view man/xemacs/new.texi @ 5353:38e24b8be4ea

Improve the lexical scoping in #'block, #'return-from. lisp/ChangeLog addition: 2011-02-07 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el: * bytecomp.el (byte-compile-initial-macro-environment): Shadow `block', `return-from' here, we implement them differently when byte-compiling. * bytecomp.el (byte-compile-active-blocks): New. * bytecomp.el (byte-compile-block-1): New. * bytecomp.el (byte-compile-return-from-1): New. * bytecomp.el (return-from-1): New. * bytecomp.el (block-1): New. These are two aliases that exist to have their own associated byte-compile functions, which functions implement `block' and `return-from'. * cl-extra.el (cl-macroexpand-all): Fix a bug here when macros in the environment have been compiled. * cl-macs.el (block): * cl-macs.el (return): * cl-macs.el (return-from): Be more careful about lexical scope in these macros. * cl.el: * cl.el ('cl-block-wrapper): Removed. * cl.el ('cl-block-throw): Removed. These aren't needed in code generated by this XEmacs. They shouldn't be needed in code generated by XEmacs 21.4, but if it turns out the packages do need them, we can put them back. 2011-01-30 Mike Sperber <mike@xemacs.org> * font-lock.el (font-lock-fontify-pending-extents): Don't fail if `font-lock-mode' is unset, which can happen in the middle of `revert-buffer'. 2011-01-23 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (delete): * cl-macs.el (delq): * cl-macs.el (remove): * cl-macs.el (remq): Don't use the compiler macro if these functions were given the wrong number of arguments, as happens in lisp-tests.el. * cl-seq.el (remove, remq): Removed. I added these to subr.el, and forgot to remove them from here. 2011-01-22 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el (byte-compile-setq, byte-compile-set): Remove kludge allowing keywords' values to be set, all the code that does that is gone. * cl-compat.el (elt-satisfies-test-p): * faces.el (set-face-parent): * faces.el (face-doc-string): * gtk-font-menu.el: * gtk-font-menu.el (gtk-reset-device-font-menus): * msw-font-menu.el: * msw-font-menu.el (mswindows-reset-device-font-menus): * package-get.el (package-get-installedp): * select.el (select-convert-from-image-data): * sound.el: * sound.el (load-sound-file): * x-font-menu.el (x-reset-device-font-menus-core): Don't quote keywords, they're self-quoting, and the win from backward-compatibility is sufficiently small now that the style problem overrides it. 2011-01-22 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (block, return-from): Require that NAME be a symbol in these macros, as always documented in the #'block docstring and as required by Common Lisp. * descr-text.el (unidata-initialize-unihan-database): Correct the use of non-symbols in #'block and #'return-from in this function. 2011-01-15 Aidan Kehoe <kehoea@parhasard.net> * cl-extra.el (concatenate): Accept more complicated TYPEs in this function, handing the sequences over to #'coerce if we don't understand them here. * cl-macs.el (inline): Don't proclaim #'concatenate as inline, its compiler macro is more useful than doing that. 2011-01-11 Aidan Kehoe <kehoea@parhasard.net> * subr.el (delete, delq, remove, remq): Move #'remove, #'remq here, they don't belong in cl-seq.el; move #'delete, #'delq here from fns.c, implement them in terms of #'delete*, allowing support for sequences generally. * update-elc.el (do-autoload-commands): Use #'delete*, not #'delq here, now the latter's no longer dumped. * cl-macs.el (delete, delq): Add compiler macros transforming #'delete and #'delq to #'delete* calls. 2011-01-10 Aidan Kehoe <kehoea@parhasard.net> * dialog.el (make-dialog-box): Correct a misplaced parenthesis here, thank you Mats Lidell in 87zkr9gqrh.fsf@mail.contactor.se ! 2011-01-02 Aidan Kehoe <kehoea@parhasard.net> * dialog.el (make-dialog-box): * list-mode.el (display-completion-list): These functions used to use cl-parsing-keywords; change them to use defun* instead, fixing the build. (Not sure what led to me not including this change in d1b17a33450b!) 2011-01-02 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (define-star-compiler-macros): Make sure the form has ITEM and LIST specified before attempting to change to calls with explicit tests; necessary for some tests in lisp-tests.el to compile correctly. (stable-union, stable-intersection): Add compiler macros for these functions, in the same way we do for most of the other functions in cl-seq.el. 2011-01-01 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (dolist, dotimes, do-symbols, macrolet) (symbol-macrolet): Define these macros with defmacro* instead of parsing the argument list by hand, for the sake of style and readability; use backquote where appropriate, instead of calling #'list and and friends, for the same reason. