Re: CC Mode and electric-pair "problem".

[Alan Mackenzie <acm@muc.de>]

Hello, João.

On Thu, May 31, 2018 at 19:37:22 +0100, João Távora wrote:
> Alan Mackenzie <acm@muc.de> writes:

> > Hello, João
> >
> > On Thu, May 31, 2018 at 17:07:43 +0100, João Távora wrote:

[ .... ]

> > Yes.  A string in C(++) mode extending over several lines is only
> > valid when the newlines are escaped.  The generic string syntax is
> > partly an artifice to get font-lock-warning-face, but is also
> > deliberately intended to cut the opener of the invalid string off
> > from any subsequent double quote.

> But is there another goal here, apart from the goal of visually
> annotating the error?

Well, "error" might be putting it a bit strongly.  Mainly, it's a
reminder to somebody typing in a string to close it off properly.

> If the intent is only to annotate the error visually, I'd rather leave
> that to something like Flymake.  Admiteddly, it's not practical now,
> since Flymake usually works by running the whole buffer through an
> external syntax check tool, which may take ages compared to using syntax
> hints from within emacs.

> But that could be changed, my goal is to let Flymake call backends with
> only recently changed parts of the buffer, and a much faster
> syntax-checking backend could be devised.

All I can reply with, at the moment, is ... Hmmmm.  :-)

> Which reminds me, I never did get an answer to

>    https://lists.gnu.org/archive/html/emacs-devel/2017-10/msg00448.html

> did I?

No, but you've got one now.  :-)

> > OK.  I'll need to mull this over.

> OK, do. If you come to the conclusion that it is very important, and
> when the code becomes stable, I can can increase the complexity of
> elec-pair.el a bit to make it work in c++-mode.

I think the increase in complexity would be quite small, and very local.

> BTW do all cc-based modes "forbid" multi-line strings?

No.  Pike Mode has a special feature whereby a string starting with #" is
a multiline string.  I think in D Mode (not maintained here), strings
simply are multiline, and there is no such thing as an escaped EOL.

The writer of the mode sets the CC Mode "language variable"
c-multiline-string-start-char to the character # for Pike Mode, or some
non-character non-nil value for D Mode (usually t, of course).

[ .... ]

> João

-- 
Alan Mackenzie (Nuremberg, Germany).