bug#43609: 28.0.50; eldoc-documentation-function

[martin rudalics]

> You might want to read the docstring for
> eldoc-documentation-functions, in particular the part where "Each hook
> function is called with at least one argument CALLBACK".

That was the first thing I tried to do.  For beginners, I don't know
what a "Hook of functions" is.  And I completely fail to understand what
a "hook function" in this context is and when and why it gets called.
In short, I completely fail to understand the logic behind this
variable.  All I know is that I do not want to write a hook function and
I do not want to get called by any agent here.

> I agree that the latest changes make Eldoc gratuitously more complex,
> though. You can read bug#41531, where they started.

I never read that thread (it started around a time when my mailboxes
were thrashed due to almost simultaneous crashes of two of my mail
receiving machines) and I subsequently had to drop a few thousands of
mails I received earlier.  I've still not recuperated from that state.

I now spent more than an hour reading that thread and am as clever as
before.  The first post in that thread seems to say everything already:

  This enables eldoc.el to exert control over how (and crucially also
  when) to display the docstrings to the user.

In a nutshell: With eldoc-tooltip it's me and only me who decides when
and how to display a doc string.  I do not want to leave this decision
to a package that tries to judge whether and when that Procrustean bed
called echo area is ready to display that doc string, whether and how to
truncate it and when to make it disappear.  Sadly, this doesn't work any
more in Emacs 28.  Maybe there's a simple solution to my problem but
nobody pointed me to it so far ...

Thanks for the response, martin