@c -*-texinfo-*-
@c This is part of the XEmacs Lisp Reference Manual.
@c Copyright (C) 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
@c Copyright (C) 1996 Ben Wing.
@c See the file lispref.texi for copying conditions.
@setfilename ../../info/keymaps.info
@node Keymaps, Menus, Command Loop, Top
@chapter Keymaps
@cindex keymap

@c This section is largely different from the one in FSF Emacs.

  The bindings between input events and commands are recorded in data
structures called @dfn{keymaps}.  Each binding in a keymap associates
(or @dfn{binds}) an individual event type either with another keymap or
with a command.  When an event is bound to a keymap, that keymap is
used to look up the next input event; this continues until a command
is found.  The whole process is called @dfn{key lookup}.

@menu
* Keymap Terminology::       Definitions of terms pertaining to keymaps.
* Format of Keymaps::        What a keymap looks like as a Lisp object.
* Creating Keymaps::         Functions to create and copy keymaps.
* Inheritance and Keymaps::  How one keymap can inherit the bindings
                                of another keymap.
* Key Sequences::            How to specify key sequences.
* Prefix Keys::              Defining a key with a keymap as its definition.
* Active Keymaps::           Each buffer has a local keymap
                                to override the standard (global) bindings.
                                A minor mode can also override them.
* Key Lookup::               How extracting elements from keymaps works.
* Functions for Key Lookup:: How to request key lookup.
* Changing Key Bindings::    Redefining a key in a keymap.
* Key Binding Commands::     Interactive interfaces for redefining keys.
* Scanning Keymaps::         Looking through all keymaps, for printing help.
* Remapping commands::       Specifying that one command should override
                                another.
* Other Keymap Functions::   Miscellaneous keymap functions.
@end menu

@node Keymap Terminology, Format of Keymaps, Keymaps, Keymaps
@section Keymap Terminology
@cindex key
@cindex keystroke
@cindex key binding
@cindex binding of a key
@cindex complete key
@cindex undefined key

  A @dfn{keymap} is a table mapping event types to definitions (which
can be any Lisp objects, though only certain types are meaningful for
execution by the command loop).  Given an event (or an event type) and a
keymap, XEmacs can get the event's definition.  Events mapped in keymaps
include keypresses, button presses, and button releases
(@pxref{Events}).

  A sequence of input events that form a unit is called a
@dfn{key sequence}, or @dfn{key} for short.  A sequence of one event
is always a key sequence, and so are some multi-event sequences.

  A keymap determines a binding or definition for any key sequence.  If
the key sequence is a single event, its binding is the definition of the
event in the keymap.  The binding of a key sequence of more than one
event is found by an iterative process: the binding of the first event
is found, and must be a keymap; then the second event's binding is found
in that keymap, and so on until all the events in the key sequence are
used up.

  If the binding of a key sequence is a keymap, we call the key sequence
a @dfn{prefix key}.  Otherwise, we call it a @dfn{complete key} (because
no more events can be added to it).  If the binding is @code{nil},
we call the key @dfn{undefined}.  Examples of prefix keys are @kbd{C-c},
@kbd{C-x}, and @kbd{C-x 4}.  Examples of defined complete keys are
@kbd{X}, @key{RET}, and @kbd{C-x 4 C-f}.  Examples of undefined complete
keys are @kbd{C-x C-g}, and @kbd{C-c 3}.  @xref{Prefix Keys}, for more
details.

  The rule for finding the binding of a key sequence assumes that the
intermediate bindings (found for the events before the last) are all
keymaps; if this is not so, the sequence of events does not form a
unit---it is not really a key sequence.  In other words, removing one or
more events from the end of any valid key must always yield a prefix
key.  For example, @kbd{C-f C-n} is not a key; @kbd{C-f} is not a prefix
key, so a longer sequence starting with @kbd{C-f} cannot be a key.

  Note that the set of possible multi-event key sequences depends on the
bindings for prefix keys; therefore, it can be different for different
keymaps, and can change when bindings are changed.  However, a one-event
sequence is always a key sequence, because it does not depend on any
prefix keys for its well-formedness.

  At any time, several primary keymaps are @dfn{active}---that is, in
use for finding key bindings.  These are the @dfn{global map}, which is
shared by all buffers; the @dfn{local keymap}, which is usually
associated with a specific major mode; and zero or more @dfn{minor mode
keymaps}, which belong to currently enabled minor modes.  (Not all minor
modes have keymaps.)  The local keymap bindings shadow (i.e., take
precedence over) the corresponding global bindings.  The minor mode
keymaps shadow both local and global keymaps.  @xref{Active Keymaps},
for details.

@node Format of Keymaps, Creating Keymaps, Keymap Terminology, Keymaps
@section Format of Keymaps
@cindex format of keymaps
@cindex keymap format

  A keymap is a primitive type that associates events with their
bindings.  Note that this is different from Emacs 18 and FSF Emacs,
where keymaps are lists.

@defun keymapp object
This function returns @code{t} if @var{object} is a keymap, @code{nil}
otherwise.
@end defun

@node Creating Keymaps, Inheritance and Keymaps, Format of Keymaps, Keymaps
@section Creating Keymaps
@cindex creating keymaps

  Here we describe the functions for creating keymaps.

@defun make-keymap &optional name
This function constructs and returns a new keymap object.  All entries
in it are @code{nil}, meaning ``command undefined''.

Optional argument @var{name} specifies a name to assign to the keymap,
as in @code{set-keymap-name}.  This name is only a debugging
convenience; it is not used except when printing the keymap.
@end defun

@defun make-sparse-keymap &optional name
This function constructs and returns a new keymap object.  All entries
in it are @code{nil}, meaning ``command undefined''.  The only
difference between this function and @code{make-keymap} is that this
function returns a ``smaller'' keymap (one that is expected to contain
fewer entries).  As keymaps dynamically resize, this distinction is not
great.

Optional argument @var{name} specifies a name to assign to the keymap,
as in @code{set-keymap-name}.  This name is only a debugging
convenience; it is not used except when printing the keymap.
@end defun

@defun set-keymap-name keymap new-name
This function assigns a ``name'' to a keymap.  The name is only a
debugging convenience; it is not used except when printing the keymap.
@end defun

@defun keymap-name keymap
This function returns the ``name'' of a keymap, as assigned using
@code{set-keymap-name}.
@end defun

@defun copy-keymap keymap
This function returns a copy of @var{keymap}.  Any keymaps that
appear directly as bindings in @var{keymap} are also copied recursively,
and so on to any number of levels.  However, recursive copying does not
take place when the definition of a character is a symbol whose function
definition is a keymap; the same symbol appears in the new copy.

@example
@group
(setq map (copy-keymap (current-local-map)))
@result{} #<keymap 3 entries 0x21f80>
@end group

@group
(eq map (current-local-map))
    @result{} nil
@end group
@ignore @c Doesn't work!
@group
(equal map (current-local-map))
    @result{} t
@end group
@end ignore
@end example
@end defun

@node Inheritance and Keymaps, Key Sequences, Creating Keymaps, Keymaps
@section Inheritance and Keymaps
@cindex keymap inheritance
@cindex inheriting a keymap's bindings
@cindex keymap parent
@cindex parent of a keymap

  A keymap can inherit the bindings of other keymaps.  The other
keymaps are called the keymap's @dfn{parents}, and are set with
@code{set-keymap-parents}.  When searching for a binding for a key
sequence in a particular keymap, that keymap itself will first be
searched; then, if no binding was found in the map and it has parents,
the first parent keymap will be searched; then that keymap's parent will
be searched, and so on, until either a binding for the key sequence is
found, or a keymap without a parent is encountered.  At this point,
the search will continue with the next parent of the most recently
encountered keymap that has another parent, etc.  Essentially, a
depth-first search of all the ancestors of the keymap is conducted.

