GNU Emacs NEWS -- history of user-visible changes. Copyright (C) 2022-2023 Free Software Foundation, Inc. See the end of the file for license conditions. Please send Emacs bug reports to 'bug-gnu-emacs@gnu.org'. If possible, use 'M-x report-emacs-bug'. This file is about changes in Emacs version 30. See file HISTORY for a list of GNU Emacs versions and release dates. See files NEWS.29, NEWS.28, ..., NEWS.18, and NEWS.1-17 for changes in older Emacs versions. You can narrow news to a specific version by calling 'view-emacs-news' with a prefix argument or by typing 'C-u C-h C-n'. Temporary note: +++ indicates that all relevant manuals in doc/ have been updated. --- means no change in the manuals is needed. When you add a new item, use the appropriate mark if you are sure it applies, and please also update docstrings as needed. * Installation Changes in Emacs 30.1 +++ ** Emacs has been ported to the Android operating system. This requires Emacs to be compiled on another computer. The Android NDK, SDK, and a suitable Java compiler must also be installed. See the file 'java/INSTALL' for more details. --- ** Native compilation is now enabled by default. 'configure' will enable the Emacs Lisp native compiler, so long as libgccjit is present and functional on the system. To disable native compilation, configure Emacs with the option: ./configure --with-native-compilation=no --- ** Emacs now defaults to ossaudio library for sound on NetBSD and OpenBSD. Previously configure used ALSA libraries if installed on the system when configured '--with-sound=yes' (which is the default), with fallback to libossaudio. The libossaudio library included with the base system is now used even if ALSA is found to avoid relying on external packages and to resolve potential incompatibilities between Linux and BSD versions of ALSA. Use '--with-sound=alsa' to build with ALSA on these operating systems instead. * Startup Changes in Emacs 30.1 ** On GNU/Linux, Emacs is now the default application for 'org-protocol'. Org mode provides a way to quickly capture bookmarks, notes, and links using 'emacsclient': emacsclient "org-protocol://store-link?url=URL&title=TITLE" Previously, users had to manually configure their GNU/Linux desktop environment to open 'org-protocol' links in Emacs. These links should now open in Emacs automatically, as the "emacsclient.desktop" file now arranges for Emacs to be the default application for the 'org-protocol' URI scheme. See the Org mode manual, Info node "(org) Protocols" for more details. * Incompatible Changes in Emacs 30.1 +++ ** URL now never sends user email addresses in HTTP requests. Emacs never sent email addresses by default, but it used to be possible to customize 'url-privacy-level' so that the users email address was sent along in HTTP requests. This feature has now been removed, as it was considered more dangerous than useful. RFC 9110 (§ 10.1.2) also recommends against it. The user option 'url-personal-mail-address' is now also obsolete. To send an email address in the header of individual HTTP requests, see the variable 'url-request-extra-headers'. * Changes in Emacs 30.1 ** Emacs now supports Unicode Standard version 15.1. ** Network Security Manager +++ *** The Network Security Manager now warns about 3DES by default. This cypher is no longer recommended owing to a major vulnerability disclosed in 2016, and its small 112 bit key size. Emacs now warns about its use also when 'network-security-level' is set to 'medium' (the default). See 'network-security-protocol-checks'. --- *** The Network Security Manager now warns about <2048 bits in DH key exchange. Emacs used to warn for Diffie-Hellman key exchanges with prime numbers smaller than 1024 bits. Since more servers now support it, this number has been bumped to 2048 bits. ** Help *** 'describe-function' shows function inferred type when available. For native compiled Lisp functions 'describe-function' prints (after the signature) the automatically inferred function type as well. --- *** New user option 'describe-bindings-outline-rules'. This user option controls outline visibility in the output buffer of 'describe-bindings' when 'describe-bindings-outline' is non-nil. ** X selection requests are now handled much faster and asynchronously. This means it should be less necessary to disable the likes of 'select-active-regions' when Emacs is running over a slow network connection. ** Emacs now updates invisible frames that are made visible by a compositor. If an invisible or an iconified frame is shown to the user by the compositing manager, Emacs will now redisplay such a frame even though 'frame-visible-p' returns nil or 'icon' for it. This can happen, for example, as part of preview for iconified frames. --- ** New user option 'menu-bar-close-window'. When non-nil, selecting "Close" from the "File" menu or clicking "Close" in the tool bar will result in the current window being closed, if possible. +++ ** 'write-region-inhibit-fsync' now defaults to t in interactive mode, as it has in batch mode since Emacs 24. +++ ** New user option 'remote-file-name-inhibit-delete-by-moving-to-trash'. When non-nil, this option suppresses moving remote files to the local trash when deleting. Default is nil. --- ** New user option 'remote-file-name-inhibit-auto-save'. If this user option is non-nil, 'auto-save-mode' will not auto-save remote buffers. The default is nil. +++ ** New user option 'remote-file-name-access-timeout'. When a positive number, this option limits the call of 'access-file' for remote files to this number of seconds. Default is nil. +++ ** New user option 'yes-or-no-prompt'. This allows the user to customize the prompt that is appended by 'yes-or-no-p' when asking questions. The default value is "(yes or no) ". --- ** New face 'display-time-date-and-time'. This is used for displaying the time and date components of 'display-time-mode'. --- ** New icon images for general use. Several symbolic icons are added to "etc/images/symbols", including plus, minus, check-mark, start, etc. +++ ** Tool bars can now be placed on the bottom on more systems. The 'tool-bar-position' frame parameter can be set to 'bottom' on all window systems other than Nextstep. +++ ** New global minor mode 'modifier-bar-mode'. When this minor mode is enabled, buttons representing modifier keys are displayed along the tool bar. +++ ** "d" in the mode line now indicates that the window is dedicated. Windows have always been able to be dedicated to a specific buffer; see 'window-dedicated-p'. Now the mode line indicates the dedicated status of a window, with "d" appearing in the mode line if a window is dedicated and "D" if the window is strongly dedicated. This indicator appears before the buffer name, and after the buffer modification and remote buffer indicators (usually "---" together). +++ ** New command 'toggle-window-dedicated'. This makes it easy to interactively mark a specific window as dedicated, so it won't be reused by 'display-buffer'. This can be useful for complicated window setups. It is bound to 'C-x w d' globally. --- ** New user option 'uniquify-dirname-transform'. This can be used to customize how buffer names are uniquified, by making arbitrary transforms on the buffer's directory name (whose components are used to uniquify buffer names when they clash). You can use this to distinguish between buffers visiting files with the same base name that belong to different projects by using the provided transform function 'project-uniquify-dirname-transform'. ** 'insert-directory-program' is now a user option. On *BSD and macOS systems, this user option now defaults to the "gls" executable, if it exists. This should remove the need to change its value when installing GNU coreutils using something like ports or Homebrew. +++ ** cl-print +++ *** You can expand the "..." truncation everywhere. The code that allowed "..." to be expanded in the "*Backtrace*" buffer should now work anywhere the data is generated by 'cl-print'. +++ *** The 'backtrace-ellipsis' button is replaced by 'cl-print-ellipsis'. +++ *** hash-tables' contents can be expanded via the ellipsis. +++ *** Modes can control the expansion via 'cl-print-expand-ellipsis-function'. +++ *** New setting 'raw' for 'cl-print-compiled'. This setting causes byte-compiled functions to be printed in full by 'prin1'. A button on this output can be activated to disassemble the function. +++ *** There is a new chapter in the CL manual documenting cl-print.el. See the Info node "(cl) Printing". ** Modeline elements can now be right-aligned. Anything following the symbol 'mode-line-format-right-align' in 'mode-line-format' will be right-aligned. Exactly where it is right-aligned to is controlled by the new user option 'mode-line-right-align-edge'. ** Tab Bars and Tab Lines *** New user option 'tab-bar-tab-name-format-functions'. It can be used to add, remove and reorder functions that change the appearance of every tab on the tab bar. +++ ** New optional argument for modifying directory-local variables. The commands 'add-dir-local-variable', 'delete-dir-local-variable' and 'copy-file-locals-to-dir-locals' now take an optional prefix argument, to enter the file you want to modify. ** Miscellaneous --- *** New face 'appt-notification' for 'appt-display-mode-line'. It can be used to customize the look of the appointment notification displayed on the mode line when 'appt-display-mode-line' is non-nil. --- *** Emacs now recognizes shebang lines that pass '-S'/'--split-string' to 'env'. When visiting a script that invokes 'env -S INTERPRETER ARGS...' in its shebang line, Emacs will now skip over 'env -S' and deduce the major mode based on the interpreter after 'env -S'. ** Emacs Server and Client --- *** 'server-eval-args-left' can be used to pop and eval subsequent args. When '--eval' is passed to emacsclient and Emacs is evaluating each argument, this variable is set to those arguments not yet evaluated. It can be used to 'pop' arguments and process them by the function called in the '--eval' expression, which is useful when those arguments contain arbitrary characters that otherwise might require elaborate and error-prone escaping (to protect them from the shell). +++ ** 'recover-file' can show diffs between auto save file and current file. When answering the prompt with "diff" or "=", it now shows the diffs between the auto save file and the current file. --- ** 'ffap-lax-url' now defaults to nil. Previously, it was set to 'ffap-lax-url' to t but this broke remote file name detection. * Editing Changes in Emacs 30.1 +++ ** New user option 'gud-highlight-current-line'. When enabled, Gud will visually emphasize the line being executed upon pauses in the debugee's execution, such as those occasioned by breakpoints being hit. --- ** New global minor mode 'kill-ring-deindent-mode'. When enabled, text being saved to the kill ring will be de-indented by the column number at its start. For example, saving the entire function call within: foo () { long_function_with_several_arguments (argument_1_compute (), argument_2_compute (), argument_3_compute ()); } will save: long_function_with_several_arguments (argument_1_compute (), argument_2_compute (), argument_3_compute ()) to the kill ring, omitting the two columns of extra indentation that would otherwise be present in the second and third lines of the function call. +++ ** Emacs now has better support for touchscreen devices. Many touch screen gestures are now implemented and translated into mouse or gesture events, and support for tapping tool bar buttons and opening menus has been written. Countless packages, such as Dired and Custom have been adjusted to better understand touch screen input. --- ** On X, Emacs now supports input methods which perform "string conversion". This means an input method can now ask Emacs to delete text surrounding point and replace it with something else, as well as query Emacs for surrounding text. If your input method allows you to "undo" mistaken compositions, this will now work as well. --- ** New command 'kill-matching-buffers-no-ask'. This works like 'kill-matching-buffers', but without asking for confirmation. --- ** New user option 'duplicate-region-final-position'. It controls the placement of point and the region after duplicating a region with 'duplicate-dwim'. +++ ** New user option 'mouse-prefer-closest-glyph'. When enabled, clicking or dragging with the mouse will put the point or start the drag in front of the buffer position corresponding to the glyph with the closest X coordinate to the click or start of the drag. In other words, if the mouse pointer is in the right half of a glyph, point will be put after the buffer position corresponding to that glyph, whereas if the mouse pointer is in the left half of a glyph, point will be put in front the buffer position corresponding to that glyph. By default this is disabled. ** Internationalization --- *** Users in CJK locales can control width of some non-CJK characters. Some characters are considered by Unicode as "ambiguous" with respect to their display width: either "full-width" (i.e. taking 2 columns on display) or "narrow" (taking 1 column). The actual width depends on the fonts used for these characters by Emacs or (for text-mode frames) by the terminal emulator. Traditionally, font sets in CJK locales were set up so as to display these characters as full-width, and thus Emacs modified the char-width table in those locales to follow suit. Lately, the tendency is to display these characters as narrow. The new user option 'cjk-ambiguous-chars-are-wide' allows users to control whether Emacs considers these characters as full-width (the default) or narrow (if the variable is customized to the nil value). This setting affects the results of 'string-width' and similar functions in CJK locales. --- *** New input methods for the Urdu, Pashto, and Sindhi languages. These languages are spoken in Pakistan and Afganistan. *** Additional 'C-x 8' key translations for "æ" and "Æ". These characters can now be input with 'C-x 8 a e' and 'C-x 8 A E', respectively, in addition to the existing translations 'C-x 8 / e' and 'C-x 8 / E'. * Changes in Specialized Modes and Packages in Emacs 30.1 +++ ** New command 'lldb'. Run the LLDB debugger, analogous to the 'gud-gdb' command. Note that you might want to add these settings to your ".lldbinit" file, to reduce the output in the LLDB output when stepping through source files. settings set stop-line-count-before 0 settings set stop-line-count-after 0 ** gdb-mi --- *** Variable order and truncation can now be configured in 'gdb-many-windows'. The new user option 'gdb-locals-table-row-config' allows users to configure the order and max length of various properties in the local variables buffer when using 'gdb-many-windows'. By default, this user option is set to write the properties in the order: name, type and value, where the name and type are truncated to 20 characters, and the value is truncated according to the value of 'gdb-locals-value-limit'. If you want to get back the old behavior, set the user option to the value (setopt gdb-locals-table-row-config `((type . 0) (name . 0) (value . ,gdb-locals-value-limit))) --- *** New user option 'gdb-display-io-buffer'. If this is nil, 'M-x gdb' will neither create nor display a separate buffer for the I/O of the program being debugged, but will instead redirect the program's interaction to the GDB execution buffer. The default is t, to preserve previous behavior. ** Grep *** New user option 'grep-use-headings'. When non-nil, the output of Grep is split into sections, one for each file, instead of having file names prefixed to each line. It is equivalent to the "--heading" option of some tools such as 'git grep' and 'rg'. The headings are displayed using the new 'grep-heading' face. ** Compilation mode --- *** The 'omake' matching rule is now disabled by default. This is because it partly acts by modifying other rules which may occasionally be surprising. It can be re-enabled by adding 'omake' to 'compilation-error-regexp-alist'. ** Project +++ *** New user option 'project-mode-line'. When non-nil, display the name of the current project on the mode line. Clicking 'mouse-1' on the project name pops up the project menu. The default value is nil. *** New user option 'project-file-history-behavior'. Customizing it to 'relativize' makes commands like 'project-find-file' and 