Re: Ctrl-[ ?

[Eli Zaretskii]

> From: Francis Belliveau <f.belliveau@comcast.net>
> Date: Sat, 8 Jun 2019 17:03:06 -0400
> 
> It is my assumption in what I say below that EMACS is trusting the OS to 
> perform the keystroke translations for it.

This is only correct up to a point.  Modern GUI environments allow
Emacs to distinguish between, say, Delete the function key and DEL the
ASCII octal 177 code.  They also allow it to distinguish between an
ASCII key pressed together with Ctrl and the corresponding lower ASCII
control code.  Emacs does the conversion to conflate those, at least
by default, because otherwise most users will be flabbergasted to
learn that, say, C-[ doesn't produce the same effect as ESC.

Documenting these conversion is not easy, because many of them have to
do with deep internals of character and key representation in various
parts of Emacs.  For example, Ctrl and Meta modifiers have 2 different
representations, and Emacs by default goes out of its way to hide this
difference.