@code{(current-global-map)} is the default parent of all keymaps.

@defun set-keymap-parents keymap parents
This function sets the parent keymaps of @var{keymap} to the list
@var{parents}.

If you change the bindings in one of the keymaps in @var{parents} using
@code{define-key} or other key-binding functions, these changes are
visible in @var{keymap} unless shadowed by bindings in that map or in
earlier-searched ancestors.  The converse is not true: if you use
@code{define-key} to change @var{keymap}, that affects the bindings in
that map, but has no effect on any of the keymaps in @var{parents}.
@end defun

@defun keymap-parents keymap
This function returns the list of parent keymaps of @var{keymap}, or
@code{nil} if @var{keymap} has no parents.
@end defun

  As an alternative to specifying a parent, you can also specify a
@dfn{default binding} that is used whenever a key is not otherwise bound
in the keymap.  This is useful for terminal emulators, for example,
which may want to trap all keystrokes and pass them on in some modified
format.  Note that if you specify a default binding for a keymap,
neither the keymap's parents nor the current global map are searched for
key bindings.

@defun set-keymap-default-binding keymap command
This function sets the default binding of @var{keymap} to @var{command},
or @code{nil} if no default is desired.
@end defun

@defun keymap-default-binding keymap
This function returns the default binding of @var{keymap}, or @code{nil}
if it has none.
@end defun

@node Key Sequences, Prefix Keys, Inheritance and Keymaps, Keymaps
@section Key Sequences
@cindex key sequences

  Contrary to popular belief, the world is not @sc{ascii}.  When running
under a window manager, XEmacs can tell the difference between, for
example, the keystrokes @kbd{control-h}, @kbd{control-shift-h}, and
@kbd{backspace}.  You can, in fact, bind different commands to each of
these.

  A @dfn{key sequence} is a set of keystrokes.  A @dfn{keystroke} is a
keysym and some set of modifiers (such as @key{CONTROL} and @key{META}).
A @dfn{keysym} is what is printed on the keys on your keyboard.

  A keysym may be represented by a symbol, by a character, or by a
character's Mule code. The @kbd{A} key may be represented by the symbol
@code{A}, the character @code{?A}, or by the number 65.  The @kbd{break}
key may be represented only by the symbol @code{break}, and non-ASCII
X11 keys in general are limited to the symbol form with XEmacs.
@footnote{A quirk of our X11 implementation means that non-ASCII keysyms
have different internal representations in the X11 (with GTK) and other
worlds (like the TTY, or Microsoft Windows), so, for example, binding
@kbd{EuroSign} to a command will normally work, but will not invoke that
command if someone presses the Euro sign in a TTY console; conversely,
binding @code{(make-char 'latin-iso8859-15 #xa4)} or @code{(char-to-int
(make-char 'latin-iso8859-15 #xa4))} to a command will call that command
on a TTY console, but not in an X11 window of the same process.}
@footnote{See the documentation for `set-input-mode' and
`set-console-tty-coding-system' if you're having trouble inputting
non-ASCII characters in the TTY.}

  A keystroke may be represented by a list: the last element of the list
is the key (a symbol, character, or number, as above) and the preceding
elements are the symbolic names of modifier keys (@key{CONTROL},
@key{META}, @key{SUPER}, @key{HYPER}, @key{ALT}, and @key{SHIFT}).
Thus, the sequence @kbd{control-b} is represented by the forms
@code{(control b)}, @code{(control ?b)}, and @code{(control 98)}.  A
keystroke may also be represented by an event object, as returned by the
@code{next-command-event} and @code{read-key-sequence} functions.

  Note that in this context, the keystroke @kbd{control-b} is @emph{not}
represented by the number 2 (the @sc{ascii} code for @samp{^B}) or the
character @code{?\^B}.  See below.

  The @key{SHIFT} modifier is somewhat of a special case.  You should
not (and cannot) use @code{(meta shift a)} to mean @code{(meta A)},
since for characters that have @sc{ascii} equivalents, the state of the
shift key is implicit in the keysym (@samp{a} vs. @samp{A}).  You also
cannot say @code{(shift =)} to mean @code{+}, as that sort of thing
varies from keyboard to keyboard.  The @key{SHIFT} modifier is for use
only with characters that do not have a second keysym on the same key,
such as @code{backspace} and @code{tab}.

  A key sequence is a vector of keystrokes.  As a degenerate case,
elements of this vector may also be keysyms if they have no modifiers.
That is, the @kbd{A} keystroke is represented by all of these forms:

@example
        A       ?A      65      (A)     (?A)    (65)
        [A]     [?A]    [65]    [(A)]   [(?A)]  [(65)]
@end example

the @kbd{control-a} keystroke is represented by these forms:

@example
        (control A)     (control ?A)    (control 65)
        [(control A)]   [(control ?A)]  [(control 65)]
@end example

the key sequence @kbd{control-c control-a} is represented by these
forms:

@example
        [(control c) (control a)]       [(control ?c) (control ?a)]
        [(control 99) (control 65)]     etc.
@end example

  Mouse button clicks work just like keypresses: @code{(control
button1)} means pressing the left mouse button while holding down the
control key.  @code{[(control c) (shift button3)]} means
@kbd{control-c}, hold @key{SHIFT}, click right.

  Commands may be bound to the mouse-button up-stroke rather than the
down-stroke as well.  @code{button1} means the down-stroke, and
@code{button1up} means the up-stroke.  Different commands may be bound
to the up and down strokes, though that is probably not what you want,
so be careful.

  For backward compatibility, a key sequence may also be represented by
a string.  In this case, it represents the key sequence(s) that would
produce that sequence of @sc{ascii} characters in a purely @sc{ascii}
world.  For example, a string containing the @sc{ascii} backspace
character, @code{"\^H"}, would represent two key sequences:
@code{(control h)} and @code{backspace}.  Binding a command to this will
actually bind both of those key sequences.  Likewise for the following
pairs:

@example
                control h       backspace
                control i       tab
                control m       return
                control j       linefeed
                control [       escape
                control @@      control space
@end example

  After binding a command to two key sequences with a form like

@example
        (define-key global-map "\^X\^I" 'command-1)
@end example

@noindent
it is possible to redefine only one of those sequences like so:

@example
        (define-key global-map [(control x) (control i)] 'command-2)
        (define-key global-map [(control x) tab] 'command-3)
@end example

  Of course, all of this applies only when running under a window
system.  If you're talking to XEmacs through a @sc{tty} connection, you
don't get any of these features.

@defun event-matches-key-specifier-p event key-specifier
This function returns non-@code{nil} if @var{event} matches
@var{key-specifier}, which can be any valid form representing a key
sequence.  This can be useful, e.g., to determine if the user pressed
@code{help-char} or @code{quit-char}.
@end defun

@node Prefix Keys, Active Keymaps, Key Sequences, Keymaps
@section Prefix Keys
@cindex prefix key

  A @dfn{prefix key} has an associated keymap that defines what to do
with key sequences that start with the prefix key.  For example,
@kbd{C-x} is a prefix key, and it uses a keymap that is also stored in
the variable @code{ctl-x-map}.  Here is a list of the standard prefix
keys of XEmacs and their keymaps:

@itemize @bullet
@item
@cindex @kbd{C-h}
@code{help-map} is used for events that follow @kbd{C-h}.

@item
@cindex @kbd{C-c}
@vindex mode-specific-map
@code{mode-specific-map} is for events that follow @kbd{C-c}.  This
map is not actually mode specific; its name was chosen to be informative
for the user in @kbd{C-h b} (@code{display-bindings}), where it
describes the main use of the @kbd{C-c} prefix key.

@item
@cindex @kbd{C-x}
@vindex ctl-x-map
@findex Control-X-prefix
@code{ctl-x-map} is the map used for events that follow @kbd{C-x}.  This
map is also the function definition of @code{Control-X-prefix}.

@item
@cindex @kbd{C-x 4}
@vindex ctl-x-4-map
@code{ctl-x-4-map} is used for events that follow @kbd{C-x 4}.

@c Emacs 19 feature
@item
@cindex @kbd{C-x 5}
@vindex ctl-x-5-map
@code{ctl-x-5-map} is used for events that follow @kbd{C-x 5}.

@c Emacs 19 feature
@item
@cindex @kbd{C-x n}
@cindex @kbd{C-x r}
@cindex @kbd{C-x a}
The prefix keys @kbd{C-x n}, @kbd{C-x r} and @kbd{C-x a} use keymaps
that have no special name.

@item
@vindex esc-map
@findex ESC-prefix
@code{esc-map} is an evil hack that is present for compatibility
purposes with Emacs 18.  Defining a key in @code{esc-map} is equivalent
to defining the same key in @code{global-map} but with the @key{META}
prefix added.  You should @emph{not} use this in your code. (This map is
also the function definition of @code{ESC-prefix}.)
@end itemize

  The binding of a prefix key is the keymap to use for looking up the
events that follow the prefix key.  (It may instead be a symbol whose
function definition is a keymap.  The effect is the same, but the symbol
serves as a name for the prefix key.)  Thus, the binding of @kbd{C-x} is
the symbol @code{Control-X-prefix}, whose function definition is the
keymap for @kbd{C-x} commands.  (The same keymap is also the value of
@code{ctl-x-map}.)

  Prefix key definitions can appear in any active keymap.  The
definitions of @kbd{C-c}, @kbd{C-x}, @kbd{C-h} and @key{ESC} as prefix
keys appear in the global map, so these prefix keys are always
available.  Major and minor modes can redefine a key as a prefix by
putting a prefix key definition for it in the local map or the minor
mode's map.  @xref{Active Keymaps}.

  If a key is defined as a prefix in more than one active map, then its
various definitions are in effect merged: the commands defined in the
minor mode keymaps come first, followed by those in the local map's
prefix definition, and then by those from the global map.

  In the following example, we make @kbd{C-p} a prefix key in the local
keymap, in such a way that @kbd{C-p} is identical to @kbd{C-x}.  Then
the binding for @kbd{C-p C-f} is the function @code{find-file}, just
like @kbd{C-x C-f}.  The key sequence @kbd{C-p 6} is not found in any
active keymap.

@example
@group
(use-local-map (make-sparse-keymap))
    @result{} nil
@end group
@group
(local-set-key "\C-p" ctl-x-map)
    @result{} nil
@end group
@group
(key-binding "\C-p\C-f")
    @result{} find-file
@end group

@group
(key-binding "\C-p6")
    @result{} nil
@end group
@end example

@defun define-prefix-command symbol &optional mapvar
@cindex prefix command
This function defines @var{symbol} as a prefix command: it creates a
keymap and stores it as @var{symbol}'s function definition.
Storing the symbol as the binding of a key makes the key a prefix key
that has a name.  If optional argument @var{mapvar} is not specified,
it also sets @var{symbol} as a variable, to have the keymap as its
value. (If @var{mapvar} is given and is not @code{t}, its value is
stored as the value of @var{symbol}.) The function returns @var{symbol}.

  In Emacs version 18, only the function definition of @var{symbol} was
set, not the value as a variable.
@end defun

@node Active Keymaps, Key Lookup, Prefix Keys, Keymaps
@section Active Keymaps
@cindex active keymap
@cindex global keymap
@cindex local keymap

  XEmacs normally contains many keymaps; at any given time, just a few of
them are @dfn{active} in that they participate in the interpretation
of user input.  These are the global keymap, the current buffer's
local keymap, and the keymaps of any enabled minor modes.

  The @dfn{global keymap} holds the bindings of keys that are defined
regardless of the current buffer, such as @kbd{C-f}.  The variable
@code{global-map} holds this keymap, which is always active.

  Each buffer may have another keymap, its @dfn{local keymap}, which may
contain new or overriding definitions for keys.  The current buffer's
local keymap is always active except when @code{overriding-local-map} or
@code{overriding-terminal-local-map} overrides it.  Extents and text
properties can specify an alternative local map for certain parts of the
buffer; see @ref{Extents and Events}.

  Each minor mode may have a keymap; if it does, the keymap is active
when the minor mode is enabled.

  The variable @code{overriding-local-map} and
@code{overriding-terminal-local-map}, if non-@code{nil}, specify other
local keymaps that override the buffer's local map and all the minor
mode keymaps.

  All the active keymaps are used together to determine what command to
execute when a key is entered.  XEmacs searches these maps one by one, in
order of decreasing precedence, until it finds a binding in one of the maps.

  More specifically:

  For key-presses, the order of keymaps searched is:

@itemize @bullet
@item
the @code{keymap} property of any extent(s) or text properties at point;
@item
any applicable minor-mode maps;
@item
the current local map of the current buffer;
@item
the current global map.
@end itemize

  For mouse-clicks, the order of keymaps searched is:

@itemize @bullet
@item
the current local map of the @code{mouse-grabbed-buffer} if any;
@item
the @code{keymap} property of any extent(s) at the position of the click
(this includes modeline extents);
@item
the @code{modeline-map} of the buffer corresponding to the modeline
under the mouse (if the click happened over a modeline);
@item
the value of @code{toolbar-map} in the current buffer (if the click
happened over a toolbar);
@item
the current local map of the buffer under the mouse (does not
apply to toolbar clicks);
@item
any applicable minor-mode maps;
@item
the current global map.
@end itemize

  Note that if @code{overriding-local-map} or
@code{overriding-terminal-local-map} is non-@code{nil}, @emph{only}
those two maps and the current global map are searched.

  The procedure for searching a single keymap is called
@dfn{key lookup}; see @ref{Key Lookup}.

@cindex major mode keymap
  Since every buffer that uses the same major mode normally uses the
same local keymap, you can think of the keymap as local to the mode.  A
change to the local keymap of a buffer (using @code{local-set-key}, for
example) is seen also in the other buffers that share that keymap.

  The local keymaps that are used for Lisp mode, C mode, and several
other major modes exist even if they have not yet been used.  These
local maps are the values of the variables @code{lisp-mode-map},
@code{c-mode-map}, and so on.  For most other modes, which are less
frequently used, the local keymap is constructed only when the mode is
used for the first time in a session.

  The minibuffer has local keymaps, too; they contain various completion
and exit commands.  @xref{Intro to Minibuffers}.

  @xref{Standard Keymaps}, for a list of standard keymaps.

@defun current-keymaps &optional event-or-keys
This function returns a list of the current keymaps that will be
searched for bindings.  This lists keymaps such as the current local map
and the minor-mode maps, but does not list the parents of those keymaps.
@var{event-or-keys} controls which keymaps will be listed.  If
@var{event-or-keys} is a mouse event (or a vector whose last element is
a mouse event), the keymaps for that mouse event will be listed.
Otherwise, the keymaps for key presses will be listed.
@end defun

@defvar global-map
This variable contains the default global keymap that maps XEmacs
keyboard input to commands.  The global keymap is normally this keymap.
The default global keymap is a full keymap that binds
@code{self-insert-command} to all of the printing characters.

It is normal practice to change the bindings in the global map, but you
should not assign this variable any value other than the keymap it starts
out with.
@end defvar

@defun current-global-map
This function returns the current global keymap.  This is the
same as the value of @code{global-map} unless you change one or the
other.

@example
@group
(current-global-map)
@result{} #<keymap global-map 639 entries 0x221>
@end group
@end example
@end defun

@defun current-local-map &optional buffer
This function returns @var{buffer}'s local keymap, or @code{nil}
if it has none.  @var{buffer} defaults to the current buffer.

In the following example, the keymap for the @samp{*scratch*} buffer
(using Lisp Interaction mode) has a number of entries, including one
prefix key, @kbd{C-x}.

@example
@group
(current-local-map)
@result{} #<keymap lisp-interaction-mode-map 5 entries 0x558>
(describe-bindings-internal (current-local-map))
@result{}  ; @r{Inserted into the buffer:}
backspace       backward-delete-char-untabify
linefeed        eval-print-last-sexp
delete          delete-char
C-j             eval-print-last-sexp
C-x             << Prefix Command >>
M-tab           lisp-complete-symbol
M-;             lisp-indent-for-comment
M-C-i           lisp-complete-symbol
M-C-q           indent-sexp
M-C-x           eval-defun
Alt-backspace   backward-kill-sexp
Alt-delete      kill-sexp
@end group

@group
C-x x           edebug-defun
@end group
@end example
@end defun

@defun current-minor-mode-maps
This function returns a list of the keymaps of currently enabled minor modes.
@end defun

@defun use-global-map keymap
This function makes @var{keymap} the new current global keymap.  It
returns @code{nil}.

It is very unusual to change the global keymap.
@end defun

@defun use-local-map keymap &optional buffer
This function makes @var{keymap} the new local keymap of @var{buffer}.
@var{buffer} defaults to the current buffer.  If @var{keymap} is
@code{nil}, then the buffer has no local keymap.  @code{use-local-map}
returns @code{nil}.  Most major mode commands use this function.
@end defun

@c Emacs 19 feature
@defvar minor-mode-map-alist
This variable is an alist describing keymaps that may or may not be
active according to the values of certain variables.  Its elements look
like this:

@example
(@var{variable} . @var{keymap})
@end example

The keymap @var{keymap} is active whenever @var{variable} has a
non-@code{nil} value.  Typically @var{variable} is the variable that
enables or disables a minor mode.  @xref{Keymaps and Minor Modes}.

Note that elements of @code{minor-mode-map-alist} do not have the same
structure as elements of @code{minor-mode-alist}.  The map must be the
@sc{cdr} of the element; a list with the map as the second element will
not do.

What's more, the keymap itself must appear in the @sc{cdr}.  It does not
work to store a variable in the @sc{cdr} and make the map the value of
that variable.

When more than one minor mode keymap is active, their order of priority
is the order of @code{minor-mode-map-alist}.  But you should design
minor modes so that they don't interfere with each other.  If you do
this properly, the order will not matter.

See also @code{minor-mode-key-binding}, above.  See @ref{Keymaps and
Minor Modes}, for more information about minor modes.
@end defvar

@defvar modeline-map
This variable holds the keymap consulted for mouse-clicks on the
modeline of a window.  This variable may be buffer-local; its value will
be looked up in the buffer of the window whose modeline was clicked
upon.
@end defvar

@defvar toolbar-map
This variable holds the keymap consulted for mouse-clicks over a
toolbar.
@end defvar

@defvar mouse-grabbed-buffer
If non-@code{nil}, a buffer which should be consulted first for all
mouse activity.  When a mouse-click is processed, it will first be
looked up in the local-map of this buffer, and then through the normal
mechanism if there is no binding for that click.  This buffer's value of
@code{mode-motion-hook} will be consulted instead of the
@code{mode-motion-hook} of the buffer of the window under the mouse.
You should @emph{bind} this, not set it.
@end defvar

@defvar overriding-local-map
If non-@code{nil}, this variable holds a keymap to use instead of the
buffer's local keymap and instead of all the minor mode keymaps.  This
keymap, if any, overrides all other maps that would have been active,
except for the current global map.
@end defvar

@defvar overriding-terminal-local-map
If non-@code{nil}, this variable holds a keymap to use instead of the
buffer's local keymap and instead of all the minor mode keymaps, but for
the selected console only. (In other words, this variable is always
console-local; putting a keymap here only applies to keystrokes coming
from the selected console.  @xref{Consoles and Devices}.) This keymap,
if any, overrides all other maps that would have been active, except for
the current global map.
@end defvar

@node Key Lookup, Functions for Key Lookup, Active Keymaps, Keymaps
@section Key Lookup
@cindex key lookup
@cindex keymap entry

  @dfn{Key lookup} is the process of finding the binding of a key
sequence from a given keymap.  Actual execution of the binding is not
part of key lookup.

  Key lookup uses just the event type of each event in the key
sequence; the rest of the event is ignored.  In fact, a key sequence
used for key lookup may designate mouse events with just their types
(symbols) instead of with entire mouse events (lists).  @xref{Events}.
Such a pseudo-key-sequence is insufficient for @code{command-execute},
but it is sufficient for looking up or rebinding a key.

  When the key sequence consists of multiple events, key lookup
processes the events sequentially: the binding of the first event is
found, and must be a keymap; then the second event's binding is found in
that keymap, and so on until all the events in the key sequence are used
up.  (The binding thus found for the last event may or may not be a
keymap.)  Thus, the process of key lookup is defined in terms of a
simpler process for looking up a single event in a keymap.  How that is
done depends on the type of object associated with the event in that
keymap.

  Let's use the term @dfn{keymap entry} to describe the value found by
looking up an event type in a keymap.  (This doesn't include the item
string and other extra elements in menu key bindings because
@code{lookup-key} and other key lookup functions don't include them in
the returned value.)  While any Lisp object may be stored in a keymap as
a keymap entry, not all make sense for key lookup.  Here is a list of
the meaningful kinds of keymap entries:

@table @asis
@item @code{nil}
@cindex @code{nil} in keymap
@code{nil} means that the events used so far in the lookup form an
undefined key.  When a keymap fails to mention an event type at all, and
has no default binding, that is equivalent to a binding of @code{nil}
for that event type.

@item @var{keymap}
@cindex keymap in keymap
The events used so far in the lookup form a prefix key.  The next
event of the key sequence is looked up in @var{keymap}.

@item @var{command}
@cindex command in keymap
The events used so far in the lookup form a complete key,
and @var{command} is its binding.  @xref{What Is a Function}.

@item @var{array}
@cindex string in keymap
The array (either a string or a vector) is a keyboard macro.  The events
used so far in the lookup form a complete key, and the array is its
binding.  See @ref{Keyboard Macros}, for more information. (Note that
you cannot use a shortened form of a key sequence here, such as
@code{(control y)}; you must use the full form @code{[(control y)]}.
@xref{Key Sequences}.)

@item @var{list}
@cindex list in keymap
The meaning of a list depends on the types of the elements of the list.

@itemize @bullet
@item
@cindex @code{lambda} in keymap
If the @sc{car} of @var{list} is @code{lambda}, then the list is a
lambda expression.  This is presumed to be a command, and is treated as
such (see above).

@item
If the @sc{car} of @var{list} is a keymap and the @sc{cdr} is an event
type, then this is an @dfn{indirect entry}:

@example
(@var{othermap} . @var{othertype})
@end example

When key lookup encounters an indirect entry, it looks up instead the
binding of @var{othertype} in @var{othermap} and uses that.

This feature permits you to define one key as an alias for another key.
For example, an entry whose @sc{car} is the keymap called @code{esc-map}
and whose @sc{cdr} is 32 (the code for @key{SPC}) means, ``Use the global
binding of @kbd{Meta-@key{SPC}}, whatever that may be.''
@end itemize

@item @var{symbol}
@cindex symbol in keymap
The function definition of @var{symbol} is used in place of
@var{symbol}.  If that too is a symbol, then this process is repeated,
any number of times.  Ultimately this should lead to an object that is
a keymap, a command or a keyboard macro.  A list is allowed if it is a
keymap or a command, but indirect entries are not understood when found
via symbols.

Note that keymaps and keyboard macros (strings and vectors) are not
valid functions, so a symbol with a keymap, string, or vector as its
function definition is invalid as a function.  It is, however, valid as
a key binding.  If the definition is a keyboard macro, then the symbol
is also valid as an argument to @code{command-execute}
(@pxref{Interactive Call}).

@cindex @code{undefined} in keymap
The symbol @code{undefined} is worth special mention: it means to treat
the key as undefined.  Strictly speaking, the key is defined, and its
binding is the command @code{undefined}; but that command does the same
thing that is done automatically for an undefined key: it rings the bell
(by calling @code{ding}) but does not signal an error.

@cindex preventing prefix key
@code{undefined} is used in local keymaps to override a global key
binding and make the key ``undefined'' locally.  A local binding of
@code{nil} would fail to do this because it would not override the
global binding.

@item @var{anything else}
If any other type of object is found, the events used so far in the
lookup form a complete key, and the object is its binding, but the
binding is not executable as a command.
@end table

  In short, a keymap entry may be a keymap, a command, a keyboard macro,
a symbol that leads to one of them, or an indirection or @code{nil}.

@node Functions for Key Lookup, Changing Key Bindings, Key Lookup, Keymaps
@section Functions for Key Lookup

  Here are the functions and variables pertaining to key lookup.

@defun lookup-key keymap key &optional accept-defaults
This function returns the definition of @var{key} in @var{keymap}.  If
the string or vector @var{key} is not a valid key sequence according to
the prefix keys specified in @var{keymap} (which means it is ``too
long'' and has extra events at the end), then the value is a number, the
number of events at the front of @var{key} that compose a complete key.

@c Emacs 19 feature
If @var{accept-defaults} is non-@code{nil}, then @code{lookup-key}
considers default bindings as well as bindings for the specific events
in @var{key}.  Otherwise, @code{lookup-key} reports only bindings for
the specific sequence @var{key}, ignoring default bindings except when
you explicitly ask about them.

All the other functions described in this chapter that look up keys use
@code{lookup-key}.

@example
@group
(lookup-key (current-global-map) "\C-x\C-f")
    @result{} find-file
@end group
@group
(lookup-key (current-global-map) "\C-x\C-f12345")
    @result{} 2
@end group
@end example

  If @var{key} begins with the character whose value is contained in
@code{meta-prefix-char}, that character is implicitly removed and the
@key{META} modifier added to the key.  Thus, the first example below is
handled by conversion into the second example.

@example
@group
(lookup-key (current-global-map) "\ef")
    @result{} forward-word
@end group
@group
(lookup-key (current-global-map) "\M-f")
    @result{} forward-word
@end group
@end example

Unlike @code{read-key-sequence}, this function does not modify the
specified events in ways that discard information (@pxref{Key Sequence
Input}).  In particular, it does not convert letters to lower case.
@end defun

@deffn Command undefined
Used in keymaps to undefine keys.  If a key sequence is defined to this,
invoking this key sequence causes a ``key undefined'' error, just as if
the key sequence had no binding.
@end deffn

@defun key-binding key &optional accept-defaults
This function returns the binding for @var{key} in the current
keymaps, trying all the active keymaps.  The result is @code{nil} if
@var{key} is undefined in the keymaps.

@c Emacs 19 feature
The argument @var{accept-defaults} controls checking for default
bindings, as in @code{lookup-key} (above).

@example
@group
(key-binding "\C-x\C-f")
    @result{} find-file
(key-binding '(control home))
    @result{} beginning-of-buffer
(key-binding [escape escape escape])
    @result{} keyboard-escape-quit
@end group
@end example
@end defun

@defun local-key-binding keys &optional accept-defaults
This function returns the binding for @var{keys} in the current
local keymap, or @code{nil} if it is undefined there.

@c Emacs 19 feature
The argument @var{accept-defaults} controls checking for default bindings,
as in @code{lookup-key} (above).
@end defun

@defun global-key-binding keys &optional accept-defaults
This function returns the binding for command @var{keys} in the
current global keymap, or @code{nil} if it is undefined there.

@c Emacs 19 feature
The argument @var{accept-defaults} controls checking for default bindings,
as in @code{lookup-key} (above).
@end defun

@c Emacs 19 feature
@defun minor-mode-key-binding key &optional accept-defaults
This function returns a list of all the active minor mode bindings of
@var{key}.  More precisely, it returns an alist of pairs
@code{(@var{modename} . @var{binding})}, where @var{modename} is the
variable that enables the minor mode, and @var{binding} is @var{key}'s
binding in that mode.  If @var{key} has no minor-mode bindings, the
value is @code{nil}.

If the first binding is not a prefix command, all subsequent bindings
from other minor modes are omitted, since they would be completely
shadowed.  Similarly, the list omits non-prefix bindings that follow
prefix bindings.

The argument @var{accept-defaults} controls checking for default
bindings, as in @code{lookup-key} (above).
@end defun

@defvar meta-prefix-char
@cindex @key{ESC}
This variable is the meta-prefix character code.  It is used when
translating a two-character sequence to a meta character so it can be
looked up in a keymap.  For useful results, the value should be a prefix
event (@pxref{Prefix Keys}).  The default value is @code{?\^[} (integer
27), which is the @sc{ascii} character usually produced by the @key{ESC}
key.

  As long as the value of @code{meta-prefix-char} remains @code{?\^[},
key lookup translates @kbd{@key{ESC} b} into @kbd{M-b}, which is
normally defined as the @code{backward-word} command.  However, if you
set @code{meta-prefix-char} to @code{?\^X} (i.e. the keystroke
@kbd{C-x}) or its equivalent @sc{ascii} code @code{24}, then XEmacs will
translate @kbd{C-x b} (whose standard binding is the
@code{switch-to-buffer} command) into @kbd{M-b}.

@smallexample
@group
meta-prefix-char                    ; @r{The default value.}
     @result{} ?\^[   ; @r{Under XEmacs 20.}
     @result{} 27     ; @r{Under XEmacs 19.}
@end group
@group
(key-binding "\eb")
     @result{} backward-word
@end group
@group
?\C-x                               ; @r{The print representation}
                                           ;   @r{of a character.}
     @result{} ?\^X   ; @r{Under XEmacs 20.}
     @result{} 24     ; @r{Under XEmacs 19.}
@end group
@group
(setq meta-prefix-char 24)
     @result{} 24
@end group
@group
(key-binding "\C-xb")
     @result{} backward-word            ; @r{Now, typing @kbd{C-x b} is}
                                    ;   @r{like typing @kbd{M-b}.}

(setq meta-prefix-char ?\e)          ; @r{Avoid confusion!}
                                     ; @r{Restore the default value!}
     @result{} ?\^[   ; @r{Under XEmacs 20.}
     @result{} 27     ; @r{Under XEmacs 19.}
@end group
@end smallexample
@end defvar

@node Changing Key Bindings, Key Binding Commands, Functions for Key Lookup, Keymaps
@section Changing Key Bindings
@cindex changing key bindings
@cindex rebinding

  The way to rebind a key is to change its entry in a keymap.  If you
change a binding in the global keymap, the change is effective in all
buffers (though it has no direct effect in buffers that shadow the
global binding with a local one).  If you change the current buffer's
local map, that usually affects all buffers using the same major mode.
The @code{global-set-key} and @code{local-set-key} functions are
convenient interfaces for these operations (@pxref{Key Binding
Commands}).  You can also use @code{define-key}, a more general
function; then you must specify explicitly the map to change.

  The way to specify the key sequence that you want to rebind is
described above (@pxref{Key Sequences}).

  For the functions below, an error is signaled if @var{keymap} is not a
keymap or if @var{key} is not a string or vector representing a key
sequence.  You can use event types (symbols) as shorthand for events
that are lists.

@defun define-key keymap key binding
This function sets the binding for @var{key} in @var{keymap}.  (If
@var{key} is more than one event long, the change is actually made
in another keymap reached from @var{keymap}.)  The argument
@var{binding} can be any Lisp object, but only certain types are
meaningful.  (For a list of meaningful types, see @ref{Key Lookup}.)
The value returned by @code{define-key} is @var{binding}.

@cindex invalid prefix key error
@cindex key sequence error
Every prefix of @var{key} must be a prefix key (i.e., bound to a
keymap) or undefined; otherwise an error is signaled.

If some prefix of @var{key} is undefined, then @code{define-key} defines
it as a prefix key so that the rest of @var{key} may be defined as
specified.
@end defun

  Here is an example that creates a sparse keymap and makes a number of
bindings in it:

@smallexample
@group
(setq map (make-sparse-keymap))
    @result{} #<keymap 0 entries 0xbee>
@end group
@group
(define-key map "\C-f" 'forward-char)
    @result{} forward-char
@end group
@group
map
    @result{} #<keymap 1 entry 0xbee>
(describe-bindings-internal map)
@result{}   ; @r{(Inserted in buffer)}
C-f             forward-char
@end group

@group
;; @r{Build sparse submap for @kbd{C-x} and bind @kbd{f} in that.}
(define-key map "\C-xf" 'forward-word)
    @result{} forward-word
@end group
@group
map
    @result{} #<keymap 2 entries 0xbee>
(describe-bindings-internal map)
@result{}   ; @r{(Inserted in buffer)}
C-f             forward-char
C-x             << Prefix Command >>

C-x f           forward-word
@end group

@group
;; @r{Bind @kbd{C-p} to the @code{ctl-x-map}.}
(define-key map "\C-p" ctl-x-map)
;; @code{ctl-x-map}
@result{} #<keymap Control-X-prefix 77 entries 0x3bf>
@end group

@group
;; @r{Bind @kbd{C-f} to @code{foo} in the @code{ctl-x-map}.}
(define-key map "\C-p\C-f" 'foo)
@result{} foo
@end group
@group
map
    @result{} #<keymap 3 entries 0xbee>
(describe-bindings-internal map)
@result{}   ; @r{(Inserted in buffer)}
C-f             forward-char
C-p             << Prefix command Control-X-prefix >>
C-x             << Prefix Command >>

C-p tab         indent-rigidly
C-p $           set-selective-display
C-p '           expand-abbrev
C-p (           start-kbd-macro
C-p )           end-kbd-macro
   @dots{}
C-p C-x         exchange-point-and-mark
C-p C-z         suspend-or-iconify-emacs
C-p M-escape    repeat-complex-command
C-p M-C-[       repeat-complex-command

C-x f           forward-word

C-p 4 .         find-tag-other-window
   @dots{}
C-p 4 C-o       display-buffer

C-p 5 0         delete-frame
   @dots{}
C-p 5 C-f       find-file-other-frame

   @dots{}

C-p a i g       inverse-add-global-abbrev
C-p a i l       inverse-add-mode-abbrev
@end group
@end smallexample

@noindent
Note that storing a new binding for @kbd{C-p C-f} actually works by
changing an entry in @code{ctl-x-map}, and this has the effect of
changing the bindings of both @kbd{C-p C-f} and @kbd{C-x C-f} in the
default global map.

@defun substitute-key-definition olddef newdef keymap &optional oldmap prefix
@cindex replace bindings
This function replaces @var{olddef} with @var{newdef} for any keys in
@var{keymap} that were bound to @var{olddef}.  In other words,
@var{olddef} is replaced with @var{newdef} wherever it appears.  Prefix
keymaps are checked recursively.

The function returns @code{nil}.  @pxref{Remapping commands} for a more
robust way of doing the same thing.

For example, this redefines @kbd{C-x C-f}, if you do it in an XEmacs with
standard bindings:

@smallexample
@group
(substitute-key-definition
 'find-file 'find-file-read-only (current-global-map))
@end group
@end smallexample

@c Emacs 19 feature
If @var{oldmap} is non-@code{nil}, then its bindings determine which
keys to rebind.  The rebindings still happen in @var{keymap}, not in
@var{oldmap}.  Thus, you can change one map under the control of the
bindings in another.  For example,

@smallexample
(substitute-key-definition
  'delete-backward-char 'my-funny-delete
  my-map global-map)
@end smallexample

@noindent
puts the special deletion command in @code{my-map} for whichever keys
are globally bound to the standard deletion command.

If argument @var{prefix} is non-@code{nil}, then only those occurrences
of @var{olddef} found in keymaps accessible through the keymap bound to
@var{prefix} in @var{keymap} are redefined.  See also
@code{accessible-keymaps}.

@ignore
@c Emacs 18 only
Prefix keymaps that appear within @var{keymap} are not checked
recursively for keys bound to @var{olddef}; they are not changed at all.
Perhaps it would be better to check nested keymaps recursively.
@end ignore

@ignore @c #### fix this up.
Here is an example showing a keymap before and after substitution:

@smallexample
@group
(setq map '(keymap
            (?1 . olddef-1)
            (?2 . olddef-2)
            (?3 . olddef-1)))
@result{} (keymap (49 . olddef-1) (50 . olddef-2) (51 . olddef-1))
@end group

@group
(substitute-key-definition 'olddef-1 'newdef map)
@result{} nil
@end group
@group
map
@result{} (keymap (49 . newdef) (50 . olddef-2) (51 . newdef))
@end group
@end smallexample
@end ignore
@end defun

@defun suppress-keymap keymap &optional nodigits
@cindex @code{self-insert-command} override
This function changes the contents of the full keymap @var{keymap} by
making all the printing characters undefined.  More precisely, it binds
them to the command @code{undefined}.  This makes ordinary insertion of
text impossible.  @code{suppress-keymap} returns @code{nil}.