'project-find-dir' display previous history entries relative to the current project. *** New user option 'project-key-prompt-style'. The look of the key prompt in the project switcher has been changed slightly. To get the previous one, set this option to 'brackets'. *** 'project-try-vc' tries harder to find the responsible VCS. When 'project-vc-extra-root-markers' is non-nil, and causes a subdirectory project to be detected which is not a VCS root, we now additionally traverse the parent directories until a VCS root is found (if any), so that the ignore rules for that repository are used, and the file listing's performance is still optimized. *** New commands 'project-any-command' and 'project-prefix-or-any-command'. The former is now bound to 'C-x p o' by default. The latter is designed primarily for use as a value of 'project-switch-commands'. If instead of a short menu you prefer to have access to all keys defined inside 'project-prefix-map', as well as global bindings (to run other commands inside the project root), you can add this to your init script: (setopt project-switch-commands #'project-prefix-or-any-command) ** VC --- *** Log-Edit buffers now display a tool bar. This tool bar contains items for committing log entries and editing or generating log entries, among other editing operations. --- *** New user option 'vc-git-shortlog-switches'. This is a string or a list of strings that specifies the Git log switches for shortlogs, such as the one produced by 'C-x v L'. 'vc-git-log-switches' is no longer used for shortlogs. --- *** New value 'no-backend' for user option 'vc-display-status'. With this value only the revision number is displayed on the mode-line. --- *** Obsolete command 'vc-switch-backend' re-added as 'vc-change-backend'. The command was previously obsoleted and unbound in Emacs 28. *** Support for viewing VC change history across renames. When a fileset's VC change history ('C-x v l') ends at a rename, we now print the old name(s) and a button which jumps to their history. Git and Hg are supported. Naturally, 'vc-git-print-log-follow' should be nil for this to work (or '--follow' should not be in 'vc-hg-print-log-switches', in Hg's case). Unlike when the '--follow' switch is used, commands to see the diff of the old revision ('d'), check out an old file version ('f') or annotate it right away ('a'), also work on revisions which precede renames. --- *** 'vc-annotate' now abbreviates the Git revision in the buffer name. When using the Git backend, 'vc-annotate' will use an abbreviated revision identifier in its buffer name. To restore the previous behavior, set 'vc-annotate-use-short-revision' to nil. *** New option 'vc-git-file-name-changes-switches'. It allows tweaking the thresholds for rename and copy detection. ** Diff mode +++ *** 'diff-ignore-whitespace-hunk' can now be applied to all hunks. When called with a non-nil prefix argument, 'diff-ignore-whitespace-hunk' now iterates over all the hunks in the current diff, regenerating them without whitespace changes. +++ *** New user option 'diff-ignore-whitespace-switches'. This allows changing which type of whitespace changes are ignored when regenerating hunks with 'diff-ignore-whitespace-hunk'. Defaults to the previously hard-coded "-b". *** New command 'diff-apply-buffer' bound to 'C-c RET a'. It applies the diff in the entire diff buffer and saves all modified file buffers. ** Isearch and Replace *** New command 'replace-regexp-as-diff'. It reads a regexp to search for and a string to replace with, then displays a buffer with replacements as diffs. After reviewing the changes in the output buffer you can apply the replacements as a patch to the current file buffer. There are also new commands 'multi-file-replace-regexp-as-diff' that shows as diffs replacements in a list of specified files, and 'dired-do-replace-regexp-as-diff' that shows as diffs replacements in the marked files in Dired. ** Dired --- *** New user option 'dired-movement-style'. When non-nil, make 'dired-next-line', 'dired-previous-line', 'dired-next-dirline', 'dired-prev-dirline' skip empty lines. It also controls how to move point when encountering a boundary (e.g., if every line is visible, invoking 'dired-next-line' at the last line will move to the first line). The default is nil. *** New user option 'dired-filename-display-length'. It is an integer representing the maximum display length of filenames. The middle part of a filename whose length exceeds the restriction is hidden and an ellipsis is displayed instead. A value of 'window' means using the right edge of window as the display restriction. The default is nil. *** New user option 'shell-command-guess-functions'. It defines how to populate a list of commands available for 'M-!', 'M-&', '!', '&' and the context menu "Open With" based on marked files in Dired. Possible backends are 'dired-guess-default', MIME types, XDG configuration and a universal command such as "open" or "start" that delegates to the OS. *** New command 'dired-do-open'. This command is bound to "Open" in the context menu; it "opens" the marked or clicked on files according to the OS conventions. For example, on systems supporting XDG, this runs 'xdg-open' on the files. +++ *** 'dired-listing-switches' handles connection-local values if exist. This allows to customize different switches for different remote machines. ** Registers +++ *** New mode of prompting for register names and showing preview. The new user option 'register-use-preview' can be customized to the value t to request a different user interface of prompting for register names and previewing the registers: Emacs will require confirmation for overwriting the value of a register, and will show the preview of registers without delay. You can also customize this new option to disable the preview completely. The default value of 'register-use-preview' preserves the behavior of Emacs 29 and before. See the Info node "(emacs) Registers" for more details about the new UI and its variants. ** Ediff --- *** New user option 'ediff-floating-control-frame'. If non-nil, try making the control frame be floating rather than tiled. Many X tiling window managers make the Ediff control frame a tiled window equal in size to the main Emacs frame, which works poorly. This option is useful to set if you use such a window manager. ** Buffer Selection --- *** New user option 'bs-default-action-list'. You can now configure how to display the "*buffer-selection*" buffer using this new option. (Or set 'display-buffer-alist' directly.) ** Eshell +++ *** New builtin Eshell command 'compile'. This command runs another command, sending its output to a compilation buffer when the command would output interactively. This can be useful when defining aliases so that they produce a compilation buffer when appropriate, but still allow piping the output elsewhere if desired. For more information, see the "(eshell) Built-ins" node in the Eshell manual. +++ *** New special reference type '#'. This special reference type returns a marker at 'POSITION' in 'BUFFER'. You can insert it by typing or using the new interactive command 'eshell-insert-marker'. You can also insert markers of any type with the new command 'eshell-insert-special-reference'. See the "(eshell) Arguments" node in the Eshell manual for more details. +++ *** New splice operator for Eshell dollar expansions. Dollar expansions in Eshell now let you splice the elements of the expansion in-place using '$@expr'. This makes it easier to fill lists of arguments into a command, such as when defining aliases. For more information, see the "(eshell) Dollars Expansion" node in the Eshell manual. +++ *** You can now splice Eshell globs in-place into argument lists. By setting 'eshell-glob-splice-results' to a non-nil value, Eshell will expand glob results in-place as if you had typed each matching file name individually. For more information, see the "(eshell) Globbing" node in the Eshell manual. +++ *** Eshell now supports negative numbers and ranges for indices. Now, you can retrieve the last element of a list with '$my-list[-1]' or get a sublist of elements 2 through 4 with '$my-list[2..5]'. For more information, see the "(eshell) Dollars Expansion" node in the Eshell manual. +++ *** Eshell commands can now be explicitly-remote (or local). By prefixing a command name in Eshell with a remote identifier, like "/ssh:user@remote:whoami", you can now run commands on a particular host no matter your current directory. Likewise, you can run a command on your local system no matter your current directory via "/:whoami". For more information, see the "(eshell) Remote Access" node in the Eshell manual. +++ *** Eshell's '$UID' and '$GID' variables are now connection-aware. Now, when expanding '$UID' or '$GID' in a remote directory, the value is the user or group ID associated with the remote connection. --- *** Eshell now uses 'field' properties in its output. In particular, this means that pressing the '' key moves the point to the beginning of your input, not the beginning of the whole line. If you want to go back to the old behavior, add something like this to your configuration: (keymap-set eshell-mode-map "" #'eshell-bol-ignoring-prompt) This also means you no longer need to adjust 'eshell-prompt-regexp' when customizing your Eshell prompt. --- *** You can now properly unload Eshell. Calling '(unload-feature 'eshell)' no longer signals an error, and now correctly unloads Eshell and all of its modules. +++ *** 'eshell-read-aliases-list' is now an interactive command. After manually editing 'eshell-aliases-file', you can use this command to load the edited aliases. +++ *** 'rgrep' is now a builtin command. Running 'rgrep' in Eshell now uses the Emacs grep facility instead of calling external rgrep. +++ *** If a command exits abnormally, the Eshell prompt now shows its exit code. +++ *** New user option 'eshell-history-append'. If non-nil, each Eshell session will save history by appending new entries of that session to the history file rather than overwriting the file with the whole history of the session. The default is nil. ** Minibuffer and Completions *** New commands 'previous-line-completion' and 'next-line-completion'. Bound to '' and '' arrow keys, respectively, they navigate the "*Completions*" buffer vertically by lines, wrapping at the top/bottom when 'completion-auto-wrap' is non-nil. *** New user option 'minibuffer-visible-completions'. When customized to non-nil, you can use arrow keys in the minibuffer to navigate the completions displayed in the "*Completions*" window. Typing 'RET' selects the highlighted candidate. 'C-g' hides the completions window. When the completions window is not visible, then all these keys have their usual meaning in the minibuffer. This option is supported for in-buffer completion as well. *** Selected completion candidates are deselected on typing. When you type at the minibuffer prompt, the current completion candidate will be un-highlighted, and point in the "*Completions*" window will be moved off that candidate. 'minibuffer-choose-completion' ('M-RET') will still choose a previously-selected completion candidate, but the new command 'minibuffer-choose-completion-or-exit' (bound to 'RET' by 'minibuffer-visible-completions') will exit with the minibuffer contents instead. This deselection behavior can be controlled with the new user option 'completion-auto-deselect', which is t by default. *** New value 'historical' for user option 'completions-sort'. When 'completions-sort' is set to 'historical', completion candidates will be first sorted alphabetically, and then re-sorted by their order in the minibuffer history, with more recent candidates appearing first. ** Pcomplete --- *** New user option 'pcomplete-remote-file-ignore'. When this option is non-nil, remote file names are not completed by Pcomplete. Packages, like 'shell-mode', could set this in order to suppress remote file name completion at all. --- *** Completion for the 'doas' command has been added. Command completion for 'doas' in Eshell and Shell mode will now work. ** Shell mode +++ *** New user option 'shell-get-old-input-include-continuation-lines'. When this user option is non-nil, 'shell-get-old-input' ('C-RET') includes multiple shell "\" continuation lines from command output. Default is nil. ** Make mode *** The Makefile browser is now obsolete. The command 'makefile-switch-to-browser' command is now obsolete, together with related commands used in the "*Macros and Targets*" buffer. We recommend using an alternative like 'imenu' instead. ** Prog mode +++ *** New command 'prog-fill-reindent-defun'. This command either fills a single paragraph in a defun, such as a docstring, or a comment, or (re)indents the surrounding defun if point is not in a comment or a string. It is by default bound to 'M-q' in 'prog-mode' and all its descendants. ** Which Function mode +++ *** Which Function mode can now display function names on the header line. The new user option 'which-func-display' allows choosing where the function name is displayed. The default is 'mode' to display in the mode line. 'header' will display in the header line; 'mode-and-header' displays in both the header line and mode line. ** Tramp +++ *** New connection methods "toolbox" and "flatpak". They allow accessing system containers provided by Toolbox or sandboxes provided by Flatpak. +++ *** Connection method "kubernetes" supports now optional container name. The host name for Kubernetes connections can be of kind [CONTAINER.]POD, in order to specify a dedicated container. If there is just the pod name, the first container in the pod is taken. The new user options 'tramp-kubernetes-context' and 'tramp-kubernetes-namespace' allow accessing pods with different context or namespace but the default one. +++ *** Rename 'tramp-use-ssh-controlmaster-options' to 'tramp-use-connection-share'. The old name still exists as obsolete variable alias. This user option controls now connection sharing for both ssh-based and plink-based methods. It allows the values t, nil, and 'suppress'. The latter suppresses also "ControlMaster" settings in the user's "~/.ssh/config" file, or connection share configuration in PuTTY sessions, respectively. +++ *** New command 'tramp-cleanup-some-buffers'. It kills only a subset of opened remote buffers, subject to the user option 'tramp-cleanup-some-buffers-hook'. +++ *** New command 'inhibit-remote-files'. This command disables the handling of file names with the special remote file name syntax. It should be applied only when remote files won't be used in this Emacs instance. It provides a slightly improved performance of file name handling in Emacs. +++ *** New macro 'without-remote-files'. This macro could wrap code which handles local files only. Due to the temporary deactivation of remote files, it results in a slightly improved performance of file name handling in Emacs. +++ *** New user option 'tramp-completion-multi-hop-methods'. It contains a list of connection methods for which completion should be attempted at the end of a multi-hop chain. This allows completion candidates to include a list of, for example, containers running on a remote docker host. +++ *** New command 'tramp-revert-buffer-with-sudo'. It reverts the current buffer to visit with "sudo" permissions. The buffer must either visit a file, or it must run 'dired-mode'. Another method but "sudo" can be configured with user option 'tramp-file-name-with-method'. --- *** Direct asynchronous processes use 'tramp-remote-path'. When a direct asynchronous process is invoked, it uses 'tramp-remote-path' for setting the remote PATH environment variable. ** File Notifications +++ *** All backends except w32notify detect unmounting of a watched filesystem now. ** EWW +++ *** 'eww-open-file' can now display the file in a new buffer. By default, the command reuses the "*eww*" buffer, but if called with the new argument NEW-BUFFER non-nil, it will use a new buffer instead. Interactively, invoke 'eww-open-file' with a prefix argument to activate this behavior. --- *** 'eww' URL or keyword prompt now has tab completion. The interactive minibuffer prompt when invoking 'eww' now has support for tab completion. +++ *** 'eww' URL and keyword prompt now completes suggested URIs and bookmarks. The interactive minibuffer prompt when invoking 'eww' now provides completions from 'eww-suggest-uris'. 