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * x-misc.el (device-x-display): Provide this function, documented in the Lispref for years, but not existing previously. Thank you Julian Bradfield, thank you Jeff Mincy. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * cl-seq.el: Move the heavy lifting from this file to C. Dump the cl-parsing-keywords macro, but don't use defun* for the functions we define that do take keywords, dynamic scope lossage makes that not practical. * subr.el (sort, fillarray): Move these aliases here. (map-plist): #'nsublis is now built-in, but at this point #'eql isn't necessarily available as a test; use #'eq. * obsolete.el (cl-delete-duplicates): Make this available for old compiler macros and old code. (memql): Document that this is equivalent to #'member*, and worse. * cl.el (adjoin, subst): Removed. These are in C. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * simple.el (assoc-ignore-case): Remove a duplicate definition of this function (it's already in subr.el). * iso8859-1.el (char-width): On non-Mule, make this function equivalent to that produced by (constantly 1), but preserve its docstring. * subr.el (subst-char-in-string): Define this in terms of #'substitute, #'nsubstitute. (string-width): Define this using #'reduce and #'char-width. (char-width): Give this a simpler definition, it makes far more sense to check for mule at load time and redefine, as we do in iso8859-1.el. (store-substring): Implement this in terms of #'replace, now #'replace is cheap. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * update-elc.el (lisp-files-needed-for-byte-compilation) (lisp-files-needing-early-byte-compilation): cl-macs belongs in the former, not the latter, it is as fundamental as bytecomp.el. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * cl.el: Provde the Common Lisp program-error, type-error as error symbols. This doesn't nearly go far enough for anyone using the Common Lisp errors. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (delete-duplicates): If the form has an incorrect number of arguments, don't attempt a compiler macroexpansion. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (cl-safe-expr-p): Forms that start with the symbol lambda are also safe. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (= < > <= >=): For these functions' compiler macros, the optimisation is safe even if the first and the last arguments have side effects, since they're only used the once. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (inline-side-effect-free-compiler-macros): Unroll a loop here at macro-expansion time, so these compiler macros are compiled. Use #'eql instead of #'eq in a couple of places for better style. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-extra.el (notany, notevery): Avoid some dynamic scope stupidity with local variable names in these functions, when they weren't prefixed with cl-; go into some more detail in the doc strings. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * byte-optimize.el (side-effect-free-fns): #'remove, #'remq are free of side-effects. (side-effect-and-error-free-fns): Drop dot, dot-marker from the list. 2010-11-17 Aidan Kehoe <kehoea@parhasard.net> * cl-extra.el (coerce): In the argument list, name the first argument OBJECT, not X; the former name was always used in the doc string and is clearer. Handle vector type specifications which include the length of the target sequence, error if there's a mismatch. * cl-macs.el (cl-make-type-test): Handle type specifications starting with the symbol 'eql. 2010-11-14 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (eql): Don't remove the byte-compile property of this symbol. That was necessary to override a bug in bytecomp.el where #'eql was confused with #'eq, which bug we no longer have. If neither expression is constant, don't attempt to handle the expression in this compiler macro, leave it to byte-compile-eql, which produces better code anyway. * bytecomp.el (eq): #'eql is not the function associated with the byte-eq byte code. (byte-compile-eql): Add an explicit compile method for this function, for cases where the cl-macs compiler macro hasn't reduced it to #'eq or #'equal. 