emacs/etc/NEWS

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


* Startup Changes in Emacs 30.1


* Changes in Emacs 30.1

** 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.

+++
** '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 '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'.


* Editing Changes in Emacs 30.1

---
** 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.


* Changes in Specialized Modes and Packages in Emacs 30.1

---
** 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)))

** Compile

*** 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.

** VC

---
*** 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.

** 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".

** 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 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.

+++
*** 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 now uses 'field' properties in its output.
In particular, this means that pressing the '<home>' 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 "<home>" #'eshell-bol-ignoring-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.

** 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.

** Tramp

+++
*** New connection method "toolbox".
This allows accessing system containers provided by Toolbox.

+++
*** New value 'suppress' for user option 'tramp-use-ssh-controlmaster-options'.
This user option allows now the values t, nil, and 'suppress'.  The
latter suppresses also "ControlMaster" settings in the user's
"~/.ssh/config" file.

** 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.

** 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, call the 'man' program synchronously rather than
asynchronously (which is the default behavior).


* 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.

---
** The highly accessible Modus themes collection has six 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' and 'modus-vivendi-deuteranopia' to
cover the needs of users with red-green color deficiency.  The Info
manual "(modus-themes) Top" describes the details and showcases all
their customization options.


* Incompatible Lisp Changes in Emacs 30.1

** 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 correspending feature.  Instead, you should use
hooks named after the feature name, like 'esh-mode-unload-hook'.


* Lisp Changes in Emacs 30.1

** 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 buffer-local variable 'treesit-sentence-type-regexp'.
Similarly to 'treesit-defun-type-regexp', this variable is used to
define "sentences" in tree-sitter enabled modes.

*** New function 'treesit-forward-sentence'.
All tree-sitter enabled modes that define 'treesit-sentence-type-regexp'
now set 'forward-sentence-function' to call 'treesit-forward-sentence'.

** Functions and variables to move by program sexps

*** New buffer-local variable 'treesit-sexp-type-regexp'.
Similarly to 'treesit-defun-type-regexp', this variable is used to
define "sexps" in tree-sitter enabled modes.

*** New function 'treesit-forward-sexp'.
Tree-sitter conditionally sets 'forward-sexp-function' for major modes
that have defined 'treesit-sexp-type-regexp' to enable sexp-related
motion commands.

** New or changed byte-compilation warnings

---
*** 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'.

+++
** New function 'file-user-uid'.
This function is like 'user-uid', but is aware of file name handlers,
so it will return the remote UID for remote files (or -1 if the
connection has no associated user).

+++
** 'fset' and 'defalias' now signal an error for circular alias chains.
Previously, 'fset' and 'defalias' could be made to build circular
function indirection chains as in

    (defalias 'able 'baker)
    (defalias 'baker 'able)

but trying to call them would often 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' and
'indirect-function' will never signal an error.  Their second
'noerror' arguments have no effect and are therefore obsolete.


* 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 <https://www.gnu.org/licenses/>.


Local variables:
coding: utf-8
mode: outline
mode: emacs-news
paragraph-separate: "[	 ]"
end: