert-alien to convert a BibTeX database
4995from alien sources.
4996
4997*** New function bibtex-complete-key (similar to bibtex-complete-string)
4998to complete prefix to a key defined in buffer. Mainly useful in
4999crossref entries.
5000
5001*** New function bibtex-count-entries to count entries in buffer or
5002region.
5003
5004*** Added support for imenu.
5005
5006*** The function `bibtex-validate' now checks current region instead
5007of buffer if mark is active. Now it shows all errors of buffer in a
5008`compilation mode' buffer. You can use the normal commands (e.g.
5009`next-error') for compilation modes to jump to errors.
5010
5011*** New variable `bibtex-string-file-path' to determine where the files
5012from `bibtex-string-files' are searched.
5013
5014** Iso Accents mode now supports Latin-3 as an alternative.
5015
5016** The function using-unix-filesystems has been replaced by the
5017functions add-untranslated-filesystem and remove-untranslated-filesystem.
5018Each of these functions takes the name of a drive letter or directory
5019as an argument.
5020
5021When a filesystem is added as untranslated, all files on it are read
5022and written in binary mode (no cr/lf translation is performed).
5023
5024** browse-url changes
5025
5026*** New methods for: Grail (browse-url-generic), MMM (browse-url-mmm),
5027Lynx in a separate xterm (browse-url-lynx-xterm) or in an Emacs window
5028(browse-url-lynx-emacs), remote W3 (browse-url-w3-gnudoit), generic
5029non-remote-controlled browsers (browse-url-generic) and associated
5030customization variables.
5031
5032*** New commands `browse-url-of-region' and `browse-url'.
5033
5034*** URLs marked up with <URL:...> (RFC1738) work if broken across
5035lines. Browsing methods can be associated with URL regexps
5036(e.g. mailto: URLs) via `browse-url-browser-function'.
5037
5038** Changes in Ediff
5039
5040*** Clicking Mouse-2 on a brief command description in Ediff control panel
5041pops up the Info file for this command.
5042
5043*** There is now a variable, ediff-autostore-merges, which controls whether
5044the result of a merge is saved in a file. By default, this is done only when
5045merge is done from a session group (eg, when merging files in two different
5046directories).
5047
5048*** Since Emacs 19.31 (this hasn't been announced before), Ediff can compare
5049and merge groups of files residing in different directories, or revisions of
5050files in the same directory.
5051
5052*** Since Emacs 19.31, Ediff can apply multi-file patches interactively.
5053The patches must be in the context format or GNU unified format. (The bug
5054related to the GNU format has now been fixed.)
5055
5056** Changes in Viper
5057
5058*** The startup file is now .viper instead of .vip
5059*** All variable/function names have been changed to start with viper-
5060 instead of vip-.
5061*** C-\ now simulates the meta-key in all Viper states.
5062*** C-z in Insert state now escapes to Vi for the duration of the next
5063Viper command. In Vi and Insert states, C-z behaves as before.
5064*** C-c \ escapes to Vi for one command if Viper is in Insert or Emacs states.
5065*** _ is no longer the meta-key in Vi state.
5066*** The variable viper-insert-state-cursor-color can be used to change cursor
5067color when Viper is in insert state.
5068*** If search lands the cursor near the top or the bottom of the window,
5069Viper pulls the window up or down to expose more context. The variable
5070viper-adjust-window-after-search controls this behavior.
5071
5072** Etags changes.
5073
5074*** In C, C++, Objective C and Java, Etags tags global variables by
5075default. The resulting tags files are inflated by 30% on average.
5076Use --no-globals to turn this feature off. Etags can also tag
5077variables which are members of structure-like constructs, but it does
5078not by default. Use --members to turn this feature on.
5079
5080*** C++ member functions are now recognized as tags.
5081
5082*** Java is tagged like C++. In addition, "extends" and "implements"
5083constructs are tagged. Files are recognised by the extension .java.
5084
5085*** Etags can now handle programs written in Postscript. Files are
5086recognised by the extensions .ps and .pdb (Postscript with C syntax).
5087In Postscript, tags are lines that start with a slash.
5088
5089*** Etags now handles Objective C and Objective C++ code. The usual C and
5090C++ tags are recognized in these languages; in addition, etags
5091recognizes special Objective C syntax for classes, class categories,
5092methods and protocols.
5093
5094*** Etags also handles Cobol. Files are recognised by the extension
5095.cobol. The tagged lines are those containing a word that begins in
5096column 8 and ends in a full stop, i.e. anything that could be a
5097paragraph name.
5098
5099*** Regexps in Etags now support intervals, as in ed or grep. The syntax of
5100an interval is \{M,N\}, and it means to match the preceding expression
5101at least M times and as many as N times.
5102
5103** The format for specifying a custom format for time-stamp to insert
5104in files has changed slightly.
5105
5106With the new enhancements to the functionality of format-time-string,
5107time-stamp-format will change to be eventually compatible with it.
5108This conversion is being done in two steps to maintain compatibility
5109with old time-stamp-format values.
5110
5111In the new scheme, alternate case is signified by the number-sign
5112(`#') modifier, rather than changing the case of the format character.
5113This feature is as yet incompletely implemented for compatibility
5114reasons.
5115
5116In the old time-stamp-format, all numeric fields defaulted to their
5117natural width. (With format-time-string, each format has a
5118fixed-width default.) In this version, you can specify the colon
5119(`:') modifier to a numeric conversion to mean "give me the historical
5120time-stamp-format width default." Do not use colon if you are
5121specifying an explicit width, as in "%02d".
5122
5123Numbers are no longer truncated to the requested width, except in the
5124case of "%02y", which continues to give a two-digit year. Digit
5125truncation probably wasn't being used for anything else anyway.
5126
5127The new formats will work with old versions of Emacs. New formats are
5128being recommended now to allow time-stamp-format to change in the
5129future to be compatible with format-time-string. The new forms being
5130recommended now will continue to work then.
5131
5132See the documentation string for the variable time-stamp-format for
5133details.
5134
5135** There are some additional major modes:
5136
5137dcl-mode, for editing VMS DCL files.
5138m4-mode, for editing files of m4 input.
5139meta-mode, for editing MetaFont and MetaPost source files.
5140
5141** In Shell mode, the command shell-copy-environment-variable lets you
5142copy the value of a specified environment variable from the subshell
5143into Emacs.
5144
5145** New Lisp packages include:
5146
5147*** battery.el displays battery status for laptops.
5148
5149*** M-x bruce (named after Lenny Bruce) is a program that might
5150be used for adding some indecent words to your email.
5151
5152*** M-x crisp-mode enables an emulation for the CRiSP editor.
5153
5154*** M-x dirtrack arranges for better tracking of directory changes
5155in shell buffers.
5156
5157*** The new library elint.el provides for linting of Emacs Lisp code.
5158See the documentation for `elint-initialize', `elint-current-buffer'
5159and `elint-defun'.
5160
5161*** M-x expand-add-abbrevs defines a special kind of abbrev which is
5162meant for programming constructs. These abbrevs expand like ordinary
5163ones, when you type SPC, but only at the end of a line and not within
5164strings or comments.
5165
5166These abbrevs can act as templates: you can define places within an
5167abbrev for insertion of additional text. Once you expand the abbrev,
5168you can then use C-x a p and C-x a n to move back and forth to these
5169insertion points. Thus you can conveniently insert additional text
5170at these points.
5171
5172*** filecache.el remembers the location of files so that you
5173can visit them by short forms of their names.
5174
5175*** find-func.el lets you find the definition of the user-loaded
5176Emacs Lisp function at point.
5177
5178*** M-x handwrite converts text to a "handwritten" picture.
5179
5180*** M-x iswitchb-buffer is a command for switching to a buffer, much like
5181switch-buffer, but it reads the argument in a more helpful way.
5182
5183*** M-x landmark implements a neural network for landmark learning.
5184
5185*** M-x locate provides a convenient interface to the `locate' program.
5186
5187*** M4 mode is a new mode for editing files of m4 input.
5188
5189*** mantemp.el creates C++ manual template instantiations
5190from the GCC error messages which indicate which instantiations are needed.
5191
5192*** mouse-copy.el provides a one-click copy and move feature.
5193You can drag a region with M-mouse-1, and it is automatically
5194inserted at point. M-Shift-mouse-1 deletes the text from its
5195original place after inserting the copy.
5196
5197*** mouse-drag.el lets you do scrolling by dragging Mouse-2
5198on the buffer.
5199
5200You click the mouse and move; that distance either translates into the
5201velocity to scroll (with mouse-drag-throw) or the distance to scroll
5202(with mouse-drag-drag). Horizontal scrolling is enabled when needed.
5203
5204Enable mouse-drag with:
5205 (global-set-key [down-mouse-2] 'mouse-drag-throw)
5206-or-
5207 (global-set-key [down-mouse-2] 'mouse-drag-drag)
5208
5209*** mspools.el is useful for determining which mail folders have
5210mail waiting to be read in them. It works with procmail.
5211
5212*** Octave mode is a major mode for editing files of input for Octave.
5213It comes with a facility for communicating with an Octave subprocess.
