Re: Ctrl-[ ?

[Eli Zaretskii <eliz@gnu.org>]

> From: Jean-Christophe Helary <jean.christophe.helary@traduction-libre.org>
> Date: Sat, 8 Jun 2019 22:54:17 +0900
> 
> > We have an enormously complex piece of software on
> > our hands, and we have no better choice than going the "inconvenient"
> > ways when we want to rebind an unusual key.
> 
> In all honesty:
> 
> (define-key input-decode-map "\C-[" [C-left-bracket])
> (define-key global-map [C-left-bracket] 'myfunction)
> 
> is not inconvenient at all. What is inconvenient is the discovery process.

AFAIU, that discovery process, and the fact that you need 2 lines of
code rather than just one, was what was referred to as "inconvenient".

> Knowing what I know about emacs (which is above the casual user) and even with the willingness to go through the manual, it would have been (it *has* been) impossible for me to find that solution.

FWIW, I consider this not to be a catastrophe, far from it.  Emacs is
an enormously complex package, so it's impractical to require that
everything in it is immediately discoverable and easily customizable.
Especially when what you want to do is something as unusual as the
case in point.  I still hear every day one or two things I didn't know
about Emacs, after all those years of using, customizing, and hacking
it.  We could (and do) add stuff to the manuals and the doc strings,
but there's limit to how this could improve discoverability.  We
shouldn't expect, let alone demand, unreachable goals.

> Now, what I'd love to know is what are the other "unusual" keys, because as a group, they deserve a few more lines in the manual.

I suggest a careful reading of keymap.c and keyboard.c, the answer to
this question is there.