Subject: Re: bug#24172: 25.1; Doc of parse-sexp-ignore-comments: what does a value of nil mean?

From: Lars Ingebrigtsen <[email-masked]>
Date: Sat, 27 Jul 2019 17:21:42 +0200

Michael Heerdegen <[email-masked]> writes:

> in the docstring of `parse-sexp-ignore-comments' (or at least in the
> manual), I miss a description about what a value of nil exactly means:
> How are comments treated then?  Are they treated as separate units that
> can then be parsed as well, but separately from code, or are they treated
> as indistinguishable from code?
>
> For example, if parsing starts from within a comment, and parsing finds
> the end of the comment and is not yet finished, is parsing just
> continued inside the following code, or does it fail?

After doing some testing, it seems that if it's nil, the commands
affected by the setting just treat the commented-out text as if it
wasn't commented out.

So the answer to your last question seems to be "yes".

;; (foo

(bar zot))

However, pretty much the same thing happens with a non-nil value, too --
with point before (foo C-M-f will advance past zot)).

So it doesn't treat comments as whitespace, really -- it only does that
if point is outside (before, at the end of a line, etc) the comment to
begin with.  Seems like you could write an essay about it, but perhaps
it's not worth listing the eccentricities here which I guess could change.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no