This file is about changes in Emacs version 25.
+See file HISTORY for a list of GNU Emacs versions and release dates.
See files NEWS.24, NEWS.23, NEWS.22, NEWS.21, NEWS.20, NEWS.19, NEWS.18,
and NEWS.1-17 for changes in older Emacs versions.
+++
** Building Emacs now requires C99 or later.
++++
** Building Emacs now requires GNU make, version 3.81 or later.
++++
** New configure option --with-cairo.
-Maybe add text based on http://lists.gnu.org/archive/html/emacs-devel/2015-05/msg00689.html
+This builds Emacs with Cairo drawing. As a side effect, it provides
+support for built-in printing, when Emacs was built with GTK+.
+
+** New configure option --with-modules.
+This enables support for loading dynamic modules; see below.
+---
** By default, Emacs no longer works on IRIX. We expect that Emacs
users are not affected by this, as SGI stopped supporting IRIX in
December 2013. If you are affected, please send a bug report. You
undumping code to GCC under IRIX, or by configuring --with-wide-int,
or by sticking with Emacs 24.4.
+---
+** The Emacs garbage collector assumes GC_MARK_STACK == GC_MAKE_GCPROS_NOOPS.
+The GC_MAKE_GCPROS_NOOPS stack-marking variant has been the default
+since Emacs 24.4, and the other variants were undocumented and were
+obstacles to maintenance and development. GC_MARK_STACK and its
+related symbols have been removed from the C internals.
+
+---
** 'configure' now prefers gnustep-config when configuring GNUstep.
If gnustep-config is not available, the old heuristics are used.
This affects only the 'movemail' utility; Emacs itself can still
process MMDF-format files as before.
++++
** The configure option '--enable-silent-rules' is now the default,
and silent rules are now quieter. To get the old behavior where
'make' chatters a lot, configure with '--disable-silent-rules' or
It has no particular connection to Emacs and has not changed in years,
so if you want to use it, you can always take a copy from an older Emacs.
+---
+** Emacs 25 comes with a new set of icons.
+Various resolutions are available as etc/images/icons/hicolor/*/apps/emacs.png.
+The old Emacs logo icons are available as `emacs23.png' in the same location.
+
\f
* Startup Changes in Emacs 25.1
and *Buffer List*. This makes Emacs convenient to use from the
command line when `initial-buffer-choice' is non-nil.
++++
+** The value of ‘initial-scratch-message’ is now treated as a doc string
+and can contain escape sequences for command keys, quotes, and the like.
+
\f
* Changes in Emacs 25.1
-** New display-buffer action function display-buffer-use-some-frame
++++
+** Any file of the form .dir-locals*.el is now considered a dir-local
+file, and multiple such files can be used in the same directory. See
+the variable `dir-locals-file' for more information.
+
+---
+** `xref-find-definitions' and `describe-function' now display
+information about mode local overrides (defined by cedet/mode-local.el
+`define-overloadable-function' `define-mode-local-overrides').
+
++++
+** New `display-buffer' action function `display-buffer-use-some-frame'.
This displays the buffer in an existing frame other than the current
frame, and allows the caller to specify a frame predicate to exclude
frames.
-** New doc command `describe-symbol'. Works for functions, vars, faces, etc...
-
-** `isearch' and `query-replace' now perform character folding in matches.
-This is analogous to case-folding, but applies between Unicode
-characters and their ASCII counterparts. This means many characters
-will match entire groups of characters.
-
-For instance, the " will match all variants of unicode double quotes
-(like “ and ”), and the letter a will match all of its accented
-cousins, even those composed of multiple characters, as well as many
-other symbols like ℀, ℁, ⒜, and ⓐ.
-
-** New function `character-folded-regexp' can be used
-by searching commands to produce a a regexp matching anything that
-character-folds into STRING.
-
-** New command `checkdoc-package-keywords' checks if the
-current package keywords are recognized. Set the new option
-`checkdoc-package-keywords-flag' to non-nil to make
-`checkdoc-current-buffer' call this function automatically.
-
-** New function `checkdoc-file' checks for style errors.
-It's meant for use together with `compile':
-emacs -batch --eval "(checkdoc-file \"subr.el\")"
-
-** New command `comment-line' bound to `C-x C-;'.
++++
+** New documentation command `describe-symbol'.