2010-10-25 Aidan Kehoe <kehoea@parhasard.net> Add compiler macros and compilation sanity-checking for various functions that take keywords. * byte-optimize.el (side-effect-free-fns): #'symbol-value is side-effect free and not error free. * bytecomp.el (byte-compile-normal-call): Check keyword argument lists for sanity; store information about the positions where keyword arguments start using the new byte-compile-keyword-start property. * cl-macs.el (cl-const-expr-val): Take a new optional argument, cl-not-constant, defaulting to nil, in this function; return it if the expression is not constant. (cl-non-fixnum-number-p): Make this into a separate function, we want to pass it to #'every. (eql): Use it. (define-star-compiler-macros): Use the same code to generate the member*, assoc* and rassoc* compiler macros; special-case some code in #'add-to-list in subr.el. (remove, remq): Add compiler macros for these two functions, in preparation for #'remove being in C. (define-foo-if-compiler-macros): Transform (remove-if-not ...) calls to (remove ... :if-not) at compile time, which will be a real win once the latter is in C. (define-substitute-if-compiler-macros) (define-subst-if-compiler-macros): Similarly for these functions. (delete-duplicates): Change this compiler macro to use #'plists-equal; if we don't have information about the type of SEQUENCE at compile time, don't bother attempting to inline the call, the function will be in C soon enough. (equalp): Remove an old commented-out compiler macro for this, if we want to see it it's in version control. (subst-char-in-string): Transform this to a call to nsubstitute or nsubstitute, if that is appropriate. * cl.el (ldiff): Don't call setf here, this makes for a load-time dependency problem in cl-macs.el 2010-06-14 Stephen J. Turnbull <stephen@xemacs.org> * term/vt100.el: Refer to XEmacs, not GNU Emacs, in permissions. * term/bg-mouse.el: * term/sup-mouse.el: Put copyright notice in canonical "Copyright DATE AUTHOR" form. Refer to XEmacs, not GNU Emacs, in permissions. * site-load.el: Add permission boilerplate. * mule/canna-leim.el: * alist.el: Refer to XEmacs, not APEL/this program, in permissions. * mule/canna-leim.el: Remove my copyright, I've assigned it to the FSF. 2010-06-14 Stephen J. Turnbull <stephen@xemacs.org> * gtk.el: * gtk-widget-accessors.el: * gtk-package.el: * gtk-marshal.el: * gtk-compose.el: * gnome.el: Add copyright notice based on internal evidence. 2010-06-14 Stephen J. Turnbull <stephen@xemacs.org> * easymenu.el: Add reference to COPYING to permission notice. * gutter.el: * gutter-items.el: * menubar-items.el: Fix typo "Xmacs" in permissions notice. 2010-06-14 Stephen J. Turnbull <stephen@xemacs.org> * auto-save.el: * font.el: * fontconfig.el: * mule/kinsoku.el: Add "part of XEmacs" text to permission notice. 2010-10-14 Aidan Kehoe <kehoea@parhasard.net> * byte-optimize.el (side-effect-free-fns): * cl-macs.el (remf, getf): * cl-extra.el (tailp, cl-set-getf, cl-do-remf): * cl.el (ldiff, endp): Tighten up Common Lisp compatibility for #'ldiff, #'endp, #'tailp; add circularity checking for the first two. #'cl-set-getf and #'cl-do-remf were Lisp implementations of #'plist-put and #'plist-remprop; change the names to aliases, changes the macros that use them to using #'plist-put and #'plist-remprop directly. 2010-10-12 Aidan Kehoe <kehoea@parhasard.net> * abbrev.el (fundamental-mode-abbrev-table, global-abbrev-table): Create both these abbrev tables using the usual #'define-abbrev-table calls, rather than attempting to special-case them. * cl-extra.el: Force cl-macs to be loaded here, if cl-extra.el is being loaded interpreted. Previously other, later files would redundantly call (load "cl-macs") when interpreted, it's more reasonable to do it here, once. * cmdloop.el (read-quoted-char-radix): Use defcustom here, we don't have any dump-order dependencies that would prevent that. * custom.el (eval-when-compile): Don't load cl-macs when interpreted or when byte-compiling, rely on cl-extra.el in the former case and the appropriate entry in bytecomp-load-hook in the latter. Get rid of custom-declare-variable-list, we have no dump-time dependencies that would require it. * faces.el (eval-when-compile): Don't load cl-macs when interpreted or when byte-compiling. * packages.el: Remove some inaccurate comments. * post-gc.el (cleanup-simple-finalizers): Use #'delete-if-not here, now the order of preloaded-file-list has been changed to make it available. * subr.el (custom-declare-variable-list): Remove. No need for it. Also remove a stub define-abbrev-table from this file, given the current order of preloaded-file-list there's no need for it. 2010-10-10 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el (byte-compile-constp) Forms quoted with FUNCTION are also constant. (byte-compile-initial-macro-environment): In #'the, if FORM is constant and does not match TYPE, warn at byte-compile time. 2010-10-10 Aidan Kehoe <kehoea@parhasard.net> * backquote.el (bq-vector-contents, bq-list*): Remove; the former is equivalent to (append VECTOR nil), the latter to (list* ...). (bq-process-2): Use (append VECTOR nil) instead of using #'bq-vector-contents to convert to a list. (bq-process-1): Now we use list* instead of bq-list * subr.el (list*): Moved from cl.el, since it is now required to be available the first time a backquoted form is encountered. * cl.el (list*): Move to subr.el. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * test-harness.el (Check-Message): Add an omitted comma here, thank you the buildbot. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * hash-table.el (hash-table-key-list, hash-table-value-list) (hash-table-key-value-alist, hash-table-key-value-plist): Remove some useless #'nreverse calls in these files; our hash tables have no order, it's not helpful to pretend they do. * behavior.el (read-behavior): Do the same in this file, in some code evidently copied from hash-table.el. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * info.el (Info-insert-dir): * format.el (format-deannotate-region): * files.el (cd, save-buffers-kill-emacs): Use #'some, #'every and related functions for applying boolean operations to lists, instead of rolling our own ones that cons and don't short-circuit. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el (byte-compile-initial-macro-environment): * cl-macs.el (the): Rephrase the docstring, make its implementation when compiling files a little nicer. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * descr-text.el (unidata-initialize-unicodedata-database) (unidata-initialize-unihan-database, describe-char-unicode-data) (describe-char-unicode-data): Wrap calls to the database functions with (with-fboundp ...), avoiding byte compile warnings on builds without support for the database functions. (describe-char): (reduce #'max ...), not (apply #'max ...), no need to cons needlessly. (describe-char): Remove a redundant lambda wrapping #'extent-properties. (describe-char-unicode-data): Call #'nsubst when replacing "" with nil in the result of #'split-string, instead of consing inside mapcar. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * x-faces.el (x-available-font-sizes): * specifier.el (let-specifier): * package-ui.el (pui-add-required-packages): * msw-faces.el (mswindows-available-font-sizes): * modeline.el (modeline-minor-mode-menu): * minibuf.el (minibuf-directory-files): Replace the O2N (delq nil (mapcar (lambda (W) (and X Y)) Z)) with the ON (mapcan (lambda (W) (and X (list Y))) Z) in these files. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (= < > <= >=): When these functions are handed more than two arguments, and those arguments have no side effects, transform to a series of two argument calls, avoiding funcall in the byte-compiled code. * mule/mule-cmds.el (finish-set-language-environment): Take advantage of this change in a function called 256 times at startup. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el (byte-compile-function-form, byte-compile-quote) (byte-compile-quote-form): Warn at compile time, and error at runtime, if a (quote ...) or a (function ...) form attempts to quote more than one object. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * byte-optimize.el (byte-optimize-apply): Transform (apply 'nconc (mapcar ...)) to (mapcan ...); warn about use of the first idiom. * update-elc.el (do-autoload-commands): * packages.el (packages-find-package-library-path): * frame.el (frame-list): * extents.el (extent-descendants): * etags.el (buffer-tag-table-files): * dumped-lisp.el (preloaded-file-list): * device.el (device-list): * bytecomp-runtime.el (proclaim-inline, proclaim-notinline) Use #'mapcan, not (apply #'nconc (mapcar ...) in all these files. * bytecomp-runtime.el (eval-when-compile, eval-and-compile): In passing, mention that these macros also evaluate the body when interpreted. tests/ChangeLog addition: 2011-02-07 Aidan Kehoe <kehoea@parhasard.net> * automated/lisp-tests.el: Test lexical scope for `block', `return-from'; add a Known-Bug-Expect-Failure for a contorted example that fails when byte-compiled.
author Aidan Kehoe <kehoea@parhasard.net>
date Mon, 07 Feb 2011 12:01:24 +0000
parents b7b90f750a78
children
line wrap: on
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@iftex
@unnumbered XEmacs Features

This section describes the difference between Emacs Version 18 and 
XEmacs.

@unnumberedsec General Changes

@itemize @bullet
@ignore
@item 
XEmacs has a new vi emulation mode called evi mode.  To
start evi mode in Emacs, type the command @kbd{M-x evi}.  If you want
Emacs to automatically put you in evi-mode all the time, include this
line in your init file:
@example
(setq term-setup-hook 'evi)
@end example
@xref{evi Mode} for a brief discussion.
@xref{Init File}.
@end ignore

@item 
XEmacs has a new vi emulation mode called ``viper'' mode.  To start
viper mode in XEmacs, type the command @kbd{M-x viper-mode}.  If you
want XEmacs to automatically put you in viper-mode all the time, include
this line in your init file:
@example
(viper-mode)
@end example
@xref{Init File}.

@item
Earlier versions of Emacs only allowed keybindings to ASCII character
sequences.  XEmacs has greatly expanded this by allowing you to
use a vector of key sequences which are in turn composed of a modifier
and a keysym. @xref{Keystrokes} for more information.

@item
The keymap data structure has been reimplemented to allow the use of a
character set larger than ASCII. Keymaps are no longer alists and/or
vectors; they are a new primary data type.  Consequently, code which
manipulated keymaps with list or array manipulation functions will no
longer work.  It must use the functions @code{define-key} or
@code{map-keymap} and @code{set-keymap-parent} (the new keymap
functions).  @xref{Key Bindings} for more information.

@item
Input and display of all ISO-8859-1 characters is supported.

@item
Multiple fonts, including variable-width fonts, and fonts of differing
heights, are supported.

@item
There is a new @file{tags} package and a new UNIX manual browsing
package. They are similar to earlier versions; for more information look
at the source code. 

@item
There is a new implementation of Dired, with many new features. The
online info for Dired, @i{not} the Dired node of Emacs info, provides
more detail. 

@item
GNUS (a network news reader), VM (an alternative mail reader), ILISP (a
package for interacting with inferior Lisp processes), ANGE-FTP (a package
for making FTP-accessible files appear just like files on the local disk,
even to Dired), Calendar (an Emacs-based calendar and appointment-
management tool), and W3 (an interface to the World Wide Web) are a part
of the XEmacs Lisp library.  See the related documentation in the
online info browser.

@item
Emacs now supports floating-point numbers.

@item
When you send mail, mail aliases are now expanded in the buffer. In
earlier versions, they were expanded after the mail-sending command was
executed.

@item
The initial value of @code{load-path} is computed when Emacs starts up,
instead of being hardcoded in when Emacs is compiled. As a result, you
can now move the Emacs executable and Lisp library to a
different location in the file system without having to recompile.

@item
Any existing subdirectories of the Emacs Lisp directory are now added to the
@code{load-path} by default.

@item
On some machines, you can change the audible bell using the
@code{sound-alist} variable. @xref{Audible Bell} for more information. 

@item
You can use multiple X windows to display multiple Emacs frames. 

@item
You can use the X selection mechanism to copy material from other
applications and into other applications.  You can also use all Emacs
region commands on a region selected with the mouse. @xref{Mouse
Selection} for more information.

@item
By default, the variable @code{zmacs-regions} is set to highlight the region
between point and the mark.  This unifies X selection and Emacs selection
behavior.  

@item
XEmacs has a menu bar for mouse-controlled operations in addition to
keystrokes.  @xref{Pull-down Menus}.

@item
You can look in the file @file{/usr/local/lib/xemacs-19.11/etc/Emacs.ad} for 
a list of Emacs X resources.  You can set these resources in your X 
environment to set your preferences for color, fonts, location, and the size 
of XEmacs frames.  Refer to your X documentation for more information 
about resources.

@unnumberedsec New Commands and Variables

There are many new functions in XEmacs, and many existing functions
whose semantics have been expanded.  Most of these are only of interest
to the Emacs-Lisp programmer; see the NEWS file @kbd{C-h n} for a complete
list.  What follows is a partial list of the new interactive commands:

@findex byte-compile-and-load-file
@findex byte-compile-buffer
@item
@code{byte-compile-and-load-file} and @code{byte-compile-buffer}
byte-compile the contents of a file or buffer.

@findex conx
The new @code{conx} function lets you generate random sentences for your
amusement.

@findex compile-defun
@item
@code{compile-defun} compiles and evaluates the current top-level
form.

@findex find-this-file
@findex find-this-file-other-window
@item
@code{find-this-file} and @code{find-this-file-other-window} can be used
interactively with a prefix argument to switch to the filename at point
in the buffer.  @code{find-this-file-other-window} displays the file in
another window.

@findex invert-face
@findex make-face-bold
@findex make-face-bold-italic
@findex make-face-italic
@findex make-face-unbold
@findex make-face-unitalic
@findex set-face-background
@findex set-face-background-pixmap
@findex set-face-font
@findex set-face-foreground
@findex set-face-underline-p
@item
Several new functions have been added that allow you to customize the
color and font attributes of a region of text: @code{invert-face},
@code{make-face-bold}, @code{make-face-bold-italic},
@code{make-face-italic}, @code{make-face-unbold},
@code{make-face-unitalic}, @code{set-face-background},
@code{set-face-background-pixmap}, @code{set-face-font},
@code{set-face-foreground}, and @code{set-face-underline-p}.

@findex load-default-sounds
@findex load-sound-file
@findex play-sound
@item
@code{load-default-sounds} and @code{load-sound-file} allow you to
customize the audible bell sound.  @code{load-default-sounds} loads and
installs sound files.  @code{load-sound-file} reads in audio files and
adds them to the sound alist. @code{play-sound} plays the specified
sound type.

@findex locate-library
@item
@code{locate-library} finds the file that the function
@code{load-library} loads, and it displays the file's full pathname.

@findex make-directory
@findex remove-directory
@item
@code{make-directory} creates a directory, while @code{remove-directory}
removes a directory.

@findex mark-beginning-of-buffer
@findex mark-end-of-buffer
@item
@code{mark-beginning-of-buffer} and @code{mark-end-of-buffer} push the
mark to the beginning or end of a buffer, respectively.

@findex mouse-del-char
@findex mouse-delete-window
@findex mouse-keep-one-window
@findex mouse-kill-line
@findex mouse-line-length
@findex mouse-scroll
@findex mouse-select
@findex mouse-select-and-split
@findex mouse-set-mark
@findex mouse-set-point
@findex mouse-track
@findex mouse-track-adjust
@findex mouse-track-and-copy-to-cutbuffer
@findex mouse-track-delete-and-insert
@findex mouse-track-insert
@findex mouse-window-to-region
Several functions have been added that allow you to perform various
editing, region, and window operations using the mouse:
@code{mouse-del-char}, @code{mouse-delete-window},
@code{mouse-keep-one-window}, @code{mouse-kill-line},
@code{mouse-line-length}, @code{mouse-scroll}, @code{mouse-select},
@code{mouse-select-and-split}, @code{mouse-set-mark},
@code{mouse-set-point}, @code{mouse-track}, @code{mouse-track-adjust},
@code{mouse-track-and-copy-to-cutbuffer},
@code{mouse-track-delete-and-insert}, @code{mouse-track-insert}, and
@code{mouse-window-to-region}.

@findex compare-windows 
@item
@code{compare-windows} takes an argument @var{ignore-whitespace}.
The argument means ignore changes in whitespace.

@end itemize

You can conditionalize your @file{.emacs} file as follows so that XEmacs 
commands are invoked only when you are in XEmacs:

@cindex version number
@example
(cond ((string-match "XEmacs" emacs-version)
       ;;
       ;; Code for any version of XEmacs goes here.
       ;;
       ))

(cond ((not (string-match "XEmacs" emacs-version)))
       ;;
       ;; Code for any version of GNU Emacs goes here.
       ;;
       ))

(cond ((and (string-match "XEmacs" emacs-version)
            (emacs-version>= 21 4))
       ;;
       ;; Code which requires XEmacs version 21.4 or newer goes here
       ;;
       ))

