Re: C-x C-e with prefix arg

[Juri Linkov]

> Personally, I think that was a dumb - er - misguided user interface that never
> should have been plopped on top of the longstanding eval-and-maybe-print
> functionality.  Others are free, of course, to think it is handy and extremely
> clever.
>
> The surprise expressed by Kelly Dean in his report for bug #12985 supports my
> view of the UI somewhat, I think.  The right fix is not just to document the
> feature (finally, years after it was introduced) but to just rip it out.  
> (There
> are other ways to print an integer value in various formats, and it is easy
> enough to have a separate command that does just that.)

There are many other commands that change their behavior when called twice,
e.g. running `recenter' twice doesn't recenter but unexpectedly moves
the current line to window's top.  Do you think that typing `C-l' twice
is dumb and should be ripped out and reverted to the longstanding
recentering functionality because there are other ways to do that?
(This question is rhetorical, I don't want to remove it.)

> But I doubt the feature will be removed in consequence.

The feature could be removed if we will find a better replacement.
I see at least two alternatives to improve the `eval-expression'
functionality:

1. Use the prefix arg `M-0' to request more information about the value
   printed by `C-x C-e', `M-:', and `C-j'.  Then typing `M-0 C-x C-e'
   will have the same effect as typing `C-x C-e' twice (the same way
   as typing `M-0 C-l' has the same effect as typing `C-l' twice).

2. Add a new customizable option to define the default printing format
   for the numeric values printed by `C-x C-e', `M-:', and `C-j'
   to accompany two other existing options `eval-expression-print-length'
   and `eval-expression-print-level' that define the format of the list
   values while printing list value in `eval-expression'.