5214
5215*** ogonek
5216
5217The ogonek package provides functions for changing the coding of
5218Polish diacritic characters in buffers. Codings known from various
5219platforms are supported such as ISO8859-2, Mazovia, IBM Latin2, and
5220TeX. For example, you can change the coding from Mazovia to
5221ISO8859-2. Another example is a change of coding from ISO8859-2 to
5222prefix notation (in which `/a' stands for the aogonek character, for
5223instance) and vice versa.
5224
5225To use this package load it using
5226 M-x load-library [enter] ogonek
5227Then, you may get an explanation by calling one of
5228 M-x ogonek-jak -- in Polish
5229 M-x ogonek-how -- in English
5230The info specifies the commands and variables provided as well as the
5231ways of customization in `.emacs'.
5232
5233*** Interface to ph.
5234
5235Emacs provides a client interface to CCSO Nameservers (ph/qi)
5236
5237The CCSO nameserver is used in many universities to provide directory
5238services about people. ph.el provides a convenient Emacs interface to
5239these servers.
5240
5241*** uce.el is useful for replying to unsolicited commercial email.
5242
5243*** vcursor.el implements a "virtual cursor" feature.
5244You can move the virtual cursor with special commands
5245while the real cursor does not move.
5246
5247*** webjump.el is a "hot list" package which you can set up
5248for visiting your favorite web sites.
5249
5250*** M-x winner-mode is a minor mode which saves window configurations,
5251so you can move back to other configurations that you have recently used.
5252
5253** movemail change
5254
5255Movemail no longer needs to be installed setuid root in order for POP
5256mail retrieval to function properly. This is because it no longer
5257supports the RPOP (reserved-port POP) protocol; instead, it uses the
5258user's POP password to authenticate to the mail server.
5259
5260This change was made earlier, but not reported in NEWS before.
5261\f
5262* Emacs 20.1 changes for MS-DOS and MS-Windows.
5263
5264** Changes in handling MS-DOS/MS-Windows text files.
5265
5266Emacs handles three different conventions for representing
5267end-of-line: CRLF for MSDOS, LF for Unix and GNU, and CR (used on the
5268Macintosh). Emacs determines which convention is used in a specific
5269file based on the contents of that file (except for certain special
5270file names), and when it saves the file, it uses the same convention.
5271
5272To save the file and change the end-of-line convention, you can use
5273C-x RET f (set-buffer-file-coding-system) to specify a different
5274coding system for the buffer. Then, when you save the file, the newly
5275specified coding system will take effect. For example, to save with
5276LF, specify undecided-unix (or some other ...-unix coding system); to
5277save with CRLF, specify undecided-dos.
5278\f
5279* Lisp Changes in Emacs 20.1
5280
5281** Byte-compiled files made with Emacs 20 will, in general, work in
5282Emacs 19 as well, as long as the source code runs in Emacs 19. And
5283vice versa: byte-compiled files made with Emacs 19 should also run in
5284Emacs 20, as long as the program itself works in Emacs 20.
5285
5286** Windows-specific functions and variables have been renamed
5287to start with w32- instead of win32-.
5288
5289In hacker language, calling something a "win" is a form of praise. We
5290don't want to praise a non-free Microsoft system, so we don't call it
5291"win".
5292
5293** Basic Lisp changes
5294
5295*** A symbol whose name starts with a colon now automatically
5296evaluates to itself. Therefore such a symbol can be used as a constant.
5297
5298*** The defined purpose of `defconst' has been changed. It should now
5299be used only for values that should not be changed whether by a program
5300or by the user.
5301
5302The actual behavior of defconst has not been changed.
5303
5304*** There are new macros `when' and `unless'
5305
5306(when CONDITION BODY...) is short for (if CONDITION (progn BODY...))
5307(unless CONDITION BODY...) is short for (if CONDITION nil BODY...)
5308
5309*** Emacs now defines functions caar, cadr, cdar and cddr with their
5310usual Lisp meanings. For example, caar returns the car of the car of
5311its argument.
5312
5313*** equal, when comparing strings, now ignores their text properties.
5314
5315*** The new function `functionp' tests whether an object is a function.
5316
5317*** arrayp now returns t for char-tables and bool-vectors.
5318
5319*** Certain primitives which use characters (as integers) now get an
5320error if the integer is not a valid character code. These primitives
5321include insert-char, char-to-string, and the %c construct in the
5322`format' function.
5323
5324*** The `require' function now insists on adding a suffix, either .el
5325or .elc, to the file name. Thus, (require 'foo) will not use a file
5326whose name is just foo. It insists on foo.el or foo.elc.
5327
5328*** The `autoload' function, when the file name does not contain
5329either a directory name or the suffix .el or .elc, insists on
5330adding one of these suffixes.
5331
5332*** string-to-number now takes an optional second argument BASE
5333which specifies the base to use when converting an integer.
5334If BASE is omitted, base 10 is used.
5335
5336We have not implemented other radices for floating point numbers,
5337because that would be much more work and does not seem useful.
5338
5339*** substring now handles vectors as well as strings.
5340
5341*** The Common Lisp function eql is no longer defined normally.
5342You must load the `cl' library to define it.
5343
5344*** The new macro `with-current-buffer' lets you evaluate an expression
5345conveniently with a different current buffer. It looks like this:
5346
5347 (with-current-buffer BUFFER BODY-FORMS...)
5348
5349BUFFER is the expression that says which buffer to use.
5350BODY-FORMS say what to do in that buffer.
5351
5352*** The new primitive `save-current-buffer' saves and restores the
5353choice of current buffer, like `save-excursion', but without saving or
5354restoring the value of point or the mark. `with-current-buffer'
5355works using `save-current-buffer'.
5356
5357*** The new macro `with-temp-file' lets you do some work in a new buffer and
5358write the output to a specified file. Like `progn', it returns the value
5359of the last form.
5360
5361*** The new macro `with-temp-buffer' lets you do some work in a new buffer,
5362which is discarded after use. Like `progn', it returns the value of the
5363last form. If you wish to return the buffer contents, use (buffer-string)
5364as the last form.
5365
5366*** The new function split-string takes a string, splits it at certain
5367characters, and returns a list of the substrings in between the
5368matches.
5369
5370For example, (split-string "foo bar lose" " +") returns ("foo" "bar" "lose").
5371
5372*** The new macro with-output-to-string executes some Lisp expressions
5373with standard-output set up so that all output feeds into a string.
5374Then it returns that string.
5375
5376For example, if the current buffer name is `foo',
5377
5378(with-output-to-string
5379 (princ "The buffer is ")
5380 (princ (buffer-name)))
5381
5382returns "The buffer is foo".
5383
5384** Non-ASCII characters are now supported, if enable-multibyte-characters
5385is non-nil.
5386
5387These characters have character codes above 256. When inserted in the
5388buffer or stored in a string, they are represented as multibyte
5389characters that occupy several buffer positions each.
5390
5391*** When enable-multibyte-characters is non-nil, a single character in
5392a buffer or string can be two or more bytes (as many as four).
5393
5394Buffers and strings are still made up of unibyte elements;
5395character positions and string indices are always measured in bytes.
5396Therefore, moving forward one character can increase the buffer
5397position by 2, 3 or 4. The function forward-char moves by whole
5398characters, and therefore is no longer equivalent to
5399 (lambda (n) (goto-char (+ (point) n))).
5400
5401ASCII characters (codes 0 through 127) are still single bytes, always.
5402Sequences of byte values 128 through 255 are used to represent
5403non-ASCII characters. These sequences are called "multibyte
5404characters".
5405
5406The first byte of a multibyte character is always in the range 128
5407through 159 (octal 0200 through 0237). These values are called
5408"leading codes". The second and subsequent bytes are always in the
5409range 160 through 255 (octal 0240 through 0377). The first byte, the
5410leading code, determines how many bytes long the sequence is.
5411
5412*** The function forward-char moves over characters, and therefore
5413(forward-char 1) may increase point by more than 1 if it moves over a
5414multibyte character. Likewise, delete-char always deletes a
5415character, which may be more than one buffer position.
5416
5417This means that some Lisp programs, which assume that a character is
5418always one buffer position, need to be changed.
5419
5420However, all ASCII characters are always one buffer position.
5421
5422*** The regexp [\200-\377] no longer matches all non-ASCII characters,
5423because when enable-multibyte-characters is non-nil, these characters
5424have codes that are not in the range octal 200 to octal 377. However,
5425the regexp [^\000-\177] does match all non-ASCII characters,
5426guaranteed.
5427
5428*** The function char-boundary-p returns non-nil if position POS is
5429between two characters in the buffer (not in the middle of a
5430character).
5431
5432When the value is non-nil, it says what kind of character follows POS:
5433
5434 0 if POS is at an ASCII character or at the end of range,
5435 1 if POS is before a 2-byte length multi-byte form,
5436 2 if POS is at a head of 3-byte length multi-byte form,
5437 3 if POS is at a head of 4-byte length multi-byte form,
5438 4 if POS is at a head of multi-byte form of a composite character.
5439
5440*** The function char-bytes returns how many bytes the character CHAR uses.
5441
5442*** Strings can contain multibyte characters. The function
5443`length' returns the string length counting bytes, which may be
5444more than the number of characters.
5445
5446You can include a multibyte character in a string constant by writing
5447it literally. You can also represent it with a hex escape,
5448\xNNNNNNN..., using as many digits as necessary. Any character which
5449is not a valid hex digit terminates this construct. If you want to
5450follow it with a character that is a hex digit, write backslash and
5451newline in between; that will terminate the hex escape.
