RE: should non-breaking space chars act as whitespace for Lisp?

[Drew Adams]

> >> >   (let ((timelist (split-string time ":")))
> >> > When I dan give M-x getMinutes and on the prompt give: 00:18, I get:
> >> > Symbol's function definition is void: let
> >>
> >> most likely because there's a hard space after let.
> >
> > This makes me wonder if hard-space chars shouldn't act as
> whitespace as far
> > as Lisp is concerned, as opposed to having symbol syntax (or
> whatever - I
> > didn't check this). I don't have an opinion on the matter, but
> I think this
> > is not the first question of this sort I've seen on
> help-gnu-emacs: users
> > are surprised when what they see as whitespace does act as they expect
> > whitespace to ace.
>
> Actually, I would not want to have code riddled with unintended
> unbreakable spaces (introduced by KNode here, but possible also with
> other tools) without Lisp complaining.  There are enough
> whitespace-related problems (like trailing space, or tab/space
> conversions) already without adding more to it.

I don't even know if this is a problem with Emacs 22. The OP said something
about intending to upgrade to 22 with the hope of alleviating this problem.

I don't think anyone is suggesting that users should riddle their code with
unbreakable spaces. The question is how Lisp should react when you, say, cut
and paste code that contains them, say from a Web page. When you do that,
you are usually not aware that the spaces are nonbreakable whitespace is,
well, invisible stuff.

Currently, Lisp does not complain in a manner that makes it obvious what the
problem is. The user thinks that Lisp is complaining, say, that `let' is
undefined, when in fact it might be complaining that `let ' is undefined,
where the ` ' is an unbreakable space.

We should be able to find some way to make things clear to a user that s?he
needs to convert nonbreakable spaces to spaces, or else we should treat
nonbreakable spaces as whitespace for Lisp code. I don't have a strong
opinion about the solution, but I think a problem has been pointed out to
which we should find a good solution.