Re: (interactive) and &optional

[Dr Rainer Woitok <rainer.woitok@gmail.com>]

Philip,

On Thursday, 2023-03-23 19:20:29 +0000, you wrote:

> ...
> > as expected,  while calling "M-x fun" and then just typing  "RET" at the
> > prompt returns
> >
> >   val:.\n
> >
> > that is, an empty symbol or string.
> 
> Right.

That's a bit flabbergasting: experimenting some more with my function, I
found that "symbolp" really returns t in case of empty responses,  mean-
ing there really is such a thing as an empty symbol.   So how can I test
for an empty symbol?  There doesn't seem to be a function "symbol-empty-
p" while, strictly speaking,  "string-empty-p" shouldn't be applyable to
symbols at all, should it?  Does an empty symbol have an external repre-
sentation like an empty list or string, allowing the use of "eq"?

Sincerely,
  Rainer