5452
5453*** The function concat-chars takes arguments which are characters
5454and returns a string containing those characters.
5455
5456*** The function sref access a multibyte character in a string.
5457(sref STRING INDX) returns the character in STRING at INDEX. INDEX
5458counts from zero. If INDEX is at a position in the middle of a
5459character, sref signals an error.
5460
5461*** The function chars-in-string returns the number of characters
5462in a string. This is less than the length of the string, if the
5463string contains multibyte characters (the length counts bytes).
5464
5465*** The function chars-in-region returns the number of characters
5466in a region from BEG to END. This is less than (- END BEG) if the
5467region contains multibyte characters (the length counts bytes).
5468
5469*** The function string-to-list converts a string to a list of
5470the characters in it. string-to-vector converts a string
5471to a vector of the characters in it.
5472
5473*** The function store-substring alters part of the contents
5474of a string. You call it as follows:
5475
5476 (store-substring STRING IDX OBJ)
5477
5478This says to alter STRING, by storing OBJ starting at index IDX in
5479STRING. OBJ may be either a character or a (smaller) string.
5480This function really does alter the contents of STRING.
5481Since it is impossible to change the length of an existing string,
5482it is an error if OBJ doesn't fit within STRING's actual length.
5483
5484*** char-width returns the width (in columns) of the character CHAR,
5485if it were displayed in the current buffer and the selected window.
5486
5487*** string-width returns the width (in columns) of the text in STRING,
5488if it were displayed in the current buffer and the selected window.
5489
5490*** truncate-string-to-width shortens a string, if necessary,
5491to fit within a certain number of columns. (Of course, it does
5492not alter the string that you give it; it returns a new string
5493which contains all or just part of the existing string.)
5494
5495(truncate-string-to-width STR END-COLUMN &optional START-COLUMN PADDING)
5496
5497This returns the part of STR up to column END-COLUMN.
5498
5499The optional argument START-COLUMN specifies the starting column.
5500If this is non-nil, then the first START-COLUMN columns of the string
5501are not included in the resulting value.
5502
5503The optional argument PADDING, if non-nil, is a padding character to be added
5504at the beginning and end the resulting string, to extend it to exactly
5505WIDTH columns. If PADDING is nil, that means do not pad; then, if STRING
5506is narrower than WIDTH, the value is equal to STRING.
5507
5508If PADDING and START-COLUMN are both non-nil, and if there is no clean
5509place in STRING that corresponds to START-COLUMN (because one
5510character extends across that column), then the padding character
5511PADDING is added one or more times at the beginning of the result
5512string, so that its columns line up as if it really did start at
5513column START-COLUMN.
5514
5515*** When the functions in the list after-change-functions are called,
5516the third argument is the number of bytes in the pre-change text, not
5517necessarily the number of characters. It is, in effect, the
5518difference in buffer position between the beginning and the end of the
5519changed text, before the change.
5520
5521*** The characters Emacs uses are classified in various character
5522sets, each of which has a name which is a symbol. In general there is
5523one character set for each script, not for each language.
5524
5525**** The function charsetp tests whether an object is a character set name.
5526
5527**** The variable charset-list holds a list of character set names.
5528
5529**** char-charset, given a character code, returns the name of the character
5530set that the character belongs to. (The value is a symbol.)
5531
5532**** split-char, given a character code, returns a list containing the
5533name of the character set, followed by one or two byte-values
5534which identify the character within that character set.
5535
5536**** make-char, given a character set name and one or two subsequent
5537byte-values, constructs a character code. This is roughly the
5538opposite of split-char.
5539
5540**** find-charset-region returns a list of the character sets
5541of all the characters between BEG and END.
5542
5543**** find-charset-string returns a list of the character sets
5544of all the characters in a string.
5545
5546*** Here are the Lisp facilities for working with coding systems
5547and specifying coding systems.
5548
5549**** The function coding-system-list returns a list of all coding
5550system names (symbols). With optional argument t, it returns a list
5551of all distinct base coding systems, not including variants.
5552(Variant coding systems are those like latin-1-dos, latin-1-unix
5553and latin-1-mac which specify the end-of-line conversion as well
5554as what to do about code conversion.)
5555
5556**** coding-system-p tests a symbol to see if it is a coding system
5557name. It returns t if so, nil if not.
5558
5559**** file-coding-system-alist specifies which coding systems to use
5560for certain file names. It works like network-coding-system-alist,
5561except that the PATTERN is matched against the file name.
5562
5563Each element has the format (PATTERN . VAL), where PATTERN determines
5564which file names the element applies to. PATTERN should be a regexp
5565to match against a file name.
5566
5567VAL is a coding system, a cons cell containing two coding systems, or
5568a function symbol. If VAL is a coding system, it is used for both
5569decoding what received from the network stream and encoding what sent
5570to the network stream. If VAL is a cons cell containing two coding
5571systems, the car specifies the coding system for decoding, and the cdr
5572specifies the coding system for encoding.
5573
5574If VAL is a function symbol, the function must return a coding system
5575or a cons cell containing two coding systems, which is used as above.
5576
5577**** The variable network-coding-system-alist specifies
5578the coding system to use for network sockets.
5579
5580Each element has the format (PATTERN . VAL), where PATTERN determines
5581which network sockets the element applies to. PATTERN should be
5582either a port number or a regular expression matching some network
5583service names.
5584
5585VAL is a coding system, a cons cell containing two coding systems, or
5586a function symbol. If VAL is a coding system, it is used for both
5587decoding what received from the network stream and encoding what sent
5588to the network stream. If VAL is a cons cell containing two coding
5589systems, the car specifies the coding system for decoding, and the cdr
5590specifies the coding system for encoding.
5591
5592If VAL is a function symbol, the function must return a coding system
5593or a cons cell containing two coding systems, which is used as above.
5594
5595**** process-coding-system-alist specifies which coding systems to use
5596for certain subprocess. It works like network-coding-system-alist,
5597except that the PATTERN is matched against the program name used to
5598start the subprocess.
5599
5600**** The variable default-process-coding-system specifies the coding
5601systems to use for subprocess (and net connection) input and output,
5602when nothing else specifies what to do. The value is a cons cell
5603(OUTPUT-CODING . INPUT-CODING). OUTPUT-CODING applies to output
5604to the subprocess, and INPUT-CODING applies to input from it.
5605
5606**** The variable coding-system-for-write, if non-nil, specifies the
5607coding system to use for writing a file, or for output to a synchronous
5608subprocess.
5609
5610It also applies to any asynchronous subprocess or network connection,
5611but in a different way: the value of coding-system-for-write when you
5612start the subprocess or connection affects that subprocess or
5613connection permanently or until overridden.
5614
5615The variable coding-system-for-write takes precedence over
5616file-coding-system-alist, process-coding-system-alist and
5617network-coding-system-alist, and all other methods of specifying a
5618coding system for output. But most of the time this variable is nil.
5619It exists so that Lisp programs can bind it to a specific coding
5620system for one operation at a time.
5621
5622**** coding-system-for-read applies similarly to input from
5623files, subprocesses or network connections.
5624
5625**** The function process-coding-system tells you what
5626coding systems(s) an existing subprocess is using.
5627The value is a cons cell,
5628 (DECODING-CODING-SYSTEM . ENCODING-CODING-SYSTEM)
5629where DECODING-CODING-SYSTEM is used for decoding output from
5630the subprocess, and ENCODING-CODING-SYSTEM is used for encoding
5631input to the subprocess.
5632
5633**** The function set-process-coding-system can be used to
5634change the coding systems in use for an existing subprocess.
5635
5636** Emacs has a new facility to help users manage the many
5637customization options. To make a Lisp program work with this facility,
5638you need to use the new macros defgroup and defcustom.
5639
5640You use defcustom instead of defvar, for defining a user option
5641variable. The difference is that you specify two additional pieces of
5642information (usually): the "type" which says what values are
5643legitimate, and the "group" which specifies the hierarchy for
5644customization.
5645
5646Thus, instead of writing
5647
5648 (defvar foo-blurgoze nil
5649 "*Non-nil means that foo will act very blurgozely.")
5650
5651you would now write this:
5652
5653 (defcustom foo-blurgoze nil
5654 "*Non-nil means that foo will act very blurgozely."
5655 :type 'boolean
5656 :group foo)
5657
5658The type `boolean' means that this variable has only
5659two meaningful states: nil and non-nil. Other type values
5660describe other possibilities; see the manual for Custom
5661for a description of them.
5662
5663The "group" argument is used to specify a group which the option
5664should belong to. You define a new group like this:
5665
5666 (defgroup ispell nil
5667 "Spell checking using Ispell."
5668 :group 'processes)
5669
5670The "group" argument in defgroup specifies the parent group. The root
5671group is called `emacs'; it should not contain any variables itself,
5672but only other groups. The immediate subgroups of `emacs' correspond
5673to the keywords used by C-h p. Under these subgroups come
5674second-level subgroups that belong to individual packages.
5675
5676Each Emacs package should have its own set of groups. A simple
5677package should have just one group; a more complex package should
5678have a hierarchy of its own groups. The sole or root group of a
5679package should be a subgroup of one or more of the "keyword"
5680first-level subgroups.