+Works for functions, variables, faces, etc. It is bound to `C-h o' by
+default.
++++
** New function `custom-prompt-customize-unsaved-options' checks for
-unsaved customizations and prompts user to customize (if found).
+unsaved customizations and prompts user to customize (if found). It
+is intended for adding to 'kill-emacs-query-functions'.
+++
** Network security (TLS/SSL certificate validity and the like) is
added via the new Network Security Manager (NSM) and controlled via
the `network-security-level' variable.
++++
** C-h l now also lists the commands that were run.
----
-** The new M-s M-w key binding uses eww to search the web for the
-text in the region.
-
-** M-x suggests shorthands and ignores obsolete commands for completion.
-** x-select-enable-clipboard is renamed select-enable-clipboard.
-x-select-enable-primary and renamed select-enable-primary.
++++
+** x-select-enable-clipboard is renamed select-enable-clipboard
+and x-select-enable-primary is renamed select-enable-primary.
Additionally they both now apply to all systems (OSX, GNUstep, Windows, you
name it), with the proviso that on some systems (e.g. Windows)
select-enable-primary is ineffective since the system doesn't
+++
** New macro `define-advice'.
++++
** `insert-register' now leaves point after the inserted text
when called interactively. A prefix argument toggles this behavior.
-** New var `truncate-string-ellipsis' to choose how to indicate truncation.
-
+++
** The new variable `term-file-aliases' replaces some files from lisp/term.
The function `tty-run-terminal-initialization' consults this variable
hiding character but the default `.' can be used by let-binding the
variable `read-hide-char'.
-** The new functions `string-collate-lessp' and `string-collate-equalp'
-preserve the collation order as defined by the system's locale(1)
-environment. For the time being this is implemented for modern POSIX
-systems and for MS-Windows, for other systems they fall back to their
-counterparts `string-lessp' and `string-equal'.
-
-*** The ls-lisp package uses `string-collate-lessp' to sort file names.
-If you want the old, locale-independent sorting, customize the new
-option `ls-lisp-use-string-collate' to a nil value.
-
-*** The MS-Windows specific variable `w32-collate-ignore-punctuation',
-if set to a non-nil value, causes the above 2 functions to ignore
-symbol and punctuation characters when collating strings. This
-emulates the behavior of modern Posix platforms when the locale's
-codeset is "UTF-8" (as in "en_US.UTF-8"). This is needed because
-MS-Windows doesn't support UTF-8 as codeset in its locales.
-
-+++
-** The new function `bidi-find-overridden-directionality' allows to
-find characters whose directionality was, perhaps maliciously,
-overridden by directional override control characters. Lisp programs
-can use this to detect potential phishing of URLs and other links that
-exploits bidirectional display reordering.
-
-+++
-** The new function `buffer-substring-with-bidi-context' allows to
-copy a portion of a buffer into a different location while preserving
-the visual appearance both of the copied text and the text at
-destination, even when the copied text includes mixed bidirectional
-text and directional control characters.
-
-** New variable `ns-use-fullscreen-animation' controls animation for
-non-native NS fullscreen. The default is nil. Set to t to enable
-animation when entering and leaving fullscreen. For native OSX fullscreen
-this has no effect.
-
-** A new text property `inhibit-read-only' can be used in read-only
-buffers to allow certain parts of the text to be writable.
+** Emacs can now load shared/dynamic libraries (modules).
+A dynamic Emacs module is a shared library that provides additional
+functionality for use in Emacs Lisp programs, just like a package
+written in Emacs Lisp would. The functions `load', `require',
+`load-file', etc. were extended to load such modules, as they do with
+Emacs Lisp packages. The new variable `module-file-suffix' holds the
+system-dependent value of the file-name extension (`.so' on Posix
+hosts) of the module files.
+
+A module should export a C-callable function named
+`emacs_module_init', which Emacs will call as part of the call to
+`load' or `require' which loads the module. It should also export a
+symbol named `plugin_is_GPL_compatible' to indicate that its code is
+released under the GPL or compatible license; Emacs will refuse to
+load modules that don't export such a symbol.
+
+If a module needs to call Emacs functions, it should do so through the
+API defined and documented in the header file `emacs-module.h'. Note
+that any module that provides Lisp-callable functions will have to use
+Emacs functions such as `fset' and `funcall', in order to register its
+functions with the Emacs Lisp interpreter.