'eww-suggest-uris' now includes bookmark URIs. +++ *** New command 'eww-copy-alternate-url'. It copies an alternate link on the page currently visited in EWW into the kill ring. Alternate links are optional metadata that HTML pages use for linking to their alternative representations, such as translated versions or associated RSS feeds. +++ *** 'eww-open-in-new-buffer' supports the prefix argument. When invoked with the prefix argument ('C-u'), 'eww-open-in-new-buffer' will not make the new buffer the current one. This is useful for continuing reading the URL in the current buffer when the new URL is fetched. ** go-ts-mode +++ *** New command 'go-ts-mode-docstring'. This command adds a docstring comment to the current defun. If a comment already exists, point is only moved to the comment. It is bound to 'C-c C-d' in 'go-ts-mode'. ** Man mode +++ *** New user option 'Man-prefer-synchronous-call'. When this is non-nil, run the 'man' command synchronously rather than asynchronously (which is the default behavior). +++ *** New user option 'Man-support-remote-systems'. This option controls whether the man page is formatted on the remote system when the current buffer's default-directory is remote. You can invoke the 'man' command with a prefix argument to countermand the value of this option for the current invocation of 'man'. ** DocView --- *** New face 'doc-view-svg-face'. This replaces 'doc-view-svg-foreground' and 'doc-view-svg-background'. If you don't like the colors produced by the default definition of this new face when DocView displays documents, customize this face to restore the colors you were used to, or to get colors more to your liking. --- *** DocView buffers now display a new tool bar. This tool bar contains options for searching and navigating within the document, replacing the incompatible items for incremental search and editing within the default tool bar displayed in the past. ** Shortdoc +++ *** New function 'shortdoc-function-examples'. This function returns examples of use of a given Emacs Lisp function from the available shortdoc information. +++ *** New function 'shortdoc-help-fns-examples-function'. This function inserts into the current buffer examples of use of a given Emacs Lisp function, which it gleans from the shortdoc information. If you want 'describe-function' ('C-h f') to insert examples of using the function into regular "*Help*" buffers, add the following to your init file: (add-hook 'help-fns-describe-function-functions #'shortdoc-help-fns-examples-function) ** Package --- *** New user option 'package-vc-register-as-project'. When non-nil, it will automatically register every package as a project, that you can quickly select using 'project-switch-project' ('C-x p p'). --- *** New user option 'package-vc-allow-build-commands'. Controls for which packages Emacs runs extra build commands when installing directly from the package VCS repository. --- *** New command to start an inferior Emacs loading only specific packages. The new command 'package-isolate' will start a new Emacs process, as a sub-process of Emacs where you invoke the command, in a way that causes the new process to load only some of the installed packages. The command prompts for the packages to activate in this sub-process, and is intended for testing Emacs and/or the packages in a clean environment. ** Flymake +++ *** New user option 'flymake-show-diagnostics-at-end-of-line'. When non-nil, Flymake shows summarized descriptions of diagnostics at the end of the line. Depending on your preference, this can either be distracting and easily confused with actual code, or a significant early aid that relieves you from moving the buffer or reaching for the mouse to consult an error message. ** JS mode. The binding 'M-.' has been removed from the major mode keymaps in 'js-mode' and 'js-ts-mode', having it default to the global binding which calls 'xref-find-definitions'. If the previous one worked better for you, use 'define-key' in your init script to bind 'js-find-symbol' to that combination again. ** Python mode --- *** New user option 'python-indent-block-paren-deeper'. If non-nil, increase the indentation of the lines inside parens in a header of a block when they are indented to the same level as the body of the block: if (some_expression and another_expression): do_something() instead of: if (some_expression and another_expression): do_something() *** New user option 'python-interpreter-args'. This allows the user to specify command line arguments to the non interactive Python interpreter specified by 'python-interpreter'. ** use-package +++ *** New ':vc' keyword. This keyword enables the user to install packages using 'package-vc'. ** Gnus *** The 'nnweb-type' option 'gmane' has been removed. The gmane.org website is, sadly, down since a number of years with no prospect of it coming back. Therefore, it is no longer valid to set the user option 'nnweb-type' to 'gmane'. ** Rmail --- *** New commands for reading mailing lists. The new Rmail commands 'rmail-mailing-list-post', 'rmail-mailing-list-unsubscribe', 'rmail-mailing-list-help', and 'rmail-mailing-list-archive' allow, respectively, posting to, unsubscribing from, requesting help about, and browsing the archives of, the mailing list from which the current email message was delivered. ** Dictionary --- *** New user option 'dictionary-search-interface'. Controls how the 'dictionary-search' command prompts for and displays dictionary definitions. Customize this user option to 'help' to have 'dictionary-search' display definitions in a "*Help*" buffer and provide dictionary-based minibuffer completion for word selection. --- *** New user option 'dictionary-read-word-prompt'. This allows the user to customize the prompt that is used by 'dictionary-search' when asking for a word to search in the dictionary. --- *** New user option 'dictionary-display-definition-function'. This allows the user to customize the way in which 'dictionary-search' displays word definitions. If non-nil, this user option should be set to a function that displays a word definition obtained from a dictionary server. The new function 'dictionary-display-definition-in-help-buffer' can be used to display the definition in a "*Help*" buffer, instead of the default "*Dictionary*" buffer. --- *** New user option 'dictionary-read-word-function'. This allows the user to customize the way in which 'dictionary-search' prompts for a word to search in the dictionary. This user option should be set to a function that lets the user select a word and returns it as a string. The new function 'dictionary-completing-read-word' can be used to prompt with completion based on dictionary matches. --- *** New user option 'dictionary-read-dictionary-function'. This allows the user to customize the way in which 'dictionary-search' prompts for a dictionary to search in. This user option should be set to a function that lets the user select a dictionary and returns its name as a string. The new function 'dictionary-completing-read-dictionary' can be used to prompt with completion based on dictionaries that the server supports. ** Pp *** New 'pp-default-function' user option replaces 'pp-use-max-width'. *** New default pretty printing function, which tries to obey 'fill-column'. *** 'pp-to-string' takes an additional PP-FUNCTION argument. This argument specifies the prettifying algorithm to use. ** Emacs Lisp mode --- *** ',@' now has 'prefix' syntax. Previously, the '@' character, which normally has 'symbol' syntax, would combine with a following Lisp symbol and interfere with symbol searching. ** CPerl mode --- *** Subroutine signatures are now supported. CPerl mode fontifies subroutine signatures like variable declarations which makes them visually distinct from subroutine prototypes. *** Syntax of Perl up to version 5.38 is supported. CPerl mode supports the new keywords for exception handling and the object oriented syntax which were added in Perl 5.36 and 5.38. *** New user option 'cperl-fontify-trailer'. This user option takes the values 'perl-code' or 'comment' and treats text after an "__END__" or "__DATA__" token accordingly. The default value of 'perl-code' is useful for trailing POD and