Re: Font Lock Problems

[Stefan Monnier]

> Should I here for explicitly change the syntax table or is it enough
> to set the 'comment-start' and 'comment-end' variables? Or should I
> not confuse the variable 'comment-start' and the 'comment-start
> sequence' syntax table entries.  If this is so for what purposes do I
> need the variable 'comment-start' and 'comment-end'. Do I need
> 'comment-start' and 'comment-end' maybe for fill-paragraph.

The comment-start and comment-end variables are used by things like
newcomment (i.e. comment-region, auto-fill, ...).  The syntax-table's
comment markers are used by things like forward-sexp, font-lock, and also
newcomment.el (though it still requires the comment-start and comment-end
things as well).

The default filling code (which is separate from auto-fill) does not know
about comments at all.  In Emacs-CVS, this has been improved a little, so
that it now uses comment-start (as well as syntax-tables sometimes), but
only for \n-terminated comments and it doesn't work right in
all circumstances.

I.e. you need to set both the variables and the syntax-table and if you want
fill-paragraph to pay attention to comments, you either need to use
Emacs-CVS or to write your own fill-paragraph-function.  Take a look at the
lisp-paragraph-function used in lisp-mode for an example (it is the function
that got generalized and moved to fill.el in Emacs-CVS).

This is an area that still requires a good deal of improvement, as you
can see.


        Stefan