+
+Modules can create `user-ptr' Lisp objects that embed pointers to C
+struct's defined by the module. This is useful for keeping around
+complex data structures created by a module, to be passed back to the
+module's functions. User-ptr objects can also have associated
+"finalizers" -- functions to be run when the object is GC'ed; this is
+useful for freeing any resources allocated for the underlying data
+structure, such as memory, open file descriptors, etc. A new
+predicate `user-ptrp' returns non-nil if its argument is a `user-ptr'
+object.
+
+Loadable modules in Emacs are an experimental feature, and subject to
+change in future releases. For that reason, their support is disabled
+by default, and must be enabled by using the `--with-modules' option
+at configure time.
-** A new function `directory-files-recursively' returns all matching
-files (recursively) under a directory.
+---
+** New input method: `tamil-dvorak'.
-** The new function `directory-name-p' can be used to check whether a file
-name (as returned from, for instance, `file-name-all-completions' is
-a directory file name. It returns non-nil if the last character in
-the name is a forward slash.
+\f
+* Editing Changes in Emacs 25.1
+++
-** New variable `fast-but-imprecise-scrolling' inhibits
-fontification during full screen scrolling operations, giving less
-hesitant operation during auto-repeat of C-v, M-v at the cost of
-possible inaccuracies in the end position.
-
-** The function `font-info' now returns more details about a font.
-In particular, it now returns the average width of the font's
-characters, which can be used for geometry-related calculations.
-
-** A new function `default-font-width' returns the average width of a
-character in the current buffer's default font. If the default face
-is remapped (see `face-remapping-alist'), the value for the remapped
-face is returned. This function complements the existing function
-`default-font-height'.
-
-** New functions `window-font-height' and `window-font-width' return
-the height and average width of characters in a specified face and
-window. If FACE is remapped (see `face-remapping-alist'), the
-function returns the information for the remapped face.
-
-** A new function `window-max-chars-per-line' returns the maximal
-number of characters that can be displayed on one line. If a face
-and/or window are provided, these values are used for the
-calculation. This function is different from `window-body-width' in
-that it accounts for (i) continuation glyphs, (ii) the size of the
-font, and (iii) the specified window.
+** M-x suggests shorthands and ignores obsolete commands for completion.
-** New possible value for `system-type': nacl.
+** Changes in undo
+++
-** New variable `inhibit-message', when bound to non-nil, inhibits
- `message' and related functions from displaying messages the Echo
- Area. The output is still logged to the *Messages* buffer.
+*** Successive single-char deletions are collapsed in the undo-log just like
+successive char insertions. Which commands invoke this behavior is
+controlled by the new `undo-auto-amalgamate' function. See the node
+"Undo" in the ELisp manual for more details.
+++
-** It is now safe for a mode that derives `tabulated-list-mode' to not
-call `tabulated-list-init-header', in which case it will have no
-header.
+*** The heuristic used to insert `undo-boundary' after each command
+has changed, so that if a command causes changes in more than just the
+current buffer, Emacs now calls `undo-boundary' in every buffer
+affected by the command.
+++
-** `tabulated-list-print' takes a second optional argument, update,
-which specifies an alternative printing method which is faster when
-few or no entries have changed.
-
-\f
-* Editing Changes in Emacs 25.1
+** New command `comment-line' bound to `C-x C-;'.
-** Successive single-char deletions are collapsed in the undo-log just like
-successive char insertions.
+** New and improved facilities for inserting Unicode characters
-** Unicode names entered via C-x 8 RET now use substring completion by default.
+---
+*** Unicode names entered via C-x 8 RET now use substring completion by default.
-** C-x 8 now has shorthands for these chars: ‐ ‑ ‒ – — ― ‘ ’ “ ” † ‡ • ′ ″
++++
+*** C-x 8 now has shorthands for these chars: ‐ ‑ ‒ – — ― ‘ ’ “ ” † ‡ • ′ ″
€ № ← → ↔ − ≈ ≠ ≤ ≥. As before, you can type C-x 8 C-h to list shorthands.
-** New minor mode electric-quote-mode for quoting ‘like this’ and “like this”.
++++
+*** New minor mode electric-quote-mode for quoting ‘like this’ and “like this”
+as you type. See also the new variable ‘text-quoting-style’.
