@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
@c Copyright (C) 1999, 2002-2011  Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.

@c This node must have no pointers.

@node Antinews, GNU Free Documentation License, Packaging, Top
@appendix Emacs 22 Antinews
@c Update the elisp.texi, vol1.texi, vol2.texi Antinews menu entries
@c with the above version number.

For those users who live backwards in time, here is information about
downgrading to Emacs version 22.3.  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 22

@itemize @bullet
@item
The internal character representation used by Emacs is not longer
based on Unicode.  In this representation, called @code{emacs-mule},
each character belongs to one and only one script.  Emacs makes no
attempt to distinguish between ``similar'' characters occurring in
different scripts.

@item
The @code{^} interactive spec code, the function
@code{handle-shift-selection}, and the variable
@code{this-command-keys-shift-translated} have all been removed.
Shift-translated keys are no longer treated specially, making Emacs'
handling of keybindings much more consistent.

@item
Temporarily-active regions are not created by giving the variable
@code{transient-mark-mode} values of the form @code{(only
. @var{oldvar})}.  We instead use a more complicated scheme:
setting @code{transient-mark-mode} to @code{only} enables Transient
Mark mode for the following command only, during which the value of
@code{transient-mark-mode} is set to @code{identity}; if it is still
@code{identity} at the end of the command, Transient Mark mode is
disabled.

@item
Many minibuffer functions, such as @code{read-file-name} and
@code{minibuffer-complete}, have been rewritten in C for greater
speed.  The completion code has been considerably simplified; the
completion style can no longer be changed via
@code{completion-styles-alist}, and @code{completing-read} no longer
recognizes the special values @code{confirm-only} and
@code{confirm-after-completion} for its @var{require-match} argument.

@item
Emacs no longer supports explicitly-numbered groups in regular
expressions.

@item
The @code{permanent-local-hook} function property has no special
meaning.

@item
The @code{functionp} function now returns @code{t} for special forms.

@item
The @code{interactive-form} symbol property has no special meaning.
Once you supply a function with an interactive form, the only way to
change it is to redefine the function.

@item
The @code{ignore-errors} macro has been moved into the @code{cl}
package.

@item
Variables can now be both buffer-local and frame-local; buffer-local
bindings take precedence over frame-local bindings.

@item
Faces can no longer be remapped.

@item
Lisp programs now specify fonts by their names, which are strings
following the XLFD (X logical font descriptor) format.  Fonts are no
longer represented using a special set of ``font'' data types.  The
various functions that act on these data types, such as @code{fontp},
@code{font-spec}, and @code{list-fonts}, have all been deleted.

@item
Emacs does not recognize the @code{FontBackend} X resource and the
@code{font-backend} frame parameter.  On the X Window System, fonts
are always drawn using the X core font driver.

@item
Display terminals are no longer represented using a ``terminal'' data
type; this is not necessary, because we have removed the ability to
display on graphical and text-only terminals simultaneously.  For the
same reason, the @code{window-system} variable is no longer
frame-local, and the @code{window-system} function has been removed.

@item
The functions @code{list-system-processes} and
@code{process-attributes} have been removed.  To get information about
system processes, call an external program, such as @command{ps}.

@item
The function @code{locate-user-emacs-file} and the variable
@code{user-emacs-directory} have been removed.  Instead, use
hard-coded values pointing to @file{~/.emacs.d}.

@item
@code{vertical-motion} can no longer be told to move to a specific
column; it always puts point on the first column of a line.

@item
Windows no longer have parameters.

@item
The @code{display-buffer} function has been rewritten in C.  Its
window-splitting heuristics are a little less sophisticated, and a
little less documented.  Window-splitting is handled internally,
instead of using @code{split-window-preferred-function} (which has
been removed).  Windows are never split horizontally; the variable
@code{split-width-threshold} has been removed.

@item
The @code{mode-name} variable now accepts only string values, and
cannot take the form of a mode-line construct.

@item
The behavior of @code{map-char-table} has changed.  It calls the
mapping function for every single character in the table, instead of
using cons cells to represent contiguous character code ranges.

@item
Several keymaps have been eliminated: @code{input-decode-map},
@code{local-function-key-map}, @code{search-map},
@code{multi-query-replace-map}, and
@code{minibuffer-local-shell-command-map}.

@item
Many functions have been removed, including: @code{buffer-swap-text},
@code{emacs-init-time}, @code{emacs-uptime}, @code{use-region-p},
@code{region-active-p}, @code{start-file-process},
@code{process-lines}, @code{image-refresh},
@code{match-substitute-replacement}, @code{word-search-forward-lax},
and @code{word-search-backward-lax}.

@item
Many variables have been removed, including @code{read-circle},
@code{after-init-time} and @code{before-init-time},
@code{generate-autoload-cookie}, @code{file-local-variables-alist},
@code{replace-search-function} and @code{replace-re-search-function},
@code{inhibit-changing-match-data}, @code{wrap-prefix}, and
@code{line-prefix},
@end itemize
