Subject: Unable to use anonymous functions for Key Translations

From: Barry OReilly <[email-masked]>
Date: Sat, 21 Jul 2012 22:53:05 -0400

Using an anonymous function to translate keys as described in the Elisp
manual at
http://www.gnu.org/software/emacs/manual/html_node/elisp/Translation-Keymaps.htmldoes
not work as expected.

Using a named function to map C-e to C-c, the Key Translation is successful:
  (progn (fset 'foo (lambda (prompt) (kbd "C-c")))
         (define-key key-translation-map (kbd "C-e") 'foo))

Using an anonymous function for another keymap binds C-e to the
lambda-defined command.
  (define-key global-map
              (kbd "C-e")
              (lambda () (interactive) (message "Inside C-e's lambda")))

But using an anonymous function for key-translation-map does not change
behavior of inputting C-e:
  (define-key key-translation-map
              (kbd "C-e")
              (lambda (prompt) (kbd "C-c")))

I find no reason why the last Elisp shouldn't define a Key Translation.
The Elisp manual section on Anonymous Functions states "Anonymous functions
are valid wherever function names are."  (
http://www.gnu.org/software/emacs/manual/html_node/elisp/Anonymous-Functions.html)

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Please describe exactly what actions triggered the bug, and
the precise symptoms of the bug.  If you can, give a recipe
starting from `emacs -Q':

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
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For information about debugging Emacs, please read the file
/home/epich/sw/emacs-24.1/install/share/emacs/24.1/etc/DEBUG.

In GNU Emacs 24.1.1 (i686-pc-linux-gnu, X toolkit, Xaw scroll bars)
 of 2012-07-07 on epich-hp
Windowing system distributor `The X.Org Foundation', version 11.0.11001000
Configured using:
 `configure '--prefix=/home/epich/sw/emacs-24.1/install''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
C-y <return> C-y <return> C-y <up> <up> <up> <up> <up>
<up> <up> <up> <up> <up> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> C-e M-x e v a l - l a s t s
e x p <backspace> <backspace> <backspace> <backspace>
- s e x p <return> <left> <left> <left> C-e C-g <right>
<right> <right> <return> <return> ( d e f i n e - k
e y SPC k e y - t r a n s l a t i o n - m a p SPC (
k b d SPC " C - e " SPC n i l ) ) M-x e v i l <backspace>
<backspace> a l - l a s t - s e x p <return> <down-mouse-1>
<mouse-movement> <mouse-1> <right> ) <right> <right>
<right> <right> <right> <right> <backspace> <left>
<right> <right> <left> SPC M-x e v a l - l a s t -
s e x p <return> <left> <left> <left> <left> C-e <down>
<down> <down> <up> <left> <left> <down> <down> C-e
M-x e v a l - l a s t - s e x p <return> <left> <left>
<left> C-e <down> <down> <down> <down> M-x e v a l
- l a s t - s e x p <return> <left> <left> C-e C-e
<left> <left> C-e M-x r e p o r t - e m a c s - <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <down-mouse-1>
q <mouse-1> q <down-mouse-1> <mouse-1> M-x r e p o
r t - e m a c s - b u g <return>

Recent messages:
You can run the command `eval-last-sexp' with C-x C-e
(lambda nil (interactive) (message "Inside C-e's lambda"))
You can run the command `eval-last-sexp' with C-x C-e
Inside C-e's lambda
(lambda (prompt) (kbd "C-c"))
You can run the command `eval-last-sexp' with C-x C-e
Inside C-e's lambda [3 times]
delete-backward-char: Text is read-only [2 times]
Quit
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