+---
** New minor mode global-eldoc-mode is enabled by default.
+---
** Emacs now supports "bracketed paste mode" when running on a terminal
that supports it. This facility allows Emacs to understand pasted
chunks of text as strings to be inserted, instead of interpreting each
paste experience similar to that under a window system, and significant
performance improvements when pasting large amounts of text.
++++
** Emacs now supports the latest version of the UBA.
The Emacs implementation of the Unicode Bidirectional Algorithm (UBA)
was updated to support all the latest additions and changes introduced
Bidirectional Parentheses Algorithm (BPA) specified by these Unicode
standards.
++++
** You can access `mouse-buffer-menu' (C-down-mouse-1) using C-f10.
+++
** New buffer-local `electric-pair-local-mode'.
++++
+** New variable `fast-but-imprecise-scrolling' inhibits
+fontification during full screen scrolling operations, giving less
+hesitant operation during auto-repeat of C-v, M-v at the cost of
+possible inaccuracies in the end position.
+
\f
* Changes in Specialized Modes and Packages in Emacs 25.1
+** Checkdoc
+
++++
+*** New command `checkdoc-package-keywords' checks if the
+current package keywords are recognized. Set the new option
+`checkdoc-package-keywords-flag' to non-nil to make
+`checkdoc-current-buffer' call this function automatically.
+
++++
+*** New function `checkdoc-file' checks for style errors.
+It's meant for use together with `compile':
+emacs -batch --eval "(checkdoc-file \"subr.el\")"
+
++++
+** New function `bookmark-set-no-overwrite' bound to C-x r M.
+It raises an error if a bookmark of that name already exists,
+unlike `bookmark-set' which silently updates an existing bookmark.
+
+** JSON
+
+---
+*** `json-pretty-print' and `json-pretty-print-buffer' now maintain
+the ordering of object keys by default.
+
+---
+*** New commands `json-pretty-print-ordered' and
+`json-pretty-print-buffer-ordered' pretty prints JSON objects with
+object keys sorted alphabetically.
+
+** You can recompute the VC state of a file buffer with `M-x vc-refresh-state'
+
** Prog mode has some support for multi-mode indentation.
See `prog-indentation-context' and `prog-widen'.
+** Prettify Symbols mode
+
+*** Prettify Symbols mode supports custom composition predicates. By
+overriding the default `prettify-symbols-compose-predicate', modes can
+specify in which contexts a symbol map be composed to some unicode
+character. `prettify-symbols-default-compose-p' is the default which
+is suitable for most programming languages such as C or Lisp (but not
+(La)TeX).
+
+*** Symbols can be unprettified while point is inside them.
+New variable `prettify-symbols-unprettify-at-point' configures this.
+
** New `xterm-screen-extra-capabilities' config.
** The `save-place' variable is replaced by a `save-place-mode'.
** ERC
-*** Hide message types by network or channel. `erc-hide-list' will
+*** Hide message types by network or channel. `erc-hide-list' will
hide all messages of the specified type, where `erc-network-hide-list'
and `erc-channel-hide-list' will only hide the specified message types
for the respective specified targets.
** Midnight-mode
+
*** `midnight-mode' is a proper minor mode.
+
*** clean-buffer-*-regexps can now specify buffers via predicate functions.
** In xterms, killing text now also sets the CLIPBOARD/PRIMARY selection
*** If a package is available on multiple archives and one has higher
priority (as per `package-archive-priorities') only that one is
-listed. This can be configured with `package-menu-hide-low-priority'.
+listed. This can be configured with `package-menu-hide-low-priority'.
*** `package-menu-toggle-hiding' now toggles the hiding of packages.
This includes the above-mentioned low-priority packages, as well as
*** New custom variable `package-selected-packages' tracks packages
which were installed by the user (as opposed to installed as
-dependencies). This variable can also be manually customized.
+dependencies). This variable can also be manually customized.
*** New command `package-install-user-selected-packages' installs all
packages from `package-selected-packages' which are currently missing.
(add-to-list 'display-buffer-alist
'("^\\*shell\\*$" . (display-buffer-same-window))).
-
** EIEIO
+++
*** The `:protection' slot option is not obeyed any more.
** Search and Replace
++++
+*** New user option `search-default-regexp-mode'
+specifies the default mode for I-search.
