mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-21 10:24:55 +00:00
ecc6530da9
Let makeinfo figure them out, as is recommended.
141 lines
5.5 KiB
Plaintext
141 lines
5.5 KiB
Plaintext
@c -*-texinfo-*-
|
|
@c This is part of the GNU Emacs Lisp Reference Manual.
|
|
@c Copyright (C) 1999, 2002-2012 Free Software Foundation, Inc.
|
|
@c See the file elisp.texi for copying conditions.
|
|
|
|
@c This node must have no pointers.
|
|
|
|
@node Antinews
|
|
@appendix Emacs 23 Antinews
|
|
@c Update the elisp.texi Antinews menu entry with the above version number.
|
|
|
|
For those users who live backwards in time, here is information about
|
|
downgrading to Emacs version 23.4. We hope you will enjoy the greater
|
|
simplicity that results from the absence of many Emacs @value{EMACSVER}
|
|
features.
|
|
|
|
@section Old Lisp Features in Emacs 23
|
|
|
|
@itemize @bullet
|
|
@item
|
|
Support for lexical scoping has been removed; all variables are
|
|
dynamically scoped. The @code{lexical-binding} variable has been
|
|
removed, and so has the @var{lexical} argument to @code{eval}. The
|
|
@code{defvar} and @code{defconst} forms no longer mark variables as
|
|
dynamic, since all variables are dynamic.
|
|
|
|
Having only dynamic binding follows the spirit of Emacs extensibility,
|
|
for it allows any Emacs code to access any defined variable with a
|
|
minimum of fuss. But @xref{Dynamic Binding Tips}, for tips to avoid
|
|
making your programs hard to understand.
|
|
|
|
@item
|
|
Calling a minor mode function from Lisp with a nil or omitted argument
|
|
does not enable the minor mode unconditionally; instead, it toggles
|
|
the minor mode---which is the straightforward thing to do, since that
|
|
is the behavior when invoked interactively. One downside is that it
|
|
is more troublesome to enable minor modes from hooks; you have to do
|
|
something like
|
|
|
|
@example
|
|
(add-hook 'foo-hook (lambda () (bar-mode 1)))
|
|
@end example
|
|
|
|
@noindent
|
|
or define @code{turn-on-bar-mode} and call that from the hook.
|
|
|
|
@item
|
|
The @code{prog-mode} dummy major mode has been removed. Instead of
|
|
using it as a crutch to meet programming mode conventions, you should
|
|
explicitly ensure that your mode follows those conventions.
|
|
@xref{Major Mode Conventions}.
|
|
|
|
@item
|
|
Emacs no longer supports bidirectional display and editing. Since
|
|
there is no need to worry about the insertion of right-to-left text
|
|
messing up how lines and paragraphs are displayed, the function
|
|
@code{bidi-string-mark-left-to-right} has been removed; so have many
|
|
other functions and variables related to bidirectional display.
|
|
Unicode directionality characters like @code{U+200E} ("left-to-right
|
|
mark") have no special effect on display.
|
|
|
|
@item
|
|
Emacs windows now have most of their internal state hidden from Lisp.
|
|
Internal windows are no longer visible to Lisp; functions such as
|
|
@code{window-parent}, window parameters related to window arrangement,
|
|
and window-local buffer lists have all been removed. Functions for
|
|
resizing windows can delete windows if they become too small.
|
|
|
|
The ``action function'' feature for controlling buffer display has
|
|
been removed, including @code{display-buffer-overriding-action} and
|
|
related variables, as well as the @var{action} argument to
|
|
@code{display-buffer} and other functions. The way to
|
|
programmatically control how Emacs chooses a window to display a
|
|
buffer is to bind the right combination of
|
|
@code{special-display-regexps}, @code{pop-up-frames}, and other
|
|
variables.
|
|
|
|
@item
|
|
The standard completion interface has been simplified, eliminating the
|
|
@code{completion-extra-properties} variable, the @code{metadata}
|
|
action flag for completion functions, and the concept of
|
|
``completion categories''. Lisp programmers may now find the choice
|
|
of methods for tuning completion less bewildering, but if a package
|
|
finds the streamlined interface insufficient for its needs, it must
|
|
implement its own specialized completion feature.
|
|
|
|
@item
|
|
@code{copy-directory} now behaves the same whether or not the
|
|
destination is an existing directory: if the destination exists, the
|
|
@emph{contents} of the first directory are copied into it (with
|
|
subdirectories handled recursively), rather than copying the first
|
|
directory into a subdirectory.
|
|
|
|
@item
|
|
The @var{trash} arguments for @code{delete-file} and
|
|
@code{delete-directory} have been removed. The variable
|
|
@code{delete-by-moving-to-trash} must now be used with care; whenever
|
|
it is non-@code{nil}, all calls to @code{delete-file} or
|
|
@code{delete-directory} use the trash.
|
|
|
|
@item
|
|
Because Emacs no longer supports SELinux file contexts, the
|
|
@var{preserve-selinux-context} argument to @code{copy-file} has been
|
|
removed. The return value of @code{backup-buffer} no longer has an
|
|
entry for the SELinux file context.
|
|
|
|
@item
|
|
For mouse click input events in the text area, the Y pixel coordinate
|
|
in the @var{position} list (@pxref{Click Events}) now counts from the
|
|
top of the header line, if there is one, rather than the top of the
|
|
text area.
|
|
|
|
@item
|
|
Bindings in menu keymaps (@pxref{Format of Keymaps}) now sometimes get
|
|
an additional @var{cache} entry in their definitions, like this:
|
|
|
|
@example
|
|
(@var{type} @var{item-name} @var{cache} . @var{binding})
|
|
@end example
|
|
|
|
@noindent
|
|
The @var{cache} entry is used internally by Emacs to record equivalent
|
|
keyboard key sequences for invoking the same command; Lisp programs
|
|
should never use it.
|
|
@c Not really NEWS-worthy then...
|
|
|
|
@item
|
|
The @code{gnutls} library has been removed, and the function
|
|
@code{open-network-stream} correspondingly simplified.
|
|
Lisp programs that want an encrypted network connection must now call
|
|
external utilities such as @command{starttls} or @command{gnutls-cli}.
|
|
|
|
@item
|
|
Tool bars can no longer display separators, which frees up several
|
|
pixels of space on each graphical frame.
|
|
|
|
@item
|
|
As part of the ongoing quest for simplicity, many other functions and
|
|
variables have been eliminated.
|
|
@end itemize
|