Re: Alt as meta, except for certain keys, how?

[Kevin Rodgers <ihs_4664@yahoo.com>]

Ehud Karni wrote:

>On Fri, 08 Aug 2003 12:51:59 -0600, Kevin Rodgers <ihs_4664@yahoo.com> wrote:
>>Ehud Karni wrote:
>>>On my system it shows for Alt-7:
>>>  Character typed is "7", (octal=20000067, decimal=4194359, hexa=400037)
>>
>>Just evaluate ?\M-7.  On my system, it is -134217673, which is the crux of the
>>problem: meta-modified characters may have a negative character code, and thus
>>may not be a valid index into a char-table.
>>
> 
> I did evaluate ?\M-7 and I get the same result (-134217673) as you.
> It is NOT what my function returns (4194359) !!!


Hmmm, here's what I get:


Character typed is (No description), (octal=37000000067, decimal=-134217673, 
hexa=f8000037)

 
>>>So if you do:
>>>  (define-key key-translation-map [4194359] "|")
>>
>>key-translation-map takes character arguments, not (vector or string) keys:
> 
> Not true, see below.
...
>>>Because key-translation-map may not exist, you better protect yourself
>>>by adding the following (before the define-key command):
>>>  (if (not key-translation-map)
>>>      (make-sparse-keymap key-translation-map))
>>>
>>key-translation-map is now a char-table, not a keymap (see the Translating Input
>>node of the Emacs Lisp manual).
> 
> I don't know which Emacs are you using, I checked it on 21.2, 21.3. and
> 21.3.50 (CVS HEAD version). On all the documentation for `
> key-translation-map' says:
> 
>   Keymap of key translations that can override keymaps.
>   This keymap works like `function-key-map', but comes after that,
>   and applies even for keys that have ordinary bindings.
> 
> I think you confuse it with `keyboard-translate-table' which is
> used/created by the `keyboard-translate' command.

Ah, you're correct of course!  Sorry about that.

But the manual says that "The intent of `key-translation-map' is for
users to map one character set to another", so doesn't this count as
abuse (rather than use) of that feature?  It seems odd to me --
backwards, even -- that keyboard-translate-table can't handle all the
events (such as meta-modified characters) that the keyboard can
generate, but that key-translation-map can (even though it is intended
to map only characters).

-- 
Kevin Rodgers