On Wed, Jul 10, 2019 at 10:59:38AM +0200, Emanuel Berg via help-gnu-emacs wrote:
> Anders Dalskov wrote:
> 
> > Emacs sometimes inserts an ellipsis if the
> > result is longer than some threshold (what
> > that threshold is, I don't know).
> >
> > Though this only happens with s-expressions,
> > not strings, afaict.
> 
> Okay, but the strangest thing is sometimes
> I get the entire string, sometimes the
> "insertion of ellipsis", for the same command
> and result! Same result, I assume! Otherwise it
> is even more strange...

You're most probably seeing this abbreviation in the message
line (which ends up in *Messages* or something).

There are two levels here:

The "print" function, which is the generic S-expression printer,
obeys two variables: "print-length" and "print-level", which can
limit how wide and deep to print S-expressions. By default they
are both nil, which means "print everything.

For the message area, "eval-expression" calls on "print" to
present the results, but "eval-expression-print-length" and
"eval-expression-print-depth" take over, and by default, both
are set to finite values.

Cheers
-- t