Re: Ctrl-[ ?

[Eli Zaretskii]

> From: Mattias Engdegård <address@hidden>
> Date: Thu, 6 Jun 2019 14:44:31 +0200
> Cc: Emacs developers <address@hidden>,
>         Jean-Christophe Helary <address@hidden>
> 
> 6 juni 2019 kl. 12.12 skrev Eli Zaretskii <address@hidden>:
> > 
> > It isn't hardcoded in Emacs, it' "hardcoded" in the way the OS produces 
> > character codes when you type keys on the keyboard.  C-[ produces ESC for 
> > the same reason C-i produces TAB and C-j produces RET: these keys emit the 
> > same codes as the corresponding Ctrl sequences.
> 
> The above is true when Emacs is running in a terminal. Otherwise, Emacs has 
> code to emulate that behaviour (make_ctrl_char), so that we can enjoy a whiff 
> of early 1960s bit-paired keyboards. And this does appear to be hard-coded, 
> in the sense that it cannot be disabled.

Why is it useful to have different behavior on GUI and TTY frames?