+
++++
+*** `isearch' and `query-replace' can now perform character folding in matches.
+Isearch does that by default, while `query-replace' will do that if
+the new variable `replace-character-fold' is customized to a non-nil
+value. This is analogous to case folding, but instead of disregarding
+case variants, it disregards wider classes of distinctions between
+similar characters. (Case folding is a special case of character
+folding.) This means many characters in the search string will match
+entire groups of characters instead of just themselves.
+
+For instance, the " will match all variants of double quotes (like “
+and ”), and the letter a will match all of its accented cousins, even
+those composed of multiple characters, as well as many other symbols
+like ℀, ℁, ⒜, and ⓐ.
+
++++
+*** New function `character-fold-to-regexp' can be used
+by searching commands to produce a regexp matching anything that
+character-folds into STRING.
+
++++
+*** The new M-s M-w key binding uses eww to search the web for the
+text in the region. The search engine to use for this is specified by
+the customizable variable `eww-search-prefix'.
+
++++
*** Query-replace history is enhanced.
When query-replace reads the FROM string from the minibuffer, typing
`M-p' will now show previous replacements as "FROM SEP TO", where FROM
*** If `quick-calc' is called with a prefix argument, insert the
result of the calculation into the current buffer.
++++
+** In Edebug, you can now set the initial mode with C-x C-a C-m. With
+this you can tell Edebug not to stop at the start of the first
+instrumented function.
+
** ElDoc
*** New minor mode `global-eldoc-mode'
*** `eldoc-documentation-function' now defaults to `ignore'
** cl-lib
*** New functions cl-fresh-line, cl-digit-char-p and cl-parse-integer.
-** seq
-*** New seq library:
-The seq library adds sequence manipulation functions and macros that
-complement basic functions provided by subr.el. All functions are
-prefixed with `seq-' and work on lists, strings and vectors.
-
-** map
-*** New map library:
-The map library provides map-manipulation functions that work on alists,
-hash-table and arrays. All functions are prefixed with "map-".
-
** Calendar and diary
+++
** SES now supports local printer functions; see `ses-define-local-printer'.
-** In sh-mode, you can now use `sh-shell' as a file-local variable to
+** sh-script
+*** In sh-mode you can now use `sh-shell' as a file-local variable to
specify the type of shell in use (bash, csh, etc).
+*** New value `always' for sh-indent-after-continuation.
+This provides old-style ("dumb") indentation of continued lines.
+
** TLS
---
*** Fatal TLS errors are now silent by default.
** Tramp
++++
+*** New connection method "afp", which allows to access Mac OS X
+volumes via the Apple Filing Protocol.
+
++++
*** New connection method "nc", which allows to access dumb busyboxes.
++++
*** Method-specific parameters can be overwritten now with variable
`tramp-connection-properties'.
+---
+*** Handler for `file-notify-valid-p' for remote machines that support
+filesystem notifications.
+
** SQL mode
*** New user variable `sql-default-directory' enables remote
interactive macro evaluation and automatic scanning of #defined symbols.
*** New custom variable `hide-ifdef-header-regexp' to define C/C++ header file
-name patterns. Default case-insensitive .h, .hh, .hpp and .hxx.
+name patterns. Default case-insensitive .h, .hh, .hpp, .hxx, and .h++.
*** New custom variable `hide-ifdef-expand-reinclusion-protection' to prevent
reinclusion protected header files from being fully hidden.
*** New custom variable `hide-ifdef-exclude-define-regexp' to define symbol
-name patterns (e.x. all "FOR_DOXYGEN_ONLY_*") to be excluded.
+name patterns (e.g. all "FOR_DOXYGEN_ONLY_*") to be excluded.
** TeX mode
*** New custom variable `tex-print-file-extension' to help users who
use PDF instead of DVI.
+*** TeX mode now supports Prettify Symbols mode. When enabling
+`prettify-symbols-mode' in a tex-mode buffer, \alpha ... \omega, and
+many other math macros are displayed using unicode characters.
+
** whitespace-mode: new 'big-indent style highlighting too much indentation.
By default, 32 spaces and four TABs are considered to be too much but
`whitespace-big-indent-regexp' can be configured to change that.
allow overriding the regular expression that recognizes the ldapsearch
command line's password prompt.
