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Re: Ctrl-[ ?
From: |
Stefan Monnier |
Subject: |
Re: Ctrl-[ ? |
Date: |
Fri, 14 Jun 2019 02:51:45 -0400 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) |
> Thank you Stefan for the enlightenment. I did say that I have never
> looked into the source code. Given what you say, I am curious why C-h
> is not known as Backspace.
There are always 3 entities at play here:
ASCII-control | GUI key | GUI control-modified-key
---------------------------------------------------
TAB | tab | control i
ESC | escape | control [
RET | return | control m
LF | linefeed | control j
...
And in Emacs, the mapping from the 3rd column to the 1st is hardcoded in
make_ctrl_char while the mapping from the 2nd to the first is
implemented in function-key-map, which can be easily overridden by the
end-user.
for "backspace" the situation is affected by the fact that some
text-terminal sent "EFF" (aka C-h) for the backspace key while others
sent DEL (aka C-? but it is really the code 127). Overtime, the C-?
camp won, so Emacs kind of uses:
DEL | backspace | control ?
except that it seems the mapping from "control ?" to DEL is not
hardcoded in the same way so `C-h k C-?` doesn't bring you to the
key binding of DEL.
> Another possibility is that since your patch was applied to all keys, maybe
> it should only check for "special" keys, like these two. That would
> certainly reduce side effects like you mention.
Indeed.
> Either way the next step would be to make people like me happy and provide
> a default binding that undoes the patch.
> Since this discussion began, I started taking notice of how often I use
> these short-cuts. I actually caught myself using the sequence C-pC-i today
> to fix indentation on a couple of lines. I also seem to use C-[C-\ a lot
> because it eliminates the need for me to change modifier-fingering.
If we ever implement a change similar to the proof-of-concept patch
I sent, then of course it would strive to not modify the default
behavior, except maybe in some hard-to-cover corner cases.
Stefan
- Re: Ctrl-[ ?, (continued)
- Re: Ctrl-[ ?, Francis Belliveau, 2019/06/08
- Re: Ctrl-[ ?, Óscar Fuentes, 2019/06/08
- Re: Ctrl-[ ?, Stefan Monnier, 2019/06/08
- Re: Ctrl-[ ?, Óscar Fuentes, 2019/06/08
- Re: Ctrl-[ ?, Stefan Monnier, 2019/06/18
- Re: Ctrl-[ ?, Francis Belliveau, 2019/06/11
- Re: Ctrl-[ ?,
Stefan Monnier <=
- [offtopic] Re: Ctrl-[ ?, Van L, 2019/06/14
- Re: [offtopic] Re: Ctrl-[ ?, tomas, 2019/06/14
- Re: [offtopic] Re: Ctrl-[ ?, Van L, 2019/06/15
- Re: [offtopic] Re: Ctrl-[ ?, tomas, 2019/06/15
- Re: [offtopic] Re: Ctrl-[ ?, Van L, 2019/06/15
- Re: Ctrl-[ ?, Eli Zaretskii, 2019/06/09