Re: Mysterious fontification/C++ context issue - Patch for beginning-of-defun-raw.

[David Kastrup <dak@gnu.org>]

Alan Mackenzie <acm@muc.de> writes:

> Yet we're Emacs experts.  I think we're placing too little
> importance on the shock and emotional distress that such a bug
> [totally hosed fontification over an entire screen] will cause an
> ordinary Emacs user.  Even highlighting these parens might well
> puzzle, rather than help, this user.

Fontification is known not to be perfect, and there is an easy way
around if you feel shocked: change the input.  Such a change is
required for a number of other source code management tools like ctags
anyway.

This is a one-time effect.  In contrast, editing slowdowns are
permanent and incurable.

There are other modes, like LaTeX-mode, where the fontification engine
has no chance of figuring out everything correctly.  So one uses
simple hacks like

\def\xxx#1{\if$#1% $

where a comment is added that does nothing but close a $ math
environment that would otherwise be highlighted permanently.

People are _used_ to putting such stuff in if it annoys them too much.
It _is_ important, however, that there are easy workarounds.  For that
reason, AUCTeX matches dollar signs in line comments (one developer
made them ignored out of "correctness" concerns, and I vetoes this,
since it is impossible to get TeX fontification correct automatically,
anyway, and making the workarounds harder is a nuisance).

In the case of C-mode, there is a perfect workaround that requires no
undue amount of tap-dancing.

I don't see any reason to introduce little-tested, slow code that
already has lead to infinite loops and quite a bit of trouble at this
point of time in pretest.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum