Added command remapping.

etc/NEWS

@@ -136,6 +136,27 @@ C-h C-e displays the PROBLEMS file.
 The info-search bindings on C-h C-f, C-h C-k and C-h C-i
 have been moved to C-h F, C-h K and C-h S.
 
+C-h c, C-h k, C-h w, and C-h f now handle remapped interactive commands.
+
+- C-h c and C-h k report the actual command (after possible remapping)
+  run by the key sequence.
+
+- C-h w and C-h f on a command which has been remapped now report the
+  command it is remapped to, and the keys which can be used to run
+  that command.
+
+For example, if C-k is bound to kill-line, and kill-line is remapped
+to new-kill-line, these commands now report: 
+
+- C-h c and C-h k C-k reports:
+  C-k runs the command new-kill-line
+
+- C-h w and C-h f kill-line reports:
+  kill-line is remapped to new-kill-line which is on C-k, <deleteline>
+
+- C-h w and C-h f new-kill-line reports:
+  new-kill-line is on C-k
+
 ** C-w in incremental search now grabs either a character or a word,
 making the decision in a heuristic way.  This new job is done by the
 command `isearch-yank-word-or-char'.  To restore the old behavior,
@@ -416,6 +437,66 @@ SQL buffer.
 
 * Lisp Changes in Emacs 21.3
 
+** Interactive commands can be remapped through keymaps.
+
+This is an alternative to using defadvice or substitute-key-definition
+to modify the behaviour of a key binding using the normal keymap
+binding and lookup functionality.
+
+When a key sequence is bound to a command, and that command is
+remapped to another command, that command is run instead of the
+original command.
+
+Example:
+Suppose that minor mode my-mode has defined the commands
+my-kill-line and my-kill-word, and it wants C-k (and any other key
+bound to kill-line) to run the command my-kill-line instead of
+kill-line, and likewise it wants to run my-kill-word instead of
+kill-word.
+
+Instead of rebinding C-k and the other keys in the minor mode map,
+command remapping allows you to directly map kill-line into
+my-kill-line and kill-word into my-kill-word through the minor mode
+map using define-key:
+
+   (define-key my-mode-map 'kill-line 'my-kill-line)
+   (define-key my-mode-map 'kill-word 'my-kill-word)
+
+Now, when my-mode is enabled, and the user enters C-k or M-d,
+the commands my-kill-line and my-kill-word are run.
+
+Notice that only one level of remapping is supported.  In the above
+example, this means that if my-kill-line is remapped to other-kill,
+then C-k still runs my-kill-line.
+
+The following changes have been made to provide command remapping:
+
+- define-key now accepts a command name as the KEY argument.
+  This identifies the command to be remapped in the specified keymap.
+  This is equivalent to specifying the command name as the only
+  element of a vector, e.g [kill-line], except that when KEY is a
+  symbol, the DEF argument must also be a symbol.
+
+- In calls from Lisp, global-set-key, global-unset-key, local-set-key,
+  and local-unset-key also accept a command name as the KEY argument.
+
+- key-binding now remaps interactive commands unless the optional
+  third argument NO-REMAP is non-nil.  It also accepts a command name
+  as the KEY argument.
+
+- lookup-key now accepts a command name as the KEY argument.
+
+- where-is-internal now returns nil for a remapped command (e.g.
+  kill-line if my-mode is enabled), and the actual key binding for
+  the command it is remapped to (e.g. C-k for my-kill-line).
+  It also has a new optional fifth argument, NO-REMAP, which inhibits
+  remapping if non-nil (e.g. it returns C-k for kill-line and
+  <kill-line> for my-kill-line).
+
+- The new variable `this-original-command' contains the original
+  command before remapping.  It is equal to `this-command' when the
+  command was not remapped.
+
 ** Atomic change groups.
 
 To perform some changes in the current buffer "atomically" so that

lisp/ChangeLog

@@ -1,3 +1,12 @@
+2002-02-06  Kim F. Storm  <storm@cua.dk>
+
+	* help.el (where-is): Report remapped commands.
+
+	* help-fns.el (describe-function-1): Ditto.
+
+	* subr.el (global-set-key, local-set-key): Accept a symbol for the
+	KEY argument (like define-key).
+
 2002-02-06  Pavel Jan,Bm(Bk  <Pavel@Janik.cz>
 
 	* textmodes/flyspell.el (flyspell-insert-function): Doc fix.

src/ChangeLog

@@ -1,3 +1,25 @@
+2002-02-06  Kim F. Storm  <storm@cua.dk>
+
+	* keymap.c (Fdefine_key): Allow symbol as KEY argument for
+	defining command remapping.  Doc updated.
+	(Flookup_key): Remap command through keymap if KEY is a symbol.
+	(is_command_symbol): New function.
+	(Fkey_binding): Use it.  New optional argument NO-REMAP.  Doc
+	updated.  Callers changed.  Perform command remapping via
+	recursive call unless that arg is non-nil.
+	(where_is_internal): New argument no_remap.  Callers changed.
+	Call recursively to find original key bindings for a remapped
+	comand unless that arg is non-nil.
+	(Fwhere_is_internal): New optional argument NO-REMAP.  Doc
+	updated.  Callers changed.  Pass arg to where_is_internal. 
+
+	* keymap.h (Fkey_binding, Fwhere_is_internal): Update prototype.
+	(is_command_symbol): Added prototype.
+
+	* keyboard.c (Vthis_original_command): New variable.
+	(syms_of_keyboard): DEFVAR_LISP it.
+	(command_loop_1): Set it, and perform command remapping.
+
 2002-02-06  Pavel Jan,Bm(Bk  <Pavel@Janik.cz>
 
 	* keyboard.c (recursive_edit_1): Call cancel_hourglass