Re: Does a diagram of the key input subsystem exist?

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 1 Sep 2021 08:44:07 -0400
> Cc: emacs-devel@gnu.org
> From: "Perry E. Metzger" <perry@piermont.com>
> 
> On 8/31/21 22:30, Eli Zaretskii wrote:
> >> Is there anything like a document or diagram that lists the steps,
> >> translation tables, maps, etc. that every keystroke goes through in its
> >> journey? My guess is no, but I thought I would ask.
> > You mean, the description of what the read_char does?
> >
> read_char is only a portion of the overall processing path, but a 
> description of read_char would definitely need to be part of such a thing.

So what else, in addition to read_char, are you interested in?  maybe
if you'd ask more specific question, we could answer some of them.

To answer your question: the only documentation of this I know of is
in the Command Loop chapter of the ELisp manual.  Some more is in
large comments in keyboard.c.

I think we do understand the overall picture, and could describe it
(which it would perhaps then make sense to put the description into
the comments in keyboard.c), but only on a high enough level,
disregarding low-level details.  You'd need to read the code to find
out the rest.