If @var{nodigits} is @code{nil}, then @code{suppress-keymap} defines
digits to run @code{digit-argument}, and @kbd{-} to run
@code{negative-argument}.  Otherwise it makes them undefined like the
rest of the printing characters.

@cindex yank suppression
@cindex @code{quoted-insert} suppression
The @code{suppress-keymap} function does not make it impossible to
modify a buffer, as it does not suppress commands such as @code{yank}
and @code{quoted-insert}.  To prevent any modification of a buffer, make
it read-only (@pxref{Read Only Buffers}).

Since this function modifies @var{keymap}, you would normally use it
on a newly created keymap.  Operating on an existing keymap
that is used for some other purpose is likely to cause trouble; for
example, suppressing @code{global-map} would make it impossible to use
most of XEmacs.

Most often, @code{suppress-keymap} is used to initialize local
keymaps of modes such as Rmail and Dired where insertion of text is not
desirable and the buffer is read-only.  Here is an example taken from
the file @file{emacs/lisp/dired.el}, showing how the local keymap for
Dired mode is set up:

@smallexample
@group
  @dots{}
  (setq dired-mode-map (make-keymap))
  (suppress-keymap dired-mode-map)
  (define-key dired-mode-map "r" 'dired-rename-file)
  (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted)
  (define-key dired-mode-map "d" 'dired-flag-file-deleted)
  (define-key dired-mode-map "v" 'dired-view-file)
  (define-key dired-mode-map "e" 'dired-find-file)
  (define-key dired-mode-map "f" 'dired-find-file)
  @dots{}
@end group
@end smallexample
@end defun

@node Key Binding Commands, Scanning Keymaps, Changing Key Bindings, Keymaps
@section Commands for Binding Keys

  This section describes some convenient interactive interfaces for
changing key bindings.  They work by calling @code{define-key}.

  People often use @code{global-set-key} in their @file{.emacs} file for
simple customization.  For example,

@smallexample
(global-set-key "\C-x\C-\\" 'next-line)
@end smallexample

@noindent
or

@smallexample
(global-set-key [(control ?x) (control ?\\)] 'next-line)
@end smallexample

@noindent
or

@smallexample
(global-set-key [?\C-x ?\C-\\] 'next-line)
@end smallexample

@noindent
redefines @kbd{C-x C-\} to move down a line.

@smallexample
(global-set-key [(meta button1)] 'mouse-set-point)
@end smallexample

@noindent
redefines the first (leftmost) mouse button, typed with the Meta key, to
set point where you click.

@deffn Command global-set-key key definition
This function sets the binding of @var{key} in the current global map
to @var{definition}.

@smallexample
@group
(global-set-key @var{key} @var{definition})
@equiv{}
(define-key (current-global-map) @var{key} @var{definition})
@end group
@end smallexample
@end deffn

@deffn Command global-unset-key key
@cindex unbinding keys
This function removes the binding of @var{key} from the current
global map.

One use of this function is in preparation for defining a longer key
that uses @var{key} as a prefix---which would not be allowed if
@var{key} has a non-prefix binding.  For example:

@smallexample
@group
(global-unset-key "\C-l")
    @result{} nil
@end group
@group
(global-set-key "\C-l\C-l" 'redraw-display)
    @result{} nil
@end group
@end smallexample

This function is implemented simply using @code{define-key}:

@smallexample
@group
(global-unset-key @var{key})
@equiv{}
(define-key (current-global-map) @var{key} nil)
@end group
@end smallexample
@end deffn

@deffn Command local-set-key key definition
This function sets the binding of @var{key} in the current local
keymap to @var{definition}.

@smallexample
@group
(local-set-key @var{key} @var{definition})
@equiv{}
(define-key (current-local-map) @var{key} @var{definition})
@end group
@end smallexample
@end deffn

@deffn Command local-unset-key key
This function removes the binding of @var{key} from the current
local map.

@smallexample
@group
(local-unset-key @var{key})
@equiv{}
(define-key (current-local-map) @var{key} nil)
@end group
@end smallexample
@end deffn

@node Scanning Keymaps, Remapping commands, Key Binding Commands, Keymaps
@section Scanning Keymaps

  This section describes functions used to scan all the current keymaps,
or all keys within a keymap, for the sake of printing help information.

@defun accessible-keymaps keymap &optional prefix
This function returns a list of all the keymaps that can be accessed
(via prefix keys) from @var{keymap}.  The value is an association list
with elements of the form @code{(@var{key} .@: @var{map})}, where
@var{key} is a prefix key whose definition in @var{keymap} is
@var{map}.

The elements of the alist are ordered so that the @var{key} increases
in length.  The first element is always @code{([] .@: @var{keymap})},
because the specified keymap is accessible from itself with a prefix of
no events.

If @var{prefix} is given, it should be a prefix key sequence; then
@code{accessible-keymaps} includes only the submaps whose prefixes start
with @var{prefix}.  These elements look just as they do in the value of
@code{(accessible-keymaps)}; the only difference is that some elements
are omitted.

  In the example below, the returned alist indicates that the key
@kbd{C-x}, which is displayed as @samp{[(control x)]}, is a prefix key
whose definition is the keymap @code{#<keymap ((control x) #<keymap
emacs-lisp-mode-map 8 entries 0x546>) 1 entry 0x8a2>}. (The strange
notation for the keymap's name indicates that this is an internal submap
of @code{emacs-lisp-mode-map}.  This is because
@code{lisp-interaction-mode-map} has set up @code{emacs-lisp-mode-map}
as its parent, and @code{lisp-interaction-mode-map} defines no key
sequences beginning with @kbd{C-x}.)

@smallexample
@group
(current-local-map)
@result{} #<keymap lisp-interaction-mode-map 5 entries 0x558>
(accessible-keymaps (current-local-map))
@result{}(([] . #<keymap lisp-interaction-mode-map 5 entries 0x558>)
    ([(control x)] .
     #<keymap ((control x) #<keymap emacs-lisp-mode-map 8 entries 0x546>)
              1 entry 0x8a2>))
@end group
@end smallexample

  The following example shows the results of calling
@code{accessible-keymaps} on a large, complex keymap.  Notice how
some keymaps were given explicit names using @code{set-keymap-name};
those submaps without explicit names are given descriptive names
indicating their relationship to their enclosing keymap.