(cond ((and (string-match "XEmacs" emacs-version)
            (emacs-version>= 21 4 12)
            (not (emacs-version>= 21 4 15)))
       ;;
       ;; Code which requires exactly XEmacs version 21.4.12 through
       ;; 21.4.14, inclusive, goes here. (e.g. A bug was introduced in
       ;; 21.4.12 and fixed in 21.4.15 but many of the versions of
       ;; XEmacs around in the computer laboratory run those versions,
       ;; so I need to introduce a workaround.  In such a case, you
       ;; should ideally try to conditionalize on something else,
       ;; e.g. a feature symbol or a simple test that can be run to
       ;; smoke out the bug.)
       ;;
       ))

(cond ((and (not (string-match "XEmacs" emacs-version)
            (emacs-version>= 20 2))
       ;;
       ;; Code which requires GNU Emacs version 20.2 or newer, but not XEmacs,
       ;; goes here
       ;;
       ))

@end example

@emph{NOTE}: @strong{DO} use @code{(emacs-version>= ...)}.  @strong{DO NOT}
try to do this yourself using @code{emacs-major-version} and
@code{emacs-minor-version}.  You will, with high probability, get it
wrong.  Typical attempts to replace @code{(emacs-version>= 21 4)} use

@example
(and (>= emacs-major-version 21)
     (>= emacs-minor-version 4))
@end example

which correctly excludes 21.3 and all previous versions,
but also excludes 22.0 through 22.3, 23.0 through 23.3, etc.

A "more clever" version, as advocated in earlier versions
of this very manual, was like this:

@example
(or (> emacs-major-version 21)
    (>= emacs-minor-version 4))
@end example

which correctly includes 21.4 and all following versions,
but also includes 20.4 through 20.99999, 19.4 through
19.99999, etc.

Alternatively, use @file{.xemacs/init.el} for an init file.  @xref{Init File}.

Of particular interest for use in  files are:

@itemize @bullet
@findex add-menu
@findex add-menu-item
@findex delete-menu-item
@findex disable-menu-item
@findex enable-menu-item
@findex relabel-menu-item
@item
@code{add-menu} lets you add a new menu to the menubar or a submenu to a
pull-down menu.  @code{add-menu-item}, @code{disable-menu-item},
@code{delete-menu-item}, @code{enable-menu-item}, and
@code{relabel-menu-item} allow you to customize the XEmacs
pull-down menus.

@findex make-frame
@item
@code{make-frame} creates a new Emacs frame (X window).

@end itemize

These new variables are only present in XEmacs:

@itemize @bullet

@vindex minibuffer-confirm-incomplete
@item
@code{minibuffer-confirm-incomplete} prompts for confirmation in 
contexts where @code{completing-read} allows answers that are not valid
completions.

@vindex x-mode-pointer-shape
@vindex x-nontext-pointer-shape
@vindex x-pointer-background-color
@vindex x-pointer-foreground-color
@vindex x-pointer-shape
@item
Several variables have been added that allow you to customize the color
and shape of the mouse pointer: @code{x-pointer-background-color},
@code{x-pointer-foreground-color}, @code{x-mode-pointer-shape},
@code{x-pointer-shape}, and @* @code{x-nontext-pointer-shape}.

@vindex zmacs-regions
@item
@code{zmacs-regions} determines whether LISPM-style active regions
should be used.
@end itemize

@unnumberedsec Changes in Key Bindings

XEmacs has the following new default function keybindings:

@table @kbd
@item @key{HELP}
Same as @kbd{C-h}.

@item @key{UNDO}
Same as @kbd{M-x undo}.

@item @key{CUT}
Same as the Cut menu item; that is, it copies the selected text to
the X Clipboard selection.

@item @key{COPY}
Same as the Copy menu item.

@item @key{PASTE}
Same as the Paste menu item.

@item @key{PGUP}
Same as @kbd{M-v}.

@item @key{PGDN}
Same as @kbd{C-v}.

@item @key{HOME}
Same as @kbd{M-<}.

@item @key{END}
Same as @kbd{M->}.

@item @key{LEFT-ARROW}
Same as the function @code{backward-char}.

@item @key{RIGHT-ARROW}
Same as the function @code{forward-char}.

@item @key{UP-ARROW}
Same as the function @code{previous-line}.

@item @key{DOWN-ARROW}
Same as the function @code{next-line}.

@end table


@end iftex