for AutoSplit modules, the value 'comment' makes CPerl mode treat trailers as comment, like Perl mode does. *** Commands using the Perl info page are obsolete. The Perl documentation in info format is no longer distributed with Perl or on CPAN since more than 10 years. Perl documentation can be read with 'cperl-perldoc' instead. *** Highlighting trailing whitespace has been removed. The user option 'cperl-invalid-face' is now obsolete, and does nothing. See the user option 'show-trailing-whitespace' instead. ** Emacs Sessions (Desktop) +++ *** Restoring buffers visiting remote files can now time out. When a buffer is restored which visits a remote file, the restoration of the session could hang if the remote host is off-line or slow to respond. Setting the user option 'remote-file-name-access-timeout' to a positive number will abandon the attempt to restore such buffers after a timeout of that many seconds, thus allowing the rest of desktop restoration to continue. ** Recentf +++ *** Checking recent remote files can now time out. Similarly to buffer restoration by Desktop, 'recentf-mode' checking of the accessibility of remote files can now time out if 'remote-file-name-access-timeout' is set to a positive number. ** Notifications +++ *** Allow using Icon Naming Specification for ':app-icon'. You can use a symbol as the value for ':app-icon' to provide icon name without specifying a file, like this: (notifications-notify :title "I am playing music" :app-icon 'multimedia-player) ** Image Dired *** New user option 'image-dired-thumb-naming'. You can now configure how a thumbnail is named using this option. ** ERT +++ *** New macro 'skip-when' to skip 'ert-deftest' tests. This can help avoid some awkward skip conditions. For example '(skip-unless (not noninteractive))' can be changed to the easier to read '(skip-when noninteractive)'. +++ *** Syntax highlighting unit testing support. An ERT extension ('ert-font-lock') now provides support for face assignment unit testing. For more information, see the "(ert) Syntax Highlighting Tests" node in the ERT manual. ** URL +++ *** 'url-gateway-broken-resolution' is now obsolete. This option was intended for use on SunOS 4.x and Ultrix systems, neither of which have been supported by Emacs since version 23.1. The user option 'url-gateway-nslookup-program' and the function 'url-gateway-nslookup-host' are consequently also obsolete. ** Socks +++ *** Socks supports version 4a. The 'socks-server' user option accepts '4a' as a value for its version field. ** Edmacro +++ *** New command 'edmacro-set-macro-to-region-lines'. Bound to 'C-c C-r', this command replaces the macro text with the lines of the region. If needed, the region is extended to include whole lines. If the region ends at the beginning of a line, that last line is excluded. +++ *** New user option 'edmacro-reverse-macro-lines'. When this is non-nil, the lines of key sequences are displayed with the most recent line first. This is can be useful when working with macros with many lines, such as from 'kmacro-edit-lossage'. ** Miscellaneous --- *** Webjump now assumes URIs are HTTPS instead of HTTP. For links in 'webjump-sites' without an explicit URI scheme, it was previously assumed that they should be prefixed with "http://". Such URIs are now prefixed with "https://" instead. --- *** 'bug-reference-mode' now supports 'thing-at-point'. Now, calling '(thing-at-point 'url)' when point is on a bug reference will return the URL for that bug. +++ *** New user option 'rcirc-log-time-format' This allows for rcirc logs to use a custom timestamp format, than the chat buffers use by default. ** Customize +++ *** New command 'customize-dirlocals'. This command pops up a buffer to edit the settings in ".dir-locals.el". * New Modes and Packages in Emacs 30.1 ** New major modes based on the tree-sitter library +++ *** New major mode 'html-ts-mode'. An optional major mode based on the tree-sitter library for editing HTML files. --- *** New major mode 'heex-ts-mode'. A major mode based on the tree-sitter library for editing HEEx files. --- *** New major mode 'elixir-ts-mode'. A major mode based on the tree-sitter library for editing Elixir files. --- *** New major mode 'lua-ts-mode'. A major mode based on the tree-sitter library for editing Lua files. ** Minibuffer and Completions +++ *** New global minor mode 'minibuffer-regexp-mode'. This is a minor mode for editing regular expressions in the minibuffer. It highlights parens via ‘show-paren-mode’ and ‘blink-matching-paren’ in a user-friendly way, avoids reporting alleged paren mismatches and makes sexp navigation more intuitive. +++ *** New minor mode 'completion-preview-mode'. This minor mode shows you symbol completion suggestions as you type, using an inline preview. New user options in the 'completion-preview' customization group control exactly when Emacs displays this preview. --- ** The highly accessible Modus themes collection has eight items. The 'modus-operandi' and 'modus-vivendi' are the main themes that have been part of Emacs since version 28. The former is light, the latter dark. In addition to these, we now have 'modus-operandi-tinted' and 'modus-vivendi-tinted' for easier legibility, as well as 'modus-operandi-deuteranopia', 'modus-vivendi-deuteranopia', 'modus-operandi-tritanopia', and 'modus-vivendi-tritanopia' to cover the needs of users with red-green or blue-yellow color deficiency. The Info manual "(modus-themes) Top" describes the details and showcases all their customization options. * Incompatible Lisp Changes in Emacs 30.1 +++ ** 'M-TAB' now invokes 'completion-at-point' also in Text mode. Text mode no longer binds 'M-TAB' to 'ispell-complete-word', and instead this mode arranges for 'completion-at-point', globally bound to 'M-TAB', to perform word completion as well. If you want 'M-TAB' to invoke 'ispell-complete-word', as it did in previous Emacs versions, customize the new user option 'text-mode-meta-tab-ispell-complete-word' to non-nil. ** 'pp' and 'pp-to-string' now always include a terminating newline. In the past they included a terminating newline in most cases but not all. ** 'buffer-match-p' and 'match-buffers' take '&rest args'. They used to take a single '&optional arg' and were documented to use an unreliable hack to try and support condition predicates that don't accept this optional arg. The new semantics makes no such accommodation, but the code still supports it (with a warning) for backward compatibility. ** 'post-gc-hook' runs after updating 'gcs-done' and 'gcs-elapsed'. --- ** The escape sequence '\x' not followed by hex digits is now an error. Previously, '\x' without at least one hex digit denoted character code zero (NUL) but as this was neither intended nor documented or even known by anyone, it is now treated as an error by the Lisp reader. --- ** Connection-local variables are applied in buffers visiting a remote file. This overrides possible directory-local or file-local variables with the same name. --- ** User option 'tramp-completion-reread-directory-timeout' has been removed. This user option has been obsoleted in Emacs 27, use 'remote-file-name-inhibit-cache' instead. --- ** User options 'eshell-NAME-unload-hook' are now obsolete. These hooks were named incorrectly, and so they never actually ran when unloading the corresponding feature. Instead, you should use hooks named after the feature name, like 'esh-mode-unload-hook'. +++ ** 'copy-tree' now copies records when its optional 2nd argument is non-nil. +++ ** Regexp zero-width assertions followed by operators are better defined. Previously, regexps such as "xy\\B*" would have ill-defined behavior. Now any operator following a zero-width assertion applies to that assertion only (which is useless). For historical compatibility, an operator character following '^' or '\`' becomes literal, but we advise against relying on this. --- ** Mode-line mnemonics for some coding-systems have changed. The mode-line mnemonic for 'utf-7' is now the lowercase 'u', to be consistent with the other encodings of this family. The mode-line mnemonic for 'koi8-u' is now 'У', U+0423 CYRILLIC CAPITAL LETTER U, to distinguish between this encoding and the UTF-8/UTF-16 family. If