+EUDC's BBDB backend now supports BBDB 3.
+
** Eshell
+++
** tar-mode: new `tar-new-entry' command, allowing for new members to
be added to the archive.
+---
** Autorevert: dired buffers are also auto-reverted via file
notifications, if Emacs is compiled with file notification support.
+** File Notifications
+
++++
+*** The new event `stopped' signals, that a file notification watch is
+not active any longer.
+
++++
+*** The new function `file-notify-valid-p' checks, whether a file
+notification descriptor still corresponds to an activate watch.
+
+** Dired
+
++++
+*** The command `dired-do-compress' bound to `Z' now can compress
+directories and decompress zip files.
+
++++
+*** New command `dired-do-compress-to' bound to `c' can be used to
+compress many marked files into a single named archive. The
+compression command is determined from the new
+`dired-compress-files-alist' variable.
+
+** Tabulated List Mode
+
++++
+*** It is now safe for a mode that derives `tabulated-list-mode' to not
+call `tabulated-list-init-header', in which case it will have no
+header.
+
++++
+*** `tabulated-list-print' takes a second optional argument, update,
+which specifies an alternative printing method which is faster when
+few or no entries have changed.
+
** Obsolete packages
---
*** landmark.el (moved to elpa.gnu.org)
-+++
-** The character classes [:graph:] and [:print:] in regular expressions
-no longer match every multibyte character. Instead, Emacs now
-consults the Unicode character properties to determine which
-characters are graphic or printable. In particular, surrogates and
-unassigned codepoints are now rejected. If you want the old behavior,
-use [:multibyte:] instead.
-
\f
* New Modes and Packages in Emacs 25.1
forbidden by Czech and Polish typography (and may be discouraged in
other languages), so `auto-tildify-mode' makes it easier to create
a typographically-correct documents.
+
+** The `seq' library adds sequence manipulation functions and macros
+that complement basic functions provided by subr.el. All functions
+are prefixed with `seq-' and work on lists, strings and vectors.
+
+** The `map' library provides map-manipulation functions that work on
+alists, hash-table and arrays. All functions are prefixed with
+`map-'.
+
+** The `thunk' library provides functions and macros to control the
+evaluation of forms.
+
+** js-jsx-mode (a minor variant of js-mode) provides indentation
+support for JSX, an XML-like syntax extension to ECMAScript.
+
\f
* Incompatible Lisp Changes in Emacs 25.1
+---
+** `setq' and `setf' must now be called with an even number of
+arguments. The earlier behavior of silently supplying a nil to the
+last variable when there was an odd number of arguments has been
+eliminated.
+
+** `syntax-begin-function' is declared obsolete.
+Removed font-lock-beginning-of-syntax-function and the SYNTAX-BEGIN
+slot in font-lock-defaults.
+
++++
+** `package-initialize' now sets `package-enable-at-startup' to nil if
+called during startup. Users who call this function in their init
+file and still expect it to be run after startup should set
+`package-enable-at-startup' to t after the call to
+`package-initialize'.
+
** `:global' minor mode use `setq-default' rather than `setq'.
This means that you can't use `make-local-variable' and expect them to
"magically" become buffer-local.
pointer shape during dragging, should bind the variable `track-mouse'
to the special value `dragging' in the body of the form.
+---
** The optional `predicate' argument of `lisp-complete-symbol' no longer
has any effect. (This change was made in Emacs 24.4 but was not
advertised at the time.)
** `indirect-function' does not signal `void-function' any more.
This is mostly a bug-fix, since this change was missed back in 24.4 when
symbol-function was changed not to signal `void-function' any more.
+
*** As a consequence, the second arg of `indirect-function' is now obsolete.
** Comint, term, and compile do not set the EMACS env var any more.
in languages like German where downcasing rules depend on grammar.
+++
-** ‘format’ now replaces curved single quotes.
-That is, it replaces strings' curved single quotes (also known as
-curly quotes) as per the value of the new custom variable
-‘text-quoting-style’: ‘curve’ means replace curved quotes with
-themselves ‘like this’, ‘straight’ means use straight apostrophes
-'like this', ‘grave’ means use grave accent and apostrophe `like
-this', and nil (default) means use curved quotes if displayable and
-grave accent and apostrophe otherwise. Because it now may be used
-in many contexts where it's a no-op, ‘format’ is no longer required to
-create a string, and may return its first argument if the argument
-already has the correct value.