@smallexample
@group
(accessible-keymaps (current-global-map))
@result{} (([] . #<keymap global-map 639 entries 0x221>)
   ([(control c)] . #<keymap mode-specific-command-prefix 1 entry 0x3cb>)
   ([(control h)] . #<keymap help-map 33 entries 0x4ec>)
   ([(control x)] . #<keymap Control-X-prefix 77 entries 0x3bf>)
   ([(meta escape)] .
      #<keymap ((meta escape) #<keymap global-map 639 entries 0x221>)
               3 entries 0x3e0>)
   ([(meta control \[)] .
      #<keymap ((meta escape) #<keymap global-map 639 entries 0x221>)
               3 entries 0x3e0>)
   ([f1] . #<keymap help-map 33 entries 0x4ec>)
   ([(control x) \4] . #<keymap ctl-x-4-prefix 9 entries 0x3c5>)
   ([(control x) \5] . #<keymap ctl-x-5-prefix 8 entries 0x3c8>)
   ([(control x) \6] . #<keymap 13 entries 0x4d2>)
   ([(control x) a] .
      #<keymap (a #<keymap Control-X-prefix 77 entries 0x3bf>)
               8 entries 0x3ef>)
   ([(control x) n] . #<keymap narrowing-prefix 3 entries 0x3dd>)
   ([(control x) r] . #<keymap rectangle-prefix 18 entries 0x3e9>)
   ([(control x) v] . #<keymap vc-prefix-map 13 entries 0x60e>)
   ([(control x) a i] .
     #<keymap (i #<keymap (a #<keymap Control-X-prefix 77 entries 0x3bf>)
                          8 entries 0x3ef>)
              2 entries 0x3f5>))
@end group
@end smallexample
@end defun

@defun map-keymap function keymap &optional sort-first
This function applies @var{function} to each element of @var{keymap}.
@var{function} will be called with two arguments: a key-description
list, and the binding.  The order in which the elements of the keymap
are passed to the function is unspecified.  If the function inserts new
elements into the keymap, it may or may not be called with them later.
No element of the keymap will ever be passed to the function more than
once.

The function will not be called on elements of this keymap's parents
(@pxref{Inheritance and Keymaps}) or upon keymaps which are contained
within this keymap (multi-character definitions).  It will be called on
@key{META} characters since they are not really two-character sequences.

If the optional third argument @var{sort-first} is non-@code{nil}, then
the elements of the keymap will be passed to the mapper function in a
canonical order.  Otherwise, they will be passed in hash (that is,
random) order, which is faster.
@end defun

@defun keymap-fullness keymap
This function returns the number of bindings in the keymap.
@end defun

@defun where-is-internal definition &optional keymaps firstonly noindirect event-or-keys
This function returns a list of key sequences (of any length) that are
bound to @var{definition} in a set of keymaps.

The argument @var{definition} can be any object; it is compared with all
keymap entries using @code{eq}.

@var{keymaps} can be either a keymap (meaning search in that keymap and the
current global keymap) or a list of keymaps (meaning search in exactly
those keymaps and no others).  If @var{keymaps} is nil, search in the currently
applicable maps for @var{event-or-keys}.

If @var{keymaps} is a keymap, then the maps searched are @var{keymaps} and
the global keymap.  If @var{keymaps} is a list of keymaps, then the maps
searched are exactly those keymaps, and no others.  If @var{keymaps} is
@code{nil}, then the maps used are the current active keymaps for
@var{event-or-keys} (this is equivalent to specifying
@code{(current-keymaps @var{event-or-keys})} as the argument to
@var{keymaps}).

If @var{firstonly} is non-@code{nil}, then the value is a single
vector representing the first key sequence found, rather than a list of
all possible key sequences.
@ignore @c #### Should fix where-is to be more like FSF
If @var{firstonly} is @code{non-ascii}, then the value is a single
string representing the first key sequence found, rather than a list of
all possible key sequences.  If @var{firstonly} is @code{t}, then the
value is the first key sequence, except that key sequences consisting
entirely of @sc{ascii} characters (or meta variants of @sc{ascii}
characters) are preferred to all other key sequences.
@end ignore

If @var{noindirect} is non-@code{nil}, @code{where-is-internal} doesn't
follow indirect keymap bindings.  This makes it possible to search for
an indirect definition itself.

This function is used by @code{where-is} (@pxref{Help, , Help, xemacs,
The XEmacs Lisp Reference Manual}).

@smallexample
@group
(where-is-internal 'describe-function)
    @result{} ([(control h) d] [(control h) f] [f1 d] [f1 f])
@end group
@end smallexample
@end defun

@defun describe-bindings-internal map &optional all shadow prefix mouse-only-p
This function inserts (into the current buffer) a list of all defined
keys and their definitions in @var{map}.  Optional second argument
@var{all} says whether to include even ``uninteresting'' definitions,
i.e.  symbols with a non-@code{nil} @code{suppress-keymap} property.
Third argument @var{shadow} is a list of keymaps whose bindings shadow
those of map; if a binding is present in any shadowing map, it is not
printed.  Fourth argument @var{prefix}, if non-@code{nil}, should be a
key sequence; only bindings which start with that key sequence will be
printed.  Fifth argument @var{mouse-only-p} says to only print bindings
for mouse clicks.
@end defun

  @code{describe-bindings-internal} is used to implement the
help command @code{describe-bindings}.

@deffn Command describe-bindings &optional prefix mouse-only-p
This function creates a listing of all defined keys and their
definitions.  It writes the listing in a buffer named @samp{*Help*} and
displays it in a window.

If optional argument @var{prefix} is non-@code{nil}, it should be a
prefix key; then the listing includes only keys that start with
@var{prefix}.

When several characters with consecutive @sc{ascii} codes have the
same definition, they are shown together, as
@samp{@var{firstchar}..@var{lastchar}}.  In this instance, you need to
know the @sc{ascii} codes to understand which characters this means.
For example, in the default global map, the characters @samp{@key{SPC}
..@: ~} are described by a single line.  @key{SPC} is @sc{ascii} 32,
@kbd{~} is @sc{ascii} 126, and the characters between them include all
the normal printing characters, (e.g., letters, digits, punctuation,
etc.@:); all these characters are bound to @code{self-insert-command}.

If the second optional argument @var{mouse-only-p} (prefix arg,
interactively) is non-@code{nil} then only the mouse bindings are
displayed.
@end deffn

@node Remapping commands, Other Keymap Functions, Scanning Keymaps, Keymaps
@section Remapping commands

This section describes some functionality to allow commands to be
remapped, e.g. when providing workalike commands.

@defun remap-command keymap old new
This function ensures that in @var{keymap} any command lookups that
would previously have given @var{old} now give @var{new}.  This is
equivalent to the following GNU-compatible code, which also works in
XEmacs:

@smallexample
(define-key KEYMAP [remap OLD] NEW)
@end smallexample
@end defun

@defun command-remapping command &optional position keymaps
If @var{command} has a remapping in @var{keymaps}, this function returns
that remapping.  Otherwise it returns @var{nil}.  @var{keymaps} defaults
to the currently active keymaps. @var{position} specifies the relevant buffer
position where keymaps should be searched for, and overrides
@var{keymaps}.  It can also be a marker or an event.
@end defun

@defun commands-remapped-to command &optional position keymaps
This is the inverse operation of @code{command-remapping}; it returns a
list of the commands that will never be executed in @var{keymaps}
because @var{command} will be execute instead.
@end defun

@node Other Keymap Functions,  , Remapping commands, Keymaps
@section Other Keymap Functions

@defun set-keymap-prompt keymap new-prompt
This function sets the ``prompt'' of @var{keymap} to string
@var{new-prompt}, or @code{nil} if no prompt is desired.  The prompt is
shown in the echo-area when reading a key-sequence to be looked-up in
this keymap.
@end defun

@defun keymap-prompt keymap &optional use-inherited
This function returns the ``prompt'' of the given keymap.
If @var{use-inherited} is non-@code{nil}, any parent keymaps
will also be searched for a prompt.
@end defun