your terminal cannot display 'У', or if you want to get the old behavior back for any other reason, you can do that using the 'coding-system-put' function. For example, the following restores the previous behavior of showing 'U' in the mode line for 'koi8-u': (coding-system-put 'koi8-u :mnemonic ?U) --- ** 'vietnamese-tcvn' is now a coding system alias for 'vietnamese-vscii'. VSCII-1 and TCVN-5712 are different names for the same character encoding. Therefore, the duplicate coding system definition has been dropped in favor of an alias. The mode-line mnemonic for 'vietnamese-vscii' and its aliases is the lowercase letter 'v'. +++ ** Infinities and NaNs no longer act as symbols on non-IEEE platforms. On old platforms like the VAX that do not support IEEE floating-point, tokens like 0.0e+NaN and 1.0e+INF are no longer read as symbols. Instead, the Lisp reader approximates an infinity with the nearest finite value, and a NaN with some other non-numeric object that provokes an error if used numerically. +++ ** X color support compatibility aliases are now marked obsolete. The compatibility aliases 'x-defined-colors', 'x-color-defined-p', 'x-color-values', and 'x-display-color-p' are now obsolete. +++ ** 'easy-mmode-define-{minor,global}-mode' aliases are now obsolete. Use 'define-minor-mode' and 'define-globalized-minor-mode' instead. ** The obsolete calling convention of 'sit-for' has been removed. That convention was: '(sit-for SECONDS MILLISEC &optional NODISP)'. ** The 'millisec' argument of 'sleep-for' has been declared obsolete. Use a float value for the first argument instead. ** 'eshell-process-wait-{seconds,milliseconds}' options are now obsolete. Instead, use 'eshell-process-wait-time', which supports floating-point values. * Lisp Changes in Emacs 30.1 +++ ** New variable 'lisp-eval-depth-reserve'. It puts a limit to the amount by which Emacs can temporarily increase 'max-lisp-eval-depth' when handling signals. +++ ** New special form 'handler-bind'. Provides a functionality similar to `condition-case` except it runs the handler code without unwinding the stack, such that we can record the backtrace and other dynamic state at the point of the error. +++ ** New 'pop-up-frames' action alist entry for 'display-buffer'. This has the same effect as the variable of the same name and takes precedence over the variable when present. ** New function 'merge-ordered-lists'. Mostly used internally to do a kind of topological sort of inheritance hierarchies. ** New API for 'derived-mode-p' and control of the graph of major modes. *** 'derived-mode-p' now takes the list of modes as a single argument. The same holds for 'provided-mode-derived-p'. The old calling convention where multiple modes are passed as separate arguments is deprecated. *** New functions to access the graph of major modes. While 'define-derived-mode' still only supports single inheritance, modes can declare additional parents (for tests like 'derived-mode-p') with 'derived-mode-add-parents'. Accessing the 'derived-mode-parent' property directly is now deprecated in favor of the new functions 'derived-mode-set-parent' and 'derived-mode-all-parents'. +++ ** Drag-and-drop functions can now be called once for compound drops. It is now possible for drag-and-drop handler functions to respond to drops incorporating more than one URL. Functions capable of this must set their 'dnd-multiple-handler' symbol properties to a non-nil value. See the Info node "(elisp) Drag and Drop". Incident to this change, the function 'dnd-handle-one-url' has been made obsolete, for it cannot take these new handlers into account. ** New function 're-disassemble' to see the innards of a regexp. If you compiled with '--enable-checking', you can use this to help debug either your regexp performance problems or the regexp engine. +++ ** XLFDs are no longer restricted to 255 characters. 'font-xlfd-name' now returns an XLFD even if it is greater than 255 characters in length, provided that the LONG_XLFDs argument is true. Other features in Emacs which employ XLFDs have been modified to produce and understand XLFDs larger than 255 characters. ** 'defadvice' is marked as obsolete. See the "(elisp) Porting Old Advice" Info node for help converting them to use 'advice-add' or 'define-advice' instead. ** 'cl-old-struct-compat-mode' is marked as obsolete. You may need to recompile our code if it was compiled with Emacs < 24.3. +++ ** New macro 'static-if' for conditional evaluation of code. This macro hides a form from the evaluator or byte-compiler based on a compile-time condition. This is handy for avoiding byte-compilation warnings about code that will never actually run under some conditions. +++ ** Desktop notifications are now supported on the Haiku operating system. The new function 'haiku-notifications-notify' provides a subset of the capabilities of the 'notifications-notify' function in a manner analogous to 'w32-notification-notify'. +++ ** New value 'if-regular' for the REPLACE argument to 'insert-file-contents'. It results in 'insert-file-contents' erasing the buffer instead of preserving markers if the file being inserted is not a regular file, rather than signaling an error. +++ ** New variable 'current-key-remap-sequence'. It is bound to the key sequence that caused a call to a function bound within 'function-key-map' or 'input-decode-map' around those calls. +++ ** New variables describing the names of built in programs. The new variables 'ctags-program-name', 'ebrowse-program-name', 'etags-program-name', 'hexl-program-name', 'emacsclient-program-name' 'movemail-program-name', and 'rcs2log-program-name' should be used instead of "ctags", "ebrowse", "etags", "hexl", "emacsclient", and "rcs2log", when starting one of these built in programs in a subprocess. +++ ** New variable 'case-symbols-as-words' affects case operations for symbols. If non-nil, then case operations such as 'upcase-initials' or 'replace-match' (with nil FIXEDCASE) will treat the entire symbol name as a single word. This is useful for programming languages and styles where only the first letter of a symbol's name is ever capitalized. The default value of this variable is nil. +++ ** 'x-popup-menu' now understands touch screen events. When a 'touchscreen-begin' or 'touchscreen-end' event is passed as the POSITION argument, it will behave as if that event was a mouse event. +++ ** New functions for handling touch screen events. The new functions 'touch-screen-track-tap' and 'touch-screen-track-drag' handle tracking common touch screen gestures from within a command. ** New user option 'safe-local-variable-directories'. This user option names directories in which Emacs will treat all directory-local variables as safe. +++ ** New parameter to 'touchscreen-end' events. CANCEL non-nil establishes that the touch sequence has been intercepted by programs such as window managers and should be ignored with Emacs. ** New variable 'inhibit-auto-fill' to temporarily prevent auto-fill. +++ ** New variable 'secondary-tool-bar-map'. If non-nil, this variable contains a keymap of menu items that are displayed along tool bar items inside 'tool-bar-map'. ** New variable 'completion-lazy-hilit'. Lisp programs that present completion candidates may bind this variable non-nil around calls to functions such as 'completion-all-completions'. This tells the underlying completion styles to skip eager fontification of completion candidates, which improves performance. Such a Lisp program can then use the 'completion-lazy-hilit' function to fontify candidates just in time. ** Functions and variables to transpose sexps +++ *** New helper variable 'transpose-sexps-function'. Emacs now can set this variable to customize the behavior of the 'transpose-sexps' function. +++ *** New function 'transpose-sexps-default-function'. The previous implementation is moved into its own function, to be bound by 'transpose-sexps-function'. *** New function 'treesit-transpose-sexps'. Tree-sitter now unconditionally sets 'transpose-sexps-function' for all tree-sitter enabled modes. This functionality utilizes the new 'transpose-sexps-function'. ** Functions and variables to move by program statements *** New variable 