-
-+++
-** New ‘format’ flag ‘q’
-The new ‘q’ flag causes ‘format’ to quote the output representation as
-per the value of ‘text quoting-style’. E.g., (format "%qs failed"
-"foo") might return "‘foo’ failed".
+** New variable ‘text-quoting-style’ to control how Emacs translates quotes.
+Set it to ‘curve’ for curved single quotes ‘like this’, to ‘straight’
+for straight apostrophes 'like this', and to ‘grave’ for grave accent
+and apostrophe `like this'. The default value nil acts like ‘curve’
+if curved single quotes are displayable, and like ‘grave’ otherwise.
+The new variable affects display of diagnostics and help, but not of info.
+++
** substitute-command-keys now replaces quotes.
-That is, it converts documentation strings' quoting style as per the
+That is, it converts documentation strings’ quoting style as per the
value of ‘text-quoting-style’. Doc strings in source code can use
-either curved quotes or grave accent and apostrophe. As before,
-isolated apostrophes and characters preceded by \= are output as-is.
+either curved single quotes or grave accents and apostrophes. As
+before, characters preceded by \= are output as-is.
+
++++
+** Message-issuing functions ‘error’, ‘message’, etc. now convert quotes.
+They use the new ‘format-message’ function instead of plain ‘format’,
+so that they now follow user preference as per ‘text-quoting-style’
+when processing curved single quotes, grave accents, and apostrophes
+in their format argument.
+++
** The character classes [:alpha:] and [:alnum:] in regular expressions
If you want the old behavior where they matched any character with
word syntax, use `\sw' instead.
++++
+** The character classes [:graph:] and [:print:] in regular expressions
+no longer match every multibyte character. Instead, Emacs now
+consults the Unicode character properties to determine which
+characters are graphic or printable. In particular, surrogates and
+unassigned codepoints are now rejected. If you want the old behavior,
+use [:multibyte:] instead.
+
+++
** The `diff' command uses the unified format now. To restore the old
behavior, set `diff-switches' to `-c'.
-** `grep-template' and `grep-find-template' values don't include the
---color argument anymore. It's added at the <C> place holder position
-dynamically.
-
** `grep-template' and `grep-find-template' values don't include the
--color argument anymore. It's added at the <C> place holder position
dynamically. Any third-party code that changes these templates should
be updated accordingly.
++++
+** ‘(/ N)’ is now equivalent to ‘(/ 1 N)’ rather than to ‘(/ N 1)’.
+The new behavior is compatible with Common Lisp and with XEmacs.
+This change does not affect Lisp code intended to be portable to
+Emacs 24.2 and earlier, which did not support unary ‘/’.
+
++++
+** The `default-directory' value doesn't have to end slash. To make
+that happen, `unhandled-file-name-directory' now defaults to calling
+`file-name-as-directory'.
+
\f
* Lisp Changes in Emacs 25.1
+** syntax-propertize is now automatically called on-demand during forward
+parsing functions like `forward-sexp'.
+
+** New hooks prefix-command-echo-keystrokes-functions and
+prefix-command-preserve-state-hook, to allow the definition of prefix
+commands other than the predefined C-u.
+
** New functions `filepos-to-bufferpos' and `bufferpos-to-filepos'.
** The default value of `load-read-function' is now `read'.
process filter, sentinel, etc., through keyword arguments (similar to
`make-network-process').
++++
+** A new function `directory-files-recursively' returns all matching
+files (recursively) under a directory.
+
++++
+** New variable `inhibit-message', when bound to non-nil, inhibits
+`message' and related functions from displaying messages the Echo
+Area. The output is still logged to the *Messages* buffer.
+
++++
+** A new text property `inhibit-read-only' can be used in read-only
+buffers to allow certain parts of the text to be writable.
+
** `read-buffer' takes a new `predicate' argument.
** Emacs Lisp now supports generators.
** New function `string-greaterp', which return the opposite result of
`string-lessp'.
++++
+** The new functions `string-collate-lessp' and `string-collate-equalp'
+preserve the collation order as defined by the system's locale(1)
+environment. For the time being this is implemented for modern POSIX
+systems and for MS-Windows, for other systems they fall back to their
+counterparts `string-lessp' and `string-equal'.
