Re: non-breaking hyphens

[Chong Yidong]

Eli Zaretskii <address@hidden> writes:

>> I'm not sure I understand the goal of `nobreak-char-display'.  Is it for
>> warning the user when there is an ASCII look-alike character that isn't
>> really ASCII?  I guess that's mainly to avoid issues with source code?
>
> Yes, probably.  But I'm only guessing here.  Can you find any traces
> of discussing this in the archives?

This is what I found, though it does not explain the rationale for the
feature:

http://lists.gnu.org/archive/html/emacs-devel/2004-12/msg00954.html
http://lists.gnu.org/archive/html/emacs-devel/2005-01/msg00035.html

And here was a request to consider adding U+FEFF to the list of
characters handled by nobreak-char-display, which apparently petered
out:

http://lists.gnu.org/archive/html/emacs-devel/2008-04/msg00413.html

The right way to implement this feature, as brought up in the 2004
thread, would be to specify the affected characters with a char-table
rather than hardcoding them.  But we should probably leave such a change
till after 24.1.

In the meantime, I think I'll add non-breaking hyphen and hyphen to the
hardcoded list, while deferring on the various other space characters;
many of those spaces are defined to have specific widths, so it's not
clear that changing their appearance to a highlighted space is the right
thing for Emacs to do.