5681
5682** New `widget' library for inserting UI components in buffers.
5683
5684This library, used by the new custom library, is documented in a
5685separate manual that accompanies Emacs.
5686
5687** easy-mmode
5688
5689The easy-mmode package provides macros and functions that make
5690developing minor modes easier. Roughly, the programmer has to code
5691only the functionality of the minor mode. All the rest--toggles,
5692predicate, and documentation--can be done in one call to the macro
5693`easy-mmode-define-minor-mode' (see the documentation). See also
5694`easy-mmode-define-keymap'.
5695
5696** Text property changes
5697
5698*** The `intangible' property now works on overlays as well as on a
5699text property.
5700
5701*** The new functions next-char-property-change and
5702previous-char-property-change scan through the buffer looking for a
5703place where either a text property or an overlay might change. The
5704functions take two arguments, POSITION and LIMIT. POSITION is the
5705starting position for the scan. LIMIT says where to stop the scan.
5706
5707If no property change is found before LIMIT, the value is LIMIT. If
5708LIMIT is nil, scan goes to the beginning or end of the accessible part
5709of the buffer. If no property change is found, the value is the
5710position of the beginning or end of the buffer.
5711
5712*** In the `local-map' text property or overlay property, the property
5713value can now be a symbol whose function definition is a keymap. This
5714is an alternative to using the keymap itself.
5715
5716** Changes in invisibility features
5717
5718*** Isearch can now temporarily show parts of the buffer which are
5719hidden by an overlay with a invisible property, when the search match
5720is inside that portion of the buffer. To enable this the overlay
5721should have a isearch-open-invisible property which is a function that
5722would be called having the overlay as an argument, the function should
5723make the overlay visible.
5724
5725During incremental search the overlays are shown by modifying the
5726invisible and intangible properties, if beside this more actions are
5727needed the overlay should have a isearch-open-invisible-temporary
5728which is a function. The function is called with 2 arguments: one is
5729the overlay and the second is nil when it should show the overlay and
5730t when it should hide it.
5731
5732*** add-to-invisibility-spec, remove-from-invisibility-spec
5733
5734Modes that use overlays to hide portions of a buffer should set the
5735invisible property of the overlay to the mode's name (or another symbol)
5736and modify the `buffer-invisibility-spec' to include that symbol.
5737Use `add-to-invisibility-spec' and `remove-from-invisibility-spec' to
5738manipulate the `buffer-invisibility-spec'.
5739Here is an example of how to do this:
5740
5741 ;; If we want to display an ellipsis:
5742 (add-to-invisibility-spec '(my-symbol . t))
5743 ;; If you don't want ellipsis:
5744 (add-to-invisibility-spec 'my-symbol)
5745
5746 ...
5747 (overlay-put (make-overlay beginning end) 'invisible 'my-symbol)
5748
5749 ...
5750 ;; When done with the overlays:
5751 (remove-from-invisibility-spec '(my-symbol . t))
5752 ;; Or respectively:
5753 (remove-from-invisibility-spec 'my-symbol)
5754
5755** Changes in syntax parsing.
5756
5757*** The syntax-directed buffer-scan functions (such as
5758`parse-partial-sexp', `forward-word' and similar functions) can now
5759obey syntax information specified by text properties, if the variable
5760`parse-sexp-lookup-properties' is non-nil.
5761
5762If the value of `parse-sexp-lookup-properties' is nil, the behavior
5763is as before: the syntax-table of the current buffer is always
5764used to determine the syntax of the character at the position.
5765
5766When `parse-sexp-lookup-properties' is non-nil, the syntax of a
5767character in the buffer is calculated thus:
5768
5769 a) if the `syntax-table' text-property of that character
5770 is a cons, this cons becomes the syntax-type;
5771
5772 Valid values of `syntax-table' text-property are: nil, a valid
5773 syntax-table, and a valid syntax-table element, i.e.,
5774 a cons cell of the form (SYNTAX-CODE . MATCHING-CHAR).
5775
5776 b) if the character's `syntax-table' text-property
5777 is a syntax table, this syntax table is used
5778 (instead of the syntax-table of the current buffer) to
5779 determine the syntax type of the character.
5780
5781 c) otherwise the syntax-type is determined by the syntax-table
5782 of the current buffer.
5783
5784*** The meaning of \s in regular expressions is also affected by the
5785value of `parse-sexp-lookup-properties'. The details are the same as
5786for the syntax-directed buffer-scan functions.
5787
5788*** There are two new syntax-codes, `!' and `|' (numeric values 14
5789and 15). A character with a code `!' starts a comment which is ended
5790only by another character with the same code (unless quoted). A
5791character with a code `|' starts a string which is ended only by
5792another character with the same code (unless quoted).
5793
5794These codes are mainly meant for use as values of the `syntax-table'
5795text property.
5796
5797*** The function `parse-partial-sexp' has new semantics for the sixth
5798arg COMMENTSTOP. If it is `syntax-table', parse stops after the start
5799of a comment or a string, or after end of a comment or a string.
5800
5801*** The state-list which the return value from `parse-partial-sexp'
5802(and can also be used as an argument) now has an optional ninth
5803element: the character address of the start of last comment or string;
5804nil if none. The fourth and eighth elements have special values if the
5805string/comment is started by a "!" or "|" syntax-code.
5806
5807*** Since new features of `parse-partial-sexp' allow a complete
5808syntactic parsing, `font-lock' no longer supports
5809`font-lock-comment-start-regexp'.
5810
5811** Changes in face features
5812
5813*** The face functions are now unconditionally defined in Emacs, even
5814if it does not support displaying on a device that supports faces.
5815
5816*** The function face-documentation returns the documentation string
5817of a face (or nil if it doesn't have one).
5818
5819*** The function face-bold-p returns t if a face should be bold.
5820set-face-bold-p sets that flag.
5821
5822*** The function face-italic-p returns t if a face should be italic.
5823set-face-italic-p sets that flag.
5824
5825*** You can now specify foreground and background colors for text
5826by adding elements of the form (foreground-color . COLOR-NAME)
5827and (background-color . COLOR-NAME) to the list of faces in
5828the `face' property (either the character's text property or an
5829overlay property).
5830
5831This means that you no longer need to create named faces to use
5832arbitrary colors in a Lisp package.
5833
5834** Changes in file-handling functions
5835
5836*** File-access primitive functions no longer discard an extra redundant
5837directory name from the beginning of the file name. In other words,
5838they no longer do anything special with // or /~. That conversion
5839is now done only in substitute-in-file-name.
5840
5841This makes it possible for a Lisp program to open a file whose name
5842begins with ~.
5843
5844*** If copy-file is unable to set the date of the output file,
5845it now signals an error with the condition file-date-error.
5846
5847*** The inode number returned by file-attributes may be an integer (if
5848the number fits in a Lisp integer) or a list of integers.
5849
5850*** insert-file-contents can now read from a special file,
5851as long as the arguments VISIT and REPLACE are nil.
5852
5853*** The RAWFILE arg to find-file-noselect, if non-nil, now suppresses
5854character code conversion as well as other things.
5855
5856Meanwhile, this feature does work with remote file names
5857(formerly it did not).
5858
5859*** Lisp packages which create temporary files should use the TMPDIR
5860environment variable to decide which directory to put them in.
5861
5862*** interpreter-mode-alist elements now specify regexps
5863instead of constant strings.
5864
5865*** expand-file-name no longer treats `//' or `/~' specially. It used
5866to delete all the text of a file name up through the first slash of
5867any `//' or `/~' sequence. Now it passes them straight through.
5868
5869substitute-in-file-name continues to treat those sequences specially,
5870in the same way as before.
5871
5872*** The variable `format-alist' is more general now.
5873The FROM-FN and TO-FN in a format definition can now be strings
5874which specify shell commands to use as filters to perform conversion.
5875
5876*** The new function access-file tries to open a file, and signals an
5877error if that fails. If the open succeeds, access-file does nothing
5878else, and returns nil.
5879
5880*** The function insert-directory now signals an error if the specified
5881directory cannot be listed.
5882
5883** Changes in minibuffer input
5884
5885*** The functions read-buffer, read-variable, read-command, read-string
5886read-file-name, read-from-minibuffer and completing-read now take an
5887additional argument which specifies the default value. If this
5888argument is non-nil, it should be a string; that string is used in two
5889ways:
5890
5891 It is returned if the user enters empty input.
5892 It is available through the history command M-n.
5893
5894*** The functions read-string, read-from-minibuffer,
5895read-no-blanks-input and completing-read now take an additional
5896argument INHERIT-INPUT-METHOD. If this is non-nil, then the
5897minibuffer inherits the current input method and the setting of
5898enable-multibyte-characters from the previously current buffer.
5899
5900In an interactive spec, you can use M instead of s to read an
5901argument in this way.
5902
5903*** All minibuffer input functions discard text properties
5904from the text you enter in the minibuffer, unless the variable
5905minibuffer-allow-text-properties is non-nil.
5906
5907** Echo area features
5908
5909*** Clearing the echo area now runs the normal hook
5910echo-area-clear-hook. Note that the echo area can be used while the
5911minibuffer is active; in that case, the minibuffer is still active
5912after the echo area is cleared.
5913
5914*** The function current-message returns the message currently displayed
5915in the echo area, or nil if there is none.