+
+---
+*** The ls-lisp package uses `string-collate-lessp' to sort file names.
+If you want the old, locale-independent sorting, customize the new
+option `ls-lisp-use-string-collate' to a nil value.
+
++++
+*** The MS-Windows specific variable `w32-collate-ignore-punctuation',
+if set to a non-nil value, causes the above 2 functions to ignore
+symbol and punctuation characters when collating strings. This
+emulates the behavior of modern Posix platforms when the locale's
+codeset is "UTF-8" (as in "en_US.UTF-8"). This is needed because
+MS-Windows doesn't support UTF-8 as codeset in its locales.
+
** New function `alist-get', which is also a valid place (aka lvalue).
** New function `funcall-interactively', which works like `funcall'
** New function `function-put' to use instead of `put' for function properties.
++++
+** The new function `bidi-find-overridden-directionality' allows to
+find characters whose directionality was, perhaps maliciously,
+overridden by directional override control characters. Lisp programs
+can use this to detect potential phishing of URLs and other links that
+exploits bidirectional display reordering.
+
++++
+** The new function `buffer-substring-with-bidi-context' allows to
+copy a portion of a buffer into a different location while preserving
+the visual appearance both of the copied text and the text at
+destination, even when the copied text includes mixed bidirectional
+text and directional control characters.
+
+++
** New properties that can be specified with `declare':
*** (interactive-only INSTEAD), says to use INSTEAD for non-interactive use.
** If `pwd' is called with a prefix argument, insert the current default
directory at point.
++++
+** New functions return extended information about fonts and faces.
+
++++
+*** The function `font-info' now returns more details about a font.
+In particular, it now returns the average width of the font's
+characters, which can be used for geometry-related calculations.
+
++++
+*** A new function `default-font-width' returns the average width of a
+character in the current buffer's default font. If the default face
+is remapped (see `face-remapping-alist'), the value for the remapped
+face is returned. This function complements the existing function
+`default-font-height'.
+
++++
+*** New functions `window-font-height' and `window-font-width' return
+the height and average width of characters in a specified face and
+window. If FACE is remapped (see `face-remapping-alist'), the
+function returns the information for the remapped face.
+
++++
+*** A new function `window-max-chars-per-line' returns the maximal
+number of characters that can be displayed on one line. If a face
+and/or window are provided, these values are used for the
+calculation. This function is different from `window-body-width' in
+that it accounts for (i) continuation glyphs, (ii) the size of the
+font, and (iii) the specified window.
+
---
** New utilities in subr-x.el:
*** New macros `if-let' and `when-let' allow defining bindings and to
‘text-quoting-style’, the user can specify how to display doc string
quotes.
++++
+** New function ‘format-message’ is like ‘format’ and also converts
+curved single quotes, grave accents and apostrophes as per
+‘text-quoting-style’.
+
+++
** show-help-function's arg is converted via substitute-command-keys
before being passed to the function. Help strings, help-echo
** New function `set-binary-mode' allows to switch a standard stream
of the Emacs process to binary I/O mode.
-** In locales that cannot display curved quotes, ASCII approximations
-are installed in standard-display-table.
++++
+** The new function `directory-name-p' can be used to check whether a file
+name (as returned from, for instance, `file-name-all-completions') is
+a directory file name. It returns non-nil if the last character in
+the name is a directory separator character (forward slash on GNU and
+Unix systems, forward- or backslash on MS-Windows and MS-DOS).
+
+** ASCII approximations to curved quotes are put in standard-display-table
+if the terminal cannot display curved quotes.
** Standard output and error streams now transliterate characters via
standard-display-table, and encode output using locale-coding-system.
++++
+** New var `truncate-string-ellipsis' to choose how to indicate truncation.
+
++++
+** New possible value for `system-type': `nacl'.
+This is used by Google's Native Client (NaCl).
+
** Miscellaneous name change
For consistency with the usual Emacs spelling, the Lisp variable
** OS X on PowerPC is no longer supported.
+---
+** New variable `ns-use-fullscreen-animation' controls animation for
+non-native NS fullscreen. The default is nil. Set to t to enable
+animation when entering and leaving fullscreen. For native OSX fullscreen
+this has no effect.
+
---
** The new function 'w32-application-type' returns the type of an
MS-Windows application given the name of its executable program file.