> > How about letting a non-negative prefix arg insert the full 
> > value (in effect, binding `eval-expression-print-length' and 
> > `eval-expression-print-level' to nil)?  And letting a negative
> > prefix arg do what any prefix arg does today: respect the
> > current values of `eval-expression-print-length' and
> > `eval-expression-print-level'?
> 
> Agreed.  Would you like to submit a patch here or to bug-gnu-emacs?

Attached.

I also changed `eval-print-last-sexp' similarly: a negative prefix arg for it
does what the function always did before: print the abbreviated value.
Otherwise it now prints the full value.

Someone might want to check that the other, non-interactive uses of
`eval-last-sexp' in `lisp-mode.el' still do what is expected (no change).  I
think so.

--

2013-05-04 Drew Adams  <drew.adams@oracle.com>
	* lisp-mode.el:
	(eval-last-sexp):
	Print full value if non-negative prefix arg.
	(eval-print-last-sexp):
	Added optional argument RESPECT-PRINT-OPTIONS.
	If nil, print full value, else abbreviated value.