5916
5917** Keyboard input features
5918
5919*** tty-erase-char is a new variable that reports which character was
5920set up as the terminal's erase character when time Emacs was started.
5921
5922*** num-nonmacro-input-events is the total number of input events
5923received so far from the terminal. It does not count those generated
5924by keyboard macros.
5925
5926** Frame-related changes
5927
5928*** make-frame runs the normal hook before-make-frame-hook just before
5929creating a frame, and just after creating a frame it runs the abnormal
5930hook after-make-frame-functions with the new frame as arg.
5931
5932*** The new hook window-configuration-change-hook is now run every time
5933the window configuration has changed. The frame whose configuration
5934has changed is the selected frame when the hook is run.
5935
5936*** Each frame now independently records the order for recently
5937selected buffers, in its buffer-list frame parameter, so that the
5938value of other-buffer is now based on the buffers recently displayed
5939in the selected frame.
5940
5941*** The value of the frame parameter vertical-scroll-bars
5942is now `left', `right' or nil. A non-nil value specifies
5943which side of the window to put the scroll bars on.
5944
5945** X Windows features
5946
5947*** You can examine X resources for other applications by binding
5948x-resource-class around a call to x-get-resource. The usual value of
5949x-resource-class is "Emacs", which is the correct value for Emacs.
5950
5951*** In menus, checkboxes and radio buttons now actually work.
5952The menu displays the current status of the box or button.
5953
5954*** The function x-list-fonts now takes an optional fourth argument
5955MAXIMUM which sets a limit on how many matching fonts to return.
5956A smaller value of MAXIMUM makes the function faster.
5957
5958If the only question is whether *any* font matches the pattern,
5959it is good to supply 1 for this argument.
5960
5961** Subprocess features
5962
5963*** A reminder: it is no longer necessary for subprocess filter
5964functions and sentinels to do save-match-data, because Emacs does this
5965automatically.
5966
5967*** The new function shell-command-to-string executes a shell command
5968and returns the output from the command as a string.
5969
5970*** The new function process-contact returns t for a child process,
5971and (HOSTNAME SERVICE) for a net connection.
5972
5973** An error in running pre-command-hook or post-command-hook
5974does clear the variable to nil. The documentation was wrong before.
5975
5976** In define-key-after, if AFTER is t, the new binding now always goes
5977at the end of the keymap. If the keymap is a menu, this means it
5978goes after the other menu items.
5979
5980** If you have a program that makes several changes in the same area
5981of the buffer, you can use the macro combine-after-change-calls
5982around that Lisp code to make it faster when after-change hooks
5983are in use.
5984
5985The macro arranges to call the after-change functions just once for a
5986series of several changes--if that seems safe.
5987
5988Don't alter the variables after-change-functions and
5989after-change-function within the body of a combine-after-change-calls
5990form.
5991
5992** If you define an abbrev (with define-abbrev) whose EXPANSION
5993is not a string, then the abbrev does not expand in the usual sense,
5994but its hook is still run.
5995
5996** Normally, the Lisp debugger is not used (even if you have enabled it)
5997for errors that are handled by condition-case.
5998
5999If you set debug-on-signal to a non-nil value, then the debugger is called
6000regardless of whether there is a handler for the condition. This is
6001useful for debugging problems that happen inside of a condition-case.
6002
6003This mode of operation seems to be unreliable in other ways. Errors that
6004are normal and ought to be handled, perhaps in timers or process
6005filters, will instead invoke the debugger. So don't say you weren't
6006warned.
6007
6008** The new variable ring-bell-function lets you specify your own
6009way for Emacs to "ring the bell".
6010
6011** If run-at-time's TIME argument is t, the action is repeated at
6012integral multiples of REPEAT from the epoch; this is useful for
6013functions like display-time.
6014
6015** You can use the function locate-library to find the precise file
6016name of a Lisp library. This isn't new, but wasn't documented before.
6017
6018** Commands for entering view mode have new optional arguments that
6019can be used from Lisp. Low-level entrance to and exit from view mode
6020is done by functions view-mode-enter and view-mode-exit.
6021
6022** batch-byte-compile-file now makes Emacs return a nonzero status code
6023if there is an error in compilation.
6024
6025** pop-to-buffer, switch-to-buffer-other-window and
6026switch-to-buffer-other-frame now accept an additional optional
6027argument NORECORD, much like switch-to-buffer. If it is non-nil,
6028they don't put the buffer at the front of the buffer list.
6029
6030** If your .emacs file leaves the *scratch* buffer non-empty,
6031Emacs does not display the startup message, so as to avoid changing
6032the *scratch* buffer.
6033
6034** The new function regexp-opt returns an efficient regexp to match a string.
6035The arguments are STRINGS and (optionally) PAREN. This function can be used
6036where regexp matching or searching is intensively used and speed is important,
6037e.g., in Font Lock mode.
6038
6039** The variable buffer-display-count is local to each buffer,
6040and is incremented each time the buffer is displayed in a window.
6041It starts at 0 when the buffer is created.
6042
6043** The new function compose-mail starts composing a mail message
6044using the user's chosen mail composition agent (specified with the
6045variable mail-user-agent). It has variants compose-mail-other-window
6046and compose-mail-other-frame.
6047
6048** The `user-full-name' function now takes an optional parameter which
6049can either be a number (the UID) or a string (the login name). The
6050full name of the specified user will be returned.
6051
6052** Lisp packages that load files of customizations, or any other sort
6053of user profile, should obey the variable init-file-user in deciding
6054where to find it. They should load the profile of the user name found
6055in that variable. If init-file-user is nil, meaning that the -q
6056option was used, then Lisp packages should not load the customization
6057files at all.
6058
6059** format-time-string now allows you to specify the field width
6060and type of padding. This works as in printf: you write the field
6061width as digits in the middle of a %-construct. If you start
6062the field width with 0, it means to pad with zeros.
6063
6064For example, %S normally specifies the number of seconds since the
6065minute; %03S means to pad this with zeros to 3 positions, %_3S to pad
6066with spaces to 3 positions. Plain %3S pads with zeros, because that
6067is how %S normally pads to two positions.
6068
6069** thing-at-point now supports a new kind of "thing": url.
6070
6071** imenu.el changes.
6072
6073You can now specify a function to be run when selecting an
6074item from menu created by imenu.
6075
6076An example of using this feature: if we define imenu items for the
6077#include directives in a C file, we can open the included file when we
6078select one of those items.
6079\f
6080* Emacs 19.34 is a bug-fix release with no user-visible changes.
6081\f
6082* Changes in Emacs 19.33.
6083
6084** Bibtex mode no longer turns on Auto Fill automatically. (No major
6085mode should do that--it is the user's choice.)
6086
6087** The variable normal-auto-fill-function specifies the function to
6088use for auto-fill-function, if and when Auto Fill is turned on.
6089Major modes can set this locally to alter how Auto Fill works.
6090\f
6091* Editing Changes in Emacs 19.32
6092
6093** C-x f with no argument now signals an error.
6094To set the fill column at the current column, use C-u C-x f.
6095
6096** Expanding dynamic abbrevs with M-/ is now smarter about case
6097conversion. If you type the abbreviation with mixed case, and it
6098matches the beginning of the expansion including case, then the
6099expansion is copied verbatim. Using SPC M-/ to copy an additional
6100word always copies it verbatim except when the previous copied word is
6101all caps.
6102
6103** On a non-windowing terminal, which can display only one Emacs frame
6104at a time, creating a new frame with C-x 5 2 also selects that frame.
6105
6106When using a display that can show multiple frames at once, C-x 5 2
6107does make the frame visible, but does not select it. This is the same
6108as in previous Emacs versions.
6109
6110** You can use C-x 5 2 to create multiple frames on MSDOS, just as on a
6111non-X terminal on Unix. Of course, only one frame is visible at any
6112time, since your terminal doesn't have the ability to display multiple
6113frames.
6114
6115** On Windows, set win32-pass-alt-to-system to a non-nil value
6116if you would like tapping the Alt key to invoke the Windows menu.
6117This feature is not enabled by default; since the Alt key is also the
6118Meta key, it is too easy and painful to activate this feature by
6119accident.
6120
6121** The command apply-macro-to-region-lines repeats the last defined
6122keyboard macro once for each complete line within the current region.
6123It does this line by line, by moving point to the beginning of that
6124line and then executing the macro.
6125
6126This command is not new, but was never documented before.
6127
6128** You can now use Mouse-1 to place the region around a string constant
6129(something surrounded by doublequote characters or other delimiter
6130characters of like syntax) by double-clicking on one of the delimiting
6131characters.
6132
6133** Font Lock mode
6134
6135*** Font Lock support modes
6136
6137Font Lock can be configured to use Fast Lock mode and Lazy Lock mode (see
6138below) in a flexible way. Rather than adding the appropriate function to the
6139hook font-lock-mode-hook, you can use the new variable font-lock-support-mode
6140to control which modes have Fast Lock mode or Lazy Lock mode turned on when
6141Font Lock mode is enabled.
6142
6143For example, to use Fast Lock mode when Font Lock mode is turned on, put:
6144
6145 (setq font-lock-support-mode 'fast-lock-mode)
6146
6147in your ~/.emacs.