'forward-sentence-function'. Major modes can now set this variable to customize the behavior of the 'forward-sentence' command. *** New function 'forward-sentence-default-function'. The previous implementation of 'forward-sentence' is moved into its own function, to be bound by 'forward-sentence-function'. *** New function 'treesit-forward-sentence'. All tree-sitter enabled modes that define 'sentence' in 'treesit-thing-settings' now set 'forward-sentence-function' to call 'treesit-forward-sentence'. ** Functions and variables to move by program sexps *** New function 'treesit-forward-sexp'. Tree-sitter conditionally sets 'forward-sexp-function' for major modes that have defined 'sexp' in 'treesit-thing-settings' to enable sexp-related motion commands. ** New or changed byte-compilation warnings --- *** Warn about missing 'lexical-binding' directive. The compiler now warns if an Elisp file lacks the standard '-*- lexical-binding: ... -*-' cookie on the first line. This line typically looks something like ;;; My little pony mode -*- lexical-binding: t -*- It is needed to inform the compiler about which dialect of ELisp your code is using: the modern dialect with lexical binding or the old dialect with only dynamic binding. Lexical binding avoids some name conflicts and allows the compiler to detect more mistakes and generate more efficient code, so it is recommended. For how to adapt your code to lexical binding, see the manual section "(elisp) Converting to Lexical Binding". If your code cannot be converted to lexical binding, you can insert the line ;;; -*- lexical-binding: nil -*- first in the file to declare that it uses the old dialect. --- *** Warn about empty bodies for more special forms and macros. The compiler now warns about an empty body argument to 'when', 'unless', 'ignore-error' and 'with-suppressed-warnings' in addition to the existing warnings for 'let' and 'let*'. Example: (when (> x 2)) This warning can be suppressed using 'with-suppressed-warnings' with the warning name 'empty-body'. --- *** Warn about quoted error names in 'condition-case' and 'ignore-error'. The compiler now warns about quoted condition (error) names in 'condition-case' and 'ignore-error'. Example: (condition-case nil (/ x y) ('arith-error "division by zero")) Quoting them adds the error name 'quote' to those handled or ignored respectively, which was probably not intended. --- *** Warn about comparison with literal constants without defined identity. The compiler now warns about comparisons by identity with a literal string, cons, vector, record, function, large integer or float as this may not match any value at all. Example: (eq x "hello") Only literals for symbols and small integers (fixnums), including characters, are guaranteed to have a consistent (unique) identity. This warning applies to 'eq', 'eql', 'memq', 'memql', 'assq', 'rassq', 'remq' and 'delq'. To compare by (structural) value, use 'equal', 'member', 'assoc', 'rassoc', 'remove' or 'delete' instead. Floats and bignums can also be compared using 'eql', '=' and 'memql'. Function literals cannot be compared reliably at all. This warning can be suppressed using 'with-suppressed-warnings' with the warning name 'suspicious'. --- *** Warn about 'condition-case' without handlers. The compiler now warns when the 'condition-case' form is used without any actual handlers, as in (condition-case nil (read buffer)) because it has no effect other than the execution of the body form. In particular, no errors are caught or suppressed. If the intention was to catch all errors, add an explicit handler for 'error', or use 'ignore-error' or 'ignore-errors'. This warning can be suppressed using 'with-suppressed-warnings' with the warning name 'suspicious'. --- *** Warn about 'unwind-protect' without unwind forms. The compiler now warns when the 'unwind-protect' form is used without any unwind forms, as in (unwind-protect (read buffer)) because the behavior is identical to that of the argument; there is no protection of any kind. Perhaps the intended unwind forms have been misplaced or forgotten, or the use of 'unwind-protect' could be simplified away. This warning can be suppressed using 'with-suppressed-warnings' with the warning name 'suspicious'. --- *** Warn about useless trailing 'cond' clauses. The compiler now warns when a 'cond' form contains clauses following a default (unconditional) clause. Example: (cond ((= x 0) (say "none")) (t (say "some")) (say "goodbye")) Such a clause will never be executed but is likely to be a mistake, perhaps due to misplaced brackets. This warning can be suppressed using 'with-suppressed-warnings' with the warning name 'suspicious'. --- *** Warn about mutation of constant values. The compiler now warns about code that modifies program constants in some obvious cases. Examples: (setcar '(1 2) 7) (aset [3 4] 0 8) (aset "abc" 1 ?d) Such code may have unpredictable behavior because the constants are part of the program, not data structures generated afresh during execution, and the compiler does not expect them to change. To avoid the warning, operate on an object created by the program (maybe a copy of the constant), or use a non-destructive operation instead. This warning can be suppressed using 'with-suppressed-warnings' with the warning name 'mutate-constant'. --- *** Warn about more ignored function return values. The compiler now warns when the return value from certain functions is implicitly ignored. Example: (progn (nreverse my-list) my-list) will elicit a warning because it is usually pointless to call 'nreverse' on a list without using the returned value. To silence the warning, make use of the value in some way, such as assigning it to a variable. You can also wrap the function call in '(ignore ...)', or use 'with-suppressed-warnings' with the warning name 'ignored-return-value'. The warning will only be issued for calls to functions declared 'important-return-value' or 'side-effect-free' (but not 'error-free'). --- *** The warning about wide docstrings can now be disabled separately. Its warning name is 'docstrings-wide'. +++ ** New function declaration and property 'important-return-value'. The declaration '(important-return-value t)' sets the 'important-return-value' property which indicates that the function return value should probably not be thrown away implicitly. +++ ** New functions 'file-user-uid' and 'file-group-gid'. These functions are like 'user-uid' and 'group-gid', respectively, but are aware of file name handlers, so they will return the remote UID or GID for remote files (or -1 if the connection has no associated user). +++ ** 'fset', 'defalias' and 'defvaralias' now signal an error for cyclic aliases. Previously, 'fset', 'defalias' and 'defvaralias' could be made to build circular function and variable indirection chains as in (defalias 'able 'baker) (defalias 'baker 'able) but trying to use them would sometimes make Emacs hang. Now, an attempt to create such a loop results in an error. Since circular alias chains now cannot occur, 'function-alias-p', 'indirect-function' and 'indirect-variable' will never signal an error. Their 'noerror' arguments have no effect and are therefore obsolete. +++ ** 'treesit-font-lock-rules' now accepts additional global keywords. When supplied with ':default-language LANGUAGE', rules after it will default to use 'LANGUAGE'. --- ** New optional argument to 'modify-dir-local-variable'. A 5th argument, optional, has been added to 'modify-dir-local-variable'. It can be used to specify which dir-locals file to modify. ** Connection local variables +++ *** New macros 'connection-local-p' and 'connection-local-value'. The former macro returns non-nil if a variable has a connection-local binding. The latter macro returns the connection-local value of a variable if any, or its current value. * Changes in Emacs 30.1 on Non-Free Operating Systems ---------------------------------------------------------------------- This file is part of GNU Emacs. GNU Emacs is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. GNU Emacs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Emacs. If not, see . Local variables: coding: utf-8 mode: outline mode: emacs-news paragraph-separate: "[ ]" end: