bug#43169: Emacs Lisp function list

[Alan Mackenzie]

Grüß aus Nürnberg!

In article <mailman.2094.1599061864.2469.bug-gnu-emacs@gnu.org> you wrote:
> Goood day,
> working in a file in Lisp Interaction Mode I found an unexpected 
> behavior.
> Here is a section from that file:
> ;;;  section from file in Lisp Interaction Mode  ===========

>      (list 1 2 3 4 5 6 7 8 9 10 11 12)
> (1 2 3 4 5 6 7 8 9 10 11 12)

>      (list 1 2 3 4 5 6 7 8 9 10 11 12 13)
> (1 2 3 4 5 6 7 8 9 10 11 12 ...)
> e
>      (list 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20)
> (1 2 3 4 5 6 7 8 9 10 11 12 ...)

> ;;;  another context n

>      (setq l1 (list 1 2 3 4 5 6 7 8 9 10))
> (1 2 3 4 5 6 7 8 9 10)

>      (setq l2 (list 11 12))
> (11 12)

>      (setq l3 (list 11 12 13))
> (11 12 13)

>      (append l1 l2)
> (1 2 3 4 5 6 7 8 9 10 11 12)

>      (append l1 l3)
> (1 2 3 4 5 6 7 8 9 10 11 12 ...)

> ;;;   End of section =========================================
> I supose that it is a bug ?
> I would be happy if you could send me some information
> on this!

It's not a bug, but a deliberate strategy to abbreviate long and/or
deeply nested lists.  It's annoying when you see what you have seen, but
it's also annoying when four screenfuls of output scroll rapidly past
you.

The pertinent variables are print-length and print-level, which you can
set in your .emacs.  Use C-h v to find out exactly what each of these
does.  I have both of these variables set to nil, but that's a matter of
taste.

You might also want to have a look at eval-expression-print-length and
eval-expression-print-level.

Happy hacking!

> Wolfgang Pejas,  Bielefeld, Germany

-- 
Alan Mackenzie (Nuremberg, Germany).