6148
6149*** lazy-lock
6150
6151The lazy-lock package speeds up Font Lock mode by making fontification occur
6152only when necessary, such as when a previously unfontified part of the buffer
6153becomes visible in a window. When you create a buffer with Font Lock mode and
6154Lazy Lock mode turned on, the buffer is not fontified. When certain events
6155occur (such as scrolling), Lazy Lock makes sure that the visible parts of the
6156buffer are fontified. Lazy Lock also defers on-the-fly fontification until
6157Emacs has been idle for a given amount of time.
6158
6159To use this package, put in your ~/.emacs:
6160
6161 (setq font-lock-support-mode 'lazy-lock-mode)
6162
6163To control the package behaviour, see the documentation for `lazy-lock-mode'.
6164
6165** Changes in BibTeX mode.
6166
6167*** For all entries allow spaces and tabs between opening brace or
6168paren and key.
6169
6170*** Non-escaped double-quoted characters (as in `Sch"of') are now
6171supported.
6172
6173** Gnus changes.
6174
6175Gnus, the Emacs news reader, has undergone further rewriting. Many new
6176commands and variables have been added. There should be no
6177significant incompatibilities between this Gnus version and the
6178previously released version, except in the message composition area.
6179
6180Below is a list of the more user-visible changes. Coding changes
6181between Gnus 5.1 and 5.2 are more extensive.
6182
6183*** A new message composition mode is used. All old customization
6184variables for mail-mode, rnews-reply-mode and gnus-msg are now
6185obsolete.
6186
6187*** Gnus is now able to generate "sparse" threads -- threads where
6188missing articles are represented by empty nodes.
6189
6190 (setq gnus-build-sparse-threads 'some)
6191
6192*** Outgoing articles are stored on a special archive server.
6193
6194 To disable this: (setq gnus-message-archive-group nil)
6195
6196*** Partial thread regeneration now happens when articles are
6197referred.
6198
6199*** Gnus can make use of GroupLens predictions:
6200
6201 (setq gnus-use-grouplens t)
6202
6203*** A trn-line tree buffer can be displayed.
6204
6205 (setq gnus-use-trees t)
6206
6207*** An nn-like pick-and-read minor mode is available for the summary
6208buffers.
6209
6210 (add-hook 'gnus-summary-mode-hook 'gnus-pick-mode)
6211
6212*** In binary groups you can use a special binary minor mode:
6213
6214 `M-x gnus-binary-mode'
6215
6216*** Groups can be grouped in a folding topic hierarchy.
6217
6218 (add-hook 'gnus-group-mode-hook 'gnus-topic-mode)
6219
6220*** Gnus can re-send and bounce mail.
6221
6222 Use the `S D r' and `S D b'.
6223
6224*** Groups can now have a score, and bubbling based on entry frequency
6225is possible.
6226
6227 (add-hook 'gnus-summary-exit-hook 'gnus-summary-bubble-group)
6228
6229*** Groups can be process-marked, and commands can be performed on
6230groups of groups.
6231
6232*** Caching is possible in virtual groups.
6233
6234*** nndoc now understands all kinds of digests, mail boxes, rnews news
6235batches, ClariNet briefs collections, and just about everything else.
6236
6237*** Gnus has a new backend (nnsoup) to create/read SOUP packets.
6238
6239*** The Gnus cache is much faster.
6240
6241*** Groups can be sorted according to many criteria.
6242
6243 For instance: (setq gnus-group-sort-function 'gnus-group-sort-by-rank)
6244
6245*** New group parameters have been introduced to set list-address and
6246expiration times.
6247
6248*** All formatting specs allow specifying faces to be used.
6249
6250*** There are several more commands for setting/removing/acting on
6251process marked articles on the `M P' submap.
6252
6253*** The summary buffer can be limited to show parts of the available
6254articles based on a wide range of criteria. These commands have been
6255bound to keys on the `/' submap.
6256
6257*** Articles can be made persistent -- as an alternative to saving
6258articles with the `*' command.
6259
6260*** All functions for hiding article elements are now toggles.
6261
6262*** Article headers can be buttonized.
6263
6264 (add-hook 'gnus-article-display-hook 'gnus-article-add-buttons-to-head)
6265
6266*** All mail backends support fetching articles by Message-ID.
6267
6268*** Duplicate mail can now be treated properly. See the
6269`nnmail-treat-duplicates' variable.
6270
6271*** All summary mode commands are available directly from the article
6272buffer.
6273
6274*** Frames can be part of `gnus-buffer-configuration'.
6275
6276*** Mail can be re-scanned by a daemonic process.
6277
6278*** Gnus can make use of NoCeM files to filter spam.
6279
6280 (setq gnus-use-nocem t)
6281
6282*** Groups can be made permanently visible.
6283
6284 (setq gnus-permanently-visible-groups "^nnml:")
6285
6286*** Many new hooks have been introduced to make customizing easier.
6287
6288*** Gnus respects the Mail-Copies-To header.
6289
6290*** Threads can be gathered by looking at the References header.
6291
6292 (setq gnus-summary-thread-gathering-function
6293 'gnus-gather-threads-by-references)
6294
6295*** Read articles can be stored in a special backlog buffer to avoid
6296refetching.
6297
6298 (setq gnus-keep-backlog 50)
6299
6300*** A clean copy of the current article is always stored in a separate
6301buffer to allow easier treatment.
6302
6303*** Gnus can suggest where to save articles. See `gnus-split-methods'.
6304
6305*** Gnus doesn't have to do as much prompting when saving.
6306
6307 (setq gnus-prompt-before-saving t)
6308
6309*** gnus-uu can view decoded files asynchronously while fetching
6310articles.
6311
6312 (setq gnus-uu-grabbed-file-functions 'gnus-uu-grab-view)
6313
6314*** Filling in the article buffer now works properly on cited text.
6315
6316*** Hiding cited text adds buttons to toggle hiding, and how much
6317cited text to hide is now customizable.
6318
6319 (setq gnus-cited-lines-visible 2)
6320
6321*** Boring headers can be hidden.
6322
6323 (add-hook 'gnus-article-display-hook 'gnus-article-hide-boring-headers)
6324
6325*** Default scoring values can now be set from the menu bar.
6326
6327*** Further syntax checking of outgoing articles have been added.
6328
6329The Gnus manual has been expanded. It explains all these new features
6330in greater detail.
6331\f
6332* Lisp Changes in Emacs 19.32
6333
6334** The function set-visited-file-name now accepts an optional
6335second argument NO-QUERY. If it is non-nil, then the user is not
6336asked for confirmation in the case where the specified file already
6337exists.
6338
6339** The variable print-length applies to printing vectors and bitvectors,
6340as well as lists.
6341
6342** The new function keymap-parent returns the parent keymap
6343of a given keymap.
6344
6345** The new function set-keymap-parent specifies a new parent for a
6346given keymap. The arguments are KEYMAP and PARENT. PARENT must be a
6347keymap or nil.
6348
6349** Sometimes menu keymaps use a command name, a symbol, which is really
6350an automatically generated alias for some other command, the "real"
6351name. In such a case, you should give that alias symbol a non-nil
6352menu-alias property. That property tells the menu system to look for
6353equivalent keys for the real name instead of equivalent keys for the
6354alias.
6355\f
6356* Editing Changes in Emacs 19.31
6357
6358** Freedom of the press restricted in the United States.
6359
6360Emacs has been censored in accord with the Communications Decency Act.
6361This includes removing some features of the doctor program. That law
6362was described by its supporters as a ban on pornography, but it bans
6363far more than that. The Emacs distribution has never contained any
6364pornography, but parts of it were nonetheless prohibited.
6365
6366For information on US government censorship of the Internet, and what
6367you can do to bring back freedom of the press, see the web site
6368`http://www.vtw.org/'.
6369
6370** A note about C mode indentation customization.
6371
6372The old (Emacs 19.29) ways of specifying a C indentation style
6373do not normally work in the new implementation of C mode.
6374It has its own methods of customizing indentation, which are
6375much more powerful than the old C mode. See the Editing Programs
6376chapter of the manual for details.
6377
6378However, you can load the library cc-compat to make the old
6379customization variables take effect.
6380
6381** Marking with the mouse.
6382
6383When you mark a region with the mouse, the region now remains
6384highlighted until the next input event, regardless of whether you are
6385using M-x transient-mark-mode.
6386
6387** Improved Windows NT/95 support.
6388
6389*** Emacs now supports scroll bars on Windows NT and Windows 95.
6390
6391*** Emacs now supports subprocesses on Windows 95. (Subprocesses used
6392to work on NT only and not on 95.)
6393
6394*** There are difficulties with subprocesses, though, due to problems
6395in Windows, beyond the control of Emacs. They work fine as long as
6396you run Windows applications. The problems arise when you run a DOS
6397application in a subprocesses. Since current shells run as DOS
6398applications, these problems are significant.
6399
6400If you run a DOS application in a subprocess, then the application is
6401likely to busy-wait, which means that your machine will be 100% busy.
6402However, if you don't mind the temporary heavy load, the subprocess
6403will work OK as long as you tell it to terminate before you start any
6404other DOS application as a subprocess.
6405
6406Emacs is unable to terminate or interrupt a DOS subprocess.
6407You have to do this by providing input directly to the subprocess.
6408
6409If you run two DOS applications at the same time in two separate
6410subprocesses, even if one of them is asynchronous, you will probably
6411have to reboot your machine--until then, it will remain 100% busy.
6412Windows simply does not cope when one Windows process tries to run two
6413separate DOS subprocesses. Typing CTL-ALT-DEL and then choosing
6414Shutdown seems to work although it may take a few minutes.
6415
6416** M-x resize-minibuffer-mode.
6417
6418This command, not previously mentioned in NEWS, toggles a mode in
6419which the minibuffer window expands to show as many lines as the
6420minibuffer contains.
6421
6422** `title' frame parameter and resource.
6423
6424The `title' X resource now specifies just the frame title, nothing else.
6425It does not affect the name used for looking up other X resources.
6426It works by setting the new `title' frame parameter, which likewise
6427affects just the displayed title of the frame.
6428
6429The `name' parameter continues to do what it used to do:
6430it specifies the frame name for looking up X resources,
6431and also serves as the default for the displayed title
6432when the `title' parameter is unspecified or nil.
6433
6434** Emacs now uses the X toolkit by default, if you have a new
6435enough version of X installed (X11R5 or newer).
6436
6437** When you compile Emacs with the Motif widget set, Motif handles the
6438F10 key by activating the menu bar. To avoid confusion, the usual
6439Emacs binding of F10 is replaced with a no-op when using Motif.
6440
6441If you want to be able to use F10 in Emacs, you can rebind the Motif
6442menubar to some other key which you don't use. To do so, add
6443something like this to your X resources file. This example rebinds
6444the Motif menu bar activation key to S-F12:
6445
6446 Emacs*defaultVirtualBindings: osfMenuBar : Shift<Key>F12
6447
6448** In overwrite mode, DEL now inserts spaces in most cases
6449to replace the characters it "deletes".
6450
6451** The Rmail summary now shows the number of lines in each message.
6452
6453** Rmail has a new command M-x unforward-rmail-message, which extracts
6454a forwarded message from the message that forwarded it. To use it,
6455select a message which contains a forwarded message and then type the command.
6456It inserts the forwarded message as a separate Rmail message
6457immediately after the selected one.
6458
6459This command also undoes the textual modifications that are standardly
6460made, as part of forwarding, by Rmail and other mail reader programs.
6461
6462** Turning off saving of .saves-... files in your home directory.
6463
6464Each Emacs session writes a file named .saves-... in your home
6465directory to record which files M-x recover-session should recover.
6466If you exit Emacs normally with C-x C-c, it deletes that file. If
6467Emacs or the operating system crashes, the file remains for M-x
6468recover-session.
6469
6470You can turn off the writing of these files by setting
6471auto-save-list-file-name to nil. If you do this, M-x recover-session
6472will not work.
6473
6474Some previous Emacs versions failed to delete these files even on
6475normal exit. This is fixed now. If you are thinking of turning off
6476this feature because of past experiences with versions that had this
6477bug, it would make sense to check whether you still want to do so
6478now that the bug is fixed.
6479
6480** Changes to Version Control (VC)
6481
6482There is a new variable, vc-follow-symlinks. It indicates what to do
6483when you visit a link to a file that is under version control.
6484Editing the file through the link bypasses the version control system,
6485which is dangerous and probably not what you want.
6486
6487If this variable is t, VC follows the link and visits the real file,
6488telling you about it in the echo area. If it is `ask' (the default),
6489VC asks for confirmation whether it should follow the link. If nil,
6490the link is visited and a warning displayed.
6491
6492** iso-acc.el now lets you specify a choice of language.
6493Languages include "latin-1" (the default) and "latin-2" (which
6494is designed for entering ISO Latin-2 characters).
6495
6496There are also choices for specific human languages such as French and
6497Portuguese. These are subsets of Latin-1, which differ in that they
6498enable only the accent characters needed for particular language.
6499The other accent characters, not needed for the chosen language,
6500remain normal.
6501
6502** Posting articles and sending mail now has M-TAB completion on various
6503header fields (Newsgroups, To, CC, ...).
6504
6505Completion in the Newsgroups header depends on the list of groups
6506known to your news reader. Completion in the Followup-To header
6507offers those groups which are in the Newsgroups header, since
6508Followup-To usually just holds one of those.
6509
6510Completion in fields that hold mail addresses works based on the list
6511of local users plus your aliases. Additionally, if your site provides
6512a mail directory or a specific host to use for any unrecognized user
6513name, you can arrange to query that host for completion also. (See the
6514documentation of variables `mail-directory-process' and
6515`mail-directory-stream'.)
6516
6517** A greatly extended sgml-mode offers new features such as (to be configured)
6518skeletons with completing read for tags and attributes, typing named
6519characters including optionally all 8bit characters, making tags invisible
6520with optional alternate display text, skipping and deleting tag(pair)s.
6521
6522Note: since Emacs' syntax feature cannot limit the special meaning of ', " and
6523- to inside <>, for some texts the result, especially of font locking, may be
6524wrong (see `sgml-specials' if you get wrong results).
6525
6526The derived html-mode configures this with tags and attributes more or
6527less HTML3ish. It also offers optional quick keys like C-c 1 for
6528headline or C-c u for unordered list (see `html-quick-keys'). Edit /
6529Text Properties / Face or M-g combinations create tags as applicable.
6530Outline minor mode is supported and level 1 font-locking tries to
6531fontify tag contents (which only works when they fit on one line, due
6532to a limitation in font-lock).
6533
6534External viewing via browse-url can occur automatically upon saving.
6535
6536** M-x imenu-add-to-menubar now adds to the menu bar for the current
6537buffer only. If you want to put an Imenu item in the menu bar for all
6538buffers that use a particular major mode, use the mode hook, as in
6539this example:
6540
6541 (add-hook 'emacs-lisp-mode-hook
6542 '(lambda () (imenu-add-to-menubar "Index")))
6543
6544** Changes in BibTeX mode.
6545
6546*** Field names may now contain digits, hyphens, and underscores.
6547
6548*** Font Lock mode is now supported.
6549
6550*** bibtex-make-optional-field is no longer interactive.
6551
6552*** If bibtex-maintain-sorted-entries is non-nil, inserting new
6553entries is now done with a faster algorithm. However, inserting
6554will fail in this case if the buffer contains invalid entries or
6555isn't in sorted order, so you should finish each entry with C-c C-c
6556(bibtex-close-entry) after you have inserted or modified it.
6557The default value of bibtex-maintain-sorted-entries is nil.
6558
6559*** Function `show-all' is no longer bound to a key, since C-u C-c C-q
6560does the same job.
6561
6562*** Entries with quotes inside quote-delimited fields (as `author =
6563"Stefan Sch{\"o}f"') are now supported.
6564
6565*** Case in field names doesn't matter anymore when searching for help
6566text.
6567
6568** Font Lock mode
6569
6570*** Global Font Lock mode
6571
6572Font Lock mode can be turned on globally, in buffers that support it, by the
6573new command global-font-lock-mode. You can use the new variable
6574font-lock-global-modes to control which modes have Font Lock mode automagically
6575turned on. By default, this variable is set so that Font Lock mode is turned
6576on globally where the buffer mode supports it.
6577
6578For example, to automagically turn on Font Lock mode where supported, put:
6579
6580 (global-font-lock-mode t)
6581
6582in your ~/.emacs.
6583
6584*** Local Refontification
6585
6586In Font Lock mode, editing a line automatically refontifies that line only.
6587However, if your change alters the syntactic context for following lines,
6588those lines remain incorrectly fontified. To refontify them, use the new
6589command M-g M-g (font-lock-fontify-block).
6590
6591In certain major modes, M-g M-g refontifies the entire current function.
6592(The variable font-lock-mark-block-function controls how to find the
6593current function.) In other major modes, M-g M-g refontifies 16 lines
6594above and below point.
6595
6596With a prefix argument N, M-g M-g refontifies N lines above and below point.
6597
6598** Follow mode
6599
6600Follow mode is a new minor mode combining windows showing the same
6601buffer into one tall "virtual window". The windows are typically two
6602side-by-side windows. Follow mode makes them scroll together as if
6603they were a unit. To use it, go to a frame with just one window,
6604split it into two side-by-side windows using C-x 3, and then type M-x
6605follow-mode.
6606
6607M-x follow-mode turns off Follow mode if it is already enabled.
6608
6609To display two side-by-side windows and activate Follow mode, use the
6610command M-x follow-delete-other-windows-and-split.
6611
6612** hide-show changes.
6613
6614The hooks hs-hide-hooks and hs-show-hooks have been renamed
6615to hs-hide-hook and hs-show-hook, to follow the convention for
6616normal hooks.
6617
6618** Simula mode now has a menu containing the most important commands.
6619The new command simula-indent-exp is bound to C-M-q.
6620
6621** etags can now handle programs written in Erlang. Files are
6622recognised by the extensions .erl and .hrl. The tagged lines are
6623those that begin a function, record, or macro.
6624
6625** MSDOS Changes
6626
6627*** It is now possible to compile Emacs with the version 2 of DJGPP.
6628Compilation with DJGPP version 1 also still works.
6629
6630*** The documentation of DOS-specific aspects of Emacs was rewritten
6631and expanded; see the ``MS-DOS'' node in the on-line docs.
6632
6633*** Emacs now uses ~ for backup file names, not .bak.
6634
6635*** You can simulate mouse-3 on two-button mice by simultaneously
6636pressing both mouse buttons.
6637
6638*** A number of packages and commands which previously failed or had
6639restricted functionality on MS-DOS, now work. The most important ones
6640are:
6641
6642**** Printing (both with `M-x lpr-buffer' and with `ps-print' package)
6643now works.
6644
6645**** `Ediff' works (in a single-frame mode).
6646
6647**** `M-x display-time' can be used on MS-DOS (due to the new
6648implementation of Emacs timers, see below).
6649
6650**** `Dired' supports Unix-style shell wildcards.
6651
6652**** The `c-macro-expand' command now works as on other platforms.
6653
6654**** `M-x recover-session' works.
6655
6656**** `M-x list-colors-display' displays all the available colors.
6657
6658**** The `TPU-EDT' package works.
6659\f
6660* Lisp changes in Emacs 19.31.
6661
6662** The function using-unix-filesystems on Windows NT and Windows 95
6663tells Emacs to read and write files assuming that they reside on a
6664remote Unix filesystem. No CR/LF translation is done on any files in
6665this case. Invoking using-unix-filesystems with t activates this
6666behavior, and invoking it with any other value deactivates it.
6667
6668** Change in system-type and system-configuration values.
6669
6670The value of system-type on a Linux-based GNU system is now `lignux',
6671not `linux'. This means that some programs which use `system-type'
6672need to be changed. The value of `system-configuration' will also
6673be different.
6674
6675It is generally recommended to use `system-configuration' rather
6676than `system-type'.
6677
6678See the file LINUX-GNU in this directory for more about this.
6679
6680** The functions shell-command and dired-call-process
6681now run file name handlers for default-directory, if it has them.
6682
6683** Undoing the deletion of text now restores the positions of markers
6684that pointed into or next to the deleted text.
6685
6686** Timers created with run-at-time now work internally to Emacs, and
6687no longer use a separate process. Therefore, they now work more
6688reliably and can be used for shorter time delays.
6689
6690The new function run-with-timer is a convenient way to set up a timer
6691to run a specified amount of time after the present. A call looks
6692like this:
6693
6694 (run-with-timer SECS REPEAT FUNCTION ARGS...)
6695
6696SECS says how many seconds should elapse before the timer happens.
6697It may be an integer or a floating point number. When the timer
6698becomes ripe, the action is to call FUNCTION with arguments ARGS.
6699
6700REPEAT gives the interval for repeating the timer (measured in
6701seconds). It may be an integer or a floating point number. nil or 0
6702means don't repeat at all--call FUNCTION just once.
6703
6704*** with-timeout provides an easy way to do something but give
6705up if too much time passes.
6706
6707 (with-timeout (SECONDS TIMEOUT-FORMS...) BODY...)
6708
6709This executes BODY, but gives up after SECONDS seconds.
6710If it gives up, it runs the TIMEOUT-FORMS and returns the value
6711of the last one of them. Normally it returns the value of the last
6712form in BODY.
6713
6714*** You can now arrange to call a function whenever Emacs is idle for
6715a certain length of time. To do this, call run-with-idle-timer. A
6716call looks like this:
6717
6718 (run-with-idle-timer SECS REPEAT FUNCTION ARGS...)
6719
6720SECS says how many seconds of idleness should elapse before the timer
6721runs. It may be an integer or a floating point number. When the
6722timer becomes ripe, the action is to call FUNCTION with arguments
6723ARGS.
6724
6725Emacs becomes idle whenever it finishes executing a keyboard or mouse
6726command. It remains idle until it receives another keyboard or mouse
6727command.
6728
6729REPEAT, if non-nil, means this timer should be activated again each
6730time Emacs becomes idle and remains idle for SECS seconds The timer
6731does not repeat if Emacs *remains* idle; it runs at most once after
6732each time Emacs becomes idle.
6733
6734If REPEAT is nil, the timer runs just once, the first time Emacs is
6735idle for SECS seconds.
6736
6737*** post-command-idle-hook is now obsolete; you shouldn't use it at
6738all, because it interferes with the idle timer mechanism. If your
6739programs use post-command-idle-hook, convert them to use idle timers
6740instead.
6741
6742*** y-or-n-p-with-timeout lets you ask a question but give up if
6743there is no answer within a certain time.
6744
6745 (y-or-n-p-with-timeout PROMPT SECONDS DEFAULT-VALUE)
6746
6747asks the question PROMPT (just like y-or-n-p). If the user answers
6748within SECONDS seconds, it returns the answer that the user gave.
6749Otherwise it gives up after SECONDS seconds, and returns DEFAULT-VALUE.
6750
6751** Minor change to `encode-time': you can now pass more than seven
6752arguments. If you do that, the first six arguments have the usual
6753meaning, the last argument is interpreted as the time zone, and the
6754arguments in between are ignored.
6755
6756This means that it works to use the list returned by `decode-time' as
6757the list of arguments for `encode-time'.
6758
6759** The default value of load-path now includes the directory
6760/usr/local/share/emacs/VERSION/site-lisp In addition to
6761/usr/local/share/emacs/site-lisp. You can use this new directory for
6762site-specific Lisp packages that belong with a particular Emacs
6763version.
6764
6765It is not unusual for a Lisp package that works well in one Emacs
6766version to cause trouble in another. Sometimes packages need updating
6767for incompatible changes; sometimes they look at internal data that
6768has changed; sometimes the package has been installed in Emacs itself
6769and the installed version should be used. Whatever the reason for the
6770problem, this new feature makes it easier to solve.
6771
6772** When your program contains a fixed file name (like .completions or
6773.abbrev.defs), the file name usually needs to be different on operating
6774systems with limited file name syntax.
6775
6776Now you can avoid ad-hoc conditionals by using the function
6777convert-standard-filename to convert the file name to a proper form
6778for each operating system. Here is an example of use, from the file
6779completions.el:
6780
6781(defvar save-completions-file-name
6782 (convert-standard-filename "~/.completions")
6783 "*The filename to save completions to.")
6784
6785This sets the variable save-completions-file-name to a value that
6786depends on the operating system, because the definition of
6787convert-standard-filename depends on the operating system. On
6788Unix-like systems, it returns the specified file name unchanged. On
6789MS-DOS, it adapts the name to fit the limitations of that system.
6790
6791** The interactive spec N now returns the numeric prefix argument
6792rather than the raw prefix argument. (It still reads a number using the
6793minibuffer if there is no prefix argument at all.)
6794
6795** When a process is deleted, this no longer disconnects the process
6796marker from its buffer position.
6797
6798** The variable garbage-collection-messages now controls whether
6799Emacs displays a message at the beginning and end of garbage collection.
6800The default is nil, meaning there are no messages.
6801
6802** The variable debug-ignored-errors specifies certain kinds of errors
6803that should not enter the debugger. Its value is a list of error
6804condition symbols and/or regular expressions. If the error has any
6805of the condition symbols listed, or if any of the regular expressions
6806matches the error message, then that error does not enter the debugger,
6807regardless of the value of debug-on-error.
6808
6809This variable is initialized to match certain common but uninteresting
6810errors that happen often during editing.
6811
6812** The new function error-message-string converts an error datum
6813into its error message. The error datum is what condition-case
6814puts into the variable, to describe the error that happened.
6815
6816** Anything that changes which buffer appears in a given window
6817now runs the window-scroll-functions for that window.
6818
6819** The new function get-buffer-window-list returns a list of windows displaying
6820a buffer. The function is called with the buffer (a buffer object or a buffer
6821name) and two optional arguments specifying the minibuffer windows and frames
6822to search. Therefore this function takes optional args like next-window etc.,
6823and not get-buffer-window.
6824
6825** buffer-substring now runs the hook buffer-access-fontify-functions,
6826calling each function with two arguments--the range of the buffer
6827being accessed. buffer-substring-no-properties does not call them.
6828
6829If you use this feature, you should set the variable
6830buffer-access-fontified-property to a non-nil symbol, which is a
6831property name. Then, if all the characters in the buffer range have a
6832non-nil value for that property, the buffer-access-fontify-functions
6833are not called. When called, these functions should put a non-nil
6834property on the text that they fontify, so that they won't get called
6835over and over for the same text.
6836
6837** Changes in lisp-mnt.el
6838
6839*** The lisp-mnt package can now recognize file headers that are written
6840in the formats used by the `what' command and the RCS `ident' command:
6841
6842;; @(#) HEADER: text
6843;; $HEADER: text $
6844
6845in addition to the normal
6846
6847;; HEADER: text
6848
6849*** The commands lm-verify and lm-synopsis are now interactive. lm-verify
6850checks that the library file has proper sections and headers, and
6851lm-synopsis extracts first line "synopsis'"information.
6852\f
6853* For older news, see the file ONEWS.
6854
6855----------------------------------------------------------------------
6856Copyright information:
6857
6858Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
6859
6860 Permission is granted to anyone to make or distribute verbatim copies
6861 of this document as received, in any medium, provided that the
6862 copyright notice and this permission notice are preserved,
6863 thus giving the recipient permission to redistribute in turn.
6864
6865 Permission is granted to distribute modified versions
6866 of this document, or of portions of it,
6867 under the above conditions, provided also that they
6868 carry prominent notices stating who last changed them.
6869\f
6870Local variables:
6871mode: outline
6872paragraph-separate: "[ \f]*$"
6873end: